Intervention with fructooligosaccharides, Saccharomyces boulardii, and their combination in a colitis mouse model.

Objective: To examine the effects of an intervention with fructooligosaccharides (FOS), Saccharomyces boulardii, and their combination in a mouse model of colitis and to explore the mechanisms underlying these effects. Methods: The effects of FOS, S. boulardii, and their combination were evaluated in a DSS-induced mouse model of colitis. To this end, parameters such as body weight, the disease activity index (DAI), and colon length were examined in model mice. Subsequently, ELISA was employed to detect the serum levels of proinflammatory cytokines. Histopathological analysis was performed to estimate the progression of inflammation in the colon. Gas chromatography was used to determine the content of short-chain fatty acids (SCFAs) in the feces of model mice. Finally, 16S rRNA sequencing technology was used to analyze the gut microbiota composition. Results: FOS was slight effective in treating colitis and colitis-induced intestinal dysbiosis in mice. Meanwhile, S. boulardii could significantly reduced the DAI, inhibited the production of IL-1ß, and prevented colon shortening. Nevertheless, S. boulardii treatment alone failed to effectively regulate the gut microbiota. In contrast, the combined administration of FOS/S. boulardii resulted in better anti-inflammatory effects and enabled microbiota regulation. The FOS/S. boulardii combination (109 CFU/ml and 107 CFU/ml) significantly reduced the DAI, inhibited colitis, lowered IL-1ß and TNF-α production, and significantly improved the levels of butyric acid and isobutyric acid. However, FOS/S. boulardii 109 CFU/ml exerted stronger anti-inflammatory effects, inhibited IL-6 production and attenuated colon shortening. Meanwhile, FOS/S. boulardii 107 CFU/ml improved microbial regulation and alleviated the colitis-induced decrease in microbial diversity. The combination of FOS and S. boulardii significantly increased the abundance of Parabacteroides and decreased the abundance of Escherichia-Shigella. Additionally, it promoted the production of acetic acid and propionic acid. Conclusion: Compared with single administration, the combination can significantly increase the abundance of beneficial bacteria such as lactobacilli and Bifidobacteria and effectively regulate the gut microbiota composition. These results provide a scientific rationale for the prevention and treatment of colitis using a FOS/S. boulardii combination. They also offer a theoretical basis for the development of nutraceutical preparations containing FOS and S. boulardii.

Effects of fructooligosaccharides and Saccharomyces boulardii on the compositional structure and metabolism of gut microbiota in students.

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 H2S and NH3. 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 CO2 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.

Whole-genome sequencing and analysis of Chryseobacterium arthrosphaerae from Rana nigromaculata.

Chryseobacterium arthrosphaerae strain FS91703 was isolated from Rana nigromaculata in our previous study. To investigate the genomic characteristics, pathogenicity-related genes, antimicrobial resistance, and phylogenetic relationship of this strain, PacBio RS II and Illumina HiSeq 2000 platforms were used for the whole genome sequencing. The genome size of strain FS91703 was 5,435,691 bp and GC content was 37.78%. A total of 4,951 coding genes were predicted; 99 potential virulence factors homologs were identified. Analysis of antibiotic resistance genes revealed that strain FS91703 harbored 10 antibiotic resistance genes in 6 categories and 2 multidrug-resistant efflux pump genes, including adeG and farA. Strain FS91703 was sensitive to ß-lactam combination drugs, cephem, monobactam and carbapenems, intermediately resistant to phenicol, and resistant to penicillin, aminoglycosides, tetracycline, fluoroquinolones, and folate pathway inhibitors. Phylogenetic analysis revealed that strain FS91703 and C. arthrosphaerae CC-VM-7T were on the same branch of the phylogenetic tree based on 16 S rRNA; the ANI value between them was 96.99%; and the DDH values were 80.2, 72.2 and 81.6% by three default calculation formulae. These results suggested that strain FS91703 was a species of C. arthrosphaerae. Pan-genome analysis showed FS91703 had 566 unique genes compared with 13 other C. arthrosphaerae strains, and had a distant phylogenetic relationship with the other C. arthrosphaerae strains of the same branch in phylogenetic tree based on orthologous genes. The results of this study suggest that strain FS91703 is a multidrug-resistant and highly virulent bacterium, that differs from other C. arthrosphaerae strains at the genomic level. The knowledge about the genomic characteristics and antimicrobial resistance of strain FS91703 provides valuable insights into this rare species, as well as guidance for the treatment of the disease caused by FS91703 in Rana nigromaculata.

Effects of dietary chito-oligosaccharide and ß-glucan on the water quality and gut microbiota, intestinal morphology, immune response, and meat quality of Chinese soft-shell turtle (Pelodiscus sinensis).

Chito-oligosaccharides (COS) and ß-glucan are gradually being applied in aquaculture as antioxidants and immunomodulators. However, this study examined the effects of dietary supplementation of COS and ß-glucan on the water quality, gut microbiota, intestinal morphology, non-specific immunity, and meat quality of Chinese soft-shell turtle. To investigate the possible mechanisms, 3-year-old turtles were fed basal diet (CK group) and 0.1%, 0.5%, and 1% COS or ß-glucan supplemented diet for 4 weeks. Colon, liver, blood and muscle tissues, colon contents, water and sediment of paddy field samples were collected and analyzed after feeding 2 and 4 weeks. The results indicated that COS and ß-glucan altered microbial community composition and diversity in Chinese soft-shell turtles. The relative abundance of Cellulosilyticum, Helicobacter and Solibacillus were increased after feeding COS, while Romboutsia, Akkermansia and Paraclostridium were increased after feeding ß-glucan, whereas Cetobacterium, Vibrio and Edwardsiella were enriched in the control group. Furthermore, colon morphology analysis revealed that COS and ß-glucan improved the length and number of intestinal villi, and the effect of 0.5% ß-glucan was more obvious. Both ß-glucan and COS significantly improved liver and serum lysozyme activity and antibacterial capacity. COS significantly increased the total antioxidant capacity in the liver. Further, 0.1% ß-glucan significantly increased the activity of hepatic alkaline phosphatase, which closely related to the bacteria involved in lipid metabolism. Moreover, dietary supplementation with 1% COS and 1% ß-glucan significantly enhanced the content of total amino acids, especially umami amino acids, in muscle tissue, with ß-glucan exerting a stronger effect than COS. Additionally, these two prebiotics promoted the quality of culture water in paddy fields and reshaped the bacterial community composition of aquaculture environment. All these phenotypic changes were closely associated with the gut microbes regulated by these two prebiotics. In summary, the findings suggest that dietary supplementation with COS and ß-glucan in Pelodiscus sinensis could modulate the gut microbiota, improve intestinal morphology, enhance non-specific immunity and antioxidant capacity of liver and serum, increase meat quality, and improve the culture water environment. This study provides new insights and a comprehensive understanding of the positive effects of COS and ß-glucan on Pelodiscus sinensis.

Effects of prebiotics on the gut microbiota in vitro associated with functional diarrhea in children.

Purpose: Diarrhea is among the top five causes of morbidity and mortality in children. Dysbiosis of the gut microbiota is considered the most important risk factor for diarrhea. Prebiotics have shown efficacy in treating diarrhea by regulating the balance of the gut microbiota in vivo. Methods: In this study, we used an in vitro fermentation system to prevent the interference of host-gut microbe interactions during in vivo examination and investigated the effect of fructo-oligosaccharides (FOS) on gut microbiota composition and metabolism in 39 pediatric patients with functional diarrhea. Results: 16S rRNA sequencing revealed that FOS significantly improved α- and ß-diversity in volunteers with pediatric diarrhea (p < 0.05). This improvement manifested as a significant increase (LDA > 2, p < 0.05) in probiotic bacteria (e.g., Bifidobacterium) and a significant inhibition (LDA > 2, p < 0.05) of harmful bacteria (e.g., Escherichia-Shigella). Notably, the analysis of bacterial metabolites after FOS treatment showed that the decrease in isobutyric acid, isovaleric acid, NH3, and H2S levels was positively correlated with the relative abundance of Lachnoclostridium. This decrease also showed the greatest negative correlation with the abundance of Streptococcus. Random forest analysis and ROC curve validation demonstrated that gut microbiota composition and metabolites were distinct between the FOS treatment and control groups (area under the curve [AUC] > 0.8). Functional prediction using PICRUSt 2 revealed that the FOS-induced alteration of gut microbiota was most likely mediated by effects on starch and sucrose metabolism. Conclusion: This study is the first to evince that FOS can modulate gut microbial disorders in children with functional diarrhea. Our findings provide a framework for the application of FOS to alleviate functional diarrhea in children and reduce the use of antibiotics for managing functional diarrhea-induced disturbances in the gut microbiota.

An exopolysaccharide from Lactobacillus pentosus YY-112: structure and effect on the human intestinal microbiota.

The development of novel prebiotics, which could regulate the intestinal microbiota, may help prevent and treat intestinal diseases. Here, we studied a homogeneous polysaccharide, LPE-2, produced by Lactobacillus pentosus YY-112 during fermentation. Methylation and gas chromatography-mass spectrometry analysis, combined with nuclear magnetic resonance results, suggested that the structural unit of LPE-2 comprises a branched mannan moiety and a linear glucan moiety. In vitro simulated intestinal fermentation showed that LPE-2 reduced harmful intestinal gas production and promoted short-chain fatty acid production (especially propionic acid). Moreover, it reduced the relative abundance of Escherichia-Shigella, increased that of Bifidobacterium and Lactobacillus, and had a stronger regulatory effect on intestinal flora in women than in men. The potential sex-specific prebiotic effects of LPE-2 on human intestinal health, were possibly related to its mannan branch with (1→2) and (1→3) linkages and backbones with flexible α configurations, which are sheared and degraded/utilized easier by Bifidobacterium and Lactobacillus.

Effects of urbanization and lifestyle habits on the intestinal microbiota of adolescents in eastern China.

Introduction: Owing to urbanization, living habits have changed widely, leading to alterations in the intestinal microbiota of urban residents. However, there are few studies on the characteristics of intestinal microbiota of adolescents living in different urbanized areas in China. Methods: A total of 302 fecal samples collected from adolescent students in eastern China were examined. 16S rRNA high-throughput sequencing was used to identify the fecal microbiota. These data were combined with questionnaire survey results to investigate the effect of urbanization on the intestinal microbiota of adolescents in eastern China. Moreover, the role of lifestyle habits in this relationship was also evaluated. Results: The results revealed significant differences in the structure of the intestinal microbiota among adolescents living in regions with different levels of urbanization. Adolescents living in urban regions had a significantly higher proportion of Bacteroides (p < 0.001, FDR = 0.004), whereas those living in towns and rural regions had higher proportions of Bifidobacterium (p < 0.001, FDR < 0.001) and Prevotella (p < 0.05, FDR = 0.019). The diversity of the intestinal microbiota was higher in urban residents than in adolescents living in towns and rural regions (p < 0.05). In addition, the differences in intestinal microbiota across individuals living in cities, towns, and rural regions were related to dietary preferences, flavor preferences, and sleep and exercise durations. Adolescents who ate more meat had more Dorea (LDA = 3.622, p = 0.04), while the abundance of Escherichia-Shigella is higher among adolescents who ate more condiments (LDA = 4.285, p = 0.02). The abundance of Dialister was significantly increased in adolescents with longer sleep durations (LDA = 4.066, p = 0.03). Adolescents who exercised for a long duration had more Faecalibacterium than those who exercised for a shorter duration (LDA = 4.303, p = 0.04). Discussion: Our research has preliminarily demonstrated that there were differences in the composition of Gut microbiome in stool samples of adolescents living in different urbanized areas, and provide a scientific basis for the maintenance of a healthy intentional microbota in adolescences.

Effects of several flavonoids on human gut microbiota and its metabolism by in vitro simulated fermentation.

Introduction: Flavonoids have antiviral, antitumor, anti-inflammatory, and other biological activities. They have high market value and are widely used in food and medicine fields. They also can regulate gut microbiota and promote human health. However, only a few flavonoids have been reported for their regulatory effects on human gut microbiota. Methods: The effects of hesperidin, hesperetin-7-O-glucoside, hesperetin, naringin, prunin, naringenin, rutin, isoquercitrin, and quercetin on gut microbiota structural and metabolic differences in healthy subjects were studied by means of in vitro simulated fermentation technology. Results: Results showed that the nine kinds of flavonoids mentioned above, especially hesperetin-7-O-glucoside, prunin, and isoquercitrin, were found to have more effect on the structure of human gut microbiota, and they could significantly enhance Bifidobacterium (p < 0.05). After 24 h of in vitro simulated fermentation, the relative abundance of intestinal probiotics (e.g., Lactobacillus) was increased by the three flavonoids and rutin. Furthermore, the relative abundance of potential pathogenic bacteria was decreased by the addition of hesperetin-7-O-glucoside, naringin, prunin, rutin, and isoquercitrin (e.g., Lachnoclostridium and Bilophila). Notably, prunin could also markedly decrease the content of H2S, NH3, and short-chain fatty acids. This performance fully demonstrated its broad-spectrum antibacterial activity. Discussion: This study demonstrates that flavonoids can regulate the imbalance of gut microbiota, and some differences in the regulatory effect are observed due to different structures. This work provides a theoretical basis for the wide application of flavonoids for food and medicine.

Hypoglycemic effect of the Phellinus baumii extract with α-glucosidase-inhibited activity and its modulation to gut microbiota in diabetic patients.

Phellinus baumii extract (PBE) possesses considerable α-glucosidase-inhibited activity. This study investigated the hypoglycemic effect in vitro and in vivo using a glucose consumption assay in HepG2 cells, intragastric administration for ten weeks in STZ-induced mice, and intestinal flora fermentation in patients with type 2 diabetes to reveal the possible underlying mechanisms. PBE was prepared, including α-glucosidase-inhibited ethanol extract (EE) and aqueous extract (AE). In vitro, PBE promoted glucose consumption and enhanced glycogen content and hexokinase activity but lowered phosphoenolpyruvate carboxylase kinase activity in HepG2 cells. In vivo, PBE treatment significantly reduced the body weight (p < 0.05) and fasting blood glucose levels of diabetic mice (p < 0.01), with the lowest blood glucose level observed in the EE+AE group. Furthermore, the serum insulin levels and insulin resistance index (HOMA) of PBE-treated groups decreased significantly (p < 0.01). Moreover, gene expression levels of the IRS-1/PI3K/AKT pathway were significantly upregulated by PBE treatment (p < 0.01). In vitro fermentation demonstrated that EE significantly inhibited the production of H2S and NH3 in the intestinal flora fermentation model in diabetic patients (p < 0.05). In addition, the ratio of Firmicutes to Bacteroidetes was reduced, the growth of Lactobacillus and Prevotella 9 was promoted, and Pseudomonas aeruginosa was inhibited. This study provides new insights and clues for using PBE as a functional food and clinical drug for glycemic control.

Lactobacillus johnsonii alleviates colitis by TLR1/2-STAT3 mediated CD206+ macrophagesIL-10 activation.

Imbalance of gut microbiota homeostasis is related to the occurrence of ulcerative colitis (UC), and probiotics are thought to modulate immune microenvironment and repair barrier function. Here, in order to reveal the interaction between UC and gut microbiota, we screened a new probiotic strain by 16S rRNA sequencing from Dextran Sulfate Sodium (DSS)-induced colitis mice, and explored the mechanism and clinical relevance. Lactobacillus johnsonii (L. johnsonii), as a potential anti-inflammatory bacterium was decreased colonization in colitis mice. Gavage L. johnsonii could alleviate colitis by specifically increasing the proportion of intestinal macrophages and the secretion of Il-10 with macrophages depleted model and in Il10-/- mice. We identified this subset of immune cells activated by L. johnsonii as CD206+ macrophagesIL-10. Mechanistically, L. johnsonii supplementation enhanced the mobilization of CD206+ macrophagesIL-10 through the activation of STAT3 in vivo and in vitro. In addition, we revealed that TLR1/2 was essential for the activation of STAT3 and the recognition of L. johnsonii by macrophages. Clinically, there was positive correlation between the abundance of L. johnsonii and the expression level of MRC1, IL10 and TLR1/2 in UC tissues. L. johnsonii could activate native macrophages into CD206+ macrophages and release IL-10 through TLR1/2-STAT3 pathway to relieve experimental colitis. L. johnsonii may serve as an immunomodulator and anti-inflammatory therapeutic target for UC.

Effects of Zymosan on Short-Chain Fatty Acid and Gas Production in in vitro Fermentation Models of the Human Intestinal Microbiota.

In this study, the effects of zymosan (HG, hydrolyzed glucan) on the structure and metabolism of fecal microbiota in Chinese healthy people was investigated by an in vitro simulated intestinal microecology fermentation model. We found that HG significantly regulated fecal microbiota composition, including the increase of Bifidobacterium, Faecalibacterium, Prevotella and the decrease of Escherichia-Shigella. Moreover, HG significantly increased the total production of short chain fatty acids (SCFAs) and gases, in which the production of Acetic acid, Propionic acid, CO2, and H2 significantly increased while the production of Isovaleric acid and NH3 significantly decreased. Additionally, the supplement of HG showed certain differences in the regulation of microbiota from four groups. HG significantly increased the relative abundance of Bifidobacterium and significantly decreased the relative abundance of Escherichia-Shigella excluding the older men group. Meanwhile, and the relative abundance of Lactobacillus was significantly increased in young populations. And the relative abundance of Bacteroides was significantly decreased only in the young women. Furthermore, HG significantly increased H2 concentration only in older men. These findings suggest that HG, as a new generation of prebiotics, could regulate the structure of fecal microbiota and its metabolites in a better direction, but when HG participates in precision nutrition formula, it may be necessary to consider the differences in the utilization of different populations.

Dendrobium officinale Polysaccharides Better Regulate the Microbiota of Women Than Men.

Dendrobium officinale is widely used as a health supplement, but its specific impact on healthy gut microbiota has not yet been clarified, nor has its impact on different human genders. To overcome the problems mentioned above. DOP was extracted and purified with an 8000-12,000 Da dialysis bag. The molecular weight and monosaccharide composition were determined using HPGPC and GC. Gas chromatography was used to detect the content of SCFA. 16S rDNA sequencing was used to analyze the diversity of human microbiota. The results showed that DOP contained two fractions, with an average molecular weight of 277 kDa and 1318 Da, and mainly composed of mannose and glucose. DOP can increase the relative abundance of benign microbiota and decrease the harmful types. Propionic acid content in women was significantly increased after DOP treatment. Finally, the correlation analysis revealed that DOP was beneficial to the microbiota of both men and women. It can be concluded from the results that DOP is a health supplement suitable for humans, and especially women.

In Vitro Hepatoprotective and Human Gut Microbiota Modulation of Polysaccharide-Peptides in Pleurotus citrinopileatus.

Pleurotus citrinopileatus, a golden oyster mushroom, is popular in Asia and has pharmacological functions. However, the effects of polysaccharide-peptides extracted from Pleurotus citrinopileatus and underlying mechanism on digestive systme have not yet been clarified. Here, we determined the composition of two polysaccharide-peptides (PSI and PSII) from P. citrinopileatus and investigated the protective effects of on hepatoprotective and gut microbiota. The results showed that PSI and PSII were made up of similar monosaccharide moieties, except for the varying ratios. Furthermore, PSI and PSII showed that they have the hepatoprotective effects and significantly increased the viabilities and cellular total superoxide dismutase activities increased significantly in HepG2 cells. Intracellular triglyceride content and extracellular alanine aminotransferase and aspartate transaminase contents markedly decreased following treatment with 40 and 50 µg/mL PSI and PSII, respectively. Moreover, PSI and PSII activated the adiponectin pathway and reduced lipid accumulation in liver cells. PSI and PSII elevated short-chain fatty acid concentrations, especially butyric and acetic acids. 16S rRNA gene sequencing analysis showed that PSI promoted the relative abundances of Bifidobacteria, Lactobacillus, Faecalibacterium, as well as Prevotella generas in the gut. PSII markedly suppressed the relative abundances of Escherichia-Shigella and Bacteroides generas. We speculate that the PSI and PSII play a role through liver-gut axis system. Polysaccharide-peptides metabolize by gut microbiota to produce short-chain fatty acids (SCFAs) and in turn influence liver functions.

Exopolysaccharide from Lactobacillus rhamnosus ZFM231 alleviates DSS-induced colitis in mice by regulating gut microbiota.

BACKGROUND: The exopolysaccharides (EPS) produced by Lactobacillus and other probiotics are associated with many benefits, such as immune regulation, antioxidant properties, antitumor effect, and regulation of intestinal microbe homeostasis. In the present study, the modulatory effect of EPS produced by Lactobacillus rhamnosus ZFM231 on the intestinal flora of mice with inflammatory bowel disease induced by dextran sulfate solution was investigated. RESULTS: Results indicated that weight loss, colonic length, the disease activity index score and colonic tissue damage in mice were significantly improved by EPS treatment. Compared with the model group, in the EPS-treated group, the diversity of and the composition of gut microbiota at both phylum and genus levels were found to recover to the levels of normal group, indicating the effective modulation on gut microbiota by EPS; short-chain fatty acids, including acetic acid, propionic acid and butyric acid produced by intestinal microbial metabolism, increased significantly; the level of anti-inflammatory factor transforning growth factor-ß significantly increased and the level of pro-inflammatory factor tumor necrosis factor-α significantly decreased in the colonic cells of EPS-treated mice. CONCLUSION: It is clear that EPS produced by L. rhamnosus ZFM231 could find application in functional foods with the property of anti-ulcerative colitis. The experimental results provide new insights into the probiotic effect of EPS. © 2022 Society of Chemical Industry.

The Methanol Extract of Polygonatum odoratum Ameliorates Colitis by Improving Intestinal Short-Chain Fatty Acids and Gas Production to Regulate Microbiota Dysbiosis in Mice.

The potential impacts of methanol extract from Polygonatum odoratum on (YZM) colonic histopathology, gut gas production, short-chain fatty acids (SCFAs), and intestinal microbiota composition were evaluated with dextran sulfate sodium (DSS)-induced colitis mice in this study. These results indicated that YZM increased colon length and ameliorated colonic histopathology in DSS-induced colitis mice. Moreover, YZM administration reversed intestinal microbiota compositions leading to the inhibition of H2S-related bacteria (e.g., Desulfovibrionaceae) and the lower level of H2S and higher contents of SCFA-related bacteria (e.g., Muribaculaceae). Taken together, the effects of methanol extract from Polygonatum odoratum are studied to provide new enlightenment and clues for its application as a functional food and clinical drug. Our study first revealed the relationship between intestinal gas production and key bacteria in ulcerative colitis.

Digestive Characteristics of Hericium erinaceus Polysaccharides and Their Positive Effects on Fecal Microbiota of Male and Female Volunteers During in vitro Fermentation.

Hericium erinaceus polysaccharides (HEPs) have attracted widespread attention in regulating gut microbiota (GM). To investigate digestibility and fermentation of HEPs and their effects on GM composition, three polysaccharide fractions, namely, HEP-30, HEP-50, and HEP-70, were fractionally precipitated with 30%, 50%, and 70% ethanol concentrations (v/v) from hot water-soluble extracts of Hericium erinaceus, respectively. Three kinds of prepared HEPs were structurally characterized and simulated gastrointestinal digestion, and their effects on human fecal microbiota fermentations of male and female and short-chain fatty acid (SCFA) production in vitro were clarified. Under digestive conditions simulating saliva, stomach, and small intestine, HEPs were not significantly influenced and safely reached the distal intestine. After 24 h of in vitro fermentation, the content of SCFAs was significantly enhanced (p < 0.05), and the retention rates of total and reducing sugars and pH value were significantly decreased (p < 0.05). Thus, HEPs could be utilized by GM, especially HEP-50, and enhanced the relative abundance of SCFA-producing bacteria, e.g., Bifidobacterium, Faecalibacterium, Blautia, Butyricicoccus, and Lactobacillus. Furthermore, HEPs reduced the relative abundances of opportunistic pathogenic bacteria, e.g., Escherichia-Shigella, Klebsiella, and Enterobacter. This study suggests that gradual ethanol precipitation is available for the preparation of polysaccharides from Hericium erinaceus, and the extracted polysaccharide could be developed as functional foods with great development value.

Effects of Different Feeding Methods on the Structure, Metabolism, and Gas Production of Infant and Toddler Intestinal Flora and Their Mechanisms.

In this study, we evaluated the effects of different feeding methods on the characteristics of intestinal flora and gas production in infants and toddlers by using an in vitro simulated intestinal microecology fermentation and organoid model. We found that the feeding method influences intestinal gas and fecal ammonia production in infants and toddlers. Supplementation with milk powder for infants in the late lactation period could promote the proliferation of beneficial bacteria, including Bifidobacteria. Intestinal flora gas production in a culture medium supplemented with fucosyllactose (2'-FL) was significantly lower than that in media containing other carbon sources. In conclusion, 2'-FL may reduce gas production in infant and toddler guts through two mechanisms: first, it cannot be used by harmful intestinal bacteria to produce gas; second, it can inhibit intestinal mucosa colonization by harmful bacteria by regulating the expression of intestinal epithelial pathogenic genes/signaling pathways, thus reducing the proliferation of gas-producing harmful bacteria in the gut.

Effects of Live Combined Bacillus subtilis and Enterococcus faecium on Gut Microbiota Composition in C57BL/6 Mice and in Humans.

Probiotics, prebiotics, and synbiotics can alleviate metabolic syndrome by altering the composition of the gut microbiota. Live combined Enterococcus faecium and Bacillus subtilis has been indicated to promote growth and reduce inflammation in animal models. However, the modulatory effects of live combined B. subtilis R-179 and E. faecium R-026 (LCBE) on human microbiota remain unclear. The current study examined the growth of these two strains in the presence of various oligosaccharides and assessed the effects of this probiotic mixture on human and murine gut microbiota in vitro and in vivo. Oligosaccharides improved the growth of E. faecium R-026 and B. subtilis R-179 as well as increased their production of short-chain fatty acids. E. faecium R-026 or B. subtilis R-179 co-incubated with Bifidobacterium and Clostridium significantly increased the number of the anaerobic bacteria Bifidobacterium longum and Clostridium butyricum by in vitro fermentation. Moreover, LCBE significantly reduced plasma cholesterol levels in mouse models of hyperlipidemia. LCBE combined with galacto-oligosaccharides led to a significant decrease in the Firmicutes/Bacteroidetes ratio and a significant increase in the relative abundance of Akkermansia and Bifidobacteria after treating mice with LCBE (0.23 g/day) for eight weeks. Furthermore, in vitro fermentation also showed that both the single strains and the two-strain mixture modulated human gut microbiota, resulting in increased Lactobacillus and Bifidobacteria, and decreased Escherichia-Shigella. Overall, these results suggest that LCBE can improve host health by reducing the level of cholesterol in mouse models by modifying the composition of the gut microbiota.

Carrageenan oligosaccharides and associated carrageenan-degrading bacteria induce intestinal inflammation in germ-free mice.

Carrageenans (CGNs) are widely used in foods and pharmaceuticals although their safety remains controversial. To investigate the effects of CGNs and CGN-degrading bacteria in the human colon, we screened for CGN degradation by human fecal microbiota, and for inflammatory response to CGNs and/or CGN-degrading bacteria in germ free mice. Thin-layer chromatography indicated that high molecular weight (MW) CGNs (≥100 kDa) remained undegraded in the presence of human fecal microbiota, whereas low MW CGNs, i.e., κ-carrageenan oligosaccharides (KCO, ~4.5 kDa) were degraded when exposed to seven of eight human fecal samples, although sulfate groups were not removed during degradation. Bacteroides xylanisolvens and Escherichia coli isolates from fecal samples apparently degraded KCO synergistically, with B. xylanisolvens serving as the primary degrader. Combined treatment of KCO with KCO-degrading bacteria led to greater pro-inflammatory effects in the colon and rectum of germ-free mice than either KCO or bacteria alone. Similarly, p-p38-, CD3-, and CD79a-positive immune cells were more abundant in combined treatment group mice than in either single treatment group. Our study shows that KCO-degrading bacteria and the low MW products of KCO can promote proinflammatory effects in mice, and represent two key markers for evaluating CGN safety in foods or medicines.

Age-related changes of microbiota in midlife associated with reduced saccharolytic potential: an in vitro study.

BACKGROUND: Gut microbiota is critical in maintaining human health, of which diversity and abundance are subject to significantly reduce in seniors. Gut microbiota is reported to be stable across the long adulthood in general, but lack of careful examination, especially for the midlife people. RESULTS: To characterize the gut microbiota in midlife, we investigated the faecal microbiota between two groups of healthy people, young, 20-39 years old, n = 15; and midlife, 40-60 years old, n = 15. Metabolic responses of the microbiota were studied through in vitro batch fermentation model. Although no difference was observed in the diversity indices between the two age groups, a wide range taxonomic changes were found in the faecal microbiota. Furthermore, substantial Bifidobacterium reduction was also found in both faecal and fermented samples. The faecal SCFAs are similar in both groups, as well as starch fermentation broth. However, after inulin fermentation, the acetate concentration and inulin degradation rate decreased while the gas production increased in midlife group, suggesting a deficiency of saccharolytic potential in midlife, especially for non-digestible carbohydrate. CONCLUSIONS: Our data demonstrate that gut microbiota begins to change as early as in midlife. The reduction in Bifidobacterium dominates the change of the microbiota composition in midlife resulting in attenuated saccharolytic capacity of inulin, possibly leading to insufficient acetate production which might be associated with healthy problems in this transition period from young to elderly.