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Gut microbiota can influence cognitive ability via the gut-brain axis. Lactiplantibacillus plantarum MWFLp-182 ( L. plantarum MWFLp-182) was obtained from feces of long-living individuals and could exert marked antioxidant ability. Interestingly, this strain reduced the D-galactose-induced impaired cognitive ability in BALB/c mice. To comprehensively elucidate the underlying mechanism, we evaluated the colonization, antioxidant, and anti-inflammatory activities of L. plantarum MWFLp-182, along with the expression of potential genes associated with cognitive ability influenced and gut microbiota. L. plantarum MWFLp-182 enhanced the expression of anti-inflammatory cytokines, reduced the expression of proinflammatory cytokines, and increased tight junction protein expression in the colon. Moreover, L. plantarum MWFLp-182 could modify the gut microbiota. Notably, treatment with L. plantarum MWFLp-182 upregulated the expression of postsynaptic density protein-95, nuclear factor erythroid 2-related factor, nerve growth factor, superoxide dismutase, and brain-derived neurotrophic factor/neuronal nuclei, while downregulating the expression of bcl-2-associated X and malondialdehyde in the hippocampus and upregulating short-chain fatty acids against D-galactose-induced mouse brain deficits. Accordingly, L. plantarum MWFLp-182 could improve cognitive ability in a D-galactose-inducing mouse model.

Food-fermenting lactobacilli convert glycosylated phytochemicals to glycosyl hydrolases and thereby alter their biological activity. This study aimed to investigate the microbial transformation of β-glucosides of phytochemicals in comparison with utilization of cellobiose. Four homofermentative and four heterofermentative lactobacilli were selected to represent the metabolic diversity of Lactobacillaceae . The genomes of Lactobacillus crispatus , Companilactobacillus paralimentarius , Lacticaseibacillus paracasei , and Lactiplantibacillus plantarum encoded for 8 to 22 enzymes, predominantly phospho-β-glucosidases, with predicted activity on β-glucosides. Levilactobacillus hammesii and Furfurilactobacillus milii encoded for 3 β-glucosidases, Furfurilactobacillus rossiae for one, and Fructilactobacillus sanfranciscensis for none. The hydrolysis of amygdalin, esculin, salicin, glucosides of quercetin and genistein, and ginsenosides demonstrated that several strains hydrolyzed β-glucosides of phytochemicals but not cellobiose. Taken together, several of the carbohydrate-active enzymes of food-fermenting lactobacilli are specific for glycosides of phytochemicals.

Food-derived bioactive peptides (BPs) have received considerable attention as postbiotics for human gut health. Here we used a genomics-based semirational approach to expand the postbiotic potential of collagen peptides (CPs) produced from probiotic fermentation. In silico digestion revealed distinct BPs embedded in fish collagen in a protease-dependent manner. Anaerobic digestion of collagen by representative Lactobacillaceae species revealed differential substrate utilization and collagen degradation patterns. Nanoliquid chromatography-mass spectrometry analysis of CPs showed that each species exhibited different cleavage patterns and unique peptide profiles. Remarkably, the 1-10 kDa CPs produced by Lacticaseibacillus paracasei showed agonistic activities toward G protein-coupled receptor 35 (GPR35). These CPs could repair intestinal epithelium through the GPR35-mediated extracellular signal-regulated protein kinase (ERK) 1/2 signaling pathway, suggesting that probiotic-aided collagen hydrolysates can serve as postbiotics for host-microbe interactions. Therefore, this study provides an effective strategy for the rapid screening of CPs for gut health in the gastrointestinal tract.

Whole-genome and transcriptome sequences of Lactiplantibacillus plantarum 163 are provided. There was one circular chromosome and four circular plasmids, with sizes of 3,131,367; 56,674; 49,140; 43,628; and 36,387 bp, respectively, in L. plantarum 163. The regulator Lp_2642 was selected from the genome data, the overexpression of which increased the transcriptional levels of related genes in plantaricin EF biosynthesis and enhanced plantaricin EF production. Its production was 17.30 mg/L in 163 (Lp_2642), which was 1.29-fold higher than that of the original strain. The regulation mechanism demonstrated that Lp_2642 can bind to three sites of plnA promoter, which enhances its transcription and expression, thereby increasing plantaricin EF production. Amino acids Asn-100, Asn-64, and Thr-69 may play a key role in the binding of Lp_2642. These results provide a novel strategy for mass production of plantaricin EF, which facilitates its large-scale production and application in the agriculture and food industries as a preservative.

Prebiotic human milk oligosaccharides (HMOs) are found in human milk, which are not digested by infants but are metabolized by beneficial gut bacteria. We determined the ability of 57 bacterial strains within the Family Lactobacillaceae and genera Bifidobacterium and Bacteroides and potentially pathogenic bacteria to ferment the HMOs 2'-fucosyllactose, 3-fucosyllactose, and difucosyllactose. In addition, prebiotic galacto-oligosaccharides (GOS), lactose, fucose, and glucose were evaluated as carbon sources for these bacterial strains. Bacterial growth was monitored using the automatic Bioscreen C system. Only certain bifidobacteria, such as Bifidobacterium longum subsp . infantis and Bifidobacterium bifidum , as well as Bacteroides fragilis , Bacteroides vulgatus , and Bacteroides thetaiotaomicron utilized the studied HMOs as their sole carbon source, whereas almost all studied bacterial strains were able to utilize GOS, lactose, and glucose. The selectivity in utilization of HMOs by only certain bacteria can be advantageous by promoting beneficial microbes but not supporting the harmful pathogens in contrast to other less selective prebiotics.

Brewer's spent grain (BSG) samples were subjected to a two-step aqueous processing (starch extraction and autohydrolysis) in order to assess their potential as a raw material for obtaining a mixture of arabinoxylooligosaccharides (AXOS) suitable to be use as prebiotics for elderly. After hydrothermal treatment, the liquors were refined by a sequence of purification and conditioning steps including membrane filtration, enzymatic hydrolysis, and ion exchange. The presence of both substituted (degree of polimerization (DP) = 2-10) and unsubstituted (DP = 2-16) oligosaccharides made up of xylose and arabinose (AXOS) were confirmed in purified mixtures (in which total OS content = 84% w/w) by using chromatographic techniques and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Finally, AXOS were evaluated for their prebiotic activity by in vitro fermentation assays using fecal inocula from elderly people, demonstrating that AXOS were slightly better substrates than FOS, in terms of bacterial population shifts as in the production of SCFA.

Conversion of ornithine to putrescine by Salmonella Paratyphi A, Listeria monocytogenes, Staphylococcus aureus, and Escherichia coli was investigated in ornithine decarboxylase broth (ODB) using cell-free supernatants (CFSs) obtained from Leuconostoc mesenterodies subsp. cremoris, Pediococcus acidilactici, Lactococcus lactis subsp. lactis, Streptococcus thermophilus. Two groups of cell-free supernatants (25 or 50%) and control (only ODB) were prepared to investigate putrescine (PUT) and other polyamine formation by foodborne pathogens (FBPs). Significant differences (p < 0.05) were observed among the species for each amine. All of the CFSs reduced the formation of PUT by ≥65%. The production of cadaverine (CAD) was scarcely affected by the presence of CFSs, with the exception of the samples inoculated with L. monocytogenes. The variation in polyamine was found with respect to the control samples. Spermidine (SPD) was produced in lower amount in many samples, especially in Gram-negative FBPs, whereas spermine (SPN) increased drastically in the major part of the samples concerning the control. Histamine (HIS) was characterized by a marked concentration decrease in all of the samples, and tyramine (TYR) was accumulated in very low concentrations in the controls. Therefore, the ability of bacteria to produce certain biogenic amines such as HIS, TYR, PUT, and CAD has been studied to assess their risk and prevent their formation in food products. The results obtained from this study concluded that the lactic acid bacteria (LAB) strains with non-decarboxylase activity are capable of avoiding or limiting biogenic amine formation by FBP.

Barley husks, rye bran, and a fiber residue from oat milk production were processed by heat pretreatment, various separation steps, and treatment with an endoxylanase in order to improve the prebiotic potential of these cereal byproducts. Metabolic functions were intended to improve along with improved microbial activity. The products obtained were included in a high-fat mouse diet so that all diets contained 5% dietary fiber. In addition, high-fat and low-fat controls as well as partially hydrolyzed guar gum were included in the study. The soluble fiber product obtained from rye bran caused a significant increase in the bifidobacteria (log copies of 16S rRNA genes; median (25-75 percentile): 6.38 (6.04-6.66) and 7.47 (7.30-7.74), respectively; p < 0.001) in parallel with a tendency of increased production of propionic acid and indications of improved metabolic function compared with high-fat fed control mice. The oat-derived product caused an increase in the pool of cecal propionic (from 0.62 ± 0.12 to 0.94 ± 0.08) and butyric acid (from 0.38 ± 0.04 to 0.60 ± 0.04) compared with the high-fat control, and it caused a significant increase in lactobacilli (log copies of 16S rRNA genes; median (25-75 percentile): 6.83 (6.65-7.53) and 8.04 (7.86-8.33), respectively; p < 0.01) in the cecal mucosa. However, no changes in measured metabolic parameters were observed by either oat or barley products.

EpiCor, derived from Saccharomyces cerevisiae, has been shown to have immunomodulating properties in human clinical trials and in vitro. However, the underlying mechanisms behind its immune protection via the gut remain largely unknown. Therefore, the aim of this study was to use an integrated in vitro approach to evaluate the metabolism of EpiCor by the intestinal microflora, its modulating effect on the gut microbiota, and its anti-inflammatory activity on human-derived cell lines. Using the SHIME model, in combination with a mucus adhesion assay, has shown that low doses of EpiCor have a prebiotic-like modulatory effect on the luminal- and mucosa-associated microbiota. These include gradual changes in general community structure, reduction of potential pathogens, quantitative increase in lactobacilli, and qualitative modulation of bifidobacteria. Moreover, by combination of the SHIME with Caco-2 cells and Caco-2/THP1 cocultures, a significant decrease in pro-inflammatory cytokines was observed at the end of the treatment period.

Biogenic amines in low- and reduced-fat dry fermented sausages made with konjac gel (KG) as pork backfat replacer were studied. An increase (P < 0.05) was observed in the microbial count during the fermentation process, reaching levels of over 8 Log cfu/g of total viable microorganisms and lactic acid bacteria. However, no significant differences were observed in the microbiota evolution as a function of the reformulation process (fat and konjac gel content). High levels of physiological amines (spermidine, spermine, and agmatine) were observed in the raw material. From day 2 of the fermentation process an increase (P < 0.05) was observed in tyramine and putrescine, which were the predominant amines at the end of the storage period. The increase in these amines was proportional to the presence of KG and fat reduction. This can also be seen for spermine, with agmatine showing the inverse. The biogenic amine levels in these products reformulated with KG are not considered to pose a health risk to consumers.

Fermentation properties of oligosaccharides derived from lactulose (OsLu) and lactose (GOS) have been assessed in pH-controlled anaerobic batch cultures using lactulose and Vivinal-GOS as reference carbohydrates. Changes in gut bacterial populations and their metabolic activities were monitored over 24 h by fluorescent in situ hybridization (FISH) and by measurement of short-chain fatty acid (SCFA) production. Lactulose-derived oligosaccharides were selectively fermented by Bifidobacterium and lactic acid bacterial populations producing higher SCFA concentrations compared to GOS. The highest total SCFA production was from Vivinal-GOS > lactulose > OsLu > GOS. Longer incubation periods produced a selective fermentation of OsLu when they were used as a carbon source reaching the highest selective index scores. The new oligosaccharides may constitute a good alternative to lactulose, and they could belong to a new generation of prebiotics to be used as a functional ingredient for improving the composition of gut microflora.

The role of specific components from inactive dry yeast preparations widely used in winemaking on the growth of three representative wine lactic acid bacteria (Oenococcus oeni, Lactobacillus hilgardii and Pediococcus pentosaceus) has been studied. A pressure liquid extraction technique using solvents of different polarity was employed to obtain extracts with different chemical composition from the inactive dry yeast preparations. Each of the extracts was assayed against the three lactic acid bacteria. Important differences in the effect of the extracts on the growth of the bacteria were observed, which depended on the solvent employed during the extraction, on the type of commercial preparations and on the lactic acid bacteria species. The extracts that exhibited the most different activity were chemically characterized in amino acids, free monosaccharides, monosaccharides from polysaccharides, fatty acids and volatile compounds. In general, specific amino acids and monosaccharides were related to a stimulating effect whereas fatty acid composition and likely some volatile compounds seemed to show an inhibitory effect on the growth of the lactic acid bacteria. These results may provide novel and useful information in trying to obtain better and more specific formulations of winemaking inactive dry yeast preparations.

Trace amounts of the carcinogen ethyl carbamate can appear in wine by the reaction of ethanol with compounds such as citrulline and carbamyl phosphate, which are produced from arginine degradation by some wine lactic acid bacteria (LAB). In this work, the presence of arc genes for the arginine-deiminase pathway was studied in several strains of different species of LAB. Their ability to degrade arginine was also studied. To detect the presence of arc genes, degenerate primers were designed from the alignment of protein sequences in already sequenced LAB. The usefulness of these degenerate primers has been proven by sequencing some of the amplified PCR fragments and searching for homologies with published sequences of the same species and related ones. Correlation was found between the presence of genes and the ability to degrade arginine. Degrading strains included all heterofermentative lactobacilli, Oenococcus oeni , Pediococcus pentosaceus , and some strains of Leuconostoc mesenteroides and Lactobacillus plantarum .

We examined the role of microorganisms in the degradation of the organophosphorus (OP) insecticide chlorpyrifos (CP) during kimchi fermentation. During the fermentation of kimchi, 30 mg L(-1) of CP was added and its stability assayed during fermentation. CP was degraded rapidly until day 3 (83.3%) and degraded completely by day 9. Four CP-degrading lactic acid bacteria (LAB) were isolated from kimchi fermentation in the presence of 200 mg L(-1) CP and were identified as Leuconostoc mesenteroides WCP907, Lactobacillus brevis WCP902, Lactobacillus plantarum WCP931, and Lactobacillus sakei WCP904. CP could be utilized by these four strains as the sole source of carbon and phosphorus. Coumaphos (CM), diazinon (DZ), parathion (PT), and methylparathion (MPT) were also degraded by WCP907, WCP902, WCP931, and WCP904 when provided as sole sources of carbon and phosphorus.

Although mousy off-flavor occurs infrequently in wine, it can be economically disastrous to the wine producer as, at worst, it can render the wine unpalatable or, at best, decrease the quality of the wine resulting in a lower sale price. Wines infected with either lactic acid bacteria (LAB) (particularly heterofermentative strains) or Dekkera/Brettanomyces yeast can potentially produce mousy off-flavor. There are three known compounds that cause mousy off-flavor: 2-ethyltetrahydropyridine, 2-acetyltetrahydopyridine, and 2-acetylpyrroline. Dekkera/Brettanomyces have been shown to be capable of producing at least two of these compounds, whereas LAB are capable of producing all three. The reason as to why mousy off-flavor forms in some wines and not in others is still not fully understood. The issue is further complicated by the fact that the compounds that have thus far been identified as necessary for off-flavor formation are all potentially available in wine (e.g., ethanol, L-lysine, L-ornithine, and metal ions). For these reasons, the microbe's metabolism probably plays a key role in mousy off-flavor formation. In the case of Dekkera/Brettanomyces-induced mousy off-flavor, it appears that oxygen may play a key role. Thus, a wine infected with Dekkera/Brettanomyces in the absence of oxygen may not become mousy unless exposed to oxygen via a processing or handling procedure.

The importance of carnobacteria as spoilage microorganisms or potential protective cultures in food is not resolved, and little is known about their metabolism during growth in specific products. This study used chromatographic techniques including GC-MS and HPLC to evaluate the spoilage metabolism of Carnobacterium divergens, Carnobacterium maltaromaticum, and Carnobacterium mobile. Metabolic activity was studied in cooked and peeled modified atmosphere packed (MAP) shrimp at 5 degrees C as carnobacteria has been anticipated to contribute to spoilage of shrimp products. C. divergens and C. maltaromaticum caused sensory spoilage of shrimps and generated ammonia, tyramine, and various alcohols, aldehydes, and ketones. The effects of Carnobacterium species on the growth and metabolism of Brochothrix thermosphacta were also evaluated, but metabiosis between the two groups of bacteria was not observed. C. mobile and a specific cluster of C. maltaromaticum isolates (cluster L) did not cause sensory spoilage of shrimp.

One hundred and sixty-three wines from La Rioja, Utiel-Requena, and Tarragona were analyzed to determine if there were any differences in the concentrations of six biogenic amines that are found in these three regions. The influence of grape variety, type of vinification, wine pH, malolactic fermentation, and storage in bottle on biogenic amine concentrations was studied. Results show important differences in putrescine and histamine concentrations among regions, varieties of grape, and type of wine; differences were less appreciable for the remaining biogenic amines studied. Low pH prevented biogenic amine formation. Malolactic fermentation and short storage periods in bottle (3-6 months) showed increases in histamine concentration, whereas longer periods of storage led to a general decrease in histamine. Several strains of lactic acid bacteria were isolated in this work, and their ability to form biogenic amines was assayed in synthetic media, grape must, and wine. Grape varieties, different types of winemaking, pH, and lactic acid bacteria may be responsible for the differences observed in the biogenic amine concentrations of the wines analyzed.

In wine making, the bacteriolytic activity of lysozyme has primarily been used to control the malolactic fermentation in wines. The use of lysozyme in musts before settling and the beginning of the alcoholic fermentation to inhibit the growth of lactic acid bacteria could be very beneficial. In a resistance test carried out in MT/b broth, lysozyme had greater antimicrobial activity toward Oenococcus oeni than Lactobacillus species. Several strains of wine bacteria belonging to Oenococcus proved sensitive to the bacteriolytic activity of lysozyme at low concentrations in both synthetic medium (MT/b) (50 mg/L), white must, or red must made with or without the skins (100 mg/L). Lactobacillus and Pediococcus strains survived at lysozyme concentrations of 200-500 and 500 mg/L, respectively, in MT/b and musts. Suspended solids in unclarified musts may strongly bind to lysozyme thereby causing its removal by filtration or centrifugation. One hour after lysozyme was added to musts, it was quantified by HPLC and found after centrifugation to be 40-50% and only 10% in musts made with or without the skins, respectively. Although appreciable amounts of lysozyme were bound to wine components, this did not appear to be a serious hindrance to lysozyme activity.