Bifidobacterium longum Ameliorates Dextran Sulfate Sodium-Induced Colitis by Producing Conjugated Linoleic Acid, Protecting Intestinal Mechanical Barrier, Restoring Unbalanced Gut Microbiota, and Regulating the Toll-Like Receptor-4/Nuclear Factor-κB Signaling Pathway

Structural characteristics of a polysaccharide from Armillariella tabescens and its protective effect on colitis mice via regulating gut microbiota and intestinal barrier function

A new polysaccharide fraction (ATP) was obtained from Armillariella tabescens mycelium. Structural analysis suggested that the backbone of ATP was →4)-α-D-Glcp(1 → 2)-α-D-Galp(1 → 2)-α-D-Glcp(1 → 4)-α-D-Glcp(1→, which branched at O-3 of →2)-α-D-Glcp(1 → and terminated with T-α-D-Glcp or T-α-D-Manp. Besides, ATP significantly alleviated ulcerative colitis (UC) symptoms and inhibited the production of pro-inflammation cytokines (IL-1β, IL-6). Meanwhile, ATP could improve colon tissue damage by elevating the expression of MUC2 and tight junction proteins (ZO-1, occludin and claudin-1) levels and enhance intestinal barrier function through inhibiting the activation of MMP12/MLCK/p-MLC2 signaling pathway. Further studies exhibited that ATP could increase the relative abundance of beneficial bacteria such as f. Muribaculacese, g. Muribaculaceae, and g. Alistips, and decrease the relative abundance of g. Desulfovibrio, g. Colidextribacter, g. Ruminococcaceae and g.Oscillibacter, and regulate the level of short-chain fatty acids. Importantly, FMT intervention with ATP-derived microbiome certified that gut microbiota was involved in the protective effects of ATP on UC. The results indicated that ATP was potential to be further developed into promising therapeutic agent for UC.

Lactobacillus plantarum Ameliorates Colorectal Cancer by Ameliorating the Intestinal Barrier through the CLA-PPAR-γ Axis

Colorectal cancer (CRC) is the third-largest cancer worldwide. Lactobacillus can regulate the intestinal barrier and gut microbiota. However, the mechanisms of Lactobacillus that alleviate CRC remained unknown. This study aimed to explore the regulatory effect of Lactobacillus plantarum on CRC and its potential mechanism. CCFM8661 treatment significantly ameliorated CRC compared with phosphate-buffered solution (PBS) treatment in ApcMin/+ mice. In addition, conjugated linoleic acid (CLA) was proved to be the key metabolite for CCFM8661 in ameliorating CRC by molecular biology techniques. Peroxisome proliferator-activated receptor γ (PPAR-γ) was proved to be the key receptor in ameliorating CRC by inhibitor intervention experiments. Moreover, supplementation with CCFM8661 ameliorated CRC by producing CLA to inhibit NF-κB pathway and pro-inflammatory cytokines, up-regulate ZO-1, Claudin-1, and MUC2, and promote tumor cell apoptosis in a PPAR-γ-dependent manner. Metagenomic analysis showed that CCFM8661 treatment significantly increased Odoribacter splanchnicus, which could ameliorate CRC by repairing the intestinal barrier. Clinical results showed that intestinal CLA, butyric acid, PPAR-γ, and Lactobacillus were significantly decreased in CRC patients, and these indicators were significantly negatively correlated with CRC. CCFM8661 alleviated CRC by ameliorating the intestinal barrier through the CLA-PPAR-γ axis. These results will promote the development of dietary probiotic supplements for CRC.

Probiotic Compounds Enhanced Recovery after Surgery for Patients with Distal Gastric Cancer: A Prospective, Controlled Clinical Trial

BACKGROUND

Enhanced recovery after surgery (ERAS) for radical distal gastrectomy needs to be improved urgently. We investigated the effects of probiotic compounds (including Lactobacillus plantarum, L. rhamnosus, L. acidophilus, and Bifidobacterium animalis subsp.lactis) on enhance recovery after gastrectomy.

METHODS

The patients in this prospective study were divided into probiotic group (PG group, n = 36) and placebo group (CG group, n = 38), taking corresponding capsule according to the protocol during the perioperative period. We compared the trends in perioperative hematologic findings and the postoperative outcomes. Patients' feces were collected for bacterial 16S rRNA sequencing. Patients were followed up at 1 month postoperatively.

RESULTS

After the application of probiotics, the patients' postoperative inflammatory response level was reduced, and the trend of postoperative NLR decrease was significantly faster in the patients of the PG group than in the CG group (P = 0.047, partial η2 = 0.054). The trend of postoperative increase in serum albumin concentration in the patients of the PG group was significantly better than that in the CG group (P = 0.016, partial η2 = 0.078). In addition, patients in the PG group met discharge criteria earlier postoperatively and had fewer medical expenses. The quality of life of PG group was improved postoperatively. Postoperative inflammation-related markers, including the ratio of Firmicutes/Bacteroidetes, were increasing in untreated patients. In addition, the postoperative microbial diversity and abundance in the PG group remained stable.

CONCLUSIONS

Probiotic compounds can reduce the inflammatory response after gastrectomy and enhance the recovery of the DGC patients by maintaining the stability of the gut microbiota.

Bifidobacterium bifidum Ameliorates DSS-Induced Colitis in Mice by Regulating Microbial Metabolome and Targeting Gut Microbiota

Inflammatory bowel disease (IBD) is a recurrent inflammatory condition affecting the gastrointestinal tract, and its clinical treatment remains suboptimal. Probiotics have shown effectiveness in alleviating dextran sulfate sodium salt (DSS)-induced colitis, exhibiting strain-specific anti-inflammatory properties. In this study, we compared the therapeutic effects of five strains of Bifidobacterium bifidum isolated from healthy adult feces on DSS-induced colitis in mice. Additionally, we investigated the underlying mechanisms by examining gut microbiota composition and microbial metabolome. Our findings highlighted the superior efficacy of B. bifidum M1-3 compared to other strains. It significantly improved colitis symptoms, mitigated gut barrier disruption, and reduced colonic inflammation in DSS-treated mice. Moreover, gut microbiota composition analysis revealed that B. bifidum M1-3 treatment increased the abundance and diversity of gut microbiota. Specifically, it significantly increased the abundance of Muribaculaceae, Lactobacillus, Bacteroides, and Enterorhabdus, while decreasing the abundance of Escherichia-Shigella. Furthermore, our nontargeted metabolomics analysis illustrated that B. bifidum M1-3 treatment had a regulatory effect on various metabolic pathways, including tyrosine metabolism, lysine degradation, and tryptophan metabolism. Importantly, we confirmed that the therapeutic efficiency of B. bifidum M1-3 was dependent on the gut microbiota. These results are conducive to the development of probiotic products for alleviating colitis.

An Exopolysaccharide from Genistein-Stimulated Monascus Purpureus: Structural Characterization and Protective Effects against DSS-Induced Intestinal Barrier Injury Associated with the Gut Microbiota-Modulated Short-Chain Fatty Acid-TLR4/MAPK/NF-κB Cascade Response

Inflammatory bowel disease is a major health problem that can lead to prolonged damage to the digestive system. This study investigated the effects of an exopolysaccharide from genistein-stimulated Monascus purpureus (G-EMP) in a mouse model of colitis to clarify its molecular mechanisms and identified its structures. G-EMP (Mw = 56.4 kDa) was primarily consisted of → 4)-α-D-Galp-(1 →, → 2,6)-α-D-Glcp-(1→ and →2)-β-D-Manp-(1 → , with one of the branches being α-D-Manp-(1 →. G-EMP intervention reduced the loss of body weight, degree of colonic damage and shortening, disease activity index scores, and histopathology scores, while restoring goblet cell production and oxidative homeostasis, repairing colonic functions, and regulating inflammatory cytokines. RNA sequencing and Western blot analysis indicated that G-EMP exerts anti-inflammatory properties by suppressing the TLR4/MAPK/NF-κB inflammatory signaling pathway. G-EMP modulated the gut microbiota by improving its diversities, elevating the relative abundances of beneficial bacteria, declining the Firmicutes/Bacteroidota value, and regulating the level of short-chain fatty acids (SCFAs). Correlation analysis demonstrated strong links between SCFAs, gut microbiota, and the inflammatory response, indicating the potential of G-EMP to prevent colitis.

Border Control: The Role of the Microbiome in Regulating Epithelial Barrier Function

The gut mucosal epithelium is one of the largest organs in the body and plays a critical role in regulating the crosstalk between the resident microbiome and the host. To this effect, the tight control of what is permitted through this barrier is of high importance. There should be restricted passage of harmful microorganisms and antigens while at the same time allowing the absorption of nutrients and water. An increased gut permeability, or "leaky gut", has been associated with a variety of diseases ranging from infections, metabolic diseases, and inflammatory and autoimmune diseases to neurological conditions. Several factors can affect gut permeability, including cytokines, dietary components, and the gut microbiome. Here, we discuss how the gut microbiome impacts the permeability of the gut epithelial barrier and how this can be harnessed for therapeutic purposes.

More than nutrition: Therapeutic potential and mechanism of human milk oligosaccharides against necrotizing enterocolitis

Human milk is the most valuable source of nutrition for infants. The structure and function of human milk oligosaccharides (HMOs), which are key components of human milk, have long been attracting particular research interest. Several recent studies have found HMOs to be efficacious in the prevention and treatment of necrotizing enterocolitis (NEC). Additionally, they could be developed in the future as non-invasive predictive markers for NEC. Based on previous findings and the well-defined functions of HMOs, we summarize potential protective mechanisms of HMOs against neonatal NEC, which include: modulating signal receptor function, promoting intestinal epithelial cell proliferation, reducing apoptosis, restoring intestinal blood perfusion, regulating microbial prosperity, and alleviating intestinal inflammation. HMOs supplementation has been demonstrated to be protective against NEC in both animal studies and clinical observations. This calls for mass production and use of HMOs in infant formula, necessitating more research into the safety of industrially produced HMOs and the appropriate dosage in infant formula.

Identification of OLA1 as a Novel Protein Target of Vitexin to Ameliorate Dextran Sulfate Sodium-Induced Colitis with Tissue Thermal Proteome Profiling

Vitexin, which exists in various medicinal plants and food sources, has recently received increasing attention because of its anti-inflammatory properties. This study aims to identify the protein target of vitexin that ameliorates dextran sulfate sodium (DSS)-induced colitis. The results showed that vitexin not only alleviated the clinical symptoms and colonic damage in mice with DSS-induced colitis but also suppressed the colonic production of inflammatory cytokines (IL-1β, IL-6, ICAM, and VCAM) and enhanced the expression of barrier-associated proteins (ZO-1, Occludin, and E-cadherin). Based on tissue thermal proteome profiling (Tissue-TPP) and molecular docking, OLA1 was creatively identified as a potential protein target for vitexin. Further siRNA-mediated knockdown of the OLA1 gene in Caco-2 cells demonstrated the ability of OLA1 to increase Nrf2 protein expression and, thus, mediated the anti-inflammatory effects of vitexin. Interaction of the OLA1-vitexin complex with Keap1 protein to disrupt the Keap1-Nrf2 interaction may be required for activating Nrf2. Our findings revealed a novel role for OLA1 as a protein target of vitexin that contributes to its anti-inflammatory action by activating Nrf2, which may provide a promising molecular mechanism for novel therapeutic strategies to treat colitis and the associated systemic inflammation.

Epigallocatechin Gallate Alleviates Staphylococcal Enterotoxin A-Induced Intestinal Barrier Damage by Regulating Gut Microbiota and Inhibiting the TLR4-NF-κB/MAPKs-NLRP3 Inflammatory Cascade

Natural phytochemicals have attracted increasing attention because of their promising ability to tackle bacteriotoxin-induced public safety concerns. However, it is unclear how natural phytochemicals regulate the intestinal barrier dysfunction caused by bacteriotoxin, such as staphylococcal enterotoxin A (SEA). This study aims to illustrate the in vitro and in vivo protective mechanism of epigallocatechin gallate (EGCG) on SEA-triggered intestinal barrier damage and inflammation. Results show that EGCG alleviates intestinal barrier damage by effectively inhibiting SEA-induced intestinal permeability increase, tight junction protein and mucin loss, and intestinal cell apoptosis. EGCG also reduces intestinal inflammation by suppressing the TLR4-NF-κB/MAPKs-NLRP3 pathway. Importantly, EGCG reverses gut microbiota dysbiosis and short-chain fatty acid (SCFA) content decrease induced by SEA. It is worth noting that this study also detects the direct interaction between the phytochemical and virulence factors and finds that EGCG effectively not only inhibits the secretion of SEA but also binds with the secreted SEA to attenuate its toxicity. Taken together, EGCG mitigates SEA-induced intestinal barrier dysfunction via gut microbiota SCFA-mediated TLR4-NF-κB/MAPKs-NLRP3 inflammatory cascade inhibition. Overall, this research provides enlightening insight into the application of bacteriotoxin-targeting natural compounds in the field of food safety and human wellness.

Aging characteristics of colorectal cancer based on gut microbiota

BACKGROUND

Aging is one of the factors leading to cancer. Gut microbiota is related to aging and colorectal cancer (CRC).

METHODS

A total of 11 metagenomic data sets related to CRC were collected from the R package curated Metagenomic Data. After batch effect correction, healthy individuals and CRC samples were divided into three age groups. Ggplot2 and Microbiota Process packages were used for visual description of species composition and PCA in healthy individuals and CRC samples. LEfSe analysis was performed for species relative abundance data in healthy/CRC groups according to age. Spearman correlation coefficient of age-differentiated bacteria in healthy individuals and CRC samples was calculated separately. Finally, the age prediction model and CRC risk prediction model were constructed based on the age-differentiated bacteria.

RESULTS

The structure and composition of the gut microbiota were significantly different among the three groups. For example, the abundance of Bacteroides vulgatus in the old group was lower than that in the other two groups, the abundance of Bacteroides fragilis increased with aging. In addition, seven species of bacteria whose abundance increases with aging were screened out. Furthermore, the abundance of pathogenic bacteria (Escherichia_coli, Butyricimonas_virosa, Ruminococcus_bicirculans, Bacteroides_fragilis and Streptococcus_vestibularis) increased with aging in CRCs. The abundance of probiotics (Eubacterium_eligens) decreased with aging in CRCs. The age prediction model for healthy individuals based on the 80 age-related differential bacteria and model of CRC patients based on the 58 age-related differential bacteria performed well, with AUC of 0.79 and 0.71, respectively. The AUC of CRC risk prediction model based on 45 disease differential bacteria was 0.83. After removing the intersection between the disease-differentiated bacteria and the age-differentiated bacteria from the healthy samples, the AUC of CRC risk prediction model based on remaining 31 bacteria was 0.8. CRC risk prediction models for each of the three age groups showed no significant difference in accuracy (young: AUC=0.82, middle: AUC=0.83, old: AUC=0.85).

CONCLUSION

Age as a factor affecting microbial composition should be considered in the application of gut microbiota to predict the risk of CRC.

Probiotics for the treatment of ulcerative colitis: a review of experimental research from 2018 to 2022

Ulcerative colitis (UC) has become a worldwide public health problem, and the prevalence of the disease among children has been increasing. The pathogenesis of UC has not been elucidated, but dysbiosis of the gut microbiota is considered the main cause of chronic intestinal inflammation. This review focuses on the therapeutic effects of probiotics on UC and the potential mechanisms involved. In animal studies, probiotics have been shown to alleviate symptoms of UC, including weight loss, diarrhea, blood in the stool, and a shortened colon length, while also restoring intestinal microecological homeostasis, improving gut barrier function, modulating the intestinal immune response, and attenuating intestinal inflammation, thereby providing theoretical support for the development of probiotic-based microbial products as an adjunctive therapy for UC. However, the efficacy of probiotics is influenced by factors such as the bacterial strain, dose, and form. Hence, the mechanisms of action need to be investigated further. Relevant clinical trials are currently lacking, so the extension of animal experimental findings to clinical application requires a longer period of consideration for validation.

Lycium barbarum Oligosaccharides Alleviate Hepatic Steatosis by Modulating Gut Microbiota in C57BL/6J Mice Fed a High-Fat Diet

High-fat diets (HFD) can promote the development of hepatic steatosis by altering the structure and composition of gut flora. In this study, the potential therapeutic mechanism of Lycium barbarum oligosaccharide (LBO) against hepatic steatosis was investigated by analyzing the changes in the intestinal flora and metabolites in mice. Mice on an HFD were administered LBO by gavage once daily for a continuous period of eight weeks. Compared with the HFD group, the levels of triglyceride (TG), alanine aminotransferase (ALT) in the serum, and hepatic TG were significantly reduced in the LBO group, and liver lipid accumulation was obviously improved. In addition, LBO could regulate the HFD-induced alteration of intestinal flora. The HFD increased the proportion of Barnesiellaceae, Barnesiella, and CHKCI001. LBO increased the proportion of Dubosiella, Eubacterium, and Lactobacillus. LBO also altered the fecal metabolic profile. Significantly different metabolites between LBO and the HFD, such as taurochenodeoxycholate, taurocholate, fluvastatin, and kynurenic acid, were related to the cholesterol metabolism, bile acid metabolism, and tryptophan metabolic pathways. In light of the above, LBO can alleviate HFD-induced NAFLD by modulating the components of the intestinal flora and fecal metabolites.

Bifidobacterium longum R0175 protects mice against APAP-induced liver injury by modulating the Nrf2 pathway

Acetaminophen (APAP) overdose is the most common driver of drug-induced liver injury (DILI) worldwide, and the gut microbiome plays a crucial role in this process. In this study, we estimated the effect of Bifidobacterium longum R0175 on APAP-induced liver injury in mice and discovered that B. longum R0175 alleviated liver injury by diminishing inflammation, reducing oxidative stress levels, inhibiting hepatocyte death and improving APAP-induced microbiome dysbiosis. Further studies revealed that the antioxidative effects of B. longum R0175 were primarily due to activation of the Nrf2 pathway, which was supported by the Nrf2 pathway inhibitor ML385 counteracting these ameliorative effects. B. longum R0175 modified intestinal metabolites, especially the key metabolite sedanolide, which could activate the Nrf2 pathway and contribute to the protective effects against APAP-induced liver injury. Moreover, we found that sedanolide exhibited close interrelationships with specific microbial taxa, indicating that this factor may be derived from gut microbes. In conclusion, our work demonstrated that B. longum R0175 could reduce oxidative damage, inflammation and hepatocyte death by activating the Nrf2 pathway. Importantly, we identified the microbiota-derived metabolite sedanolide, which was first discovered in the mouse intestine, as a key agonist of the Nrf2 pathway and primary effector of B. longum R0175 in APAP challenge. These findings provide new perspectives for APAP overdose therapy and demonstrate the enormous potential of B. longum R0175 in alleviating acute liver injury.

Effects of Medium- and Long-Chain Structured Triacylglycerol on the Therapeutic Efficacy of Vitamin D on Ulcerative Colitis: A Consideration for Efficient Lipid Delivery Systems

Due to intestinal malabsorption and poor water solubility, vitamin D (VitD) deficiency in ulcerative colitis (UC) continues to increase. Medium- and long-chain triacylglycerols (MLCT), as novel lipids, have been widely applied in the field of functional food and medicine nutrition. Our previous studies showed that the difference in MLCT structure could affect VitD bioaccessibility in vitro. In this study, our results further indicate that, although identical in fatty acid composition, structured triacylglycerol (STG) had a higher VitD bioavailability (AUC = 15470.81 μg/L × h) and metabolism efficacy [s-25(OH)D, p < 0.05] than physical mixtures of triacylglycerol (PM), which further affect the amelioration efficiency in UC mice. Compared with PM, the damage of colonic tissues, intestinal barrier proteins, and inflammatory cytokines in STG showed better amelioration at the same dose of VitD. This study provides a comprehensive understanding of the mechanism of nutrients in different carriers and a solution for developing nutrients with high absorption efficiency.

Role of interleukin-6-mediated inflammation in the pathogenesis of inflammatory bowel disease: focus on the available therapeutic approaches and gut microbiome

Inflammatory bowel disease (IBD) is considered a chronic inflammatory and multifactorial disease of the gastrointestinal tract. Crohn's disease (CD) and ulcerative colitis (UC) are two types of chronic IBD. Although there is no accurate information about IBD pathophysiology, evidence suggests that various factors, including the gut microbiome, environment, genetics, lifestyle, and a dysregulated immune system, may increase susceptibility to IBD. Moreover, inflammatory mediators such as interleukin-6 (IL-6) are involved in the immunopathogenesis of IBDs. IL-6 contributes to T helper 17 (Th17) differentiation, mediating further destructive inflammatory responses in CD and UC. Moreover, Th1-mediated responses participate in IBD, and the antiapoptotic IL-6/IL-6 receptor (IL-6R)/signal transducer and activator of transcription 3 (STAT3) signals are responsible for preserving Th1 cells in the site of inflammation. It has been revealed that fecal bacteria isolated from UC-active and UC-remission patients stimulate the hyperproduction of several cytokines, such as IL-6, tumor necrosis factor-α (TNF-α), IL-10, and IL-12. Given the importance of the IL-6/IL-6R axis, various therapeutic options exist for controlling or treating IBD. Therefore, alternative therapeutic approaches such as modulating the gut microbiome could be beneficial due to the failure of the target therapies so far. This review article summarizes IBD immunopathogenesis focusing on the IL-6/IL-6R axis and discusses available therapeutic approaches based on the gut microbiome alteration and IL-6/IL-6R axis targeting and treatment failure.

Bifidobacterium bifidum FJSWX19M5 alleviated 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced chronic colitis by mitigating gut barrier injury and increasing regulatory T cells

Probiotics have been evaluated as alternative approaches for preventing the relapse of Crohn's disease (CD). Previously, we observed strain-specific anti-inflammatory properties of Bifidobacterium bifidum in 2,4,6-trinitrobenzene sulfonic acid (TNBS) acute colitis models. In this study, we further assessed the effects of several B. bifidum strains on colonic damage, fibrosis, inflammatory factors, intestinal microbial and metabolic profiles, and peripheral regulatory T cells (Tregs) in the context of TNBS chronic colitis in mice. These results indicated that B. bifidum FJSWX19M5, but not FXJWS17M4, ameliorated body weight loss, reduced colonic shortening and injury, decreased markers of gut inflammation, and rebalanced colonic metabolism in TNBS-treated mice. FJSWX19M5 supplementation also promoted Treg cell differentiation and intestinal barrier restoration compared to other strains. All living B. bifidum strains (FJSWX19M5, FXJWS17M4 and FHENJZ3M6) seemed to restore the disruption of the gut microbiota caused by TNBS. The co-culture of B. bifidum strains and mesenteric lymph node cells from TNBS-treated mice showed that those strains with anti-colitis could induce higher IL-10 levels and a lower ratio of IL-22/IL-10 and IL-17/IL-10 when compared to those strains that were not protective. Furthermore, heat-killed FJSWX19M5 exhibited a relief effect on colitis-related symptoms (including body weight loss, colonic shortening and injury). These data imply that specific B. bifidum strains or their lysates may be the current therapeutic alternatives for CD.

Efficacy of Bifidobacterium longum alone or in multi-strain probiotic formulations during early life and beyond

The significance of Bifidobacterium to human health can be appreciated from its early colonization of the neonatal gut, where Bifidobacterium longum represents the most abundant species. While its relative abundance declines with age, it is further reduced in several diseases. Research into the beneficial properties of B. longum has unveiled a range of mechanisms, including the production of bioactive molecules, such as short-chain fatty acids, polysaccharides, and serine protease inhibitors. From its intestinal niche, B. longum can have far-reaching effects in the body influencing immune responses in the lungs and even skin, as well as influencing brain activity. In this review, we present the biological and clinical impacts of this species on a range of human conditions beginning in neonatal life and beyond. The available scientific evidence reveals a strong rationale for continued research and further clinical trials that investigate the ability of B. longum to treat or prevent a range of diseases across the human lifespan.

Bifico relieves irritable bowel syndrome by regulating gut microbiota dysbiosis and inflammatory cytokines

PURPOSE

Gut microbiota dysbiosis, a core pathophysiology of irritable bowel syndrome (IBS), is closely related to immunological and metabolic functions. Gut microbiota-based therapeutics have been recently explored in several studies. Bifico is a probiotic cocktail widely used in gastrointestinal disorders which relate to the imbalance of gut microbiota. However, the efficacy and potential mechanisms of Bifico treatment in IBS remains incompletely understood.

METHODS

Adopting a wrap restraint stress (WRS) -induced IBS mice model. Protective effect of Bifico in IBS mice was examined through abdominal withdrawal reflex (AWR) scores. 16S rDNA, ¹H nuclear magnetic resonance (¹H-NMR) and western blot assays were performed to analyze alterations of gut microbiota, microbiome metabolites and inflammatory cytokines, respectively.

RESULTS

Bifico could decrease intestinal visceral hypersensitivity. Although gut microbiota diversity did not increase, composition of gut microbiota was changed after treatment of Bifico, which were characterized by an increase of Proteobacteria phylum and Actinobacteria phylum, Muribaculum genus, Bifidobacterium genus and a decrease of Parabacteroides genus, Sutterella genus and Lactobacillus genus. Moreover, Bifico elevated the concentration of short-chain fatty acids (SCFAs) and reduced protein levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). From further Spearman's correlation analysis, Bifidobacterium genus were positively correlated with SCFAs including propionate, butyrate, valerate and negatively correlated with IL-6 and TNF-α.

CONCLUSION

Bifico could alleviate symptoms of IBS mice through regulation of the gut microbiota, elevating production of SCFAs and reducing the colonic inflammatory response.

Cayratia japonica Prevents Ulcerative Colitis by Promoting M2 Macrophage Polarization through Blocking the TLR4/MAPK/NF-κB Pathway

Background and Aims

Several components of Cayratia japonica (CJ) such as rutin and quercetin have shown anti-inflammatory effect, yet its function in ulcerative colitis (UC) remains to be clarified. This study focuses on the modulatory effect of CJ on UC as well as molecular mechanism by which CJ regulates macrophage polarization in UC.

Methods

The targets related to CJ components and UC were, respectively, obtained through in silico analysis, and their intersection targets were selected for pathway enrichment analysis. RAW264.7 cells were stimulated with lipopolysaccharide (LPS) to induce M1 macrophages. Expression of the macrophage polarization M1 marker CD11b and M2 marker CD206 was measured to determine the phenotype of macrophages. The mouse model was treated with dextran sodium sulfate (DSS) to induce UC to observe the effects of CJ on UC in vivo.

Results

The in silico analysis suggested the crucial significance of TLR4 and its downstream MAPK/NF-κB pathways in the modulatory effect of CJ on UC. Furthermore, experimental data revealed that CJ could promote M2 macrophage polarization but alleviate immune inflammation and reduce colon damage in DSS-evoked UC model. Additionally, CJ can inhibit the expression of TLR4/MAPK/NF-κB signaling pathway to enhance the M2-like polarization.

Conclusion

Hence, CJ may exert anti-inflammatory effects and an inhibitory role in UC by inhibiting the TLR4/MAPK/NF-κB pathway and subsequent M1-like macrophage polarization.

Potential role of gut microbiota and its metabolites in radiation-induced intestinal damage

Radiation-induced intestinal damage (RIID) is a serious disease with limited effective treatment. Nuclear explosion, nuclear release, nuclear application and especially radiation therapy are all highly likely to cause radioactive intestinal damage. The intestinal microecology is an organic whole with a symbiotic relationship formed by the interaction between a relatively stable microbial community living in the intestinal tract and the host. Imbalance and disorders of intestinal microecology are related to the occurrence and development of multiple systemic diseases, especially intestinal diseases. Increasing evidence indicates that the gut microbiota and its metabolites play an important role in the pathogenesis and prevention of RIID. Radiation leads to gut microbiota imbalance, including a decrease in the number of beneficial bacteria and an increase in the number of harmful bacteria that cause RIID. In this review, we describe the pathological mechanisms of RIID, the changes in intestinal microbiota, the metabolites induced by radiation, and their mechanism in RIID. Finally, the mechanisms of various methods for regulating the microbiota in the treatment of RIID are summarized.

Role of microbes in colorectal cancer therapy: Cross-talk between the microbiome and tumor microenvironment

The human gut microbiota is associated with the development and progression of colorectal cancer, and manipulation of the gut microbiota is a novel strategy for the prevention and treatment of colorectal cancer. Some bacteria have antitumor activity against colorectal cancer, where specific bacteria can improve the tumor microenvironment, activate immune cells including dendritic cells, helper T cells, natural killer cells, and cytotoxic T cells, and upregulate the secretion of pro-tumor immune cytokines such as interleukin-2 and interferon. In this paper, we summarize some bacteria with potential benefits in colorectal cancer and describe their roles in the tumor microenvironment, demonstrate the application of gut microbes in combination with immunosuppressive agents, and provide suggestions for further experimental studies and clinical practice applications.

Vitexin Protects against Dextran Sodium Sulfate-Induced Colitis in Mice and Its Potential Mechanisms

Vitexin, one of the major active components in hawthorn, has been shown to possess multiple pharmacological activities. Here, we sought to investigate the effect of vitexin on an ameliorating dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) mouse model and further explored its potential mechanism. The results indicated that vitexin administration could significantly alleviate the signs of colitis via suppressing body weight loss, reducing disease activity index (DAI) score, and mitigating colonic damage. Also, vitexin treatment in colitis mice markedly inhibited the production of pro-inflammation cytokines (such as IL-1β, IL-6, and TNF-α). Meanwhile, vitexin also could markedly down-regulate the phosphorylation levels of p65, IκB, and STAT1. Moreover, vitexin also dose-dependently increased the expressions of muc-2, ZO-1, and occludin proteins in colonic tissues of colitis mice. Further studies revealed that vitexin dramatically modulated the disturbed intestinal flora in colitis mice. Vitexin is beneficial for regulating abundances of some certain bacteria, such as Bacteroides, Helicobacter, Alistipes, Lachnospiraceae_NK4A136_group, and Lachnospiraceae_UCG-006. Interestingly, the correlation analysis indicated that key microbes were strongly correlated with colitis features, such as pro-inflammatory cytokines and gut barrier. Collectively, these results demonstrated that vitexin treatment alleviated inflammation, intestinal barrier dysfunction, and intestinal flora dysbiosis in colitis mice. Vitexin is expected to be a promising compound for UC treatment.

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.

Cyanidin-3-O-glucoside impacts fecal discharge of polystyrene microplastics in mice: Potential role of microbiota-derived metabolites

Microplastic particles degraded from plastic litters are recognized as a global environmental pollutant, which can be transferred and enriched via the food chain to impact ecosystems and human health. A balanced gut microbiota contributes to human health through host-gut interactions, environmentally-driven factors such as microplastic exposure would disturb the gut bacteria and affect its functionality. Dietary compounds can remodel the compositions of gut microbes, and interact with bacteria exerting profound effects on host physiology. This study explored the effects of bayberry-derived anthocyanin cyanidin-3-O-glucoside (C3G) and microplastic polystyrene (PS) on the gut microbiome in C57BL/6 mice, especially the alterations of gut bacteria and its metabolites. Using 16S rRNA high-throughput sequencing, variations in gut bacterial composition and enrichment of functional pathways were found upon PS and C3G administration. Meanwhile, the differential metabolites and metabolic pathways were identified by metabolomic analysis. Importantly, colonic and fecal PS levels were found to be strongly correlated with key microbiota-derived metabolites, which are associated with xenobiotic metabolism via regulation of xenobiotics-metabolizing enzymes and transporters. These results may offer new insights regarding the protective effects of C3G against xenobiotic PS exposure and the roles of gut bacterial metabolites.

Effect of Bifidobacterium animalis subsp. lactis SF on enhancing the tumor suppression of irinotecan by regulating the intestinal flora

The gut microbiota plays a role in tumor therapy by participating in immune regulation. Here, we demonstrated through 8-day probiotic supplementation experiments and fecal microbiota transplantation experiments that Bifidobacterium animalis subsp. lactis SF enhanced the antitumor effect of irinotecan and prevented the occurrence of intestinal damage by modulating the gut microbiota and reducing the relative abundance of pro-inflammatory microbiota. Therefore, the intestinal inflammation was inhibited, the TGF-β leakage was reduced, and the PI3K/AKT pathway activation was inhibited. Thus, the tumor apoptotic autophagy was finally promoted. Simultaneously, the reduction of TGF-β relieved the immunosuppression caused by CPT-11, promoted the differentiation of CD4⁺ and CD8⁺ T cells in tumor tissue, and consequently inhibited tumor growth and invasion. This study disclosed the mechanism of B. lactis SF assisting CPT-11 in antitumor activity and suggested that B. lactis SF plays a new role in anticancer effects as a nutritional intervention.