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The gut microbiome plays an important role in honeybee hormonal regulation and growth, but the underlying mechanisms are poorly understood. Here, we showed that the depletion of gut bacteria resulted in reduced expression of insulin-like peptide gene ( ilp ) in the head, accompanied by metabolic syndromes resembling those of Type 1 diabetes in humans: hyperglycemia, impaired lipid storage, and decreased metabolism. These symptoms were alleviated by gut bacterial inoculation. Gut metabolite profiling revealed that succinate, produced by Lactobacillus Firm-5, played deterministic roles in activating ilp gene expression and in regulating metabolism in honeybees. Notably, we demonstrated that succinate modulates host ilp gene expression through stimulating gut gluconeogenesis, a mechanism resembling that of humans. This study presents evidence for the role of gut metabolite in modulating host metabolism and contributes to the understanding of the interactions between gut microbiome and bee hosts., Competing Interests: Competing interests statement:The authors declare no competing interest.

This study aimed to evaluate the effects of fermented beetroot ketchup enriched with Lactobacillus johnsonii K4 and non-fermented beetroot ketchup on pooled fecal microbiota from healthy adults in in vitro colon model. The research focused on how these products influenced the composition and functionality of the gut microbiota, as well as metabolite production, using the validated dynamic in vitro colon model, TNO Intestinal Model (TIM-2). After an initial starvation phase, a single 60 g dose of predigested and freeze-dried ketchup was introduced into the model. The potential probiotic strain Lactobacillus johnsonii K4 was added over three days. A carbohydrate mixture of standard ileal effluent medium (SIEM) served as the control. Our analysis identified 21 bacterial taxa that were significantly modulated (q-value < 0.2) when comparing ketchup samples to control samples. Notably, the ketchup samples led to an increase in butyrate-producing taxa, including Faecalibacterium, Blautia, Ruminococcaceae, Ruminiclostridium 6, and Anaerostipes. Conversely, there was a reduction in potentially pathogenic genera Desulfovibrio and Escherichia-Shigella. Distinct profiles of short-chain fatty acids (SCFA) were observed among the fermented ketchup, non-fermented ketchup, and control samples. Non-fermented ketchup resulted in higher proportions of acetate, propionate, and butyrate compared to the other interventions. This may be related to the fermentation with lactic acid bacteria in fermented samples with lower levels of substrate for SCFAs production. However, fermented ketchup sample has higher relative abundance of beneficial bacteria like Lactobacillus, Weissella and Dorea in gut microbiota. These findings suggest that beetroot ketchup, can positively influence gut microbiota composition and function, highlighting its potential benefits for human health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Mangosteen (Garcinia mangostana L.) is a tasty, polyphenol-rich tropical fruit. The edible part is highly appreciated by its aroma, taste and texture. The non-edible part, rich in polyphenols, has been traditionally used in Thai medicine. In this work, flavonoids and phenolic acid/derivatives were identified in mangosteen extracts (ME) from edible and non-edible portions. We first studied the effects of MEs on the growth, metabolism, antioxidant capacity, biofilm formation and antimicrobial capacity of eight bifidobacteria and lactobacilli strains from intestinal origin and two commercial probiotic strains (BB536 and GG). ME concentrations higher than 10-20 % were inhibitory for all strains. However, ME concentrations of 5 % significantly (P < 0.01) increased all strains antioxidant capacity, reduced biofilm-formation, and enhanced inhibition against Gram-positive pathogens. To apply these knowledge, bifunctional fermented milk products were elaborated with 5 % ME and individual strains, which were selected taking into account their growth with ME, and the widest range of values on antioxidant capacity, biofilm formation and antimicrobial activity (bifidobacteria INIA P2 and INIA P467, lactobacilli INIA P459 and INIA P708, and reference strain GG). Most strains survived well manufacture, refrigerated storage and an in vitro simulation of major conditions encountered in the gastrointestinal tract. As expected, products supplemented with ME showed higher polyphenol content and antioxidant capacity levels than control. After sensory evaluation, products containing strains INIA P2, INIA P708 and GG outstood as best., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Although microorganisms are the main cause of spoilage in prepared beef steaks, very few deep spoilage mechanisms have been reported so far. Aiming to unravel the mechanisms during 12 days of storage at 4 °C affecting the quality of prepared beef steak, the present study investigated the changes in microbial dynamic community using a combined high-throughput sequencing combined and bioinformatics. In addition, gas chromatography-mass spectrometry combined with multivariate statistical analysis was utilized to identify marker candidates for prepared steaks. Furthermore, cloud platform analysis was applied to determine prepared beef steak spoilage, including the relationship between microbiological and physicochemical indicators and volatile compounds., Results: The results showed that the dominant groups of Pseudomonas, Brochothrix thermosphacta, Lactobacillus and Lactococcus caused the spoilage of prepared beef steak, which are strongly associated with significant changes in physicochemical properties and volatile organic compounds (furan-2-pentyl-, pentanal, 1-octanol, 1-nonanol and dimethyl sulfide). Metabolic pathways were proposed, among which lipid metabolism and amino acid metabolism were most abundant., Conclusion: The present study is helpful with respect to further understanding the relationship between spoilage microorganisms and the quality of prepared beef steak, and provides a reference for investigating the spoilage mechanism of dominant spoilage bacteria and how to extend the shelf life of meat products. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Background: Mung beans are highly nutritious but their leguminous flavor limits their development. Lactic acid bacteria (LAB) fermentation can decrease unwanted bean flavors in legumes and enhance their flavor. This study examined the influence of Lactobacillus fermentation on the flavor characteristics of mung bean flour (MBF) using volatile compounds and non-targeted metabolomics., Results: Lactobacillus plantarum LP90, Lactobacillus casei LC89, and Lactobacillus acidophilus LA85 eliminated 61.37%, 48.29%, and 43.73%, respectively, of the primary bean odor aldehydes from MBF. The relative odor activity value (ROAV) results showed that fermented mung bean flour (FMBF) included volatile chemicals that contributed to fruity, flowery, and milky aromas. These compounds included ethyl acetate, hexyl formate, 3-hydroxy-2-butanone, and 2,3-butanedione. The levels of amino acids with a fresh sweet flavor increased significantly by 93.89, 49.40, and 35.27% in LP90, LC89, and LA85, respectively. A total of 49 up-regulated and 13 down-regulated significantly differential metabolites were annotated, and ten metabolic pathways were screened for contributing to the flavor. The correlation between important volatile compounds and non-volatile substances relies on two primary metabolic pathways: the citric acid cycle pathway and the amino acid metabolic system., Conclusion: The flavor of MBF was enhanced strongly by the process of Lactobacillus fermentation, with LP90 having the most notable impact. These results serve as a reference for identifying the flavor of FMBF. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Probiotic bacteria continue to receive increasing attention in the food and feed industries. However, the production of Bifidobacterium and Lactobacillus at an industrial scale is challenging because of specific nutrient requirements and conditions, which are complicated and costly. We developed low-cost culture media by modifying the carbon and nitrogen sources for Bifidobacterium animalis subsp. lactis KMP-H9-01 and Lactobacillus reuteri KMP-P4-S03 from available food grade components. Sucrose (15 g/l) was selected as a suitable carbon source for both strains because it was the most economic and facilitated bacterial growth that was equal to that of glucose. The Bifidobacterium strain required beef extract as a nitrogen source to multiply. The fermentation of both strains using the modified media formula in 5-L and 50-L bioreactors showed that the highest cell counts of L. reuteri and B. animalis subsp. lactis were 9 and 9.8 log CFU/ml after 12-15 h, respectively. The concentration (g/l) ratio between lactate and acetate obtained from B. animalis subsp. lactis was 7:7.4 at 12 h and 11.4:10.6 at 40 h; the ratio was similar at both time points (6.9: 1.1) for L. reuteri . Thus, this economically modified food-grade medium for the large-scale fermentation of two probiotic bacteria was efficient.

Background: The general assumption that prebiotics reach the colon without any alterations has been challenged. Some in vitro and in vivo studies have demonstrated that 'non-digestible' oligosaccharides are digested to different degrees depending on their structural composition. In the present study, we compared different methods aiming to assess the digestibility of oligosaccharides synthesized by β-galactosidase (β-gal) of Lactobacillus delbruecki subsp. bulgaricus CRL450 (CRL450-β-gal) from lactose, lactulose and lactitol., Results: In the simulated gastrointestinal fluid method, no changes were observed. However, the oligosaccharides synthesized by CRL450-β-gal were partially hydrolyzed in vitro, depending on their structure and composition, with rat small intestinal extract (RSIE) and small intestinal brush-border membrane vesicles (BBMV) from pig. Digestion of some oligosaccharides increased when mixtures were fed to C57BL/6 mice used as in vivo model; however, lactulose-oligosaccharides were the most resistant to the physiological conditions of mice. In general β (1→6) linked products showed higher resistance compared to β (1→3) oligosaccharides., Conclusion: In vitro digestion methods, without disaccharidases, may underestimate the importance of carbohydrates hydrolysis in the small intestine. Although BVMM and RSIE digestion assays are appropriate in vitro methods for these studies, in vivo studies remain the most reliable for understanding what actually happens in the digestion of oligosaccharides. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

This study explored the enantiocomplementary bioreduction of substituted 1-(arylsulfanyl)propan-2-ones in batch mode using four wild-type yeast strains and two different recombinant alcohol dehydrogenases from Lactobacillus kefir and Rhodococcus aetherivorans. The selected yeast strains and recombinant alcohol dehydrogenases as whole-cell biocatalysts resulted in the corresponding 1-(arylsulfanyl)propan-2-ols with moderate to excellent conversions (60-99%) and high selectivities (ee > 95%). The best bioreductions-in terms of conversion (>90%) and enantiomeric excess (>99% ee)-at preparative scale resulted in the expected chiral alcohols with similar conversion and selectivity to the screening reactions.

Isomalto/malto-polysaccharides (IMMPs) are a novel type of soluble dietary fibres with a prebiotic potential promoting growth of beneficial microbes in the gut. However, the mode of action of IMMPs remains unknown. Previous studies on IMMPs showed an increase in total bacteria, especially lactobacilli, and higher production of short chain fatty acids (SCFA) when IMMPs were fed to rats or used during in vitro fermentation. Here we used metatranscriptomics to investigate how IMMPs with different amounts of α - (1 → 6) glycosidic linkages affected microbial function during incubation with human fecal inoculum. We showed that active microbial community dynamics during fermentation varied depending on the type of IMMP used and that the observed changes were reflected in the community gene expression profiles. Based on metatranscriptome analysis, members of Bacteroides, Lactobacillus and Bifidobacterium were the predominant degraders of IMMPs, and the increased gene expression in these bacteria correlated with high amounts of α - (1 → 6) glycosidic linkages. We also noted an increase in relative abundance of these bacteria and an activation of pathways involved in SCFA synthesis. Our findings could provide a baseline for more targeted approaches in designing prebiotics for specific bacteria and to achieve more controlled modulation of microbial activity towards desired health outcomes., (© 2024. The Author(s).)

Inulin has found commercial applications in the pharmaceutical, nutraceutical, and food industries due to its beneficial health effects. The enzymatic biosynthesis of microbial inulin has garnered increasing attention. In this study, molecular modification was applied to Lactobacillus mulieris UMB7800 inulosucrase, an enzyme that specifically produces high-molecular weight inulin, to enhance its catalytic activity and thermostability. Among the 18 variable regions, R5 was identified as a crucial region significantly impacting enzymatic activity by replacing it with more conserved sequences. Site-directed mutagenesis combined with saturated mutagenesis revealed that the mutant A250 V increased activity by 68%. Additionally, after screening candidate mutants by rational design, four single-point mutants, S344D, H434P, E526D, and G531P, were shown to enhance thermostability. The final combinational mutant, M5, exhibited a 66% increase in activity and a 5-fold enhancement in half-life at 55 °C. These findings are significant for understanding the catalytic activity and thermostability of inulosucrase and are promising for the development of microbial inulin biosynthesis platforms.

Lactobacilli fermentation possesses special nutritional and health values to food, especially in improving diseases related to the gut microbiota such as osteoporosis risk. Previous research indicates that lactobacilli-fermented foods have the potential to enhance the bone mineral density (BMD), as suggested by some clinical studies. Nonetheless, there is currently a lack of comprehensive summaries of the effects and potential mechanisms of lactobacilli-fermented foods on BMD. This review summarizes findings from preclinical and clinical studies, revealing that lactobacilli possess the potential to mitigate age-related and secondary factor-induced bone loss. Furthermore, these findings imply that lactobacilli are likely mediated through the modulation of bone remodeling via gut inflammation-related pathways. Additionally, lactobacilli fermentation may augment calcium accessibility through directly promoting calcium absorption or modifying food constituents. Considering the escalating global health challenge of bone-related issues among the elderly population, this review may offer a valuable reference for the development of food strategies aimed at preventing osteoporosis.

Elevated levels of biogenic amines (BAs) in fermented food can have negative effects on both the flavor and health. Mining enzymes that degrade BAs is an effective strategy for controlling their content. The study screened a strain of Lactobacillus hilgardii 1614 from fermented food system that can degrade BAs. The multiple copper oxidase genes LHMCO 1614 were successfully mined after the whole genome protein sequences of homologous strains were clustered and followed by homology modeling. The enzyme molecules can interact with BAs to stabilize composite structures for catalytic degradation, as shown by molecular docking results. Ingeniously, the kinetic data showed that purified LHMCO 1614 was less sensitive to the substrate inhibition of tyramine and phenylethylamine. The degradation rates of tyramine and phenylethylamine in huangjiu (18% vol) after adding LHMCO 1614 were 41.35 and 40.21%, respectively. Furthermore, LHMCO 1614 demonstrated universality in degrading tyramine and phenylethylamine present in other fermented foods as well. HS-SPME-GC-MS analysis revealed that, except for aldehydes, the addition of enzyme treatment did not significantly alter the levels of major flavor compounds in enzymatically treated fermented foods ( p > 0.05). This study presents an enzymatic approach for regulating tyramine and phenylethylamine levels in fermented foods with potential applications both targeted and universal.

DNA fragmentation index (DFI), a new biomarker to diagnose male infertility, is closely associated with poor reproductive outcomes. Previous research reported that seminal microbiome correlated with sperm DNA integrity, suggesting that the microbiome may be one of the causes of DNA damage in sperm. However, it has not been elucidated how the microbiota exerts their effects. Here, we used a combination of 16S rRNA sequencing and untargeted metabolomics techniques to investigate the role of microbiota in high sperm DNA fragmentation index (HDFI). We report that increased specific microbial profiles contribute to high sperm DNA fragmentation, thus implicating the seminal microbiome as a new therapeutic target for HDFI patients. Additionally, we found that the amount of Lactobacillus species was altered: Lactobacillus iners was enriched in HDFI patients, shedding light on the potential influence of L. iners on male reproductive health. Finally, we also identified enrichment of the acetyl-CoA fermentation to butanoate II and purine nucleobase degradation I in the high sperm DNA fragmentation samples, suggesting that butanoate may be the target metabolite of sperm DNA damage. These findings provide valuable insights into the complex interplay between microbiota and sperm quality in HDFI patients, laying the foundation for further research and potential clinical interventions.IMPORTANCEThe DNA fragmentation index (DFI) is a measure of sperm DNA fragmentation. Because high sperm DNA fragmentation index (HDFI) has been strongly associated with adverse reproductive outcomes, this has been linked to the seminal microbiome. Because the number of current treatments for HDFI is limited and most of them have no clear efficacy, it is critical to understand how semen microbiome exerts their effects on sperm DNA. Here, we evaluated the semen microbiome and its metabolites in patients with high and low sperm DNA fragmentation. We found that increased specific microbial profiles contribute to high sperm DNA fragmentation. In particular, Lactobacillus iners was uniquely correlated with high sperm DNA fragmentation. Additionally, butanoate may be the target metabolite produced by the microbiome to damage sperm DNA. Our findings support the interaction between semen microbiome and sperm DNA damage and suggest that seminal microbiome should be a new therapeutic target for HDFI patients., Competing Interests: The authors declare no conflict of interest.

Bacteria are involved in numerous interactions during infection and among host-associated microbial populations. Salmonella enterica serovar Typhimurium is a foodborne pathogen of great importance as well as a model organism to study interactions within a microbial community. In this study, we found that S . Typhimurium becomes tolerant to azithromycin when co-cultured with lactobacilli strains. Similarly, acidified media, from cell-free supernatant of lactobacilli cultures for instance, also induced the tolerance of S . Typhimurium to azithromycin. The addition of membrane disruptors restored the normal sensitivity to azithromycin in acidified media, but not when lactobacilli were present. These results suggested that the acidification of the media led to modification in envelope homeostasis, but that a different mechanism promoted the tolerance to azithromycin in the presence of lactobacilli strains. To further understand how lactobacilli strains modify the sensitivity of S . Typhimurium to azithromycin, a high-throughput assay was performed using the single-gene deletion collection of the S . Typhimurium (1) in co-culture with Lacticaseibacillus rhamnosus and (2) in sterile acidic conditions (pH 5.5 media only). As expected, both screens identified genes involved in envelope homeostasis and membrane permeability. Our results also suggest that changes in the metabolism of S . Typhimurium induce the tolerance observed in the presence of L. rhamnosus . Our results thus highlight two different mechanisms by which lactobacilli induce the tolerance of S . Typhimurium to azithromycin.IMPORTANCEThis study provides valuable insights into the intricate interactions between bacteria during infections and within host-associated microbial communities. Specifically, it sheds light on the significant role of lactobacilli in inducing antibiotic tolerance in Salmonella enterica serovar Typhimurium, a critical foodborne pathogen and model organism for microbial community studies. The findings not only uncover the mechanisms underlying this antibiotic tolerance but also reveal two distinct pathways through which strains of lactobacilli might influence Salmonella 's response to antibiotics. Understanding these mechanisms has the potential to enhance our knowledge of bacterial infections and may have implications for the development of strategies to combat antibiotic resistance in pathogens, such as Salmonella . Furthermore, our results underscore the necessity to explore beyond the direct antimicrobial effects of antibiotics, emphasizing the broader microbial community context., Competing Interests: The authors declare no conflict of interest.

In osteoarthritis (OA), extracellular matrix (ECM) digestion by cartilage-degrading enzymes drives cartilage destruction and generates ECM fragments, such as proteoglycan aggrecan (PG) peptides. PG peptides have been shown to induce immunological functions of chondrocytes. However, the role of PG peptides in stimulating catabolic mediators from chondrocytes has not been investigated. Therefore, we aim to determine the effects and its mechanism by which PG peptides induce chondrocytes to produce catabolic mediators in OA. Human chondrocytes were stimulated with IFNγ and various PG peptides either (i) with or (ii) without TLR2 blockade or (iii) with Lactobacillus species-conditioned medium (LCM), a genus of bacteria with anti-inflammatory properties. Transcriptomic analysis, cartilage-degrading enzyme production and TLR2-intracellular signaling activation were investigated. Chondrocytes treated with PG peptides p16-31 and p263-280 increased expression levels of genes associated with chondrocyte hypertrophy, cartilage degradation and proteolytic enzyme production. TLR2 downstream signaling proteins (STAT3, IkBα and MAPK9) were significantly phosphorylated in p263-280 peptide-stimulated chondrocytes. MMP-1 and ADAMTS-4 were significantly reduced in p263-280 peptides-treated condition with TLR2 blockade or LCM treatment. Phosphorylation levels of IkBa, ERK1/2 and MAPK9 were significantly decreased with TLR2 blockade, but only phosphorylation levels of MAPK9 was significantly decreased with LCM treatment. Our study showed that PG peptide stimulation via TLR2 induced cartilage-degrading enzyme production via activation of MAPK, NFκB and STAT3 pathways., (© 2024. The Author(s).)

This study aimed to investigate the interaction between L.casei and L.bulgaricus with Polygonatum sibiricum saponins (PSS) and to explore the co-microencapsulation to reduce their loss rate during storage and consumption. 1% PSS was added to the culture broth, and it was found that the growth and metabolism of the strains were accelerated, especially in the compound probiotic group, indicating that PSS has potential for prebiotics. LC-MS observed significant differences in the composition and content of saponins in PSS. The metabolomics results suggest that the addition of PSS resulted in significant changes in the metabolites of probiotics. In addition, it was found that the combination of probiotics and PSS may have stronger hypoglycemic ability (ɑ-glucosidase, HepG2). Finally, a co-microencapsulated delivery system was constructed using zein and isomaltooligosaccharide. This system can achieve more excellent resistance of probiotics and PSS in gastrointestinal fluids, effectively transporting both to the small intestine., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Gut microbiota imbalance could lead to various diseases, making it important to optimize the structure of the gut flora in adults. Lactobacillus paracasei ZFM54 is a bacteriocin- and folic acid-producing Lactobacillus strain. Herein, L. paracasei ZFM54 was used as the potentially probiotic bacterium to ferment milk together with a yogurt starter. We optimized the fermentation conditions, and the obtained yogurts were then subjected to volatile and nonvolatile metabolome analysis, showing that L. paracasei ZFM54 can not only improve the acidity, water holding capacity and live lactic acid bacteria counts, but also improve many volatile acid contents and increase some beneficial nonvolatile metabolites, such as N-ethyl glycine and l-lysine, endowing the yogurt with more flavor and better function. The regulatory effects of the co-fermented yogurt on the intestinal microecology of volunteers were investigated by 16S rRNA sequencing and short-chain fatty acid (SCFA) analysis after consuming the yogurt for a 2-wk period, showing a better effect to increase the relative abundance of beneficial bacteria such as Ruminococcus and Alistipes, decrease harmful bacteria (Escherichia-Shigella and Enterobacter), and enhance the production of SCFA (acetate, propionate, and butyric acid) compared with the control yogurt. We found that L. paracasei ZFM54 can significantly improve the health benefits of yogurt, laying the foundation for its commercial application in improving gut microbiota., (© 2024, The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Helicobacter pylori infection is the major risk factor associated with the development of gastric cancer. Currently, administration of standard antibiotic therapy combined with probiotics and postbiotics has gained significant attention in the management of H. pylori infection. In this work, the immunomodulatory effects of Lactobacillus crispatus-derived extracellular vesicles (EVs) and cell-free supernatant (CFS) were investigated on H. pylori-induced inflammatory response in human gastric adenocarcinoma (AGS) cells. L. crispatus-derived EVs were isolated by ultracentrifugation and physically characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Furthermore, the protein content of L. crispatus-derived EVs was also evaluated by SDS-PAGE. Cell viability of AGS cells exposed to varying concentrations of EVs and CFS was assessed by MTT assay. The mRNA expression of IL-1β, IL-6, IL-8, TNF-α, IL-10, and TGF-ß genes was determined by RT-qPCR. ELISA was used for the measurement of IL-8 production in AGS cells. In addition, EVs (50 μg/mL) and CFS modulated the H. pylori-induced inflammation by downregulating the mRNA expression of IL-1β, IL-6, IL-8, and TNF-α, and upregulating the expression of IL-10, and TGF-ß genes in AGS cells. Furthermore, H. pylori-induced IL-8 production was dramatically decreased after treatment with L. crispatus-derived EVs and CFS. In conclusion, our observation suggests for the first time that EVs released by L. crispatus strain RIGLD-1 and its CFS could be recommended as potential therapeutic agents against H. pylori-triggered inflammation., (© 2024. Institute of Microbiology, Academy of Sciences of the Czech Republic, v.v.i.)

Fructooligosaccharides (FOS) are a common prebiotic widely used in functional foods. Meanwhile, Saccharomyces boulardii is a fungal probiotic frequenly used in the clinical treatment of diarrhea. Compared with single use, the combination of prebiotics and probiotics as symbiotics may be more effective in regulating gut microbiota as recently reported in the literature. The present study aimed to investigate the effects of FOS, S. boulardii and their combination on the structure and metabolism of the gut microbiota in healthy primary and secondary school students using an in vitro fermentation model. The results indicated that S. boulardii alone could not effectively regulate the community structure and metabolism of the microbiota. However, both FOS and the combination of FOS and S. boulardii could effectively regulate the microbiota, significantly inhibiting the growth of Escherichia-Shigella and Bacteroides, and controlling the production of the gases including H 2 S and NH 3 . In addition, both FOS and the combination could significantly promote the growth of Bifidobacteria and Lactobacillus, lower environmental pH, and enhance several physiological functions related to synthesis and metabolism. Nevertheless, the combination had more unique benefits as it promoted the growth of Lactobacillus, significantly increased CO 2 production and enhanced the functional pathways of carbon metabolism and pyruvic acid metabolism. These findings provide guidance for clinical application and a theoretical basis for the development of synbiotic preparations., Competing Interests: Declaration of Competing Interest The authors declare no competing interests., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

This study aimed to assess the technical feasibility of incorporating selenized Lactobacillus spp. microencapsulated via spray drying into cattle feed. Gum Arabic and maltodextrin were used as encapsulating agents. The encapsulation process was carried out with a drying air flow rate of 1.75 m 3 /min, inlet air temperature of 90°C, and outlet air temperature of 75°C. The viability of the encapsulated microorganisms and the technological characteristics of the obtained microparticles were evaluated. Microorganisms were incorporated into beef cattle feed to supplement their diet with up to 0.3 mg of Se per kilogram of feed. The encapsulated particles, consisting of a 50/50 ratio of gum Arabic/maltodextrin at a 1:20 proportion of selenized biomass to encapsulant mixture, exhibited superior technical viability for application in beef cattle feed. Supplemented feeds displayed suitable moisture, water activity, and hygroscopicity values, ensuring the preservation of viable microorganisms for up to 5 months of storage, with an approximate count of 4.5 log CFU/g. Therefore, supplementing beef cattle feed with selenized and microencapsulated lactic acid bacteria represents a viable technological alternative, contributing to increased animal protein productivity through proper nutrition., (© 2024 International Union of Biochemistry and Molecular Biology, Inc.)

Synbiotics are complex preparations of prebiotics that can be selectively utilized by live microorganisms to improve host health. Synbiotics are divided into complementary synbiotics, which consist of probiotics and prebiotics with independent functions, and synergistic synbiotics, which consist of prebiotics that are selectively used by gut microorganisms. Complementary synbiotics used in human clinical trials include Lactobacillus spp. and Bifidobacterium spp. as probiotics, and fructooligosaccharides, galactooligosaccharides, and inulin as prebiotics. Over the past five years, synbiotics have been most commonly used in patients with metabolic disorders, including obesity, and immune and gastrointestinal disorders. Several studies have observed alterations in the microbial community; however, these changes did not lead to significant improvements in disease outcomes or biochemical and hematological markers. The same synbiotics have been applied to individuals with different gut environments. As a result, even with the same synbiotics, there are non-responders who do not respond to the applied synbiotics due to the different intestinal environment for each individual. Therefore, to obtain meaningful results, applying different synbiotics depending on the individual is necessary. Synergistic synbiotics are one solution to circumvent this problem, as they combine elements that can effectively improve health, even in non-responders. This review aims to explain the concept of synbiotics, highlight recent human clinical trials, and explore the current state of research on synergistic synbiotics., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

This study investigated the mechanism underlying the flavor improvement observed during fermentation of a pea protein-based beverage using Lactobacillus johnsonii NCC533. A combination of sensomics and sensoproteomics approach revealed that the fermentation process enriched or generated well-known basic taste ingredients, such as amino acids, nucleotides, organic acids, and dipeptides, besides six new taste-active peptide sequences that enhance kokumi and umami notes. The six new umami and kokumi enhancing peptides, with human recognition thresholds ranging from 0.046 to 0.555 mM, are produced through the degradation of Pisum sativum 's storage protein. Our findings suggest that compounds derived from fermentation enhance umami and kokumi sensations and reduce bitterness, thus improving the overall flavor perception of pea proteins. In addition, the analysis of intraspecific variations in the proteolytic activity of L. johnsonii and the genome-peptidome correlation analysis performed in this study point at cell-wall-bound proteinases such as PrtP and PrtM as the key genes necessary to initiate the flavor improving proteolytic cascade. This study provides valuable insights into the molecular mechanisms underlying the flavor improvement of pea protein during fermentation and identifies potential future research directions. The results highlight the importance of combining fermentation and senso(proteo)mics techniques in developing tastier and more palatable plant-based protein products.

Probiotics and prebiotics have been considered as alternative approaches for promoting health. This study aimed to investigate the anticandidal potential of various probiotic Lactobacillus strains and their cell-free supernatants (CFSs). The study assessed the impact of inulin and some fruits as prebiotics on the growth of selected probiotic strains in relation to their anticandidal activity, production of short-chain fatty acids, total phenolic content, and antioxidant activity. Results revealed variations in anticandidal activity based on the specific strains and forms of probiotics used. Non-adjusted CFSs were the most effective against Candida strains, followed by probiotic cells and adjusted CFSs (pH 7). Lacticaseibacillus rhamnosus SD4, L. rhamnosus SD11 and L. rhamnosus GG displayed the strongest anticandidal activity. Non-adjusted CFSs from L. rhamnosus SD11, L. rhamnosus SD4 and L. paracasei SD1 exhibited notable anticandidal effects. The adjusted CFSs of L. rhamnosus SD11 showed the highest anticandidal activity against all non-albicans Candida (NAC) strains, whereas the others were ineffective. Supplementation of L. rhamnosus SD11 with prebiotics, particularly 2% (w/v) mangosteen, exhibited positive results in promoting probiotic growth, short-chain fatty acids production, total phenolic contents, and antioxidant activity, and the subsequent enhancing anticandidal activity against both C. albicans and NAC strains compared to conditions without prebiotics. In conclusion, both live cells and CFSs of tested strains, particularly L. rhamnosus SD11, exhibited the best anticandidal activity. Prebiotics supplementation, especially mangosteen, enhanced probiotic growth and beneficial metabolites against Candida growth. These finding suggested that probiotics and prebiotic supplementation may be an effective alternative treatment for Candida infections., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

In order to explore the effects of ultrasonic pretreatment on the fermentation performance and quality characteristics of fermented hawthorn pulp. Five types of fermented hawthorn pulp were obtained using 0 W for 5 min, 300 W for 5 min, 360 W for 5 min, 420 W for 5 min, 540 W for 5 min. The fermentation performance and quality of fermented hawthorn pulp were characterized. The results indicated Low power ultrasound (360 W) could improve the fermentation performance and quality of FHP, and high power ultrasound (540 W) could reduce the fermentation performance and quality. Under the ultrasonic condition of 360 W for 5 min; the cell membrane of lactic acid bacteria produced repairable damage and the morphology did not change significantly, the consumption of reducing sugar, total acid, soluble solids, amino nitrogen, conductivity, and sensory quality of the fermented hawthorn pulp reached the highest. The fermentation performance and quality of fermented hawthorn pulp were improved by the optimum ultrasonic treatment, which could be used as an effective and alternative method for producing FHP with good flavor, high bioactivity and good quality., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study explores a sustainable approach for synthesizing silver nanocomposites (AgNCs) with enhanced antimicrobial and bioactivity using safe Lactobacillus strains and a whey-based medium (WBM). WBM effectively supported the growth of Lactobacillus delbrueckii and Lactobacillus acidophilus, triggering a stress response that led to AgNCs formation. The synthesized AgNCs were characterized using advanced spectroscopic and imaging techniques such as UV‒visible, Fourier transform infrared (FT-IR) spectroscopy, transmission electron (TEM), and scanning electron microscopy with energy dispersive X-ray analysis (SEM-Edx). Lb acidophilus-synthesized AgNCs in WBM (had DLS size average 817.2-974.3 ± PDI = 0.441 nm with an average of metal core size 13.32 ± 3.55 nm) exhibited significant antimicrobial activity against a broad spectrum of pathogens, including bacteria such as Escherichia coli (16.47 ± 2.19 nm), Bacillus cereus (15.31 ± 0.43 nm), Clostridium perfringens (25.95 ± 0.03 mm), Enterococcus faecalis (32.34 ± 0.07 mm), Listeria monocytogenes (23.33 ± 0.05 mm), methicillin-resistant Staphylococcus aureus (MRSA) (13.20 ± 1.76 mm), and filamentous fungi such as Aspergillus brasiliensis (33.46 ± 0.01 mm). In addition, Lb acidophilus-synthesized AgNCs in WBM exhibit remarkable free radical scavenging abilities, suggesting their potential as bioavailable antioxidants. These findings highlight the dual functionality of these biogenic AgNCs, making them promising candidates for applications in both medicine and nutrition., (© 2024. The Author(s).)

Fatty acid profiles are crucial for the functionality and viability of lactobacilli used in food applications. Tween 80™, a common culture media additive, is known to influence bacterial growth and composition. This study investigated how Tween 80™ supplementation impacts the fatty acid profiles of six mesophilic lactobacilli strains ( Lacticaseibacillus spp., Limosilactobacillus spp., Lactiplantibacillus plantarum ). Analysis of eleven strains revealed 29 distinct fatty acids. Tween 80™ supplementation significantly altered their fatty acid composition. Notably, there was a shift towards saturated fatty acids and changes within the unsaturated fatty acid profile. While some unsaturated fatty acids decreased, there was a concurrent rise in cyclic derivatives like lactobacillic acid (derived from vaccenic acid) and dihydrosterculic acid (derived from oleic acid). This suggests that despite the presence of Tween 80™ as an oleic acid source, lactobacilli prioritize the synthesis of these cyclic derivatives from precursor unsaturated fatty acids. Myristic acid and dihydrosterculic acid levels varied across strains. Interestingly, palmitic acid content increased, potentially reflecting enhanced incorporation of oleic acid from Tween 80™ into membranes. Conversely, cis-vaccenic acid levels consistently decreased across all strains. The observed fatty acid profiles differed from previous studies, likely due to a combination of factors including strain-specific variations and growth condition differences (media type, temperature, harvesting point). However, this study highlights the consistent impact of Tween 80™ on the fatty acid composition of lactobacilli, regardless of these variations. In conclusion, Tween 80™ significantly alters fatty acid profiles, influencing saturation levels and specific fatty acid proportions. This work reveals key factors, including stimulated synthesis of lactobacillic acid, competition for oleic acid incorporation, and strain-specific responses to myristic and dihydrosterculic acids. The consistent reduction in cis-vaccenic acid and the presence of cyclic derivatives warrant further investigation to elucidate their roles in response to Tween 80™ supplementation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Zaręba and Ziarno.)

Probiotics offer a promising prophylactic approach against various pathogens and represent an alternative strategy to combat biofilm-related infections. In this study, we isolated vaginal commensal microbiota from 54 healthy Indian women to investigate their probiotic traits. We primarily explored the ability of cell-free supernatant (CFS) from Lactobacilli to prevent Uropathogenic Escherichia coli (UPEC) colonization and biofilm formation. Our findings revealed that CFS effectively reduced UPEC's swimming and swarming motility, decreased cell surface hydrophobicity, and hindered matrix production by downregulating specific genes (fimA, fimH, papG, and csgA). Subsequent GC-MS analysis identified Tryptamine, a monoamine compound, as the potent bioactive substance from Lactobacilli CFS, inhibiting UPEC biofilms with an MBIC of 4 µg/ml and an MBEC of 8 µg/ml. Tryptamine induced significant changes in E. coli colony biofilm morphology, transitioning from the Red, Dry, and Rough (RDAR) to the Smooth and White phenotype, indicating reduced extracellular matrix production. Biofilm time-kill assays demonstrated a four-log reduction in UPEC viability when treated with Tryptamine, highlighting its potent antibacterial properties, comparable to CFS treatment. Biofilm ROS assays indicated a significant elevation in ROS generation within UPEC biofilms, suggesting a potential antibacterial mechanism. Gene expression studies with Tryptamine-treated samples showed a reduction in expression of curli gene (csgA), consistent with CFS treatment. This study underscores the potential of Tryptamine from probiotic Lactobacilli CFS as a promising antibiofilm agent against UPEC biofilms., (© 2024. The Author(s).)

Gluten possesses unique properties that render it only partially digestible. Consequently, it exerts detrimental effects on a part of the worldwide population who are afflicted with celiac disease (1%) or related disorders (5%), particularly due to the potential for cross-contamination even when adhering to a gluten-free diet (GFD). Finding solutions to break down gluten during digestion has a high nutritional and social impact. Here, a randomized double-blind placebo-controlled in vivo challenge investigated the gluten-degrading activity of a novel probiotic preparation comprising lactobacilli and their cytoplasmic extracts, Bacillus sp., and bacterial protease. In our clinical trial, we collected feces from 70 healthy volunteers at specific time intervals. Probiotic/placebo administration lasted 32 days, followed by 10 days of wash-out. After preliminary GFD to eliminate residual gluten from feces, increasing amounts of gluten (50 mg-10 g) were administered, each one for 4 consecutive days. Compared to placebo, the feces of volunteers fed with probiotics showed much lower amounts of residual gluten, mainly with increased intakes. Probiotics also regulate the intestinal microbial communities, improving the abundance of genera pivotal to maintaining homeostasis. Quantitative PCR confirmed that all probiotics persisted during the intervention, some also during wash-out. Probiotics promoted a fecal metabolome with potential immunomodulating activity, mainly related to derivatives of branched-chain amino acids and short-chain fatty acids., Importance: The untapped potential of gluten-degrading bacteria and their application in addressing the recognized limitations of gluten-related disorder management and the ongoing risk of cross-contamination even when people follow a gluten-free diet (GFD) emphasizes the significance of the work. Because gluten, a common protein found in many cereals, must be strictly avoided to stop autoimmune reactions and related health problems, celiac disease and gluten sensitivity present difficult hurdles. However, because of the hidden presence of gluten in many food products and the constant danger of cross-contamination during food preparation and processing, total avoidance is frequently challenging. Our study presents a novel probiotic preparation suitable for people suffering from gluten-related disorders during GFD and for healthy individuals because it enhances gluten digestion and promotes gut microbiota functionality., Competing Interests: The author B.S. is employed by Evonik Operations GmbH. The rest of the authors declare no conflicts of interest.

Long-term consumption of Western-style diet (WSD) can lead to metabolic disorders and dysbiosis of gut microbiota, presenting a critical risk factor for various chronic conditions such as fatty liver disease. In the present study, we investigated the beneficial role of co-fermented whole grain quinoa and black barley with Lactobacillus kisonensis on rats fed a WSD. Male Sprague-Dawley (SD) rats, aged six weeks and weighing 180 ± 10 g, were randomly assigned to one of three groups: the normal control group (NC, n = 7), the WSD group (HF, n = 7), and the WSD supplemented with a co-fermented whole grain quinoa with black barley (FQB) intervention group (HFF, n = 7). The findings indicated that FQB was effective in suppressing body weight gain, mitigating hepatic steatosis, reducing perirenal fat accumulation, and ameliorating pathological damage in the livers and testicular tissues of rats. Additionally, FQB intervention led to decreased levels of serum uric acid (UA), aspartate aminotransferase (AST), and alanine aminotransferase (ALT). These advantageous effects can be ascribed to the regulation of FQB on gut microbiota dysbiosis, which includes the restoration of intestinal flora diversity, reduction of the F/B ratio, and promotion of probiotics abundance, such as Akkermansia and [Ruminococcus] at the genus level. The study employed the UPLC-Q-TOF-MS E technique to analyze metabolites in fecal and hepatic samples. The findings revealed that FQB intervention led to a regression in the levels of specific metabolites in feces, including oxoadipic acid and 20a, 22b-dihydroxycholesterol, as well as in the liver, such as pyridoxamine, xanthine and xanthosine. The transcriptome sequencing of liver tissues revealed that FQB intervention modulated the mRNA expression of specific genes, including Cxcl12, Cidea, and Gck, known for their roles in anti-inflammatory and anti-insulin resistance mechanisms in the context of WSD. Our findings indicate that co-fermented whole-grain quinoa with black barley has the potential to alleviate metabolic disorders and chronic inflammation resulting from the consumption of WSD., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Inflammatory bowel disease (IBD) is one of the intractable diseases. Nutritional components associated with IBD have been identified, and it is known that excessive methionine intake exacerbates inflammation, and that tryptophan metabolism is involved in inflammation. Analysis of the gut microbiota has also progressed, where Lactobacillus regulate immune cells in the intestine and suppress inflammation. However, whether the methionine and tryptophan metabolic pathways affect the growth of intestinal Lactobacillus is unknown. Here we show how transient methionine, tryptophan, and niacin deficiency affects the host and gut microbiota in mouse models of colitis (induced by dextran sodium sulfate) fed a methionine-deficient diet (1K), tryptophan and niacin-deficient diet (2K), or methionine, tryptophan, and niacin-deficient diet (3K). These diets induced body weight decrease and 16S rRNA analysis of mouse feces revealed the alterations in the gut microbiota, leading to a dramatic increase in the proportion of Lactobacillus in mice. Intestinal RNA sequencing data confirmed that the expression of several serine proteases and fat-metabolizing enzymes were elevated in mice fed with methionine, tryptophan, and niacin (MTN) deficient diet. In addition, one-carbon metabolism and peroxisome proliferator-activated receptor (PPAR) pathway activation were also induced with MTN deficiency. Furthermore, changes in the expression of various immune-related cytokines were observed. These results indicate that methionine, tryptophan, and niacin metabolisms are important for the composition of intestinal bacteria and host immunity. Taken together, MTN deficiencies may serve as a Great Reset of gut microbiota and host gene expression to return to good health., (© 2024 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

This study investigated the effects of different pickle brines and glycine additions on biogenic amine formation in pickle fermentation. The results showed that the brines with higher biogenic amine content led to the production of more biogenic amines in the simulated pickle fermentation system. This was related to the abundance of biogenic amine-producing microorganisms in the microbial communities of the brines. Metagenome analysis of the brines and metatranscriptome analysis of the fermentation systems showed that putrescine was primarily from Lactobacillus, Oenococcus, and Pichia, while histamine and tyramine were primarily from Lactobacillus and Tetragenococcus. Addition of glycine significantly reduced the accumulation of biogenic amines in the simulated pickle fermentation system by as much as 70 %. The addition of glycine had no inhibitory effect on the amine-producing microorganisms, but it down-regulated the transcription levels of the genes for enzymes related to putrescine synthesis in Pichia, Lactobacillus, and Oenococcus, as well as the histidine decarboxylase genes in Lactobacillus and Tetragenococcus. Catalytic reaction assay using crude solutions of amino acid decarboxylase extracted from Lactobacillus brevis showed that the addition of glycine inhibited 45 %-55 % of ornithine decarboxylase and tyrosine decarboxylase activities. This study may provide a reference for the study and control of the mechanism of biogenic amine formation in pickle fermentation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

In this study, litchi polysaccharides were obtained from unfermented or fermented pulp by Lactobacillus fermentum (denoted as LP and LPF, respectively). The differences between LP and LPF in the colonic fermentation characteristics and modulatory of gut microbiota growth and metabolism were investigated with an in vitro fecal fermentation model. Results revealed that the strategies of gut bacteria metabolizing LP and LPF were different and LPF with lower molecular weight (Mw) was readily utilized by bacteria. The monosaccharide utilization sequence of each polysaccharide was Ara > Gla > GalA > GlcA ≈ Glu ≈ Man. Moreover, LPF promoted stronger proliferation of Bifidobacterium, Megamonas, Prevotella, and Bacteroides and higher SCFAs production (especially acetic and butyric acids) than LP. Correlation analysis further revealed that Mw could represent an essential structural feature of polysaccharides associated with its microbiota-regulating effect. Overall, Lactobacillus fermentation pre-treatment of litchi pulp promoted the fermentation characteristics and prebiotic activities of its polysaccharide., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Campylobacter jejuni (C. jejuni), a widely distributed global foodborne pathogen, primarily linked with contaminated chicken meat, poses a significant health risk. Reducing the abundance of this pathogen in poultry meat is challenging but essential. This study assessed the impact of Lactobacillus-fermented rapeseed meal (LFRM) on broilers exposed to C. jejuni-contaminated litter, evaluating growth performance, Campylobacter levels, and metagenomic profile., Results: By day 35, the litter contamination successfully colonized broilers with Campylobacter spp., particularly C. jejuni. In the grower phase, LFRM improved (P < 0.05) body weight and daily weight gain, resulting in a 9.2% better feed conversion ratio during the pre-challenge period (the period before artificial infection; days 13-20). The LFRM also reduced the C. jejuni concentration in the ceca (P < 0.05), without altering alpha and beta diversity. However, metagenomic data analysis revealed LFRM targeted a reduction in the abundance of C. jejuni biosynthetic pathways of l-tryptophan and l-histidine and gene families associated with transcription and virulence factors while also possibly leading to selected stress-induced resistance mechanisms., Conclusion: The study demonstrated that LFRM inclusion improved growth and decreased cecal Campylobacter spp. concentration and the relative abundance of pivotal C. jejuni genes. Performance benefits likely resulted from LFRM metabolites. At the molecular level, LFRM may have reduced C. jejuni colonization, likely by decreasing the abundance of energy transduction and l-histidine and l-tryptophan biosynthesis genes otherwise required for bacterial survival and increased virulence. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

Chemical pollutants such as mycotoxins and pesticides exert harmful effects on human health such as inflammation, oxidative stress, and cancer. Several strategies were applied for food decontamination, including physicochemical and biological strategies. The present review comprehensively discussed the recent efforts related to the biodegradation of eight food chemical contaminants, including mycotoxins, acrylamide, biogenic amines, N-nitrosamines, polycyclic aromatic hydrocarbons, bisphenol A, pesticides, and heavy metals by lactic acid bacteria (LAB). Biological detoxification by LAB such as Lactobacillus is a promising approach to remove the risks related to the presence of chemical and environmental pollutants in foodstuffs. It is a safe, efficient, environmentally friendly, and low-cost strategy to remove hazardous compounds. LAB can directly decrease these chemical pollutants by degradation or adsorption. Also, it can indirectly reduce the content of these pollutants by reducing their precursors. Hence, LAB can contribute to reducing chemical pollutants in contaminated foods and enhance food safety., Competing Interests: Declaration of competing interest The authors declare that they have no competing interest., (Copyright © 2024. Published by Elsevier Ltd.)

The study aimed to mine and characterize novel antimicrobial peptides (AMPs) from the Shanxi aged vinegar microbiome. Utilizing machine learning techniques, AlphaFold2 structure prediction and molecular dynamics simulations, six novel AMPs were innovatively mined from 98,539 peptides based on metagenomic data, of which one peptide secreted by Lactobacillus (named La-AMP) was experimentally validated to have remarkable bactericidal effects against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) with high stability and no hemolytic activity. Scanning electron microscopy revealed that La-AMP caused irreversible damage to cell membranes of S. aureus and E. coli, a finding further confirmed by calcein-AM/propidium iodide staining. Additionally, La-AMP induced nucleic acid leakage and reactive oxygen species accumulation in bacterial cells. It was found to bind to DNA gyrase through salt bridges, hydrogen bonds, and hydrophobic interactions, ultimately inducing apoptosis. Thus, La-AMP exhibited encouraging promise as a valuable bioactive component for the development of natural preservatives., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2024. Published by Elsevier Ltd.)

This study aimed to investigate the integration of cereal and germinated pseudocereals into set-type yogurt mimic, resulting in a novel and nutritious product. Four groups of yogurts mimic, namely CPY-1, CPY-2, CPY-3, and CPY-4, were prepared using different probiotic cultures, including L. acidophilus 21, L. plantarum 14, and L. rhamnosus 296 along with starter cultures. Notably, CPY-2 cultured with L. plantarum and L. rhamnosus and incubated for 12 h exhibited the most desirable attributes. The resulting yogurt demonstrated an acidity of 0.65%, pH of 4.37 and a probiotic count of 6.38 log CFU/mL. The logistic growth model fit revealed maximum growth rates (k, 1/h) and maximum bacterial counts (Nm log CFU/mL) for each CPY variant. The results revealed that CPY-2 significantly improved protein, dietary fiber, phenols and antioxidant capacities compared to the control. Scanning electron microscopy showed more structured and compact casein network in CPY-2, highlighting its superior textural characteristics. Overall, this study demonstrates the incorporation of cereal and germinated pseudocereals into set-type yogurt mimic offers health benefits through increased dietary fiber and β-glucan., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Lactobacillus strains have emerged as promising probiotics for enhancing the bioactivities of plant-based foods associated with flavonoid biotransformation. Employing microbial fermentation and mass spectrometry, we explored flavonoid metabolism in lychee pulp fermented separately by Lactiplantibacillus plantarum and Limosilactobacillus fermentum. Two novel metabolites, 3,5,7-trihydroxychromone and catechol, were exclusively identified in L. plantarum-fermented pulp. Concomitant with consumption of catechin and quercetin glycosides, dihydroquercetin glycosides, 2,4-dihydroxybenzoic acid and p-hydroxyphenyllactic acid were synthesized by two strains through hydrogenation and fission of C-ring. Quantitative analysis revealed that bound phenolics were primarily located in water-insoluble polysaccharides in lychee pulp. Quercetin 3-O-rutinoside was partially liberated from water-insoluble polysaccharides and migrated to water-soluble polysaccharides during fermentation. Meanwhile, substantial accumulations in short-chain fatty acids (increased 1.45 to 3.08-fold) and viable strains (increased by 1.97 to 2.00 Log 10 CFU/mL) were observed in fermentative pulp. These findings provide broader insight into microbial biotransformation of phenolics and possible guidance for personalized nutrition., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The primary objective of this study was to characterize lactic acid bacteria (LAB) strains derived from sourdough for possible utilization as functional starters to produce sourdough and various cereal-based fermented foods. A total of 350 autochthonous LAB strains were isolated from 65 Type I sourdough samples and characterized using six random amplified polymorphic DNA (RAPD) primers at intra- and interspecific levels. Species identification of selected strains representing distinct clusters from RAPD analysis was performed based on the 16S rRNA region. The LAB strains were identified as Companilactobacillus crustorum (n = 135), Levilactobacillus brevis (n = 125), Latilactobacillus curvatus (n = 40), Companilactobacillus paralimentarius (n = 32), and Lactiplantibacillus plantarum (n = 18). A total of 66 LAB strains were selected for technological characterization along with two commercial strains. The characterization involved acidity development, EPS production potential, leavening activity, and growth abilities under harsh conditions. Principle component analysis (PCA) identified 2 Lp. plantarum and 14 Lev. brevis strains as the most relevant technologically. Among them, Lp. plantarum L35.1 and Lev. brevis L37.1 were resistant to tetracycline. Evaluation of probiotic characteristics (survival in pH 2.5 and bile presence, auto aggregation capacity, hydrophobic activity, antioxidant activity, antimicrobial activity) by PCA identified four strains with relevance to Lactobacillus rhamnosus GG (LGG), which were further selected for in vitro digestion assays. Lactiplantibacillus plantarum L7.8, Lev. brevis L55.1, and L62.2 demonstrated similar viability indices to LGG, along with increased auto aggregation capacity and antioxidant activity. These strains are promising as candidate starters for producing sourdough and sourdough-related fermented food products., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have influenced the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Producing medium chain fatty acids (MCFAs) from waste activated sludge (WAS) is crucial for sustainable chemical industries. This study addressed the electron donor requirement for MCFAs production by inoculating Lactobacillus at varying concentrations (7.94 × 10 10 , 3.18 × 10 11 , and 6.35 × 10 11  cell/L) to supply lactate internally. Interestingly, the highest MCFAs yield (∼2000 mg COD/L) occurred at the lowest Lactobacillus inoculation. Higher inoculation concentrations redirected more carbon from WAS towards alcohols production rather than MCFAs generation, with up to 2852 mg COD/L alcohols obtained under 6.35 × 10 11  cell/L inoculation. Clostridium dominance and increased genes abundance for substrate hydrolysis, lactate conversion, and MCFAs/alcohol production collectively enhanced WAS-derived MCFAs and alcohols synthesis after Lactobacillus inoculation. Overall, the strategy of Lactobacillus inoculation regulated fermentation outcomes and subsequent carbon recovery in WAS, presenting a sustainable technology to achieve liquid bio-energy production from underutilized wet wastes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Hainan dregs vinegar (HNDV) is a traditional fermented food in China that is renowned for its unique flavor. HNDV is one of the most popular vinegars in Southeast Asia. However, research on the microorganisms and characteristic metabolites specific to HNDV is lacking. This study investigated the changes in microbial succession, volatile flavor compounds and characteristic non-volatile flavor compounds during HNDV fermentation based on metagenomics and metabolomics. The predominant microbial genera were Lactococcus, Limosilactobacillus, Lactiplantibacillus, and Saccharomyces. Unlike traditional vinegar, l-lactic acid was identified as the primary organic acid in HNDV. Noteworthy flavor compounds specific to HNDV included 3-methylthiopropanol and dl-phenylalanine. Significant associations were observed between six predominant microorganisms and six characteristic volatile flavor compounds, as well as seven characteristic non-volatile flavor compounds. The present results contribute to the development of starter cultures and the enhancement of HNDV quality., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Exploring probiotics for their crosstalk with the host microbiome through the fermentation of non-digestible dietary fibers (prebiotics) for their potential metabolic end-products, particularly short-chain fatty acids (SCFAs), is important for understanding the endogenous host-gut microbe interaction. This study was aimed at a systematic comparison of commercially available probiotics to understand their synergistic role with specific prebiotics in SCFAs production both in vitro and in the ex vivo gut microcosm model. Probiotic strains isolated from pharmacy products including Lactobacillus sporogenes (strain not labeled), Lactobacillus rhamnosus GG (ATCC53103), Streptococcus faecalis (T-110 JPC), Bacillus mesentericus (TO-AJPC), Bacillus clausii (SIN) and Saccharomyces boulardii (CNCM I-745) were assessed for their probiotic traits including survival, antibiotic susceptibility, and antibacterial activity against pathogenic strains. Our results showed that the microorganisms under study had strain-specific abilities to persist in human gastrointestinal conditions and varied anti-infective efficacy and antibiotic susceptibility. The probiotic strains displayed variation in the utilization of six different prebiotic substrates for their growth under aerobic and anaerobic conditions. Their prebiotic scores (PS) revealed which were the most suitable prebiotic carbohydrates for the growth of each strain and suggested xylooligosaccharide (XOS) was the poorest utilized among all. HPLC analysis revealed a versatile pattern of SCFAs produced as end-products of prebiotic fermentation by the strains which was influenced by growth conditions. Selected synbiotic (prebiotic and probiotic) combinations showing high PS and high total SCFAs production were tested in an ex vivo human gut microcosm model. Interestingly, significantly higher butyrate and propionate production was found only when synbiotics were applied as against when individual probiotic or prebiotics were applied alone. qRT-PCR analysis with specific primers showed that there was a significant increase in the abundance of lactobacilli and bifidobacteria with synbiotic blends compared to pre-, or probiotics alone. In conclusion, this work presents findings to suggest prebiotic combinations with different well-established probiotic strains that may be useful for developing effective synbiotic blends., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Optimized production of Aspergillus niger ATCC 26011 endo-β-mannanase (ManAn) on copra meal resulted in 2.46-fold increase (10,028 U/gds). Purified ManAn (47 kDa) showed high affinity towards guar gum (GG) as compared to konjac gum and locust bean gum with K m 2.67, 3.25 and 4.07 mg/mL, respectively. ManAn efficiently hydrolyzed GG and liberated mannooligosaccharides (MOS). Changes occurring in the rheological and compositional aspects of GG studied using Differential scanning calorimetry (DSC), Thermal gravimetric analysis (TGA) and X-ray diffraction (XRD) revealed increased thermal stability and crystallinity of the partially hydrolyzed guar gum (PHGG). Parametric optimization of the time and temperature dependent hydrolysis of GG (1% w/v) with 100 U/mL of ManAn at 60 °C and pH: 5.0 resulted in 12.126 mg/mL of mannotetraose (M4) in 5 min. Enhanced growth of probiotics Lactobacilli and production of short chain fatty acids (SCFA) that inhibited enteropathogens, confirmed the prebiotic potential of PHGG and M4., (© 2024. The Author(s).)

The gut microbiota contributes to skeletal muscle energy metabolism and is an indirect factor affecting meat quality. However, the role of specific gut microbes in energy metabolism and fiber size of skeletal muscle in chickens remains largely unknown. In this study, we first performed cecal microbiota transplantation from Chinese indigenous Jingyuan chickens (JY) to Arbor Acres chickens (AA), to determine the effects of microbiota on skeletal muscle fiber and energy metabolism. Then, we used metagenomics, gas chromatography, and metabolomics analysis to identify functional microbes. Finally, we validated the role of these functional microbes in regulating the fiber size via glucose metabolism in the skeletal muscle of chickens through feeding experiments. The results showed that the skeletal muscle characteristics of AA after microbiota transplantation tended to be consistent with that of JY, as the fiber diameter was significantly increased, and glucose metabolism level was significantly enhanced in the pectoralis muscle. L. plantarum , L. ingluviei , L. salivarius, and their mixture could increase the production of the microbial metabolites protoporphyrin IX and short-chain fatty acids, therefore increasing the expression levels of genes related to the oxidative fiber type ( MyHC SM and MyHC FRM ), mitochondrial function ( Tfam and CoxVa ), and glucose metabolism ( PFK , PK , PDH , IDH , and SDH ), thereby increasing the fiber diameter and density. These three Lactobacillus species could be promising probiotics to improve the meat quality of chicken.IMPORTANCEThis study revealed that the L. plantarum, L. ingluviei , and L. salivarius could enhance the production of protoporphyrin IX and short-chain fatty acids in the cecum of chickens, improving glucose metabolism, and finally cause the increase in fiber diameter and density of skeletal muscle. These three microbes could be potential probiotic candidates to regulate glucose metabolism in skeletal muscle to improve the meat quality of chicken in broiler production., Competing Interests: The authors declare no conflict of interest.

Iron deficiency remains a public health challenge globally. Prebiotics have the potential to improve iron bioavailability by modulating intestinal bacterial population, increasing SCFA production, and stimulating expression of brush border membrane (BBM) iron transport proteins among iron-deficient populations. This study intended to investigate the potential effects of soluble extracts from the cotyledon and seed coat of three pea ( Pisum sativum ) varieties (CDC Striker, CDC Dakota, and CDC Meadow) on the expression of BBM iron-related proteins (DCYTB and DMT1) and populations of beneficial intestinal bacteria in vivo using the Gallus gallus model by oral gavage (one day old chicks) with 1 mL of 50 mg/mL pea soluble extract solutions. The seed coat treatment groups increased the relative abundance of Bifidobacterium compared to the cotyledon treatment groups, with CDC Dakota seed coat (dark brown pigmented) recording the highest relative abundance of Bifidobacterium . In contrast, CDC Striker Cotyledon (dark-green-pigmented) significantly increased the relative abundance of Lactobacillus ( p < 0.05). Subsequently, the two dark-pigmented treatment groups (CDC Striker Cotyledon and CDC Dakota seed coats) recorded the highest expression of DCYTB. Our study suggests that soluble extracts from the pea seed coat and dark-pigmented pea cotyledon may improve iron bioavailability by affecting intestinal bacterial populations.

S-layers are crystalline arrays found on bacterial and archaeal cells. Lactobacillus is a diverse family of bacteria known especially for potential gut health benefits. This study focuses on the S-layer proteins from Lactobacillus acidophilus and Lactobacillus amylovorus common in the mammalian gut. Atomic resolution structures of Lactobacillus S-layer proteins SlpA and SlpX exhibit domain swapping, and the obtained assembly model of the main S-layer protein SlpA aligns well with prior electron microscopy and mutagenesis data. The S-layer's pore size suggests a protective role, with charged areas aiding adhesion. A highly similar domain organization and interaction network are observed across the Lactobacillus genus. Interaction studies revealed conserved binding areas specific for attachment to teichoic acids. The structure of the SlpA S-layer and the suggested incorporation of SlpX as well as its interaction with teichoic acids lay the foundation for deciphering its role in immune responses and for developing effective treatments for a variety of infectious and bacteria-mediated inflammation processes, opening opportunities for targeted engineering of the S-layer or lactobacilli bacteria in general., Competing Interests: Competing interests statement:The authors declare no competing interest.

Introduction: We assessed the in vitro anti-chlamydial activity of fresh vaginal secretions, deciphering the microbial and metabolic components able to counteract Chlamydia trachomatis viability., Methods: Forty vaginal samples were collected from a group of reproductive-aged women and their anti-chlamydial activity was evaluated by inhibition experiments. Each sample underwent 16S rRNA metabarcoding sequencing to determine the bacterial composition, as well as 1 H-NMR spectroscopy to detect and quantify the presence of vaginal metabolites., Results: Samples characterized by a high anti-chlamydial activity were enriched in Lactobacillus , especially Lactobacillus crispatus and Lactobacillus iners , while not-active samples exhibited a significant reduction of lactobacilli, along with higher relative abundances of Streptococcus and Olegusella . Lactobacillus gasseri showed an opposite behavior compared to L. crispatus , being more prevalent in not-active vaginal samples. Higher concentrations of several amino acids (i.e., isoleucine, leucine, and aspartate; positively correlated to the abundance of L. crispatus and L. jensenii ) lactate, and 4-aminobutyrate were the most significant metabolic fingerprints of highly active samples. Acetate and formate concentrations, on the other hand, were related to the abundances of a group of anaerobic opportunistic bacteria (including Prevotella, Dialister, Olegusella, Peptostreptococcus, Peptoniphilus, Finegoldia and Anaerococcus ). Finally, glucose, correlated to Streptococcus, Lachnospira and Alloscardovia genera, emerged as a key molecule of the vaginal environment: indeed, the anti-chlamydial effect of vaginal fluids decreased as glucose concentrations increased., Discussion: These findings could pave the way for novel strategies in the prevention and treatment of chlamydial urogenital infections, such as lactobacilli probiotic formulations or lactobacilli-derived postbiotics., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Morselli, Ceccarani, Djusse, Laghi, Camboni, Consolandi, Foschi, Severgnini and Marangoni.)

There are massive sources of lactic acid bacteria (LAB) in traditional dairy products. Some of these indigenous strains could be novel probiotics with applications in human health and supply the growing needs of the probiotic industry. In this work, were analyzed the probiotic and technological properties of three Lactobacilli strains isolated from traditional Brazilian cheeses. In vitro tests showed that the three strains are safe and have probiotic features. They presented antimicrobial activity against pathogenic bacteria, auto-aggregation values around 60%, high biofilm formation properties, and a survivor of more than 65% to simulated acid conditions and more than 100% to bile salts. The three strains were used as adjunct cultures separately in a pilot-scale production of Prato cheese. After 45 days of ripening, the lactobacilli counts in the cheeses were close to 8 Log CFU/g, and was observed a reduction in the lactococci counts (around -3 Log CFU/g) in a strain-dependent manner. Cheese primary and secondary proteolysis were unaffected by the probiotic candidates during the ripening, and the strains showed no lipolytic effect, as no changes in the fatty acid profile of cheeses were observed. Thus, our findings suggest that the three strains evaluated have probiotic properties and have potential as adjunct non-starter lactic acid bacteria (NSLAB) to improve the quality and functionality of short-aged cheeses., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The effect of a casein hydrolysate (CH) on the fermentation and quality of a naturally-fermented buckwheat sourdough (NFBS) were investigated, through assessing the fermentation characteristics, carbohydrate and protein degradation, texture, and bacterial composition of NFBS. According to the assaying data, CH might both increase the amount of lactic acid bacteria by 2.62 % and shorten the fermentation period by at least 3 h, subsequently leading to enhanced degradation of carbohydrate and protein, accompanied by a softer texture. More importantly, CH increased the relative abundance of lactobacillus in NFBS, making it the dominant bacterial genus and inhibited the growth of spoilage bacteria. In addition, Spearman correlation analysis indicated that the pH value, lactic and acetic acid contents, carbohydrates, protease activity, and these textural indices like hardness, elasticity, and adhesion had a positive/negative correlation with the bacterial composition of NFBS (Spearman correlation coefficient: -0.93-0.95). CH was thus regarded to be helpful to NFBS processing and production mainly by shortening its fermentation time, improving its fermentation performance, causing a finer texture and microstructure, and changing bacterial composition., Competing Interests: Declaration of competing interest We wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome., (Copyright © 2024. Published by Elsevier B.V.)