Mucosa-reparing and microbiota-balancing therapeutic effect of Bacillus subtilis alleviates dextrate sulfate sodium-induced ulcerative colitis in mice

Non-lactic acid bacteria probiotics isolated from intestine or various circumstances

Probiotics are live microorganisms beneficial to host health, predominantly comprising lactic acid bacteria (LAB) such as Lactobacillus. Additional non-LAB probiotics, termed intestinal isolates, encompass next-generation strains like Akkermansia muciniphila, Faecalibacterium prausnitzii, Christensenella minuta, Anaerobutyricum soehngenii, Oxalobacter formigenes, etc. and alongside externally sourced Bacillus, Saccharomyces cerevisiae, Clostridium butyricum, and Propionibacterium. Intestinal-derived probiotics represent strictly anaerobic strains with challenging culturing requirements, contrasting with the aerobic nature of Bacillus probiotics and the ease of culturing S. cerevisiae. These strains exhibit diverse health-promoting properties, encompassing antimicrobial, anticancer, antioxidant, and vitamin production capabilities, albeit contingent upon strain specificity. This review delineates the characteristics, culturing conditions, and health advantages associated with non-LAB probiotics.

Probiotic characterization of Bacillus smithii: Research advances, concerns, and prospective trends

Bacillus smithii is a thermophilic Bacillus that can be isolated from white wine, hot spring soil, high-temperature compost, and coffee grounds, with various biofunctions and wide applications. It is resistant to both gastric acid and high temperature, which makes it easier to perform probiotic effects than traditional commercial probiotics, so it can maintain good vitality during food processing and has great application prospects. This paper starts with the taxonomy and genetics and focuses on aspects, including genetic transformation, functional enzyme production, waste utilization, and application in the field of food science as a potential probiotic. According to available studies during the past 30 years, we considered that B. smithii is a novel class of microorganisms with a wide range of functional enzymes such as hydrolytic enzymes and hydrolases, as well as resistance to pathogenic bacteria. It is available in waste degradation, organic fertilizer production, the feed and chemical industries, the pharmaceutical sector, and food fortification. Moreover, B. smithii has great potentials for applications in the food industry, as it presents high resistance to the technological processes that guarantee its health benefits. It is also necessary to systematically evaluate the safety, flavor, and texture of B. smithii and explore its biological mechanism of action, which is of great value for further application in multiple fields, especially in food and medicine.

Conversations in the Gut: The Role of Quorum Sensing in Normobiosis

An imbalance in gut microbiota, termed dysbiosis, has been shown to affect host health. Several factors, including dietary changes, have been reported to cause dysbiosis with its associated pathologies that include inflammatory bowel disease, cancer, obesity, depression, and autism. We recently demonstrated the inhibitory effects of artificial sweeteners on bacterial quorum sensing (QS) and proposed that QS inhibition may be one mechanism behind such dysbiosis. QS is a complex network of cell-cell communication that is mediated by small diffusible molecules known as autoinducers (AIs). Using AIs, bacteria interact with one another and coordinate their gene expression based on their population density for the benefit of the whole community or one group over another. Bacteria that cannot synthesize their own AIs secretly "listen" to the signals produced by other bacteria, a phenomenon known as "eavesdropping". AIs impact gut microbiota equilibrium by mediating intra- and interspecies interactions as well as interkingdom communication. In this review, we discuss the role of QS in normobiosis (the normal balance of bacteria in the gut) and how interference in QS causes gut microbial imbalance. First, we present a review of QS discovery and then highlight the various QS signaling molecules used by bacteria in the gut. We also explore strategies that promote gut bacterial activity via QS activation and provide prospects for the future.

Enterococcus faecium R-026 combined with Bacillus subtilis R-179 alleviate hypercholesterolemia and modulate the gut microbiota in C57BL/6 mice

Probiotics have been demonstrated to lower total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in individuals with mild hypercholesterolemia. Our previous study found that intervention with Bacillus subtilis R-179 and Enterococcus faecium R-026, well-known probiotics, improved obesity-associated dyslipidemia through ameliorating the gut microbiota, but similar studies on hypercholesterolemia have not been reported to date. Here, we investigated the therapeutic effect of live combined B. subtilis R-179 and E. faecium R-026 (LCBE) in a C57BL/6 mouse model of hypercholesterolemia. A total of 40 mice were administered with a high-cholesterol diet (containing 1.2% cholesterol) to establish a state of hypercholesterolemia for 4 weeks. Then, mice were divided into one model group (group M) and three treatment groups (n = 10 per group), which were administered with LCBE at 0.023 g/mouse/day (group L) or 0.230 g/mouse/day (group H), or atorvastatin 0.010 g/kg/day (group A), for 5 weeks while on a high-cholesterol diet. LCBE at high doses significantly alleviated the symptoms of group M and reduced serum TC, LDL-C, and lipopolysaccharide (LPS). LCBE improved liver steatosis and adipocyte enlargement caused by a high-cholesterol diet. In addition, the administration of LCBE regulated the change in gut microbiota and diversity (Shannon index). Compared with group M, the relative abundance of Actinobacteriota, Colidextribacter, and Dubosiella dramatically decreased in the treatment groups, which were positively correlated with serum TC and LPS. These findings indicated that the mechanism of action of LCBE in treating hypercholesterolemia may be modulation of the gut microbiota. In conclusion, LCBE ameliorated lipid accumulation, reduced inflammation, and alleviated the gut microbiota imbalance in hypercholesterolemic mice. These findings support the probiotic role of LCBE as a clinical candidate for the treatment of hypercholesterolemia.

The potential key genes and pathways associated with Wilms tumor in quest of proper candidates for diagnostic and therapeutic purposes

To designate the probable most important differentially expressed genes and genetic pathways in Wilms tumor and assess their expression and diagnostic potential by RT-PCR and statistical analysis. Systematic review of the literature and various bioinformatics analysis was carried out to gather and narrow down data. The expression of end-resulting genes was compared in Wilms tumor and normal tissue samples using RT-PCR. Statistical tests reported the diagnostic accuracy of genes and their correlation with clinicopathological features. Four genes including CDH1, NCAM1, EGF, and IGF2 were designated. The panel combining them has 100% sensitivity and specificity in differentiating tumors from normal tissue. Eight pathways, most involved in cell-cell and cell-basal matrix junction interactions, were found to be associated with disease pathogenesis. The suggested genes should undergo further evaluation to be validated as diagnostic biomarkers. Further research on the eight proposed pathways is recommended.

ROS-responsive hyaluronic acid hydrogel for targeted delivery of probiotics to relieve colitis

Probiotics are generally used as therapeutic intervention in inflammatory bowel disease. However, the low survival rate in harsh gastrointestinal environment and limited retention in intestine greatly restrict their health benefits. To address this problem, a ROS-responsive hydrogel based on hyaluronic acid (HA) was developed for encapsulation and targeted delivery of probiotics. The hydrogel was prepared facilely by physiological crosslink with methacrylated HA and thiolated thioketal. As a model probiotic, Lactobacillu reuteri showed a significantly increased survival rate in simulated digestive conditions after encapsulated in hydrogel. The negative properties conferred the hydrogel preferential adhesions to inflammation sites. Meanwhile, the excess reactive oxygen species (ROS) produced by inflamed colon tissues selectively cleaved thioketal linkages resulted in hydrogel degradation and local probiotics release. Furthermore, the hydrogel exerted an appropriate ROS-scavenge capacity and protected HT-29 cells from oxidative damage. Animal experiments indicated that hydrogel-encapsulated L. reuteri could remarkably alleviate the symptoms and improve the survival rate of mice with dextran sulfate sodium (DSS)-induced colitis. These results suggested that the biocompatible hydrogel may be a delivery platform to target inflamed intestines and expand the application of probiotics as pharmaceuticals.

Regulation of gut microbiota-bile acids axis by probiotics in inflammatory bowel disease

Inflammatory bowel disease (IBD) is characterized by chronic and relapsing inflammation of gastrointestinal tract, with steadily increased incidence and prevalence worldwide. Although the precise pathogenesis remains unclear, gut microbiota, bile acids (BAs), and aberrant immune response play essential roles in the development of IBD. Lately, gut dysbiosis including certain decreased beneficial bacteria and increased pathogens and aberrant BAs metabolism have been reported in IBD. The bacteria inhabited in human gut have critical functions in BA biotransformation. Patients with active IBD have elevated primary and conjugated BAs and decreased secondary BAs, accompanied by the impaired transformation activities (mainly deconjugation and 7α-dehydroxylation) of gut microbiota. Probiotics have exhibited certain positive effects by different mechanisms in the therapy of IBD. This review discussed the effectiveness of probiotics in certain clinical and animal model studies that might involve in gut microbiota-BAs axis. More importantly, the possible mechanisms of probiotics on regulating gut microbiota-BAs axis in IBD were elucidated, which we focused on the elevated gut bacteria containing bile salt hydrolase or BA-inducible enzymes at genus/species level that might participate in the BA biotransformation. Furthermore, beneficial effects exerted by activation of BA-activated receptors on intestinal immunity were also summarized, which might partially explain the protect effects and mechanisms of probiotics on IBD. Therefore, this review will provide new insights into a better understanding of probiotics in the therapy targeting gut microbiota-BAs axis of IBD.

Autoclaved Diet with Inactivated Spores of Bacillus spp. Decreased Reproductive Performance of Muc2−/− and Muc2+/− Mice

Simple Summary

Within barrier facilities for the housing of laboratory animals, the sterilization of feed, bedding, and cages is used to reduce contact with bacteria. However, in nature, animals come into contact with a lot of bacteria. We investigated the effect of an autoclaved diet on the reproductive performance of Muc2^−/− mice. Muc2^−/− mice develop intestinal barrier defects and are sensitive to changes of the gut microbiota. We have shown that the autoclaved diet negatively affects the reproductive performance of Muc2^−/− females and their healthy Muc2^+/− siblings. Thus, the autoclaved diet led to earlier rectal prolapse of Muc2^−/− females combined with intestinal inflammation, compared to mice fed with the non-autoclaved diet. We hypothesize that this effect is due to the reduction of the diet nutritional value and inactivation of Bacillus spp. spores in the autoclaved diet.

Abstract

Within barrier facilities, autoclaved diet and bedding are used for husbandry of laboratory rodents. Bacillus spp. are ubiquitous in nature and some of them are known as probiotics. Inactivation of the Bacillus spores and reduction of the diet nutritional value due to autoclavation could be especially critical for immunodeficient mice. We studied the effect of the autoclaved and non-autoclaved diets on the reproductive performance and the age of prolapse manifestation in Muc2^−/− mice with impaired gut barrier function and, therefore, sensitive to change of microbiota. We found that the non-autoclaved diet led to enhancement of the fertility index of Muc2^−/− and Muc2^+/− female mice. The non-autoclaved diet affected the prolapse of Muc2^−/− mice that occurred later in comparison with females eating the autoclaved diet. We showed that Bacillus spp. was present in the non-autoclaved diet and feces of mice on the non-autoclaved diet. Bacterial strains of the non-autoclaved diet and feces belonged to B. amyloliquefaciens, B. thuringiensis, B. subtilis, Lysinibacillus macrolides, B. cereus, and other representatives of Bacillus spp. Moreover, autoclavation of the diet affected on the percent of the blood and spleen immune cells, the bacterial composition of the intestine, and increased the level of methionine in the thigh muscle of mice. Enhanced reproductive performance and delayed prolapse manifestation in Muc2^−/− mice could be due to improved digestion, as Bacillus spp. from diet and feces had enzymatic activity.

Roseburia intestinalis and Its Metabolite Butyrate Inhibit Colitis and Upregulate TLR5 through the SP3 Signaling Pathway

The pathogenesis of ulcerative colitis (UC) is unclear, but it is generally believed to be closely related to an imbalance in gut microbiota. Roseburia intestinalis (R. intestinalis) might play a key role in suppressing intestinal inflammation, but the mechanism of its anti-inflammatory effect is unknown. In this study, we investigated the role of R. intestinalis and Toll-like receptor 5 (TLR5) in relieving mouse colitis. We found that R. intestinalis significantly upregulated the transcription of TLR5 in intestinal epithelial cells (IECs) and improved colonic inflammation in a colitis mouse model. The flagellin of R. intestinalis activated the release of anti-inflammatory factors (IL-10, TGF-β) and reduced inflammation in IECs. Furthermore, butyrate, the main metabolic product secreted by R. intestinalis, regulated the expression of TLR5 in IECs. Our data show that butyrate increased the binding of the transcription factor Sp3 (specificity protein 3) to the TLR5 promoter regions, upregulating TLR5 transcription. This work provides new insight into the anti-inflammatory effects of R. intestinalis in colitis and a potential target for UC prevention and treatment.

Prebiotic Isomaltooligosaccharide Provides an Advantageous Fitness to the Probiotic Bacillus subtilis CU1

Bacillus subtilis CU1 is a probiotic strain with beneficial effects on immune health in elderly subjects and diarrhea. Commercialized under spore form, new strategies to improve the germination, fitness and beneficial effects of the probiotic once in the gut have to be explored. For this purpose, functional food ingredients, such as isomaltooligosaccharides (IMOSs), could improve the fitness of Bacillus probiotics. IMOSs are composed of α(1 → 6)- and α(1 → 4)-linked oligosaccharides and are partially indigestible. Dietary IMOSs stimulate beneficial members of intestinal microbiota, but the effect of a combination of IMOSs with probiotics, such as B. subtilis CU1, is unknown. In this study, we evaluate the potential effect of IMOSs in B. subtilis CU1 and identify the metabolic pathways involved. The biochemical analysis of the commercial IMOSs highlights a degree of polymerization (DP) comprised between 1 and 29. The metabolism of IMOSs in CU1 was attributed to an α-glucosidase, secreted in the extracellular compartment one hundred times more than with glucose, and which seems to hydrolyze high DP IMOSs into shorter oligosaccharides (DP1, DP2 and DP3) in the culture medium. Proteomic analysis of CU1 after growth on IMOSs showed a reshaping of B. subtilis CU1 metabolism and functions, associated with a decreased production of lactic acid and acetic acid by two times. Moreover, we show for the first time that IMOSs could improve the germination of a Bacillus probiotic in the presence of bile salts in vitro, with an 8 h reduced lag-time when compared to a glucose substrate. Moreover, bacterial concentration (CFU/mL) was increased by about 1 log in IMOS liquid cultures after 48 h when compared to glucose. In conclusion, the use of IMOSs in association with probiotic B. subtilis CU1 in a synbiotic product could improve the fitness and benefits of the probiotic.

A Minority Population of Non-dye-decolorizing Bacillus subtilis enhances the Azo Dye-decolorizing Activity of Enterococcus faecalis

Microbes live in communities in biological wastewater treatment plants and in the intestines. However, limited information is currently available on the mechanisms by which minority bacterial populations assist other bacteria besides syntrophic relationships as well as on the microbial food web. Therefore, the present study investigated the effects of non-dye-decolorizing Bacillus subtilis strain S4ga at population levels ranging between 0.04 and 4% on the activity of dye-decolorizing Enterococcus faecalis strain T6a1 using a dye decolorization assay. The results obtained revealed that the minority population of B. subtilis S4ga enhanced the dye-decolorizing activity of E. faecalis T6a1, resulting in a shorter lag time and longer active time of dye decolorization. These effects were related to redox potential values rather than O₂ concentrations. Comparisons of the extracellular metabolites in individual incubations of E. faecalis T6a1 and B. subtilis S4ga and a co-incubation suggested a mutual relationship through the cross-feeding of specific amino acids (tyrosine, methionine, tryptophan, phenylalanine, valine, and leucine from B. subtilis S4ga to E. faecalis T6a1; glutamine, histidine, aspartic acid, and proline from E. faecalis T6a1 to B. subtilis S4ga). An ana­lysis of intracellular primary metabolites indicated that the arginine deiminase (ADI) pathway, an ATP-producing energy-generating process, was more strongly activated in co-incubated E. faecalis T6a1 than in E. faecalis T6a1 incubated alone. These results suggest that a co-incubation with B. subtilis S4ga promoted ATP production by E. faecalis T6a1 cells and enhanced its dye-decolorizing activity.

Hydroxysafflor yellow A protects against ulcerative colitis via suppressing TLR4/NF-κB signaling pathway

Hydroxysafflower yellow A (HSYA) protects against acute kidney injury through TLR4/NF-κB pathway. However, the effect and potential mechanism of HSYA in ulcerative colitis (UC) have been rarely reported, which is thus investigated in this research. An in vivo UC model was established by oral administration of 5% dextran sulfate sodium (DSS) in Sprague-Dawley rats. After HSYA treatment, the daily body weight and colon length of rats were measured. Then rat colon tissues, myeloperoxidase (MPO) activity, and the levels of inflammatory cytokines were examined by histopathological examination (HE) staining, immunohistochemistry, ultraviolet spectrophotometry, and enzyme-linked immune sorbent assay (ELISA) respectively. The activated TLR4/NF-κB pathway was detected by Western blot. RAW 264.7 cell viability was detected by MTT assay after lipopolysaccharide (LPS) treatment, and ELISA and Western blot were performed again to investigate the effects of HSYA on LPS-treated cells. DSS administration increased body weight and colon length of rats and induced colon tissue injury. DSS or LPS treatment up-regulated the levels of TNF-α, IL-1β, and IL-6 and activated TLR4/NF-κB pathway of colon tissues and cells, respectively. HSYA partially reversed the above effect of DSS and LPS treatment, and the effects of the drug were improved with the dosage. Taken together, HSYA alleviates UC by suppressing TLR4/NF-κB signaling pathway, which may provide a new insight for the treatment of UC.

Natural compounds as safe therapeutic options for ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease of unknown etiology. Several conventional treatments for UC such as corticosteroids, immunosuppressive agents, tumor necrosis factor antagonist, integrin blockers, and interleukin antagonist, and salicylates are available but are associated with the various limitations and side-effects. None of the above treatments helps to achieve the ultimate goal of the therapy, i.e., maintenance of remission in the long-term. Natural remedies for the treatment of UC show comparatively less side effects as compared to conventional approaches, and affordable. The current review presents details on the role of herbal drugs in the treatment and cure of UC. Google, PubMed, Web of Science, and Scopus portals have been searched for potentially relevant literature to get the latest developments and updated information related to use of natural drugs in the treatment of UC. Natural products have been used over centuries to treat UC. Some of the essential herbal constituents exhibiting antiulcerogenic activity include gymnemic acid (Gymnema sylvestre), shagoal (Zingiber officinale), catechin (Camellia sinensis), curcumin (Curcuma longa), arctigenin (Arctium lappa), and boswellic acid (Boswellia serrata). Although many plant-derived products have been recommended for UC, further research to understand the exact molecular mechanism is still warranted to establish their usefulness clinically.

Long-term and continuous administration of Bacillus subtilis during remission effectively maintains the remission of inflammatory bowel disease by protecting intestinal integrity, regulating epithelial proliferation, and reshaping microbial structure and function

Gut microbiota takes part in the pathogenesis of inflammatory bowel disease (IBD). Clinical research has found that probiotics have a beneficial effect on active ulcerative colitis, but to date, significant efficacy has rarely been found in the use of probiotics in the remission phase of ulcerative colitis and Crohn's disease. More studies are needed to assess the utilization of probiotics in IBD remission. In this study, we assessed the administration of Bacillus subtilis in remission and its possible mechanism in mice with IBD. Oral administration of B. subtilis was implemented for 6 weeks (dextran sulfate sodium (DSS)-P6w group), 2 weeks (DSS-P2w group) or 0 weeks (DSS-control(CT) group) in the remission phase in rodents with (DSS)-induced IBD. The body weight, colon length and disease activity index (DAI) were recorded, and colon H&E staining was performed. The expression of tight junction proteins (ZO-1 and occludin) mRNA and epithelium proliferation-related Ki67 was detected. Gut microbiota were tested by 16S rRNA sequencing. Administration of B. subtilis in remission effectively increased the body weight and colon length and decreased DAI in the DSS-P6w group compared with the DSS-CT group, but there is no significant difference between the DSS-P2w and DSS-CT groups. The epithelial integrity was improved, and the expression of ZO-1 and occludin increased due to administration of B. subtilis in remission, which was more evident in the DSS-P6w group. The expression of Ki67 increased in the DSS-CT group compared with that in the CT group. The administration of B. subtilis effectively down-regulated the expression of Ki67 in the DSS-P6w and DSS-P2w groups compared with the DSS-CT group. Furthermore, gut microbial structure was improved, with significantly decreased Escherichia/Shigella and Enterococcus, and increased Akkermansia and corresponding microbial function in the DSS-P6w group. Short-term administration of B. subtilis in the remission phase showed no significant improvement in mice with IBD. Long-term and continuous supplementation of B. subtilis in remission could effectively maintain the remission by protecting epithelial integrity, regulating proliferation of intestinal epithelial cells, and improving gut microbiota and the corresponding microbial function.

Neuroimmunomodulation by gut bacteria: Focus on inflammatory bowel diseases

Microbes colonize the gastrointestinal tract are considered as highest complex ecosystem because of having diverse bacterial species and 150 times more genes as compared to the human genome. Imbalance or dysbiosis in gut bacteria can cause dysregulation in gut homeostasis that subsequently activates the immune system, which leads to the development of inflammatory bowel disease (IBD). Neuromediators, including both neurotransmitters and neuropeptides, may contribute to the development of aberrant immune response. They are emerging as a regulator of inflammatory processes and play a key role in various autoimmune and inflammatory diseases. Neuromediators may influence immune cell’s function via the receptors present on these cells. The cytokines secreted by the immune cells, in turn, regulate the neuronal functions by binding with their receptors present on sensory neurons. This bidirectional communication of the enteric nervous system and the enteric immune system is involved in regulating the magnitude of inflammatory pathways. Alterations in gut bacteria influence the level of neuromediators in the colon, which may affect the gastrointestinal inflammation in a disease condition. Changed neuromediators concentration via dysbiosis in gut microbiota is one of the novel approaches to understand the pathogenesis of IBD. In this article, we reviewed the existing knowledge on the role of neuromediators governing the pathogenesis of IBD, focusing on the reciprocal relationship among the gut microbiota, neuromediators, and host immunity. Understanding the neuromediators and host-microbiota interactions would give a better insight in to the disease pathophysiology and help in developing the new therapeutic approaches for the disease.

Effects of Bacillus pumilus on growth performance, immunological indicators and gut microbiota of mice

An increasing number of Bacillus strains have been developed for use as animal feed additives. The aim of the current work was to evaluate the impacts of Bacillus pumilus fsznc-09 in growth performance, organs development, blood constituents, genes expression of growth and immune in spleen and microbial communities in jejunum of weanling mice. The results showed that the body weight of mice in BP1 group increased significantly (p < 0.05) after feeding Bacillus pumilus fsznc-09. Compared with control group, the feed conversion ratio of BP1 and BP2 groups showed 13.57% (p < 0.05) and 9.64% improvements, respectively. The lengths of large intestine, small intestine in BP1 group were significantly increased (p < 0.05). While compared with control group, the organ indexes in BP1 and BP2 group did not differ significantly. Compared with control group, the activities of serum total superoxide dismutase (T-SOD), alkaline phosphatase (AKP), lysozyme (LZM) in BP1 group and T-SOD, AKP in BP2 group were significantly increased (p < 0.05). Compared with control group, the expressions of ghrelin-2 (Ghrl-2) and insulin-like growth factor 1 (Igf1) in BP1 group were significantly increased (p < 0.05). Compared with control group, the expressions of interleukin-6 (IL-6), nitric oxide synthase (INOS), tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β) in BP1 group and the expressions of IL-6, INOS, TNF-α, IL-1β and interferon alpha 11 (Ifna11) in BP2 group were slightly decreased. Moreover, compared with control group, the diversity of intestinal flora and relative abundance of potentially probiotics (e.g., Bifidobacterium, Bacillus) in BP1 and BP2 groups were increased. While compared with control group, the relative abundance of the potentially pathogenic bacterium (e.g., Staphylococcus) was reduced. The relative abundances of dominant species in BP1 (Lactobacillus johnsonii) and BP2 (Lactobacillus reuteri) groups were also higher than control group (Lactobacillus intestinalis). In conclusion, Bacillus pumilus fsznc-09 might improve the growth performance and immunity of mice.

Enterococcus faecium R0026 Combined with Bacillus subtilis R0179 Prevent Obesity-Associated Hyperlipidemia and Modulate Gut Microbiota in C57BL/6 Mice

Bacillus subtilis and Enterococcus faecium are commonly used probiotics. This study aimed to identify the effect of live combined Bacillus subtilis R0179 and Enterococcus faecium R0026 (LCBE) on obesityassociated hyperlipidemia and gut microbiota in C57BL/6 mice. Forty male C57BL/6 mice were divided into four groups: normal group (N group), model group (M group), low-dose group (L group), and high-dose group (H group). Mice were gavaged with LCBE at 0.023 g/mice/day (L group) or 0.23 g/mice/day (H group) and fed with a high-fat diet for 8 weeks. In vitro E. faecium R0026 showed an ability to lower the low-concentration of cholesterol by 46%, and the ability to lower the highconcentration of cholesterol by 58%. LCBE significantly reduced the body weight gain, Lee index, brown fat index and body mass index of mice on a high-fat diet. Moreover, LCBE markedly improved serum lipids (including serum triglyceride, total cholesterol, low-density lipoprotein and highdensity lipoprotein) while also significantly reducing liver total cholesterol. Serum lipopolysaccharide and total bile acid in L and H groups decreased significantly compared with M group. PCR-DGGE analysis showed that the composition of gut microbiota in the treatment groups was improved. Akkermansia muciniphila was found in H group. The PCA result indicated a similar gut microbiota structure between LCBE treatment groups and normal group while the number of bands and Shannon diversity index increased significantly in the LCBE treatment groups. Finally, qPCR showed Bifidobacterium spp. increased significantly in H group compared with M group, LCBE alleviated liver steatosis and improved brown adipose tissue index.

Protective Role of a New Polysaccharide Extracted from Lonicera japonica Thunb in Mice with Ulcerative Colitis Induced by Dextran Sulphate Sodium

Lonicera japonica Thunb is a traditional Chinese herbal medicine for treating intestinal inflammation. The extraction method of Lonicera japonica Thunb polysaccharide (LJP) has been developed previously by our research group. In this study, a Fourier transform infrared spectrometer (FT-IR) was used to perform a qualitative analysis of LJP and a precolumn derivatization high-performance liquid chromatography (HPLC) ((Palo Alto, CA, USA) method was used to explore the monosaccharide composition of LJP. Then, we studied the effect of LJP on the intestinal flora and immune functions of dextran sulfate sodium- (DSS-) induced colitis ulcerative mouse models. The results showed that LJP was consisted of 6 types of monosaccharides and had the characteristic absorption of typical polysaccharides. LJP can increase significantly the weight, organ index, serum cytokines (interleukin, tumor necrosis factor, and interferon-γ), secretory immunoglobulin A (SIgA) concentration, and natural killer (NK) cell and cytotoxic lymphocyte (CTL) activities in DSS-treated mice. The results of intestinal flora showed that a high dose (150 mg kg⁻¹) of LJP had the best effects on improving the intestinal probiotics (Bifidobacterium and Lactobacilli) and antagonizing the pathogenic bacteria (Escherichia coli and Enterococcus). In addition, the measurement results of the spleen lymphocyte apoptosis confirmed from another perspective that LJP had protective effects of immune cells for DSS-treated mice.

The Sporobiota of the Human Gut

The human gut microbiome is a diverse and complex ecosystem that plays a critical role in health and disease. The composition of the gut microbiome has been well studied across all stages of life. In recent years, studies have investigated the production of endospores by specific members of the gut microbiome. An endospore is a tough, dormant structure formed by members of the Firmicutes phylum, which allows for greater resistance to otherwise inhospitable conditions. This innate resistance has consequences for human health and disease, as well as in biotechnology. In particular, the formation of endospores is strongly linked to antibiotic resistance and the spread of antibiotic resistance genes, also known as the resistome. The term sporobiota has been used to define the spore-forming cohort of a microbial community. In this review, we present an overview of the current knowledge of the sporobiota in the human gut. We discuss the development of the sporobiota in the infant gut and the perinatal factors that may have an effect on vertical transmission from mother to infant. Finally, we examine the sporobiota of critically important food sources for the developing infant, breast milk and powdered infant formula.

Bacillus subtilis RZ001 improves intestinal integrity and alleviates colitis by inhibiting the Notch signalling pathway and activating ATOH-1

Intestinal mucosal barriers help the body resist many intestinal inflammatory diseases, such as inflammatory bowel disease (IBD). In this study, we identified a novel bacterium promoting the repair of intestinal mucosa and investigated the potential mechanisms underlying its activity. Culture supernatant of Bacillus subtilis RZ001 upregulated the expression of mucin 2 (MUC2) and tight junction (TJ) proteins in HT-29 cells in vitro. Oral administration of B. subtilis RZ001 may have significantly reduced symptoms such as the dextran sulfate sodium (DSS)-induced decrease in body weight, shortening of colon length and overproduction of proinflammatory factors. The number of goblet cells and levels of MUC2 and TJ proteins were significantly increased in adult mice fed with B. subtilis RZ001. B. subtilis RZ001 cells upregulated the levels of MUC2 in the intestinal organoids. Furthermore, culture supernatant of B. subtilis RZ001 could suppress the Notch signalling pathway and activate the expression of atonal homolog 1 (Atoh1). The transcription factor Atoh1 is required for intestinal secretory cell differentiation and activates transcription of MUC2 via binding to E-boxes on the MUC2 promoter. Taken together, B. subtilis strain RZ001 has the potential for treating IBD. The present study is helpful to elucidate the mechanisms of B. subtilis action.

Effect of Combined Live Probiotics Alleviating the Gastrointestinal Symptoms of Functional Bowel Disorders

Objective

Changes of the gut microbiota are related to the pathogenesis of functional bowel disorders (FBDs), and probiotic supplementation may be an effective treatment option. Therefore, we aimed to investigate the effect of combined live probiotics on the gastrointestinal symptoms of FBDs via altering the gut microbiota.

Methods

Patients with the gastrointestinal symptoms of FBDs attending the Outpatient Department, from July to November 2019, were recruited. After the bowel preparation with polyethylene glycol electrolyte powder and colonoscopy, patients with normal result of colonoscopy were randomly divided into the probiotics group and control group. Patients in the probiotics group were prescribed with combined live Bacillus subtilis and Enterococcus faecium enteric-coated capsules for 4 weeks. Small intestinal bacteria overgrowth (SIBO) was measured by lactulose hydrogen breath test, and the microbial DNA was extracted from the fecal samples and the bacteria were classified by 16S rDNA gene amplicon sequencing.

Results

Twenty-five patients of each group were recruited, and there was no significant difference between the probiotics and control groups on baseline gastrointestinal symptom rating scale (GSRS), positive rate of SIBO, and relative abundances of the gut microbiota at the phylum level. After 4 weeks of treatment, the values of the probiotics and control groups were as follows: GSRS 1.4 ± 1.4 and 3.6 ± 1.6 and positive rate of SIBO 28.0% and 56.0%, respectively. The median relative abundances of the gut microbiota were 1.01% and 5.03% Actinobacteria and 43.80% and 35.17% Bacteroidetes at the phylum level; 0.76% and 3.29% Bifidobacterium, 0.13% and 0.89% Cillinsella, 0.03% and 0.01% Enterococcus, 0.18% and 0.36% Lachnospiraceae, 0.10% and 0.16% Ruminococcus torques group, 1.31% and 2.44% Blautia, and 0.83% and 2.02% Fusicatenibacter at the genus level (P < 0.05), respectively.

Conclusion

Combined live probiotic supplementation after the bowel preparation can alter the gut microbiota, decontaminate SIBO, and alleviate the gastrointestinal symptoms of FBDs. This trial is registered with ChiCTR1900026472.

Discovery of a Novel Multi-Strains Probiotic Formulation with Improved Efficacy toward Intestinal Inflammation

Dysbiosis is commonly detected in patients with inflammatory bowel disease (IBD), supporting the concept that a dysregulated immune reaction to bacterial antigens has a pathogenic role in the development of intestinal inflammation. In the present study, we have investigated the beneficial effects of a novel probiotic formulation assembled by combining four probiotics (Streptococcus thermophilus, Lactobacillus casei, Bifidobacterium breve, Bifidobacterium animalis subsp. Lactis) with Bacillus subtilis, a Gram-positive bacterium, with extensive bio-applications. Mice rendered colitic by administration of TNBS or DSS were administered with Bacillus subtilis alone, Vivomixx® or the novel Five strains formulation. Vivomixx® attenuated the severity of inflammation and reduced the development of signs and symptoms of colitis in both models. Adding Bacillus subtilis to Vivomixx® improved the beneficial effects of the bacterial therapy. The novel Five strains formulation was as effective as Vivomixx® in reducing the development of signs and symptoms of colitis and reduced the expression of pro-inflammatory mediators including Il-6 and Tnf-α while increased the expression of Il-10 mRNA and the number of Treg. In summary, we have shown that a novel Five strains probiotics formulation exerts beneficial effects on two chemical models of colitis, establishing Bacillus subtilis as a probiotic in rodent models of inflammation.

Analysis of microbial diversity and composition in small intestine during different development times in ducks

We studied the microbial profiles of the duodenum, jejunum, and ileum during different developmental stages in the duck using high-throughput sequencing of the bacterial 16S rRNA gene. We also investigated the differences in the microbiota in the duodenum, jejunum, and ileum at different developmental times. A correlation analysis was performed between the most abundant bacterial genera and the development of the small intestine. An analysis of alpha diversity indicated different species richness and bacterial diversity in the different small intestinal segments and at different development times. A beta diversity analysis indicated differences in the bacterial community compositions across time. In a weighted UniFrac principal coordinates analysis, the samples clustered into two categories, 2 to 4 wk and 6 to 10 wk, in the duodenum, jejunum, and ileum. Our results show that the small intestine is predominantly populated by the phyla Firmicutes, Bacteroidetes, and Proteobacteria throughout the developmental stages of the duck. The duodenum, jejunum, and ileum shared most of the bacterial phyla and genera present, although they showed significant differences in their relative abundances in the intestinal segments and developmental stages. They shared different bacterial taxa during development times and among different segments when the intergroup differences were analyzed. The genera Bacillus, Corynebacterium 1, Lactococcus, Sphingomonas, and Haliangium correlated moderately positively with the increase in bodyweight and the lengths and weights of the duodenum, jejunum, and ileum, and these genera may be considered important markers when assessing the heath of the intestinal microbiota in ducks. This study provides a foundation upon which to extend our knowledge of the diversity and composition of the duck microbiota and a basis for further studies of the management of the small intestinal microbiota and improvements in the health and production of ducks.

Saccharomyces boulardii alleviates ulcerative colitis carcinogenesis in mice by reducing TNF-α and IL-6 levels and functions and by rebalancing intestinal microbiota

BACKGROUND AND AIMS

To explore the inhibition mechanism of Saccharomyces boulardii (S. boulardii) on ulcerative colitis (UC) carcinogenesis.

METHODS

C57BL/6 mice were treated with azoxymethane and dextran sulfate sodium (AOM/DSS) to develop a UC carcinogenesis model. The treatment group was lavaged with S. boulardii (5 × 10⁷ CFU/d) for 12 weeks. The mice were sacrificed and the tumor load in the treatment group was compared with that of a control group. The levels of TNF-α and IL-6 in colon tissue were measured by enzyme-linked immunosorbent assays. The influence of S. boulardii on TNF-α and IL-6 regulation was also investigated using different colon cell lines. Differences in intestinal microbiota in both stool and intestinal mucosa samples were assessed using 16S rDNA sequencing.

RESULTS

S. boulardii treatment reduced AOM/DSS-induced UC carcinogenesis in mice, as indicated by the reduced tumor load and reduced TNF-α and IL-6 levels in vivo, as well its effects on TNF-α and IL-6 activities in vitro. Significant changes in both fecal and mucosal microbiota were observed among the control, the AOM/DSS treated, and AOM/DSS plus S. boulardii treated groups. For fecal microbiota, the AOM/DSS treated group was lower in Lactobacillus, but higher in Oscillibacter and Lachnoclostridium than the control group. After intervention with S. boulardii, the percentage of Bacillus and Lactococcus increased, but Lachnoclostridium, Oscillibacter, Bacteroides, and Pseudomonas decreased. For the intestinal mucosal microbiota, the AOM/DSS treated group was lower in Bifidobacterium and Ruminococcaceae_UCG-014 and higher in Alloprevotella than the control group. After S. boulardii exposure, the percentage contributions of Lachnoclostridium and Lachnospiraceae_NK4A136 increased.

CONCLUSIONS

S. boulardii effectively reduced UC carcinogenesis in an AOM/DSS induced mice model. This positive result can likely be attributed to the reduction of TNF-α and IL-6 levels or the blockade of their function combined with alterations to the intestinal microbiota.

Effects of peanut meal extracts fermented by Bacillus natto on the growth performance, learning and memory skills and gut microbiota modulation in mice

Recent studies have demonstrated that the nutritional properties of peanut meal (PM) can be improved after being fermented. The assessment of fermented PM has been reported to be limited to various physical and chemical evaluations in vitro. In the present study, PM was fermented by Bacillus natto to explore the effects of fermented PM extract (FE) on growth performance, learning and memory ability and intestinal microflora in mice. Ninety newly weaned male Kunming (KM) mice were randomly divided into seven groups: normal group (n 20), low-dose FE group (n 10), middle-dose FE group (MFE) (n 10), high-dose FE group (HFE) (n 20), unfermented extraction group (n 10), model group (10) and natural recovery group (10). Learning and memory skills were performed by the Morris water maze (MWM) test, and the variation in gut microbiota (GM) composition was assessed by 16S rDNA amplicon sequencing. The results show that HFE remarkably improved the growth performance in mice. In the MWM test, escape latency was shortened in both MFE and HFE groups, while the percentage of time, distance in target quadrant and the number crossing over the platform were significantly increased in the HFE group. Moreover, the FE played a preventive role in the dysbacteriosis of mice induced by antibiotic and increased the richness and species evenness of GM in mice.

Changes in the intestinal microecology induced by bacillus subtilis inhibit the occurrence of ulcerative colitis and associated cancers: a study on the mechanisms

This study aimed to explore how changes in intestinal floras caused by Bacillus subtilis (Bs) inhibited occurrence of ulcerative colitis (UC) and associated cancers. Bs was used as an intervention in an azoxymethane (AOM)/dextran sodium sulfate sodium (DSS) animal model. Stool specimens were analyzed for changes in intestinal floras. Disease activity index (DAI) scores, body mass indices, cancer counts, and other indices were calculated, while changes in the colon mucosa were observed. Compared with AOM/DSS group, carcinogenesis significantly reduced and intestinal inflammations and DAI score alleviated; diversity, evenness, and number of species of floras significantly increased; and relative abundances of Rikenellaceae and Lactobacillus increased when UC developed into cancers in the AOM/DSS + Bs group. Colon epitheliums in the mice were severely damaged in the AOM/DSS group, while mucosae were repaired in the AOM/DSS + Bs group. The mRNA expression levels of IL-6 and IL-17a were lower while those of IL-10 and TGF-β1 were higher, and the expression level of Ki-67 decreased while that of caspase 3 increased in the AOM/DSS + Bs group. Bs intervention could alter the structure of intestinal floras, repair the mucosal barrier, adjust immunity, and reduce the incidence of cancer in the AOM/DSS animal model.

VSL#3 can prevent ulcerative colitis-associated carcinogenesis in mice

AIM

To investigate the effects of VSL#3 on tumor formation, and fecal and intestinal mucosal microbiota in azoxymethane/dextran sulfate sodium (AOM/DSS) induced mice model.

METHODS

C57BL/6 mice were administered AOM/DSS to develop the ulcerative colitis (UC) carcinogenesis model. Mice were treated with 5-ASA (75 mg/kg/d), VSL#3 (1.5 × 10⁹ CFU/d), or 5-ASA combined with VSL#3 by gavage from the day of AOM injection for three months (five days/week). The tumor load was compared in each group, and tumor necrosis factor (TNF-α) and interleukin (IL)-6 levels were evaluated in colon tissue. The stool and intestinal mucosa samples were collected to analyze the differences in the intestinal microbiota by 16s rDNA sequencing method.

RESULTS

VSL#3 significantly reduced the tumor load in AOM/DSS-induced mice model and decreased the level of TNF-α and IL-6 in colon tissue. The model group had a lower level of Lactobacillus and higher level of Oscillibacter and Lachnoclostridium in fecal microbiota than the control group. After the intervention with 5-ASA and VSL#3, Bacillus and Lactococcus were increased, while Lachnoclostridium and Oscillibacter were reduced. 5-ASA combined with VSL#3 increased the Lactobacillus and decreased the Oscillibacter. The intestinal mucosal microbiota analysis showed a lower level of Bifidobacterium and Ruminococcaceae_UCG-014 and higher level of Alloprevotella in the model group as compared to the control group. After supplementation with VSL#3, Bifidobacterium was increased. 5-ASA combined with VSL#3 increased the level of both Lachnoclostridium and Bifidobacterium.

CONCLUSION

VSL#3 can prevent UC-associated carcinogenesis in mice, reduce the colonic mucosal inflammation levels, and rebalance the fecal and mucosal intestinal microbiota.

Rebuilding the Gut Microbiota Ecosystem

A microbial ecosystem in which bacteria no longer live in a mutualistic association is called dysbiotic. Gut microbiota dysbiosis is a condition related with the pathogenesis of intestinal illnesses (irritable bowel syndrome, celiac disease, and inflammatory bowel disease) and extra-intestinal illnesses (obesity, metabolic disorder, cardiovascular syndrome, allergy, and asthma). Dysbiosis status has been related to various important pathologies, and many therapeutic strategies aimed at restoring the balance of the intestinal ecosystem have been implemented. These strategies include the administration of probiotics, prebiotics, and synbiotics; phage therapy; fecal transplantation; bacterial consortium transplantation; and a still poorly investigated approach based on predatory bacteria. This review discusses the various aspects of these strategies to counteract intestinal dysbiosis.

Hydrogen peroxide production by lactobacilli promotes epithelial restitution during colitis

Inflammatory bowel disease (IBD) is a multifactorial chronic inflammatory disease of the gastrointestinal tract, characterized by cycles of acute flares, recovery and remission phases. Treatments for accelerating tissue restitution and prolonging remission are scarce, but altering the microbiota composition to promote intestinal homeostasis is considered a safe, economic and promising approach. Although probiotic bacteria have not yet fulfilled fully their promise in clinical trials, understanding the mechanism of how they exert beneficial effects will permit devising improved therapeutic strategies. Here we probe if one of the defining features of lactobacilli, the ability to generate nanomolar H2O2, contributes to their beneficial role in colitis. H2O2 generation by wild type L. johnsonii was modified by either deleting or overexpressing the enzymatic H2O2 source(s) followed by orally administering the bacteria before and during DSS colitis. Boosting luminal H2O2 concentrations within a physiological range accelerated recovery from colitis, while significantly exceeding this H2O2 level triggered bacteraemia. This study supports a role for increasing H2O2 within the physiological range at the epithelial barrier, independently of the enzymatic source and/or delivery mechanism, for inducing recovery and remission in IBD.

Bacillus subtilis and Enterococcus faecium enteric-coated capsules combined with mesalazine for treatment of patients with ulcerative colitis: Efficacy and impact on serum levels of SOD, MDA, interleukins, and TNF-α

AIM

To observe the curative effect of Bacillus subtilis and Enterococcus faecium enteric-coated capsules and mesalazine in patients with ulcerative colitis and their impact on serum levels of interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor α (TNF-α), malondialdehyde (MDA), superoxide dismutase (SOD), cyclooxygenase-2 (COX-2), and nuclear factor-κB (NF-κB).

METHODS

Eighty-six patients with ulcerative colitis admitted to our hospital from August 2014 to November 2016 were selected and randomly divided into an observation group and a control group, with 43 cases in each group. Both groups were given mesalazine enteric-coated tablets, and the observation group was additionally given Bacillus subtilis and Enterococcus faecium enteric-coated capsules. After continuous treatment for 2 mo, the clinical curative effect, time to symptom relief, Rachmitewitz score, and Sutherland score were recorded. Serum levels of IL-6, IL-8, IL-10, TNF-α, MDA, SOD), COX-2, and NF-κB were measured. The patients were followed for 6 mo to record the recurrence.

RESULTS

The total effective rate in the observation group was 93.02%, which was significantly higher than that in the control group (76.74%; Z = 4.440, P = 0.035). The time to relief of symptoms such as diarrhea, abdominal pain, and mucus and blood in stool was significantly shorter in the observation group than in the control group (P < 0.05). After treatment, Rachmitewitz and Sutherland scores of both groups decreased significantly compared with those before treatment, and the scores of the observation group were significantly lower than those of the control group (P < 0.05). After treatment, the levels of IL-6, IL-8, and TNF-α in the observation group were significantly lower and that of IL-10 was significantly higher in the observation group than in the control group (P < 0.05). Moreover, the levels of MDA, COX-2, and NF-κB were significantly lower and that of SOD was significantly higher in the observation group than in the control group (P < 0.05). During a follow-up period of 6 months, the recurrence rate was lower in the observation group than in the control group (11.63% vs 16.28%).

CONCLUSION

Bacillus subtilis and Enterococcus faecium enteric-coated capsules combined with mesalazine is better than mesalazine alone in reducing clinical symptoms and improving serum levels of inflammatory cytokines and oxidative stress in patients with ulcerative colitis, with no significant effect on long-term recurrence.

Amelioration of the DSS-induced colitis in mice by pretreatment with 4,4'-diaponeurosporene-producing Bacillus subtilis

Inflammatory bowel disease (IBD) is a chronically relapsing inflammatory disorder of the gastrointestinal tract. Current IBD treatments have poor tolerability and insufficient therapeutic efficacy, thus, alternative therapeutic approaches are required. Recently, a number of dietary supplements have emerged as promising interventions. In the present study oral administration of a carotenoid (4,4'-diaponeurosporene)-producing Bacillus subtilis markedly ameliorated dextran sulfate sodium salt-induced mouse colitis, as demonstrated by a reduction in weight loss and the severity of bleeding, which indicated that 4,4'-diaponeurosporene may have beneficial effects on treatments for colitis. This preliminary study indicated that 4,4'-diaponeurosporene may function synergistically with probiotics to provide a novel and effective strategy to prevent colitis.

Secretome of Intestinal Bacilli: A Natural Guard against Pathologies

Current studies of human gut microbiome usually do not consider the special functional role of transient microbiota, although some of its members remain in the host for a long time and produce broad spectrum of biologically active substances. Getting into the gastrointestinal tract (GIT) with food, water and probiotic preparations, two representatives of Bacilli class, genera Bacillus and Lactobacillus, colonize epithelium blurring the boundaries between resident and transient microbiota. Despite their minor proportion in the microbiome composition, these bacteria can significantly affect both the intestinal microbiota and the entire body thanks to a wide range of secreted compounds. Recently, insufficiency and limitations of pure genome-based analysis of gut microbiota became known. Thus, the need for intense functional studies is evident. This review aims to characterize the Bacillus and Lactobacillus in GIT, as well as the functional roles of the components released by these members of microbial intestinal community. Complex of their secreted compounds is referred by us as the "bacillary secretome." The composition of the bacillary secretome, its biological effects in GIT and role in counteraction to infectious diseases and oncological pathologies in human organism is the subject of the review.

Bacillus As Potential Probiotics: Status, Concerns, and Future Perspectives

Spore-forming bacilli are being explored for the production and preservation of food for many centuries. The inherent ability of production of large number of secretory proteins, enzymes, antimicrobial compounds, vitamins, and carotenoids specifies the importance of bacilli in food chain. Additionally, Bacillus spp. are gaining interest in human health related functional food research coupled with their enhanced tolerance and survivability under hostile environment of gastrointestinal tract. Besides, bacilli are more stable during processing and storage of food and pharmaceutical preparations, making them more suitable candidate for health promoting formulations. Further, Bacillus strains also possess biotherapeutic potential which is connected with their ability to interact with the internal milieu of the host by producing variety of antimicrobial peptides and small extracellular effector molecules. Nonetheless, with proposed scientific evidences, commercial probiotic supplements, and functional foods comprising of Bacillus spp. had not gained much credential in general population, since the debate over probiotic vs pathogen tag of Bacillus in the research and production terrains is confusing consumers. Hence, it’s important to clearly understand the phenotypic and genotypic characteristics of selective beneficial Bacillus spp. and their substantiation with those having GRAS status, to reach a consensus over the same. This review highlights the probiotic candidature of spore forming Bacillus spp. and presents an overview of the proposed health benefits, including application in food and pharmaceutical industry. Moreover, the growing need to evaluate the safety of individual Bacillus strains as well as species on a case by case basis and necessity of more profound analysis for the selection and identification of Bacillus probiotic candidates are also taken into consideration.

Upregulation of Intestinal Barrier Function in Mice with DSS-Induced Colitis by a Defined Bacterial Consortium Is Associated with Expansion of IL-17A Producing Gamma Delta T Cells

Bacterial consortium transplantation (BCT) is a promising alternative to fecal microbiota transplantation in treating inflammatory bowel disease (IBD). Here, we showed that a defined bacterial consortium derived from healthy mice was able to enhance the intestinal barrier function of mice with dextran sulfate sodium (DSS)-induced colitis. Interestingly, we found that the bacterial consortium significantly promoted the expansion of IL-17A-producing γδT (γδT17) cells in colonic lamina propria, which was closely associated with changing of intestinal microbial composition. The increased IL-17A secretion upon treatment with microbial products derived from the bacterial consortium was accompanied with upregulation of TLR2 expression by γδT cells, and it might be responsible for the upregulation of mucosal barrier function through IL-17R-ACT1-mediated recovery of the disrupted occludin subcellular location. Changing of some specific microbial groups such as Bifidobacterium and Bacillus spp. was closely correlated with the promotion of TLR2⁺ γδT cells. Our results support that BCT can restore the alliance between commensal microbiota and intestinal γδT cells, which contributes to the improvement of intestinal barrier function. This study provides new insight into the development of bacteria transplantation therapy for the treatment of IBD.

Evidence of the Anti-Inflammatory Effects of Probiotics and Synbiotics in Intestinal Chronic Diseases

Probiotics and synbiotics are used to treat chronic diseases, principally due to their role in immune system modulation and the anti-inflammatory response. The present study reviewed the effects of probiotics and synbiotics on intestinal chronic diseases in in vitro, animal, and human studies, particularly in randomized clinical trials. The selected probiotics exhibit in vitro anti-inflammatory properties. Probiotic strains and cell-free supernatants reduced the expression of pro-inflammatory cytokines via action that is principally mediated by toll-like receptors. Probiotic administration improved the clinical symptoms, histological alterations, and mucus production in most of the evaluated animal studies, but some results suggest that caution should be taken when administering these agents in the relapse stages of IBD. In addition, no effects on chronic enteropathies were reported. Probiotic supplementation appears to be potentially well tolerated, effective, and safe in patients with IBD, in both CD and UC. Indeed, probiotics such as Bifidobacterium longum 536 improved the clinical symptoms in patients with mild to moderate active UC. Although it has been proposed that probiotics can provide benefits in certain conditions, the risks and benefits should be carefully assessed before initiating any therapy in patients with IBD. For this reason, further studies are required to understand the precise mechanism by which probiotics and synbiotics affect these diseases.