2’-Fucosyllactose alleviate immune checkpoint blockade-associated colitis by reshaping gut microbiota and activating AHR pathway

Immune checkpoint blockade(ICB)therapeutics are highly effective in cancer immunotherapy,but gastrointestinal toxicity limited the application.Intestinal microbiota plays a crucial role in ICB-associated colitis.2’-Fucosyllactose(2’FL)is most abundance prebiotic in human milk that can reshape gut microbiota and exert immune regulatory effect.The study aimed to determine the effects of 2’FL on ICB-associated colitis and to uncover the mediating mechanism.ICB-associated colitis was induced by the ipilimumab and dextran sulfate sodium.Oral administration of 2’FL(0.6 g/(kg∙day))ameliorated ICB-induced colitis by enhancing regulatory T cells(Treg)and the M2/M1 ratio of macrophages in colon.2’FL treatment also increased the expression of tight junction proteins(zonula occludens-1(ZO-1)and mucin 2(MUC2))and antioxidant stress indicators(superoxide dismutase(SOD)and catalase(CAT)).In addition,administration of 2’FL increased the abundance of Bifidobacterium and Lactobacillus,and elevated the levels of microbial metabolites,such as indole-3-lactic acid(ILA),which activated the aryl hydrocarbon receptor ligands(AHR)pathway.The protective effect of 2’FL was abolished upon depletion of gut microbiota,and ILA treatment partially simulated the protective effect of 2’FL.Notably,2’FL did not exhibit inhibition of antitumor immunity.These findings suggest that 2’FL could serve as a potential protective strategy for ICB-associated colitis by modulating the intestinal microbiota and bacterial metabolites.

Alleviative effects of Bacillus coagulans strains on irritable bowel syndrome-unraveling strain specificity through physiological and genomic analysis

The high intraspecies heterogeneity of Baciillus coagulans leads to significant phenotypic differences among different strains.Thus,6 B.coagulans strains were tested in the present study using an irritable bowel syndrome(IBS)animal model to determine whether the IBS-alleviating effects of B.coagulans strains are strain-specific.The results of this study showed that the ingestion of B.coagulans GBI-30,6086,and B.coagulans CCFM1041 significantly alleviated IBS symptoms in mice.In contrast,other B.coagulans strains showed no or limited alleviating effects on IBS symptoms.According to our experimental results,the two main common features of these strains were as follows:1)The resistance of vegetative cells to bile salts,and 2)ability to synthesize specific lipids and secondary metabolites.Screening strains based on these two indicators may greatly reduce costs and provide a basis for mining new functional B.coagulans strains.Our results also suggest that administration of B.coagulans could significantly regulate microbiota dysbiosis in animal models.Moreover,the close relationships between the gut microbiota,gut microbiota metabolites,and IBS were further confirmed in this study.

Differences in the effects and action modes of gut commensals against dextran sulfate sodium-induced intestinal inflammation

Inflammatory bowel disease(IBD)is a complex relapsing inflammatory disease in the gut and is driven by complicated host-gut microbiome interactions.Gut commensals have shown different functions in IBD prevention and treatment.To gain a mechanistic understanding of how different commensals affect intestinal inflammation,we compared the protective effects of 6 probiotics(belonging to the genera Akkermansia,Bifidobacterium,Clostridium,and Enterococcus)on dextran sulfate sodium(DSS)-induced colitis in mice with or without gut microbiota.Anti-inflammatory properties(ratio of interleukin(IL)-10 and IL-12)of these strains were also evaluated in an in vitro mesenteric lymph nodes(MLN)co-culture system.Results showed that 4 probiotics(belonging to the species Bifidobacterium breve,Bifidobacterium bifidum,and Enterococcus faecalis)can alleviate colitis in normal mice.The probiotic strains differed in regulating the intestinal microbiota,cytokines(IL-10,IL-1βand interferon(IFN)-γ),and tight junction function(Zonulin-1 and Occludin).By constrast,Akkermansia muciniphila AH39 and Clostridium butyricum FHuNHHMY49T1 were not protective.Interestingly,B.breve JSNJJNM2 with high anti-inflammatory potential in the MLN model could relieve colitis symptoms in antibiotic cocktail(Abx)-treated mice.Meanwhile,E.faecalis FJSWX25M1induced low levels of cytokines in vitro and showed no beneficial effects.Therefore,we provided insight into the clinical application of probiotics in IBD treatment.

Akkermansia muciniphila-directed polyphenol chlorogenic acid intervention for obesity in mice

Akkermansia muciniphila play an important in ameliorating obesity but is not allowed for direct consumption in most countries.To date,microbiota-directed foods selectively promote the targeted human gut microbes,providing a strategy for A.muciniphila enhancement.Multiple studies have indicated the potential regulation of the polyphenol on A.muciniphila.Therefore,a polyphenol screening based on A.muciniphila upregulation was performed in mice.Chlorogenic acid(CGA)exhibited a greater response to A.muciniphila upregulation.Furthermore,we found that CGA did not directly promote A.muciniphila growth or mucin secretion.Microbiome and metabolomics revealed that the increased abundance of A.muciniphila resulted from the inhibition of CGA on Desulfovibrio and Alistipes and the influence of docosahexaenoic acid,β-hydroxybutyrate,and N-acetyl-lactosamine.Finally,to confirm the regulation of CGA on A.muciniphila under disease conditions,high-fat diet-fed mice were established.The results showed CGA promoted A.muciniphila growth,and we expectedly found that CGA suppressed the augment in body weight of mice,significantly attenuated adipose tissue abnormality,provided liver protection and improved gut barrier integrity.These results suggest that CGA inhibits the development of obesity.Overall,our results indicate that microbiota-directed food is a promising approach for the treatment of obesity.

Lactobacillus plantarum CCFM8610 Alleviates Irritable Bowel Syndrome and Prevents Gut Microbiota Dysbiosis:A Randomized,Double-Blind,Placebo-Controlled,Pilot Clinical Trial

Irritable bowel syndrome with diarrhea(IBS-D)is chronic intestinal dysfunction with diarrhea and othercomplicated clinical symptoms,and it has a great impact on the daily life and mental state of patients.Some studies have reported that ingestion of probiotics can significantly alleviate a variety of intestinaldiseases.The pupose of this study was to investigate the IBS-D-alleviating effects of a probiotic strain,lactobacillus plantarum(L.plantarum)CCFM8610,with multiple health-promoting effects.The studywas a 12-week,randomized,double-blind,placebo-controlled,pilot clinical trial.Seventy-five patientswere randomly assigned to receive the placebo,oligosaccharides,or L.plantarum CCFM8610(1×10^(10) colony-forming units(CFU)per day),with a 2-week run-in period,an 8-week intervention period,anda 2-week follow-up observation period.The patients'clinical symptoms and quality of life were exam-ined by the IBS symptom severity scale(IBS-SsS)and the IlBS quality of life scale(IBS-QOL).Changes ingut microbiota composition and diversity were measured at the end of the intervention period.The oraladministration of L.plantarum CCFM8610 significantly decreased the IBS-SSS and IBS-QOL scores,reduced IBS-D symptom severity,recovered gut microbiota diversity,decreased the relative abundanceof bloating-related genus Methanobrevibacter,and increased the relative abundance of butyric acid-producing genera,including Anaerostipes,Anaerotruncus,Bifidobacterium,Butyricimonas,andOdoribacter.These findings suggest that ingestion of L.plantarum CCFM8610 can significantly alleviate clinical symptoms and gut microbiota dysbiosis in IBS-D patients.The IBS-D-alleviating effect of L.plan-tarum CCFM8610 may be related to theincrease in the relative abundance of butyric acid-producing genera in the intestine.

Probiotics supplementation for management of type Ⅱ diabetes risk factors in adults with polycystic ovarian syndrome: a meta-analysis of randomized clinical trial

This meta-analysis of randomized controlled trials aimed to evaluate the effects of probiotic supplementation on glucose homeostasis in patients with polycystic ovary syndrome(PCOS).The meta-analysis was performed in accordance with the Cochrane Handbook guidelines and relevant the preferred reporting items for systematic reviews and meta-analyses(PRISMA)statement criteria.Of 825 identified reports,11 randomized clinical trials were included in the meta-analysis.An analysis of pooled extracted data revealed that supplementation with probiotics significantly decreased fasting blood glucose(FBG,n=7;standardized mean difference(SMD)=−0.40;95%confidence interval(CI):−2.02,−0.02;P=0.04)and insulin levels(n=6;SMD=−0.57;95%CI:−0.89,−0.25;P=0.0004)and the homeostatic model assessment of insulin resistance(n=7;SMD=−0.64;95%CI:−0.96,−0.31;P=0.0001)while increasing the quantitative insulin sensitivity check index(QUICKI,n=5;SMD=0.58;95%CI:0.08,1.09;P=0.02)in patients with PCOS.The FBG-reducing effect decreased as the baseline body mass index(BMI)and mean age of the participants increased.Indeed,a greater number of bacterial species and a higher bacterial dose were shown to reduce QUICKI effectively.The systematic review indicated that probiotic supplementation may help to control glucose homeostasis in adults with polycystic ovarian syndrome.

Stachyose modulates gut microbiota and alleviates DSS-induced ulcerative colitis in mice

Stachyose is a prebiotic that traditionally extracted from plants,such as vegetable.It has been demonstrated to alleviate intestinal inflammation by regulating gut microbiota,but the mechanism has been unclear.This research aims to detect the potential mechanism of stachyose in alleviating the severity of ulcerative colitis(UC).The results indicated that the administration of stachyose could recover the body weight,protect against the colonic tissue damage,reduce the pro-inflammatory cytokines levels,and reverse the histological abnormalities in UC mice.Oral stachyose could restore dextran sulfate sodium(DSS)-induced disturbance in intestinal bacteria.Besides,the metabolome result of serum samples showed that stachyose treatment significantly altered serum metabolites against inflammatory responses in colitis mice.Also,a significant correlation can be found between 23 metabolite biomarkers and 18 differential genera.Our results provided a strong foundation for the future study of the protective role of stachyose in maintaining intestinal homeostasis.

Effect of bacteriocin-producing Pediococcus acidilactici strains on the immune system and intestinal flora of normal mice

This study was performed to determine the effects of bacteriocin-producing and non-bacteriocin-producing Pediococcus acidilactici strains on the immune system and intestinal flora of normal mice.Two P.acidilactici strains with antibacterial activity(P.acidilactici CCFM28 and CCFM18)were obtained based on the inhibition-zone assay.The produced components were identified as bacteriocins through protease treatment,pH adjustment and hydrogen peroxide treatment.Bacteriocin-producing and non-bacteriocin-producing P.acidilactici strains(P.acidilactici CCFM28,CCFM18 and NT17-3)caused significant changes in serum immune factors and intestinal flora of normal mice.After 14 days of intervention,the relative abundance of Firmicutes was significantly decreased,but that of Proteobacteria was significantly increased at the phylum level.At the genus level,the administration of three P.acidilactici strains resulted in the downregulation of Blautia and the upregulation of Ruminococcus and Lactobacillus.Furthermore,there were also different regulations on some probiotic strains,such as Bifidobacterium,Coprococcus and Akkermansia,which were closely related to the antibacterial ability of the bacteriocin and the type of strain.The results indicated that the intervention of different P.acidilactici strains could differently change the structure of intestinal flora in normal mice,which provided theoretical guidance for the selective use of bacteriocin-producing strains for health regulation in the future.

Effects of vegetarian diet-associated nutrients on gut microbiota and intestinal physiology

People are increasingly aware of the role of vegetarian diets in modulating human gut microbial abundance and intestinal physiology.A plant-based diet is thought to benefit host health by contributing to establish a diverse and stable microbiome.In addition,microbe-derived metabolites of specific nutrients known to be abundant in vegetarian diets(such as indigestible carbohydrates,arginine,and others) are important to promote effective intestinal immune responses,maintain intestinal barrier function,and protect against pathogens.This review explores the characteristics of the gut microbiome formed by vegetarian diets and the effects of diet-associated nutrients on intestinal microbial abundance.The interactions between the microbe-derived metabolites of vegetarian diet-associated nutrients and intestinal physiology are also discussed.

Capsular polysaccarides of probiotics and their immunomodulatory roles

Studies have determined the immunomodulatory activities of cell-surface polysaccharides of lactic acid bacteria(LAB)and Bacteroides;however,the mechanisms,synthesis,regulation,structure,and functional links have not been systematically discussed.We first introduce the structure of the capsular poly saccharides(CPS s)of commonly studied probiotics and Bacteroides.Wzx-Wzy dependent and ATP-binding cassette(ABC)transporter-dependent pathways are the two main biosynthesis and secretion of CPS pathways.The genes known to be associated with these two pathways are mainly those associated with priming glycosyltransferase(pGT);a variable number of genes encoding for different glycosyl transferases(GTs);Wzx/Wzy-encoding enzymes related to flippases and polymerases;and ABC-transporter genes.In addition,the effects of CPSs on host immunity as well as their related underlying mechanisms are described.Surface polysaccharides on probiotics can serve as a mask to aid in their escape from attacks from the host’s immune system.In turn,they also exhibit immunomodulatory activities,such as strengthening the functions of macrophages,promoting the maturation of antigen-presenting cells,and inducing regulatory T cells.All of these effects of cell-surface polysaccharides exhibit their significant protective properties in immunocompromised diseases,such as colitis,arthritis,and dermatitis.Finally,we focused on their structure and functional links.

A theoretical framework for interaction of nursing discipline with genetics and genomics

Background:Since the completion of the Human Genome Project,health science has been strongly influenced by the advances in genetics and genomics.However,the progress of embracing genetics and genomics into nursing discipline is limited.One of the main barriers is lack of understanding on the relevancy of genetics and genomics to nursing discipline.Objectives:This paper aims to synthesize and develop a theoretical framework for the interaction of nursing discipline with genetics and genomics.Methods:Through content analysis and constant comparative method,a theoretical framework was developed from synthesis of the studies regarding nursing and genetics/genomics indexed in multiple English and Chinese databases.Results:Four main theoretical statements were constructed in the framework:1)There are three ways to show how genetics and genomics can influence nursing discipline:a new specialty,new technologies and a new lens;2)The significant contribution of nursing discipline to genetics and genomics lies in how nurses could focus on the association between human responses and genes and how nurses could advocate for their clients in the genetic and genomic era;3)A paradigm shift occurs after a constant interaction of nursing discipline with genetics and genomics;4)Implementation strategies could be used to facilitate the integration of genetics and genomics to nursing discipline and advance the paradigm shift.Conclusions:The framework will help to understand the relationship between nursing discipline and genetics and genomics and implicate the future studies integrating genetics and genomic science into nursing discipline.

一种基于Caco-2细胞单层膜的筛选抵抗特定代谢性疾病益生菌的模型

最近的研究揭示了益生菌在缓解与肠道屏障功能障碍相关的代谢疾病方面的潜力。然而,目前还没有一种能高效筛选抵抗特定代谢疾病益生菌菌株的模型。本研究采用肿瘤坏死因子(TNF-α)和酒精处理的Caco-2细胞单层膜模型,评价了139株乳杆菌在体外对肠道屏障功能的影响。然后,我们选择了11株对肠道屏障具有不同调节能力的乳杆菌菌株,进一步在体内评价了它们对卵巢切除引起的骨质疏松症或慢性酒精性肝损伤的作用效果。体外细胞模型和体内动物模型数据的关联性分析显示,两种疾病模型下的Pearson系数分别为0.82和-0.97,表明使用体外细胞模型模拟益生菌在体内的保护作用是可靠的。本研究建立了一种基于Caco-2细胞单层膜模型的体外方法,用于高效筛选可以抵抗特定代谢疾病(如骨质疏松症和慢性酒精性肝病)的益生菌。

Bifidobacterium longum CCFM1077 Attenuates Hyperlipidemia by Modulating the Gut Microbiota Composition and Fecal Metabolites:A Randomized,Double-Blind,Placebo-Controlled Clinical Trial

An increasing number of studies have indicated that gut microbiota and its metabolites are crucial in the development of hyperlipidemia.Bifidobacterium longum(B.longum)CCFM1077 has been shown to have lipid-lowering effects in animals.This study aimed to evaluate the potential of B.longum CCFM1077 in lowering the lipid levels in patients with hyperlipidemia and investigate the effect of this bacterium on serum lipid abnormalities,gut microbiota,and fecal metabolites in these patients.This study was a six-week,randomized,double-blind,and placebo-controlled pilot clinical trial.Subjects with hyperlipidemia(N=62)were randomly assigned to receive placebo(N=31)or B.longum CCFM1077(1×1010colony-forming units(CFUs)per day;N=31).Serum lipid levels including total cholesterol(TC),lowdensity lipoprotein cholesterol(LDL-C),total triglyceride(TG),and high-density lipoprotein cholesterol(HDL-C)were examined at the baseline and interventio nal endpoints.Changes in the gut microbiota composition and diversity were measured based on 16S ribosomal RNA(rRNA)sequencing of the V3-V4region at the end of the intervention period.Non-targeted metabolomics of the feces was performed using ultra-performance liquid chromatography(UPLC)-Q-Exactive Orbitrap/mass spectrometer.Oral administration of B.longum CCFM1077 for six weeks significantly decreased the serum levels of TC(p<0.01)and LDL-C(p<0.01)in patients with hyperlipidemia.B.longum CCFM1077 treatment markedly increased gut microbiota diversity and the relative abundance of anti-obesity-related genera,including Lactobacillus,Butyricicoccus,Bifidobacterium,and Blautia,whereas it decreased the relative abundance of obesity-related genera,including Alistipes,Megamonas,and Catenibacterium.Additionally,some key metabolites(bile acids(BAs),biotin,and caffeine)and their corresponding metabolic pathways(primary BA biosynthesis,and taurine and hypotaurine,biotin,purine,and caffeine metabolisms)were enriched by B.longum CCFM1077,and thus it may lower lipid levels.B.longum CCFM1077 is a probiotic strain with the potential to lower serum TC and LDL-C levels patients with hyperlipidemia.The underlying mechanism may be related to the increased abundance of anti-obesity-related genera and fecal metabolites.These findings provide a foundation for future clinical applications of lipid-lowering probiotics in managing individuals with hyperlipidemia.

Phylogenetic and Comparative Genomic Analysis of Lactobacillus fermentum Strains and the Key Genes Related to their Intestinal Anti-Inflammatory Effects

Emerging evidence shows that some Lactobacillus fermentum(L.fermentum)strains can contribute to the prevention and treatment of ulcerative colitis(UC).In this study,105 isolates of L.fermentum strains were separated from fecal samples of populations in different regions in China and their draft genomes were sequenced.Pan-genomic and phylogenetic characterizations of these strains and four model strains(L.fermentum 3872,CECT5716,IF03956,and VRI003)were performed.Phylogenetic analysis ind icated that there was no significant adaptive evolution between the genomes of L.fermentum strains and the geographical location,sex,ethnicity,and age of the hosts.Three L.fermentum strains(FWXBH115,FGDLZR121,and FXJCJ61)from different branches of the phylogenetic tree and strain type L.fermentum CECT5716 were selected and their anti-inflammatory and immune modulatory activities in a dextran sulphate sodium(DSS)-induced colitis mouse model were further investigated.Both L.fermentum FXJCJ61 and CECT5716 significantly alleviated UC by reducing all colitis-associated histological indices,maintaining mucosal integrity,and stimulating replenishment of short-chain fatty acids(SCFAs),while the other two strains failed to offer similar protection.The anti-inflammato ry mechanisms of L.fermentum FXJCJ61 and CECT5716 were related to the inhibition of nuclear factor kappa-B(NF-κB)signaling pathway activation and enhancement of interleukin 10(IL-10)production.Comparative genomic analysis of these strains identified candidate genes that may contribute to the anti-inflammatory effects of specific L.fermentum strains.

肠道菌群的聚糖利用特性主导其交叉喂养网络:聚焦双歧杆菌

The diverse carbon sources in the gut tract provide various nutritional niches for the gut microbiota(GM).Differential glycan utilization influences GM formation in these niches[1].Bifidobacteria are key microorganisms in the human gut,as they maintain a long-term symbiotic relationship with their hosts,which is essential for gut homeostasis and health.The high abundance and colonization of Bifidobacteria in the gut are closely related to their strong ability to degrade human milk oligosaccharides(HMOs)and dietary glycans.

Hyaluronic acid modulates gut microbiota and metabolites relieving inflammation:A molecular weight-dependent study

Hyaluronic acid(HA),a linear glycosaminoglycan polymer,is an inherent carbon source for gut microbiota and is capable of mitigating host inflammation by modulating gut microbiota.The length of hyaluronan can range from an oligomer to an extremely long-form up to millions of Daltons,and its biological functions depend on its molecular mass[1,2].Presently,the precise mechanisms through which HA of varying molecular weights alleviates inflammation by modulating the gut microbiota remain unclear[3].

Responses of the colonic microbiota and metabolites during fermentation of alginate oligosaccharides in normal individuals: An in vitro and in vivo study

Alginate oligosaccharides(AOS)have been reported to promote gut microbiota and sperm quality in male mice treated with busulfan.However,there is little evidence that AOS is directly influenced colonic microbiota and metabolites in healthy males.We administered AOS to rats by gavage for four weeks and observed significant regulation in the abundance of microbiota,including Bifidobacterium,Bacteroides,Anaerosptipes,Akkermania,Anaeroplasma,and Blautia,in the colon of male rats.In addition,AOS intervention significantly modulated colonic metabolites(butyrate,acetate,cytarabine,glycolic acid,and 3-hydroxybutyric acid)in healthy male rats.By contrast,there were no significant differences in the colonic metabolites of female rats.Further,we performed in vitro fermentation experiments using healthy male fecal samples and verified that AOS significantly increased the levels of Bacteroides,Anaerosptipes,and Blautia and promoted the content of butyrate and acetate in the fermentation broth.We also observed that these microbiotas were significantly positively correlated with cytarabine,3-hydroxybutyric acid,and glycolic acid.This study provides new evidence that AOS is a potential prebiotic in male functional foods.

Effects of Bifidobacterium longum CCFM5871 as an adjunct starter culture on the production of fermented milk

Bifidobacterium has been widely studied for its probiotic properties. In our previous study, Bifidobacterium longum CCFM5871 (CCFM5871) showed potential to relieve inflammation and constipation. In current study, we investigated the application of CCFM5871 as an adjunct starter culture for the production of fermented milk. First, genome analysis indicated that CCFM5871 possess various carbohydrate metabolic pathways, including the Leloir pathway of galactose metabolism and galactose related genes GH2 and GH27. Comparative genomic analysis shows that similar functional gene were detected in other bifidobacteria strains applied in dairy fermentation. Then the sugar metabolism phenotype experiment verified the result of genomic analysis. Subsequently, we evaluated the effects of CCFM5871 supplementation on the production and storage of fermented milk by monitoring changes in multiple parameters over 14 days of storage at 4 °C, including pH, titratable acidity, physical properties, volatile flavor compounds, and sensory quality. The bacterial level was significantly higher at the fermentation termination than the fermentation initiation, indicating that CCFM5871 can be regarded as a candidate for adjunct start culture. Compared to the control group, supplementation with CCFM5871 increased acidification and solidification of fermented milk. Moreover, we revealed that there was no other significant difference between the yogurt fermented with CCFM5871 and the yogurt with culture only in flavor and taste. In summary, our results identified that CCFM5871 may be an appropriate co-culture for fermented milk, and the genomic analysis may be instructive for future to filter the culture in fermented milk.

Effects of Bifidobacteria bifidum strains on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced acute colitis and its potential mechanism

Microbiota-based therapies for improving symptoms of Crohn’s disease(CD)are receiving increasing attention.Probiotics and second-generation probiotics can potentially prevent this disease.However,the therapeutic action and underlying molecular mechanisms of probiotics remain largely unknown.Efficient screening of probiotics is also challenging.In this study,we screened eight B.bifidum strains with CD-relieving potential using a 2,4,6-trinitrobenzene sulfonic acid(TNBS)colitis mouse model.We also observed that B.bifidum CJ238 could prevent but not cure the colitis-symptoms(weight loss,colon shortening and connective tissue hyperplasia)in mice model.The 16S rRNA sequencing data showed that supplementation with B.bifidum did not alter the composition of the intestinal microbiota.B.bifidum CJ238 administration also provided full protection against acute colitis in pseudo germ-free mice.Therefore,we infered that the protective effect of B.bifidum strains does not depend on their interaction with the gut microbiota.Furthermore,heat-killed(95℃ for 20min)B.bifidum cells(109 CFU/mouse)also protected mice against acute colitis.In-vitro adhesion and immunomodulatory activities of the B.bifidum strains were measured.Combined with the in-vivo results,the anti-colitis effect of B.bifidum was positively associated with its strong anti-inflammatory and adhesion capacity in-vitro.This study provides insights into the in-vitro screening and clinical application of probiotics in CD prevention.

Ameliorative effects of Lactobacillus fermentum isolated from individuals following vegan, omnivorous and high-meat diets on ulcerative colitis in mice

Lactobacillus spp.can be beneficial for the prevention or treatment of ulcerative colitis(UC).In this study,153 participants who followed vegan,omnivorous,or high-meat diet were recruited.Compositional analysis of the Lactobacillus community in feces revealed that Lactobacillus fermentum strains were significantly affected by diet.Administration of mixed L.fermentum strains from vegans significantly improved inflammation compared to that from omnivores and high-meat consumers,as evidenced by a significant reduction in colonic tissue damage,improvement in inflammatory cytokines,enhanced expression of ZO-1,occludin,and claudin-3,and a significant increase in short chain fatty acids concentration.The effect of a single strain of L.fermentum was similar to that of a mixed strains of L.fermentum group.Genomic analysis suggested that L.fermentum strains from the guts of vegans possessed a higher prevalence of genes involved in carbohydrate catabolism than those from the guts of omnivores and high-meat eaters.In particular,the ME2 gene is involved in the biosynthesis of acetate,a compound considered to possess anti-inflammatory properties.In conclusion,this study indicates strain-specific differences in the ability of L.fermentum strains to alleviate UC in mice,influenced by habitual diets。