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As the country has loosened its family planning policy and living standards have improved, postnatal obesity has become a social problem seriously threatening public health in China, which has attracted widespread attention from all walks of life. Therefore, a method for improving postpartum obesity urgently needs to be explored. Intestinal microecology is critical to the health of mothers and children, and plays an important role in the occurrence and development of obesity. Improving intestinal microecology as an effective way to improve obesity has attracted more and more attention. This article focuses on the relationship between postnatal obesity and intestinal microecology and summarizes the mechanisms of action of probiotics and prebiotics in regulating intestinal microecology to suppress postpartum obesity. The purpose of this article is to provide a theoretical basis for probiotic-prebiotic intervention based on intestinal microecology to suppress postpartum obesity.

The effects of soymilk fermented with single and mixed (1:1:1) cultures of three strains of lactic acid bacteria (LAB) isolated from sourdough from Fuchun Teahouse in Yangzhou City on the fermentation characteristics of dough and the quality of steamed bun were investigated. The results showed that the acidity and viable bacterial count of soymilk fermented with the mixed culture were 85.06 °T and 9.66 (lg(CFU/mL)), respectively, which were higher than those of the single culture fermented samples. Meanwhile, compared with the control group, the addition of fermented soymilk significantly increased the organic acid content and viable bacterial count of dough. The lactic acid content and viable bacterial count of dough supplemented with Lactobacillus pentosus 203 fermented soymilk were the highest, which were 18.57 mg/g and 8.94 (lg(CFU/g)), respectively. Dough added with Lactobacillus fermentum 202 fermented soymilk had the highest acetic acid content (3.81 mg/g). Compared with control steamed buns, the specific volume, elasticity and height to diameter ratio of four steamed buns supplemented with fermented soymilk were significantly increased, while the hardness and chewiness were significantly decreased. Steamed buns added with mixed-culture fermented soymilk had the highest overall acceptability. A total of 48 volatile flavor substances were detected in the five groups of steamed buns. Among them, the relative contents and types of flavor substances in the mixed culture group were the highest, which were 71.62% and 47, respectively. After being stored at 4 ℃ for 4 days, the moisture loss rate and retrogradation enthalpy of steamed buns added with fermented soymilk were significantly lower than those of the control group; the highest moisture content of 38.53% and the lowest retrogradation enthalpy of 1.00 J/g were found in the mixed culture group. In conclusion, adding fermented soymilk can effectively improve the quality and flavor and delay the aging of steamed buns, this effect being most pronounced with the incorporation of mixed-culture fermented soymilk.

Abstract The aim of this study was to identify the antimicrobial effect and mechanism of whey protein and blueberry juice mixed systems fermented with Lactobacillus against Escherichia coli during storage. The whey protein and blueberry juice mixed systems were fermented with L. casei M54, L. plantarum 67, S. thermophiles 99 and L. bulgaricus 134 and had different antibacterial activities against E. coli during storage. The antimicrobial activity of the mixed whey protein and blueberry juice mixture systems was the highest, with an inhibition zone diameter of approximately 230 mm, compared with the whey protein or blueberry juice systems alone. There were no viable E. coli cells 7 h after treatment with of the whey protein and blueberry juice mixed systems as determined by survival curve analysis. Analysis of the inhibitory mechanism showed that the release of alkaline phosphatase, electrical conductivity, protein and pyruvic acid contents, and aspartic acid transaminase and alanine aminotransferase activity in E. coli increased. These results demonstrated that these mixed systems fermented with Lactobacillus, especially those containing blueberries, could inhibit the growth of E. coli and even cause cell death by destroying the cell membrane and cell wall.

The bactericide is one of the major objective consequences related to healthcare in the world. Natural enzymes have been broadly utilized in various applications such as biomedical areas due to their broad catalytic activities and substrate particularity. While anticipating, it has drawbacks like higher cost, low stability, and troubles in reprocessing. Additionally, artificial enzymes (nanozymes) have favors above natural enzymes, for example, the effortless yield on a big scale, low costs, and high stability in coarse surrounds. The amount of antibiotic repellent microorganisms has activated big concern in the growth of stuff with essential bactericide potentials such as metal or metal oxide nanoparticles, cationic polymeric compounds, graphene oxide, and other carbon materials that can be used as antibacterial agents by altering cell morphology. In this report, we have summarized catalytic antibacterial strategies by natural enzymes, artificial enzymes, or photocatalytic activity. Furthermore, the demands and hereafter contents about catalytic antibacterial strategies are supposed in this report.

Introduction: The free exopolysaccharide (f-EPS) produced by Streptococcus thermophilus is a natural texture modifier and has a variety of prebiotic activities. Our previous studies showed f-EPS production from S. thermophilus 937 was increased 2-fold in the presence of 15 mM of glutamate, isoleucine, and histidine in the chemically defined medium. Methods: In this study, we used transcriptomics and qPCR to further explore the specific mechanism of the enhanced effect of 3 amino acids on the f-EPS biosynthesis of S. thermophilus 937. Results: The mRNA-seq analysis and targeted pathway analysis indicated that genes associated with histidine/valine/leucine/ isoleucine/phenylalanine/tyrosine/tryptophan synthesis, galactose metabolism, purine metabolism and quorum sensing in S. thermophilus 937 were significantly upregulated under increasing concentrations of histidine, isoleucine and glutamate in chemically defined medium (CDM). qPCR results showed that the significant upregulation of galactose metabolism- and nucleotide sugar synthesis-related genes was attributed to the increase in glutamate concentration, and glutamate could induce the expression of galR. The upregulation of epsA , epsB , and epsD transcript levels was caused by the increase in histidine concentration. The upregulation of transcript levels of genes related to phenylalanine/tyrosine/tryptophan/histidine/ valine/leucine/isoleucine synthesis was caused by the increase in isoleucine concentrations. Discussion: This indicates that 3 amino acids have different mechanisms for enhancing the biosynthesis of f-EPS in S. thermophilus 937. [ABSTRACT FROM AUTHOR]

In this study, different molecular weight cut-off ultrafiltration membranes (100 and 50 kDa) were used to concentrate and separate whey protein and blueberry juice fermented system by lactic acid bacteria (LAB) to demonstrate that the mixed fermentation had a protective effect on LAB and antioxidant activity during in vitro gastrointestinal digestion. The antioxidant activity after gastrointestinal digestion, the survival rate of LAB after membrane filtration, and their ability to reflect ultraviolet light of the membrane concentrated fermented components were investigated. It was found that the ABTS cationic free radical scavenging ability of L. plantarum 67 and L. paracasei W125 fermented group increased by 7.85%, especially after digestion, which increased by 3.17% compared with the unfermented blueberry and whey protein mixed group. The survival rates of L. plantarum 67 and L. paracasei W125 in the blueberry-whey protein mixture were greater than 82.45% after digestion. The ultrafiltration membrane concentration process had little effect on the viability of LAB during 0–50 min. The mixture of L. bulgaricus 134 and S. thermophiles Grx02 fermented blueberry-whey protein showed strong UV reflection at 300 nm, reaching 27.39%. The mixture of L. plantarum 67 and L. paracasei W125 fermented blueberry-whey protein showed strong UV reflection at 335 nm, reaching 34.29%. [ABSTRACT FROM AUTHOR]

A high degree of hydrolysis can reduce the allergenicity of milk, while lactic acid bacteria (LAB) fermentation can further enhance the antioxidant ability of enzymatic milk. LAB with a strong antioxidant ability was screened, and the effects of LAB on the bitterness, taste and flavor of enzymatic skim milk (ESM) with a high degree of hydrolysis were investigated in this paper, in addition to the response surface methodology optimized the conditions of the LAB fermentation of ESM. The results indicate that the skim milk hydrolyzed by Protamex has a higher degree of hydrolysis and lower bitterness. The scavenging rate of 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical, the inhibition rate of hydroxyl radical (·OH) and the superoxide dismutase (SOD) activity of Lactiplantibacillus plantarum 16 and Lactococcus lactis subsp. lactis m16 are significantly higher than those of other strains (p < 0.05), while the improvement effect of L. plantarum 16 on the bitterness and flavor of ESM is better than that of L. lactis subsp. lactis m16. The fermented ESM has a strong antioxidant ability and low bitterness when the inoculum quantity of L. plantarum 16 is 5%, fermentation at 37 °C for 18 h and the pH of the ESM is 6.5, for which the DPPH free radical scavenging rate is 61.32%, the ·OH inhibition rate is 83.35%, the SOD activity rate is 14.58 and the sensory evaluation is 4.25. The contents of amino acids related to bitterness and antioxidants were reduced and increased, respectively. The ESM fermented by L. plantarum 16 has a good flavor, antioxidant ability and low bitterness. [ABSTRACT FROM AUTHOR]

The colonization ability of Limosilactobacillus fermentum DALI02 and the promoting effect of fermented prebiotics have been studied. This study aims to evaluate the systemic immunomodulatory effects of DALI02 and DALI02 + Prebiotics on cyclophosphamide‐induced immunosuppressed rats. We found that DALI02 and DALI02 + Prebiotics, especially DALI02 + Prebiotics, exhibited significant restorative effects on the immunocompromised state in rats (p <.05). Specifically, both of them promoted the recovery of body weight and immune organ function, enhanced the proliferative capacity of immune cells, and effectively reduced the levels of interleukin 6 (IL‐6) and tumor necrosis factor‐α (TNF‐α). Furthermore, both of them significantly reduced the levels of lipopolysaccharide (LPS) and D‐lactic acid in the blood (p <.05). Principal coordinate analysis (PCoA), principal component analysis (PCA), and unsupervised cluster analysis revealed that DALI02 and DALI02 + Prebiotics group were more similar to the blank group at the genus level of the gut microbiota. At the level of short‐chain fatty acids (SCFAs), DALI02 + Prebiotics and blank group belonged to Cluster 3. These results suggested that the intervention with DALI02 and DALI02 + Prebiotics effectively modulated the structure of the gut microbiota, and DALI02 + Prebiotics restored the dysregulation of SCFAs. In summary, DALI02 and DALI02 + Prebiotics possess immunomodulatory functions, with the latter showing superior effects. [ABSTRACT FROM AUTHOR]

Pathogenic microorganisms have been detected in fermented food. Combining the enormous class of the pathogens and their continuously appearing mutants or novel species, it is important to select suitable and safe antibacterial agents for fermented food safety. Lactic acid bacteria (LAB) which produce diverse imperative antimicrobial metabolites have an immense number of applications in the food industry. Here, the human-derived strain YT was isolated due to its cell-free supernatant (CFS-YT) and cells (Cs-YT), respectively performed obvious inhibitory ring to Gram-positive and -negative spoilage bacteria. Strain YT was identified as Lacticaseibacillus rhamnosus by the 16s rDNA sequence and morphology. The antibacterial activity of CFS-YT was demonstrated to be growth-dependent, pHs-sensitive, broadly thermostable and enzyme-insensitive. Cs-YT displayed a broad antibacterial spectrum with the action mode of bacteriostasis. The antibacterial activity of Cs-YT was due to substances located at the cell surface which were sensitive to heat, stable at broad pH gradients and sensitive to specific enzymes. These data suggested that L. rhamnosus YT could be used as an alternative antimicrobial agent in fermented food biopreservation. [ABSTRACT FROM AUTHOR]

The effects of MRS, whey protein and blueberry alone, and mixed fermentation on the survival rate of lactic acid bacteria under various freeze-drying conditions were investigated. The surface structure of the freeze-dried powders was also investigated to explore the anti-freezing protection mechanism of mixed whey protein and blueberry fermentation on the bacteria. It was found that the mixed fermentation medium of blueberry and whey protein has a protective effect on the freeze-drying bacteria and is better than the traditional MRS and whey protein medium. The optimal concentration of blueberry juice addition was 9%. The survival rate of the pre-freezing temperature at −80 °C was higher than at −20 °C after the pre-freezing and freeze-drying processes. The freeze-drying thickness of 0.3 cm could improve the survival rate of the bacteria. The Fourier transform infrared spectroscopy results indicated the interaction between the whey protein, anthocyanins, and the surface composition of the lactic acid bacteria. [ABSTRACT FROM AUTHOR]

The exopolysaccharides produced by Streptococcus thermophilus during its growth can improve the texture of fermented dairy products and have various physiological and biochemical functions. To explore the regulatory mechanism of histidine, isoleucine, and glutamate on the exopolysaccharide of S. thermophilus 937, this study analyzed the exopolysaccharide synthesis pathway of the strain through whole genome sequencing. It then explored the effects of the concentration of 3 amino acids on the strain growth, the production and properties of exopolysaccharides, and the transcription level of epsABCD of the strain. Results showed that the strain had a specific PTS for glucose and sucrose transport system and lactose osmotic enzyme. It had the potential to synthesize UDP-glucose, UDP-galactose, and dTDPrhamnose. There was the eps gene cluster composed of 18 coding genes on the chromosome. When the concentration of 3 amino acids was increased to 15 mmol/L, the exopolysaccharide production of the strain increased by 1.5 times, the molecular weight increased by 1.2 times, the molar ratio of monosaccharide composition changed, and the epsABCD transcription level was significantly upregulated (P < 0.05). The 3 amino acids enhanced the production of exopolysaccharides and regulated the properties by regulating the expression of epsABCD. The results of this study provided a better understanding of the exopolysaccharide biosynthesis of Streptococcus thermophilus at the gene level. [ABSTRACT FROM AUTHOR]

Investigating the intricate pathways through which FH06 fermentation broth exerts lipid-lowering and weight-loss effects is pivotal for advancing our comprehension of metabolic regulation and therapeutic interventions. Ultrahigh-performance liquid chromatography quadrupole electrostatic field orbit trap mass spectrometry (UHPLC-QE-MS) detection and the ChEMBL database were used to determine the effective compounds in the FH06 fermentation broth and predict their targets. The TTD database and DisGeNET database were used to query obesity-related targets. The STRING database was used to construct protein interaction information. The Gene Ontology (GO) database and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database were used to perform biological function annotation (GO) and KEGG pathway enrichment analyses of the targets. Results: A total of 85 effective compounds were screened from the fermentation broth of FH06; these compounds may act on TP53, PPARG, TNF, and other targets through 10 signaling pathways, such as the chemical carcinogenesis-receptor activation and lipid and atherosclerosis pathways, and exert pharmacological effects, such as hypoglycemic effects and weight loss. They also have anti-inflammatory, antioxidant, antitumor, and immunoregulatory effects. These findings reveal the active ingredients of FH06 fermentation broth and its multi-target and multi-channel characteristics in lipid lowering and weight loss. This study has positive implications for the clinical treatment of obesity using FH06, providing a theoretical and scientific basis for further developing of FH06-assisted lipid-lowering products. [ABSTRACT FROM AUTHOR]

Well‐designed cryoprotectants are crucial for successful probiotic application. In this study, based on literature analysis, characteristics and economic analysis of cryoprotectants, the sucrose (8.2%)–skim milk (8.0%)–inulin (8.2%) combination was proposed and optimised to enhance freeze‐drying resistance of probiotics. Survival, viable cell counts and inactivation rate during storage at 4°C of Lactiplantibacillus plantarum grx16 protected by the combination was 94.9%, 1.89 × 1011 cfu/g and 0.0116. The optimised sucrose–skim milk–polymer prebiotics combination could also effectively protect several other probiotics, with the survival rate being 89.2–95.6%. These results will aid in the rational development of synergistic cryoprotectant formulations for probiotics. [ABSTRACT FROM AUTHOR]