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Colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer-related death worldwide. It involves the complex interactions between genetic factors, environmental exposure, and gut microbiota. Specific changes in the gut microbiome and metabolome have been described in CRC, supporting the critical role of gut microbiota dysbiosis and microbiota-related metabolites in the tumorigenesis process. Short-chain fatty acids (SCFAs), the principal metabolites generated from the gut microbial fermentation of insoluble dietary fiber, can directly activate G-protein-coupled receptors (GPCRs), inhibit histone deacetylases (HDACs), and serve as energy substrates to connect dietary patterns and gut microbiota, thereby improving the intestinal health. A significantly lower abundance of SCFAs and SCFA-producing bacteria has been demonstrated in CRC, and the supplementation of SCFA-producing probiotics can inhibit intestinal tumor development. SCFAs-guided modulation in both mouse and human CRC models augmented their responses to chemotherapy and immunotherapy. This review briefly summarizes the complex crosstalk between SCFAs and CRC, which might inspire new approaches for the diagnosis, treatment and prevention of CRC on the basis of gut microbiota-derived metabolites SCFAs.

Background: Primary biliary cholangitis (PBC) is a complex disease with high heritability. We investigated the association between human leukocyte antigen (HLA)-DRB1 alleles and PBC in families and sporadic cases to evaluate the genetic components of the disease. Methods: We performed whole exome sequencing in three PBC families. We genotyped HLA-DRB1 and calculated the association between HLA-DRB1 alleles and the encoding amino acid sequences with the clinical features. Results: Ten variants harboured the HLA-DRB1 gene associated with PBC. DRB1 x07:01, 14:01 and 14:05 were highly increased in PBC. Ten coding region polymorphisms were associated with PBC that encode the amino acid variants of HLA-DR beta 54, beta 59 and beta 66 located in the peptide-binding site of the MHC molecule. Glutamine at position 54 was confirmed as a risk amino acid, verifying the results of familial aggregation analysis of PBC families. Discussion: Familial aggregation analysis indicated that HLA-DRB1 is a candidate gene for the risk of disease course. Considering that amino acid variations are critical to peptide-binding properties, they underlie the major component of MHC association with PBC. (c) 2021 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Colorectal cancer (CRC) is one of the main alimentary tract system malignancies affecting people worldwide. Adenomatous polyps are precursors of CRC, and therefore, preventing the development of these lesions may also prevent subsequent malignancy. However, the adenoma detection rate (ADR), a measure of the ability of a colonoscopist to identify and remove precancerous colorectal polyps, varies significantly among endoscopists. Here, we attempt to use a convolutional neural network (CNN) to generate a unique computer-aided diagnosis (CAD) system by exploring in detail the multiple-scale performance of deep neural networks. We applied this system to 3,375 hand-labeled images from the screening colonoscopies of 1,197 patients; of whom, 3,045 were assigned to the training dataset and 330 to the testing dataset. The images were diagnosed simply as either an adenomatous or non-adenomatous polyp. When applied to the testing dataset, our CNN-CAD system achieved a mean average precision of 89.5%. We conclude that the proposed framework could increase the ADR and decrease the incidence of interval CRCs, although further validation through large multicenter trials is required.

High‐fat diet (HFD) is a well‐known risk factor for gut microbiota dysbiosis and colorectal cancer (CRC). However, evidence relating HFD, gut microbiota and carcinogenesis is limited. Our study aimed to demonstrate that HFD‐induced gut dysbiosis promoted intestinal adenoma‐adenocarcinoma sequence. In clinical study, we found that HFD increased the incidence of advanced colorectal neoplasia (AN). The expression of monocyte chemoattractant protein 1 (MCP‐1), CC chemokine receptor 2 (CCR2) and CD163 in CRC patients with HFD was significantly higher than that in CRC patients with normal diet. When it comes to the Apcmin/+ mice, HFD consumption could induce gut dysbiosis and promote intestinal carcinogenesis, accompanying with activation of MCP‐1/CCR2 axis that recruited and polarized M2 tumour‐associated macrophages. Interestingly, transfer of faecal microbiota from HFD‐fed mice to another batch of Apcmin/+ mice in the absence of HFD could also enhance carcinogenesis without significant body weight gain and induced MCP‐1/CCR2 axis activation. HFD‐induced dysbiosis could also be transmitted. Meanwhile, antibiotics cocktail treatment was sufficient to inhibit HFD‐induced carcinogenesis, indicating the vital role of dysbiosis in cancer development. Conclusively, these data indicated that HFD‐induced dysbiosis accelerated intestinal adenoma‐adenocarcinoma sequence through activation of MCP‐1/CCR2 axis, which would provide new insight into better understanding of the mechanisms and prevention for HFD‐related CRC.

Gut microbiota dysbiosis is closely involved in intestinal carcinogenesis. A marked reduction in butyrate-producing bacteria has been observed in patients with colorectal cancer (CRC); nevertheless, the potential benefit of butyrate-producing bacteria against intestinal tumor development has not been fully investigated. We found that Clostridium butyricum (C. butyricum, one of the commonly used butyrate-producing bacteria in clinical settings) significantly inhibited high-fat diet (HFD)-induced intestinal tumor development in Apcmin/+ mice. Moreover, intestinal tumor cells treated with C. butyricum exhibited decreased proliferation and increased apoptosis. Additionally, C. butyricum suppressed the Wnt/β-catenin signaling pathway and modulated the gut microbiota composition, as demonstrated by decreases in some pathogenic bacteria and bile acid (BA)-biotransforming bacteria and increases in some beneficial bacteria, including short-chain fatty acid (SCFA)-producing bacteria. Accordingly, C. butyricum decreased the fecal secondary BA contents, increased the cecal SCFA quantities, and activated G-protein coupled receptors (GPRs), such as GPR43 and GPR109A. The anti-proliferative effect of C. butyricum was blunted by GPR43 gene silencing using small interfering RNA (siRNA). The analysis of clinical specimens revealed that the expression of GPR43 and GPR109A gradually decreased from human normal colonic tissue to adenoma to carcinoma. Together, our results show that C. butyricum can inhibit intestinal tumor development by modulating Wnt signaling and gut microbiota and thus suggest the potential efficacy of butyrate-producing bacteria against CRC.

Research has shown that maternal sucralose (MS) exposure alters the gut microbiota of offspring at weaning and predisposes the offspring to developing obesity, non-alcoholic fatty liver disease and metabolic syndrome later in life. However, the underlying mechanism remains unclear. Paneth cells are thought to critically influence the gut microbiota. This study aimed to investigate whether MS exposure induced Paneth cell defects and exacerbated gut dysbiosis of offspring. Female C57BL/6 mice were divided into the MS and control (water) groups during pregnancy and lactation. Progeny mice were fed a normal sucralose-free diet after weaning until adulthood. MS inhibited intestinal development and increased the expression of proinflammatory cytokines in the small intestines of 3-week-old progeny mice. MS increased the proportions of abnormal granule secretion by Paneth cells. The number of Paneth cells and mRNA expression of AMPs such as cryptdins and lysozyme were reduced in the MS group. MS disturbed the gut microbiota composition and diversity in the 3-week-old offspring mice. The relative abundances of pro-inflammatory bacteria, such as Desulfovibrionales, Helicobacter, Pasteurellales and Campylobacterales were significantly increased in the MS group, while anti-inflammatory bacteria, including Clostridium XI, were decreased. This dysbiosis continued into adulthood. These findings showed that MS exposure induced Paneth cell defects and exacerbated gut dysbiosis in offspring mice. Sucralose should be consumed with caution, especially during pregnancy and in early life.

ObjectiveIt was to evaluate the anti-inflammatory effect of ursodeoxycholic acid (UDCA) on concanavalin A (ConA)-induced immune hepatitis in mice and determine the molecular mechanism. MethodsFemale C57BL/6J mice were randomly classified into Control, ConA, and ConA+UDCA groups. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were measured. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to detect the expression of hepatic inflammatory factor tumor necrosis factor-α (TNF-α), and receptor-interacting protein (RIP)3 mRNA. The percentages of immune cells in liver and spleen were detected and analyzed by flow cytometry. ResultsUDCA decreased the serum ALT and AST levels, down-regulated the expression of cytokine TNF-α mRNA and necroptosis marker RIP3 mRNA in the liver tissue, up-regulated the percentages of immunomodulatory myeloid-derived suppressor cells (MDSCs) in liver and spleen tissues, and down-regulated the accumulation of liver macrophages of mice with immune hepatitis. ConclusionsUDCA attenuates ConA-induced hepatic inflammation in mice by reducing the production of hepatic inflammatory factors, inhibiting the expression of necroptosis signal proteins in hepatocytes, down-regulating the accumulation of hepatic macrophages, and increasing the percentage of MDSCs with immunomodulatory properties.

The prevalence of inflammatory bowel disease (IBD) is increasing worldwide and correlates with dysregulated immune response because of gut microbiota dysbiosis. Some adverse early life events influence the establishment of the gut microbiota and act as risk factors for IBD. Prenatal maternal stress (PNMS) induces gut dysbiosis and perturbs the neuroimmune network of offspring. In this study, we aimed to investigate whether PNMS increases the susceptibility of offspring to colitis in adulthood. The related index was assessed during the weaning period and adulthood. We found that PNMS impaired the intestinal epithelial cell proliferation, goblet cell and Paneth cell differentiation, and mucosal barrier function in 3-week-old offspring. PNMS induced low-grade intestinal inflammation, but no signs of microscopic inflammatory changes were observed. Although there was no pronounced difference between the PNMS and control offspring in terms of their overall measures of alpha diversity for the gut microbiota, distinct microbial community changes characterized by increases in Desulfovibrio, Streptococcus, and Enterococcus and decreases in Bifidobacterium and Blautia were induced in the 3-week-old PNMS offspring. Notably, the overgrowth of Desulfovibrio persisted from the weaning period to adulthood, consistent with the results observed using fluorescence in situ hybridization in the colon mucosa. Mechanistically, the fecal microbiota transplantation experiment showed that the gut microbiota from the PNMS group impaired the intestinal barrier function and induced low-grade inflammation. The fecal bacterial solution from the PNMS group was more potent than that from the control group in inducing inflammation and gut barrier disruption in CaCo-2 cells. After treatment with a TNF-α inhibitor (adalimumab), no statistical difference in the indicators of inflammation and intestinal barrier function was observed between the two groups. Finally, exposure to PNMS remarkably increased the values of the histopathological parameters and the inflammatory cytokine production in a mouse model of experimental colitis in adulthood. These findings suggest that PNMS can inhibit intestinal development, impair the barrier function, and cause gut dysbiosis characterized by the persistent overgrowth of Desulfovibrio in the offspring, resulting in exacerbated experimental colitis in adulthood.

Lactic acid, a metabolic by-product of host and intestinal microbiota, has been recovered as an active signal molecule in the immune system. In this study, a lactic acid biosynthesis pathway that directly produces lactic acid from glucose rather than ethanol with high production was reconstructed in Saccharomyces cerevisiae. The engineered S. cerevisiae showed anti-inflammatory activity in dextran sulfate sodium (DSS)-induced mice with improved histological damage, increased mucosal barrier, and decreased intestinal immune response. Lactic acid regulated the macrophage polarization state and inhibited the expression of pro-inflammatory cytokines in vivo and in vitro. Increasing the macrophage monocarboxylic acid transporter-mediated active lactic acid uptake suppressed the excessive activation of the NLRP3 inflammasome and the downstream caspase-1 pathway in macrophages. Moreover, lactic acid promoted histone H3K9 acetylation and histone H3K18 lactylation. Meanwhile, the engineered S. cerevisiae altered the diversity and composition of the intestinal microbiota and changed the abundance of metabolic products in mice with colitis. In conclusion, this study shows that the application of engineered S. cerevisiae attenuated DSS-induced colitis in mice via suppressing macrophage pyroptosis and modulating the intestinal microbiota, which is an effective and safe treatment strategy for ulcerative colitis.

High-fat diet (HFD) leads to long-term exposure to gut microbial metabolite secondary bile acids such as deoxycholic acid (DCA) in the intestine, which is closely linked to colorectal cancer (CRC). Evidence reveals that vasculogenic mimicry (VM) is a critical event for the malignant transformation of cancer. Therefore, we aimed to investigate the crucial roles of DCA on the regulation of VM and the progression of intestinal carcinogenesis. The effects of HFD on VM formation and epithelial-mesenchymal transition (EMT) in human CRC tissues were investigated. The fecal DCA level was detected in the HFD treated-Apcmin/+ mice. Then the effects of DCA on VM formation, EMT and vascular endothelial growth factor receptor 2 (VEGFR2) signaling were evaluated in vitro and in vivo. Here we demonstrated that compared with the normal diet, HFD exacerbated VM formation and EMT in CRC patients. HFD could alter the composition of the gut microbiota and significantly increase fecal DCA level in Apcmin/+ mice. More importantly, DCA promoted tumor cell proliferation and EMT, and increased VM formation accompanied by VEGFR2 activation, which led to intestinal carcinogenesis. In addition, DCA enhanced the proliferation and migration of HCT-116 cells, and induced EMT process and vitro tube formation. Furthermore, the silence of VEGFR2 blunted DCA-induced EMT, VM formation and migration. Collectively, our results indicated that microbial metabolite DCA promoted VM formation and EMT through VEGFR2 activation, which further exacerbated intestinal carcinogenesis.

Accumulating evidence from studies in humans and animal models has elucidated that gut microbiota, acting as a complex ecosystem, contributes critically to colorectal cancer (CRC). The potential mechanisms often reported emphasize the vital role of carcinogenic activities of specific pathogens, but in fact, a series of metabolites produced from exogenous dietary substrates or endogenous host compounds occupy a decisive position similarly. Detrimental gut microbiota-derived metabolites such as trimethylamine-N-oxide, secondary bile acids, hydrogen sulfide and N-nitroso compounds could reconstruct the ecological composition and metabolic activity of intestinal microorganisms and formulate a microenvironment that opens susceptibility to carcinogenic stimuli. They are implicated in the occurrence, progression and metastasis of CRC through different mechanisms, including inducing inflammation and DNA damage, activating tumorigenic signaling pathways and regulating tumor immunity. In this review, we mainly summarized the intimate relationship between detrimental gut microbiota-derived metabolites and CRC, and updated the current knowledge about detrimental metabolites in CRC pathogenesis. Then, multiple interventions targeting these metabolites for CRC management were critically reviewed, including diet modulation, probiotics/prebiotics, fecal microbiota transplantation, as well as more precise measures such as engineered bacteria, phage therapy and chemopreventive drugs. A better understanding of the interplay between detrimental microbial metabolites and CRC would hold great promise against CRC.

Recent studies have identified the critical role of microbiota in the pathophysiology of autoimmune liver diseases (AILDs), including autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC). Metagenomic studies reveal significant decrease of gut bacterial diversity in AILDs. Although profiles of metagenomic vary widely, Veillonella is commonly enriched in AIH, PBC, and PSC. Apart from gut microbiome, the oral and bile microbiome seem to be associated with these diseases as well. The functional analysis of metagenomics suggests that metabolic pathways changed in the gut microbiome of the patients. Microbial metabolites, including short-chain fatty acids (SCFAs) and microbial bile acid metabolites, have been shown to modulate innate immunity, adaptive immunity, and inflammation. Taken together, the evidence of host–microbiome interactions and in-depth mechanistic studies needs further accumulation, which will offer more possibilities to clarify the mechanisms of AILDs and provide potential molecular targets for the prevention and treatment in the future.

Inflammatory bowel disease (IBD) is a chronic, relapsing inflammatory disorder of the gastrointestinal tract, with increasing prevalence, and its pathogenesis remains unclear. Accumulating evidence suggested that gut microbiota and bile acids play pivotal roles in intestinal homeostasis and inflammation. Patients with IBD exhibit decreased microbial diversity and abnormal microbial composition marked by the depletion of phylum Firmicutes (including bacteria involved in bile acid metabolism) and the enrichment of phylum Proteobacteria. Dysbiosis leads to blocked bile acid transformation. Thus, the concentration of primary and conjugated bile acids is elevated at the expense of secondary bile acids in IBD. In turn, bile acids could modulate the microbial community. Gut dysbiosis and disturbed bile acids impair the gut barrier and immunity. Several therapies, such as diets, probiotics, prebiotics, engineered bacteria, fecal microbiota transplantation and ursodeoxycholic acid, may alleviate IBD by restoring gut microbiota and bile acids. Thus, the bile acid–gut microbiota axis is closely connected with IBD pathogenesis. Regulation of this axis may be a novel option for treating IBD.

Scope: Gut microbiome-derived metabolites are the major mediators of diet-induced host-microbial interactions. Aryl hydrocarbon receptor (AHR) plays a crucial role in glucose, lipid, and cholesterol metabolism in the liver. In this study, we aimed to investigate the role of indole-3-acetic acid (IAA) and AHR in sulforaphane (SFN) alleviates hepatic steatosis in mice fed on a high-fat diet (HFD).Methods and Results: The HFD-fed male C57BL/6 mice were intervened with SFN for 6 weeks. HFD-mice showed classical pathophysiological characteristics of hepatic steatosis. The results showed that SFN significantly reduced body weight, liver inflammation and hepatic steatosis in HFD-fed mice. SFN reduced hepatic lipogenesis by activating AHR/SREBP-1C pathway, which was confirmed in HepG2 cell experiments. Moreover, SFN increased hepatic antioxidant activity by modulating Nrf-2/NQO1 expression. SFN increased serum and liver IAA level in HFD mice. Notably, SFN manipulated the gut microbiota, resulting in reducing Deferribacteres and proportions of the phylum Firmicutes/Bacteroidetes and increasing the abundance of specific bacteria that produce IAA. Furthermore, SFN upregulated Ahr expression and decreased the expression of inflammatory cytokines in Raw264.7 cells.Conclusions: SFN ameliorated hepatic steatosis not only by modulating lipid metabolism via AHR/SREBP-1C pathway but regulating IAA and gut microbiota in HFD-induced NAFLD mice.

The prevalence of colorectal cancer (CRC) has markedly increased worldwide in the last decade. Alterations of bile acid metabolism and gut microbiota have been reported to play vital roles in intestinal carcinogenesis. About trillions of bacteria have inhabited in the human gut and maintained the balance of host metabolism. Bile acids are one of numerous metabolites that are synthesized in the liver and further metabolized by the gut microbiota, and are essential in maintaining the normal gut microbiota and lipid digestion. Multiple receptors such as FXR, GPBAR1, PXR, CAR and VDR act as sensors of bile acids have been reported. In this review, we mainly discussed interplay between bile acid metabolism and gut microbiota in intestinal carcinogenesis. We then summarized the critical role of bile acids receptors involving in CRC, and also addressed the rationale of multiple interventions for CRC management by regulating bile acids-microbiota axis such as probiotics, metformin, ursodeoxycholic acid and fecal microbiota transplantation. Thus, by targeting the bile acids-microbiota axis may provide novel therapeutic modalities in CRC prevention and treatment.

Background: Immunoglobulin G4-related disease (IgG4-RD) is an autoimmune inflammatory and fibrotic condition. The disease is characterized by tissue infiltration with dense lymphoplasmacytes and IgG4-positive plasma cells. Summary: The aim of this study was to provide gastroenterologists with novel insights into evaluating the gastroesophageal involvement with IgG4-RD or mimickers of this condition and to give special attention to clinicopathological features. A literature review was performed using the PubMed database. A total of 39 studies presenting cases in the form of isolated, typical, and nontypical gastroesophageal involvement with IgG4-RD published between 2010 and 2018 were included. These studies were thoroughly reviewed for symptoms, lesion location, lesion type, lesion size, immune-histopathology, associated diseases, treatment, and follow-up. Of the 39 studies reviewed, 9 were esophageal IgG4-RD lesions, isolated esophageal IgG4-RD 66.66% (6/9), a typical form of esophageal IgG4-RD 11.11% (1/9), and nontypical form esophageal IgG4-RD 22.22% (2/9). The 30 gastric IgG4-RD that include isolated gastric IgG4-RD 46.66% (14/30), typical gastric IgG4-RD 40% (12/30), and nontypical gastric IgG4-RD 13.33% (4/30). The majority of lesions were inflammatory tumors, ulceration, nodular lesions, chronic gastritis, and malignant lesions. Key Messages: IgG4-RD may be manifested by isolated, typical and nontypical forms of gastroesophageal lesions and should be taken into consideration in the differential diagnosis. Corticosteroids may be the sole diagnostic treatment for this condition.

The human gut is home to a large and diverse microbial community, comprising about 1,000 bacterial species. The gut microbiota exists in a symbiotic relationship with its host, playing a decisive role in the host's nutrition, immunity and metabolism. Accumulating studies have revealed the associations between gut dysbiosis or some special bacteria and various cancers. Emerging data suggest that gut microbiota can modulate the effectiveness of cancer therapies, especially immunotherapy. Manipulating the microbial populations with therapeutic intent has become a hot topic of cancer research, and the most dramatic manipulation of gut microbiota refers to fecal microbiota transplantation (FMT) from healthy individuals to patients. FMT has demonstrated remarkable clinical efficacy against Clostridium difficile infection (CDI) and it is highly recommended for the treatment of recurrent or refractory CDI. Lately, interest is growing in the therapeutic potential of FMT for other diseases, including cancers. We briefly reviewed the current researches about gut microbiota and its link to cancer, and then summarized the recent preclinical and clinical evidence to indicate the potential of FMT in cancer management as well as cancer-treatment associated complications. We also presented the rationale of FMT for cancer management such as reconstruction of intestinal microbiota, amelioration of bile acid metabolism, and modulation of immunotherapy efficacy. This article would help to better understand this new therapeutic approach for cancer patients by targeting gut microbiota.

Early life events can lead to multiple diseases in adulthood. Previous studies suggested that polysorbate 80 (P80) as a widely used emulsifier in pharmaceutical formulations and food industries could impair the intestinal barrier. However, whether maternal P80 (MP80) exposure could affect the long-term health of offspring remains unknown. In this study, we found that maternal P80 intake could retard intestinal development, disrupt the intestinal barrier, and cause low-grade intestinal inflammation in 3-week-old offspring. 16S rRNA sequencing and correlation analysis revealed that Mucispirillum, Clostridium XI, and Parabacteroides, which positively correlated with intestinal proliferation and differentiation, were decreased in the maternal P80 group. Interestingly, the increase in some harmful bacteria, including Proteobacteria, Helicobacteraceae, Campylobacterales, and Desulfovibrionales, persisted from the weaning period to adulthood (3 to 8 weeks). Furthermore, a fecal microbiota transplantation assay showed that the mice gavaged with feces from 3-week-old offspring of the MP80 group presented more severe intestinal inflammation and barrier disruption than the mice that received feces from the offspring of the control group. Finally, maternal P80 intake remarkably aggravated the structural disorder of intestinal crypt, increased proinflammatory factors, and exacerbated dextran sulfate sodium (DSS)-induced colitis in adulthood. Conclusively, maternal P80 intake could induce gut dysbiosis and promote colitis susceptibility in adulthood. This study provides new insights into the prevention of inflammatory bowel disease (IBD). IMPORTANCE The main findings of this research showed that maternal P80 intake could disrupt the intestinal barrier, induce gut dysbiosis, and promote colitis susceptibility in adulthood. This study will enhance understanding of the prevention of IBD.

Background. Patients with prolonged inflammatory bowel disease (IBD) can develop into colorectal cancer (CRC), also called colitis-associated cancer (CAC). Studies have shown the association between gut dysbiosis, abnormal bile acid metabolism, and inflammation process. Here, we aimed to investigate these two factors in the CAC model. Methods. C57BL/6 mice were randomly allocated to two groups: azoxymethane/dextran sodium sulfate (AOM/DSS) and control. The AOM/DSS group received AOM injection followed by DSS drinking water. Intestinal inflammation, mucosal barrier, and bile acid receptors were determined by real-time PCR and immunohistochemistry. Fecal microbiome and bile acids were detected via 16S rRNA sequencing and liquid chromatography-mass spectrometry. Results. The AOM/DSS group exhibited severe mucosal barrier impairment, inflammatory response, and tumor formation. In the CAC model, the richness and biodiversity of gut microbiota were decreased, along with significant alteration of composition. The abundance of pathogens was increased, while the short-chain fatty acids producing bacteria were reduced. Interestingly, Clostridium XlV and Lactobacillus, which might be involved in the bile acid deconjugation, transformation, and desulfation, were significantly decreased. Accordingly, fecal bile acids were decreased, accompanied by reduced transformation of primary to secondary bile acids. Given bile acid receptors, the ileum farnesoid X receptor-fibroblast growth factor 15 (FXR-FGF15) axis was downregulated, while Takeda G-protein receptor 5 (TGR5) was overexpressed in colonic tumor tissues. Conclusion. Gut dysbiosis might alter the metabolism of bile acids and promote CAC, which would provide a potential preventive strategy of CAC by regulating gut microbiota and bile acid metabolism.

Background: Most gastric cancer (GC) patients are diagnosed at an advanced stage, which indicates their poor prognosis. We aimed to investigate novel fecal microbial markers for clinical application in the screening and early diagnosis of gastric cancer (GC). Methods: This is an observational study from three cohorts. In discovery cohort, 16S rRNA gene analysis was performed in paired samples (gastric tissues, feces) from GC and CG patients to determine differential microbes. The relative abundances of the differential microbes were detected using qPCR in training cohort. The diagnostic efficacy of fecal marker Sa/Sc was validated in validation cohort. Findings: 575 gastric cancer (GC) patients, 468 chronic gastritis (CG) patients were enrolled from ten hospitals in China. Significant enrichments of Streptococcus anginosus (Sa) and Streptococcus constellatus (Sc) in both cancerous tissues (P < 0·05) and feces ( P < 0·0001) were observed in patients with intraepithelial neoplasia, early and advanced GC. Either the marker parallel test Sa ∪ Sc or single marker Sa/Sc demonstrated superior sensitivity (Sa: 75·6% vs. 72·1%, P

Autoimmune hepatitis (AIH) is an immune-mediated inflammatory liver disease of uncertain cause. Accumulating evidence shows that gut microbiota and intestinal barrier play significant roles in AIH thus the gut–liver axis has important clinical significance as a potential therapeutic target. In the present study, we found that Bifidobacterium animalis ssp. lactis 420 (B420) significantly alleviated S100-induced experimental autoimmune hepatitis (EAH) and modulated the gut microbiota composition. While the analysis of clinical specimens revealed that the fecal SCFA quantities were decreased in AIH patients, and B420 increased the cecal SCFA quantities in EAH mice. Remarkably, B420 application improved intestinal barrier function through upregulation of tight junction proteins in both vitro and vivo experiments. Moreover, B420 decreased the serum endotoxin level and suppressed the RIP3 signaling pathway of liver macrophages in EAH mice thus regulated the proliferation of Th17 cells. Nevertheless, the inhibition effect of B420 on RIP3 signaling pathway was blunted in vitro studies. Together, our results showed that early intervention with B420 contributed to improve the liver immune homeostasis and liver injury in EAH mice, which might be partly due to the protection of intestinal barrier. Our study suggested the potential efficacy of probiotics application against AIH and the promising therapeutic strategies targeting gut–liver axis for AIH.

Background Osteoporosis is one of the most closely related diseases associated with the elderly. In recent years, the studies found that gut microbiota can cause osteoporosis. We evaluated the role of Bacillus acidophilus in osteoporosis and its roles in proliferation and differentiation. Methods We selected 5 healthy people and 10 osteoporosis patients and analyzed their level of 25‐hydroxyvitamin D and procollagen type I N‐terminal peptide (PINP), the characteristic of gut microbiota. The effect of lactobacillus acidophilus and Lactobacillus rhamnosus supernatant and butanoic acids on proliferation, differentiation, and maturity of osteoblasts MC3T3‐E1 and osteoclasts RAW 264.7 cells and the activity of alkaline phosphatase, concentration of osteocalcin, and the expression of RUNX2, RANK, NFATc1, cathepsin K, DC‐STAMP, OSCAR, WNT2, and CTNNB1 were measured in the above cell lines. Results The diversity of gut microbiota in osteoporosis patients is decreased and imbalanced with lower abundance of lactobacillus and butyric acid bacteria; meanwhile, 25‐hydroxyvitamin D and PINP of osteoporosis patient were significantly lower than the normal group. The proliferation, differentiation, and maturity of MC3T3‐E1 cells were stimulated; the activity of alkaline phosphatase, concentration of osteocalcin, and the expression of RUNX2, NFATc1, cathepsin K, DC‐STAMP, OSCAR, WNT2, and CTNNB1 were improved by supernatant of lactobacillus acidophilus, Lactobacillus rhamnosus and butanoic acids; however, the proliferation, differentiation, maturity, and the expression of RANK, NFATc1, cathepsin K, DC‐STAMP, OSCAR, WNT2, and CTNNB1 in RAW 264.7 cells were suppressed. Conclusions The lactobacillus acidophilus and Lactobacillus rhamnosus supernatant could stimulate the proliferation, differentiation, and maturation of osteoblasts; the production of butyric acid may be the potential mechanism., The diversity of gut microbiota is decreased and imbalance with lower abundance of lactobacillus and butyric acid bacteria in osteoporosis patients. The gut microbiota regulate the proliferation, differentiation, and maturation of osteoblasts, and the production of butyric acid may be the potential mechanism.

Non-alcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease throughout the world. The relationship between gut microbiota and NAFLD has been extensively investigated. The gut microbiota is involved in the regulation of NAFLD by participating in the fermentation of indigestible food, interacting with the intestinal mucosal immune system, and influencing the intestinal barrier function, leading to signaling alteration. Meanwhile, the microbial metabolites not only affect the signal transduction pathway in the gut but also reach the liver far away from gut. In this review, we focus on the effects of certain key microbial metabolites such as short-chain fatty acids, trimethylamine-N-oxide, bile acids, and endogenous ethanol and indole in NAFLD, and also summarize several potential therapies targeting the gut-liver axis and modulation of gut microbiota metabolites including antibiotics, prebiotics, probiotics, bile acid regulation, and fecal microbiota transplantation. Understanding the complex interactions between microbial metabolites and NAFLD may provide crucial insight into the pathogenesis and treatment of NAFLD.

The development of next-generation sequencing technology has enabled researchers to explore and understand the gut microbiome from a broader and deeper perspective. However, the results of different studies on gut microbiota are highly variable even in the same disease, which makes it difficult to guide clinical diagnosis and treatment. The ideal sampling method should be non-invasive, involve little cross-contamination or bowel preparation, and collect gut microbiota at different sites. Currently, sequencing technologies are usually based on samples collected from feces, mucosal biopsy, intestinal fluid, etc. However, different parts of the gastrointestinal tract possess various physiological characteristics that are essential for particular species of living microbiota. Moreover, current sampling methods are somewhat defective. For example, fecal samples are just a proxy for intestinal microbiota, while biopsies are invasive for patients and not suitable for healthy controls. In this review, we summarize the current sampling methods and their advantages and shortcomings. New sampling technologies, such as the Brisbane Aseptic Biopsy Device and the intelligent capsule, are also mentioned to inspire the development of future precise description methods of the gut microbiome.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is considered to be associated with diet and gut dysbiosis. Excessive sucralose can induce gut dysbiosis and negatively affect host health. Maternal diet shapes the microbial communities of neonate and this effect continues in later life. We aimed to investigate the effects of maternal sucralose (MS) intake on the susceptibility of offspring to hepatic steatosis in adulthood. METHODS: C57BL/6 pregnant mice were randomized into MS group (MS during gestation and lactation) and maternal control (MC) group (MC diet). After weaning, all offspring were fed a control diet until 8 weeks of age, and then treated with a high-fat diet (HFD) for 4 weeks. The intestinal development, mucosal barrier function, and gut microbiota were assessed in the 3-week-old offspring. Moreover, the severity of hepatic steatosis, serum biochemistry, lipid metabolism, and gut microbiota was then assessed in the 12th week. RESULTS: MS significantly inhibited intestinal development and disrupted barrier function in 3-week-old offspring. MS also induced intestinal low-grade inflammation, significantly changed the compositions and diversity of gut microbiota including reducing butyrate-producing bacteria and cecal butyrate production with down-regulation of GPR43. Mechanically, blocking GPR43 blunted the anti-inflammatory effect of one of the butyrate-producing bacteria, Clostridium butyricum in vitro. After HFD treatment, MS exacerbated hepatic steatosis, and disturbed fatty acid biosynthesis and metabolism, accompanied by inducing gut dysbiosis compared with MC group. CONCLUSIONS: MS intake inhibits intestinal development, induces gut dysbiosis in offspring through down-regulation of GPR43, and exacerbates HFD-induced hepatic steatosis in adulthood.

Genipin is an aglycone derived from the geniposide, the most abundant iridoid glucoside constituent of Gardenia jasminoides Ellis. For decades, genipin is the focus of studies as a versatile compound in the treatment of various pathogenic conditions. In particularly, Gardenia jasminoides Ellis has long been used in traditional Chinese medicine for the prevention and treatment of liver disease. Mounting experimental data has proved genipin possesses therapeutic potential for cholestatic, septic, ischemia/reperfusion-triggered acute liver injury, fulminant hepatitis and NAFLD. This critical review is a reflection on the valuable lessons from decades of research regarding pharmacological activities of genipin. Of note, genipin represents choleretic effect by potentiating bilirubin disposal and enhancement of genes in charge of the efflux of a number of organic anions. The anti-inflammatory capability of genipin is mediated by suppression of the production and function of pro-inflammatory cytokines and inflammasome. Moreover, genipin modulates various transcription factor and signal transduction pathway. Genipin appears to trigger the upregulation of several key genes encoding antioxidant and xenobiotic-metabolizing enzymes. Furthermore, the medicinal impact of genipin extends to modulation of regulated cell death, including autophagic cell death, apoptosis, necroptosis and pyroptosis, and modulation of quality of cellular organelle. Another crucial effect of genipin appears to be linked to dual role in targeting uncoupling protein 2 (UCP2). As a typical UCP2-inhibiting compound, genipin could inhibit AMP-activated protein kinase or NF-κB in circumstance. On the contrary, reactive oxygen species production and cellular lipid deposits mediated by genipin through the upregulation of UCP2 is observed in liver steatosis, suggesting the precise role of genipin is disease-specific. Collectively, we comprehensively summarize the mechanisms and pathways associated with the hepatoprotective activity of genipin and discuss potential toxic impact. Notably, our focus is the direct medicinal effect of genipin itself, whereas its utility as a crosslinking agent in tissue engineering is out of scope for the current review. Further studies are therefore required to disentangle these complicated pharmacological properties to confer this natural agent a far greater potency.

Background Accumulating evidence points to a close relationship between gut dysbiosis and colorectal cancer (CRC). As >90% of CRC develop from adenoma, we aimed to investigate the crucial role of imbalanced gut microbiota on the progression of intestinal adenoma. Methods The Apcmin/+ mice gavage with phosphate-buffered saline (PBS), feces from healthy controls or CRC patients after antibiotic cocktails. The intestinal tissues were isolated for histopathology, western blotting, and RNA-seq. The microbiota of feces and short-chain fatty acids (SCFAs) were analysed by 16S rDNA Amplicon Sequencing and gas chromatography. Findings The Apcmin/+mice gavaged by feces from CRC patients had more intestinal tumours compared with those fed with feces from healthy controls or PBS. Administration of feces from CRC patients increased tumour proliferation and decreased apoptosis in tumour cells, accompanied by impairment of gut barrier function and up-regulation the pro-inflammatory cytokines profile. The up-regulated the expression of β-catenin and cyclinD1 further indicating the activation of Wnt signalling pathway. The abundance of pathogenic bacteria was increased after FMT, while producing SCFAs bacteria and SCFAs production were decreased. Interpretation Gut microbiota of CRC patients disrupted intestinal barrier, induced low-grade inflammation and dysbiosis. The altered gut microbiota enhanced the progression of intestinal adenomas in Apcmin/+mice, suggesting that a new strategy to target gut microbiota against CRC could be noted. Fund The study was supported by the National Natural Science Foundation of China, Tianjin Research Programme of Application Foundation and Advanced Technology of China, and China Postdoctoral Science Foundation.

Background and Purpose: The role of the cartilage oligomeric matrix protein (COMP) in epithelial-mesenchymal transition (EMT) in tumor progression has been studied, but its exact regulatory mechanism remains unknown. Methods: The interaction between COMP and the actin-binding protein transgelin (TAGLN) was identified by interaction protein prediction and co-immunoprecipitation and verified through the stochastic optical reconstruction microscopy (STORM) and duolink experiments. Western blot and immunofluorescence analyses were conducted to detect the changes in EMT-related markers after COMP overexpression and knockdown. Molecular docking and Biacore of the interaction interface of COMP/TAGLN revealed that Chrysin directly targeted COMP. The promotion of COMP and the Chrysin inhibition of EMT were detected through the cell migration, invasion, apoptosis, and xenotransplantation of nude mice. Results: COMP interacts with TAGLN in EMT in colorectal cancer to regulate cytoskeletal remodeling and promote malignant progression. COMP is highly expressed in highly malignant colorectal cancer and positively correlated with TAGLN expression. COMP knockdown can inhibit colorectal cancer metastasis and invasion, whereas COMP overexpression promotes EMT in colorectal cancer. Through virtual screening of the protein interaction interface, Chrysin, a flavonoid compound extracted from Oroxylum indicum, was found to have the highest docking score to the COMP/TAGLN complex. Chrysin inhibited COMP, thereby preventing EMT and the malignant progression of colorectal cancer. Conclusions: This study illustrated the role of COMP in EMT and suggested that COMP/TAGLN may be a potential tumor therapeutic target. Chrysin exhibits obvious antitumor effects. This work provides a preliminary antitumor therapy to target COMP or its interaction protein to inhibit EMT.

Background: Excessive and uncontrolled immune activation plays a deleterious role in liver damage of autoimmune hepatitis (AIH), thus, it`s of great significance to identify the regulation of immune tolerance. Receptor-interacting protein kinase 3 (RIP3) has been found to be down-regulated in tumor tissues and mediates tumor immune evasion. However, the role of RIP3 in AIH remains elusive. We aimed to investigate the role of RIP3 in the regulation of inflammation and immune tolerance in immune-mediated hepatitis (IMH). Methods: RIP3 expression was evaluated in the livers of AIH patients and mice models. Mice were treated with GSK872, a RIP3 specific inhibitor, or glucocorticoid dexamethasone before concanavalin A (ConA)-induced IMH. Real-time PCR, western blotting, and flow cytometry served to explore the molecular mechanisms involved. The depleting anti-mouse Gr-1 antibody and isotype control were used for further determine the role of MDSCs in GSK872 treatment. Findings: AIH patients and mice model displayed pronounced RIP3 activation in the liver tissues. RIP3 blockade by GSK872 prevented ConA-induced IMH by reduced hepatic proinflammatory cytokines and immune cells including Th17 cells and macrophages. Further experiments revealed that RIP3 inhibition resulted in an increase in CD11b+ Gr-1+ MDSCs with immunoregulatory properties in the livers, spleen, and peripheral blood. Moreover, the depletion of Gr-1+ MDSCs abrogated the protective effect and immune suppression function of GSK872 in ConA-induced IMH. Interpretation: RIP3 blockade prevents ConA-induced IMH through a MDSC-dependent mechanism. Inhibition of RIP3 kinase may be a novel therapeutic avenue for AIH treatment. Funding Statement: The study was supported by the National Natural Science Foundation of China (81860109). Declaration of Interests: The authors declare no conflicts of interest. Ethics Approval Statement: This study was approved by the Ethics Committee of Tianjin Medical University General Hospital, and all participants provided signed informed consents. The animal use protocol has been reviewed and approved by the Animal Ethical and Welfare Committee of Tianjin Medical University, Approval No. IRB2020-WZ-175.

Background. The enlargement of lymph nodes is a common clinical sign in connective tissue disease (CTD) and viral hepatitis. In this research, we evaluated the incidence of enlarged lymph nodes in autoimmune liver diseases (AILD). Moreover, we identified the clinical significance of abdominal lymph node enlargement in AILD. Methods. The characteristics of abdominal lymph nodes, including their morphology and distribution, were assessed by ultrasonography and computed tomography in 125 patients with AILD, 54 with viral hepatitis, 135 with CTD, and 80 healthy controls. The pathological and laboratory results of 106 AILD patients were collected to analyze the association between lymphadenectasis and disease activity. Results. Enlargement of abdominal lymph nodes was found in 69.6% of patients with AILD, 63% of patients with viral hepatitis, 29.6% of patients with CTD, and 2% of healthy controls. Alkaline phosphatase (ALP), glutamate transpeptidase (GGT), and immunoglobulin M (IgM) levels were significantly increased in AILD patients with lymphadenectasis (LA) in contrast to patients without lymphadenectasis (NLA) (P<0.05). The pathological characteristics of inflammation, cholestasis, and focal necrosis were more common in the LA group than in the NLA group (P<0.05). As shown by multivariate logistic regression analysis, interface hepatitis (OR=3.651, P<0.05), cholestasis (OR=8.137, P<0.05), and focal necrosis (OR=5.212, P<0.05) were related to LA. Conclusions. The percentage of abdominal lymph node enlargement in AILD subjects was significantly higher than that in CTD subjects. Therefore, the enlargement of lymph nodes can represent a noninvasive indicator of histological and biochemical inflammation activity in AILD.

PurposeColorectal cancer (CRC) is one of the common causes of cancer death worldwide. Obstructive sleep apnea syndrome (OSAS), sharing many risk factors in common with CRC, is prevalent among CRC patients. OSAS may promote the CRC development independently but the mechanism is still unknown. Intermittent hypoxia (IH) is one of the characteristics of OSAS, and hypoxia may influence the genes associated with CRC. Intestinal microbiota plays important role in CRC carcinogenesis, and OSAS patients have been shown to have intestinal microbiota dysbiosis. We hypothesized that IH and intestinal microbiota dysbiosis may be involved for CRC in patients with OSAS.MethodsWe established precancerous cell models of CRC with Immorto-Min colonic epithelial (IMCE) cells. First, the cells were exposed to IH in a special chamber for 4 h, 8 h, and 12 h. Feces from 6 patients with OSAS and 6 healthy controls were collected and made into sterile fecal fluid for incubation with IMCE cells for 12 h. The cells were then exposed to IH for 4 h, 8 h, and 12 h. After IH exposure, the expressions of genes and inflammation cytokines associated with CRC, such as β-catenin, STAT3, HIF-1α, IL-6, TNF-α, c-myc, and cyclinD1, were tested.ResultsIH activated the expression of HIF-1α and STAT3 both in mRNA and protein level (HIF-1α:P= 0.015 for mRNA level,P= 0.027 for protein level; STAT3:P= 0.023 for mRNA level,P= 0.023 for protein level), and promoted p-STAT3 shifting to the nucleus (P= 0.023). The mRNA of β-catenin (P= 0.022) and cyclinD1 (P= 0.023) was elevated, but there was no change for the β-catenin protein in the nucleus. Gut microbiota of OSAS patients promoted the expression of STAT3 (protein level: 0 h:P= 0.037; 4 h:P= 0.046; 8 h:P= 0.049; 12 h:P= 0.037), promoted p-STAT3 (4 h:P =0.049; 8 h:P =0.046; 12 h:P =0.046) shifting to the nucleus, and also elevated the expression of IL-6 and TNF-α in mRNA level at 4 h (IL-6:P= 0.037, TNF-α:P= 0.037) and 8 h (IL-6:P= 0.037, TNF-α:P= 0.037). The protein of β-catenin in the nucleus was not affected by IH and gut microbiota from OSAS.ConclusionsOur study demonstrated that IH and gut microbiota of patients with OSAS activated HIF-1α expression and STAT3 pathway in IMCE cells, with no influence on β-catenin pathway, which suggested that IH, STAT3 pathway, chronic inflammation, and intestinal microbiota dysbiosis may be involved in CRC carcinogenesis correlated with OSAS These findings must be interpreted cautiously and further research is necessary to clarify the causative steps in CRC development.

Effect of Lactobacillus rhamnosus GG supernatant on serotonin transporter expression in rats with post-infectious irritable bowel syndrome

The human body harbors a vast array of microbiota that modulates host pathophysiological processes and modifies the risk of diseases including cancer. With the advent of metagenomic sequencing studies, the intratumoural microbiota has been found as a component of the tumor microenvironment, imperceptibly affecting the tumor progression and response to current antitumor treatments. The underlying carcinogenic mechanisms of intratumoural microbiota, mainly including inducing DNA damages, activating oncogenic signaling pathways and suppressing the immune response, differ significantly in varied organs and are not fully understood. Some native or genetically engineered microbial species can specifically accumulate and replicate within tumors to initiate antitumor immunity, which will be conducive to pursue precise cancer therapies. In this review, we summarized the community characteristics and therapeutic potential of intratumoural microbiota across diverse tumor types. It may provide new insights for a better understanding of tumor biology and hint at the significance of manipulating intratumoural microbiota.

BACKGROUND Berberine, a herbal extract, has been reported to protect against inflammatory disorders. The adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) signaling pathway can be activated by berberine and inhibited by the synthetic, reversible AMP-competitive inhibitor, Compound C. The aim of this study was to investigate the effects of berberine on concanavalin A (Con A)-induced autoimmune hepatitis (AIH) in mice via the AMPK pathway. MATERIAL AND METHODS BALB/c mice were treated with berberine, with or without Compound C, followed by treatment with Con A. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured. Liver tissue histology was performed to evaluate hepatic injury and AIH. Cytokine levels in serum and hepatic tissue were measured by enzyme-linked immunoassay (ELISA) and used quantitative polymerase chain reaction (qPCR). Levels of phosphorylated acetyl coenzyme-A carboxylase (ACC), representing AMPK activation, were detected by Western blotting. RESULTS Serum ALT and AST levels were significantly reduced by berberine (100 and 200 mg/kg/day) in mice with Con A-induced hepatitis. Berberine also reduced Con A-induced hepatocyte swelling, cell death, and infiltration of leukocytes. Serum levels of tumor necrosis factor (TNF)-alpha, interferon (IF)-gamma, interleukin (IL)-2, and IL-1beta were reduced by berberine pre-treatment; levels of serum IL-10, an anti-inflammatory cytokine, was elevated. These protective effects of berberine on Con-A-induced AIH were reversed by treatment with Compound C. CONCLUSIONS In a murine model of Con A-induced AIH, berberine treatment reduced hepatic injury via activation of the AMPK pathway. Further studies are recommended to determine the potential therapeutic role for berberine in AIH.

Chronic constipation is a prevalent functional gastrointestinal disorder accompanied with intestinal dysbiosis. However, causal relationship between dysbiosis and constipation remains poorly understood. Serotonin transporter (SERT) is a transmembrane transport protein which re-uptakes excessive 5-hydroxytryptamine (5-HT) from effective location to terminate its physiological effects and involves in regulating gastrointestinal motility. In this study, fecal microbiota from patients with constipation and healthy controls were transplanted into the antibiotic depletion mice model. The mice which received fecal microbiota from patients with constipation presented a reducing in intestinal peristalsis and abnormal defecation parameters including the frequency of pellet expulsion, fecal weight and fecal water content. After fecal microbiota transplantation, the SERT expression in the colonic tissue was significantly upregulated, and the content of 5-HT was decreased which negatively correlated with the gastrointestinal transit time. Moverover, fecal microbiota from the mice which received fecal microbiota from patients with constipation also upregulated SERT in Caco-2 cells. Besides, this process accompanied with the decreased abundance of Clostridium, Lactobacillus, Desulfovibrio, and Methylobacterium and an increased tend of Bacteroides and Akkermansia, which also involved in the impairment of intestinal barrier after FMT. Taken together, intestinal dysbiosis may upregulate the SERT expression and contribute to the development of chronic constipation.

The gut microbiota plays an important role in maintaining intestinal homeostasis. Dysbiosis is associated with intestinal tumorigenesis. Deoxycholic acid (DCA), a secondary bile acid increased by a western diet, correlates with intestinal carcinogenesis. However, evidence relating bile acids, intestinal microbiota and tumorigenesis are limited. In our study, we investigated the effect of DCA on induction of intestinal dysbiosis and its roles in intestinal carcinogenesis. Alteration of the composition of the intestinal microbiota was induced in DCA-treated APCmin/+ mice, which was accompanied by impaired intestinal barrier, gut low grade inflammation and tumor progression. The transfer of fecal microbiota from DCA-treated mice to another group of Apcmin/+ mice increased tumor multiplicity, induced inflammation and recruited M2 phenotype tumor-associated macrophages. Importantly, the fecal microbiota transplantation activated the tumor-associated Wnt/β-catenin signaling pathway. Moreover, microbiota depletion by a cocktail of antibiotics was sufficient to block DCA-induced intestinal carcinogenesis, further suggesting the role of dysbiosis in tumor development. Our study demonstrated that alteration of the microbial community induced by DCA promoted intestinal carcinogenesis.

Inflammatory bowel disease (IBD) is an idiopathic inflammatory disease characterized by chronic and relapsing manifestations. It is noteworthy that the prevalence of IBD is gradually increasing in both children and adults. Currently, the pathogenesis of IBD remains to be completely elucidated. IBD is believed to occur through interactions among genetics, environmental factors, and the gut microbiota. However, the relapsing and remitting course of IBD underlines the importance of other modifiers, such as psychological stress. Growing evidence from clinical and experimental studies suggests that stress acts as a promoting or relapsing factor for IBD. Importantly, recent studies have reported an increasing incidence of anxiety or depression in both children and adults with IBD. In this article, we review the mechanisms by which stress affects IBD, such as via impaired intestinal barrier function, disturbance of the gut microbiota, intestinal dysmotility, and immune and neuroendocrine dysfunction. With regard to both children and adults, we provide recent evidence to describe how stress can affect IBD at various stages. Furthermore, we emphasize the importance of mental healing and discuss the value of approaches targeting stress in clinical management to develop enhanced strategies for the prevention and treatment of IBD.

The human gut is inhabited by diverse microorganisms that play crucial roles in health and disease. Gut microbiota dysbiosis is increasingly considered as a vital factor in the etiopathogenesis of irritable bowel syndrome (IBS), which is a common functional gastrointestinal disorder with a high incidence all over the world. However, investigations to date are primarily directed to the bacterial community, and the gut mycobiome, another fundamental part of gut ecosystem, has been underestimated. Intestinal fungi have important effects on maintaining gut homeostasis just as bacterial species. In the present article, we reviewed the potential roles of gut mycobiome in the pathogenesis of IBS and the connections between the fungi and existing mechanisms such as chronic low-grade inflammation, visceral hypersensitivity, and brain-gut interactions. Moreover, possible strategies targeted at the gut mycobiome for managing IBS were also described. This review provides a basis for considering the role of the mycobiome in IBS and offers novel treatment strategies for IBS patients; moreover, it adds new dimensions to researches on microorganism.

Background Lactobacillus rhamnosus GG (LGG) has been reported to improve bowel function in constipation patients. However, the effects and mechanism of LGG on bowel function remains unclear. 5-Hydroxytryptamine4 Receptor is a critical receptor relating to the intestine motility and secretion function. In this study, we aimed to investigate whether LGG could improve the defecation function via upregulating 5-HT4R and modulating gut microbiota in mice. Methods Male C57BL/6 mice 6–8 weeks in age were randomly divided into 3 groups: MRS group (n=10), Tegaserod group (positive control, n=15) and LGG group (n=15), and MRS broth, tegasromide maleate andLGG supernatant were gavaged respectively for 7 days. YAMC cells and Caco2 cells were used for experiment in vitro. Defecation parameter including the number of pellets in 2 hours, fecal weight, fecal dry weight, fecal water content, and the gastrointestinal transit time (GITT) were detected. PAS and AB-PAS staining were used to evaluate goblet cells number in mice colon, and 5-HT4R and MUC2 expression were determined Real-time PCR and Western blotting in vivo and in vitro. Gut microbiota and short-chain fatty acid were analyzed by 16 sRNA pyrosequencing analysis and gas chromatography method. Results The number of defecation pellets in 2 h, fecal weight, fecal dry weight and fecal water content in the Tegasromide group and LGG group were significantly increased compared with those in the MRS group, PAS staining showed that the average number of goblet cells in Tegasromide group and LGG group were significantly increased in mice colon sections compared with MRS group. AB-PAS showed increased cavitated goblet cells in the LGG group, and the mRNA and protein levels of 5-HT4R and MUC2 were upregulated both In vitro and in vivo. In this study, increased levels of Alistipes, Allobaculum, and Desulfovibrioin were found in the LGG group which have been reported to be involved in intestine motility, intestinal barrier. Conclusions LGG supernatant could improve defecation function in mice accompanied by upregulating 5-HT4R and MUC2 production, and modulating gut microbiota. Thus, this study will provide a better understanding of probiotics for the prevention and treatment of constipation.

Background High-fat diet (HFD) is an important risk factor for colorectal cancer (CRC). However, the mechanisms remain to be clarified. The potential pathway MCP-1/CCR2 activation can recruit and polarize M2 tumor-associated macrophages(TAMs). Here we aimed to investigate the effects and mechanisms of HFD on the gut microbiota and intestinal tumor development. Methods A retrospective cohort study was performed to investigate HFD in relation to advanced colorectal neoplasia (AN). 15 CRC patients from each group for IHC staining were selected to evaluate MCP-1/CCR2 expression. Four-week-old Apcmin/+ mice were randomly divided into HFD group and control group. Intestinal tumor development, cell proliferation and apoptosis, inflammation and MCP-1/CCR2 pathway were determined. Intestinal M2 TAMs were measured by immunofluorescence double staining. Fecal pellets were collected for microbiota and short-chain fatty acids (SCFA) analysis. Antibiotics cocktail was administered with HFD to investigate the effect of crosstalk between the HFD and gut microbiota. Fecal microbiota transplantation (FMT) was used in another batch of Apcmin/+mice to determine the causality between HFD-induced dysbiosis and carcinogenesis. Results Participants with HFD were more likely to develop AN, especially invasive carcinoma. The expression of MCP-1/CCR2 and CD163 in CRC patients with HFD was significantly higher. In the Apcmin/+ mice, the total number of intestinal adenoma of HFD group was significantly increased. Pathological analysis confirmed intestinal carcinogenesis in small intestine and colon in HFD group, while there were only adenomas in the control group. This was accompanied by promoting tumor cell proliferation and decreasing apoptosis. Moreover, HFD administration altered gut microbiota, with increased opportunistic pathogens and decreased SCFA producing bacteria. The dysbiosis up-regulated the expression of MCP-1 and CCR2. And an increased M2 TAMs was observed in HFD group. And the effects of intestinal carcinogenesis can be restored by antibiotics cocktail. The transfer of fecal microbiota from HFD-fed mice also increased the tumor multiplicity and promoted carcinogenesis, while the MCP-1/CCR2 axis was also activated. Conclusions HFD-induced dysbiosis promoted the intestinal carcinogenesis through activating the MCP-1/CCR2 axis.

Background. Splenectomy can improve liver function and survival in patients with autoimmune hepatitis (AIH) and liver cirrhosis. We investigated the underlying mechanism in a mouse model of concanavalin A- (ConA-) induced liver fibrosis. Methods. We used ConA to induce immune liver fibrosis in BALB/c mice. Splenectomy was performed alone or with the administration of dexamethasone (DEX). Changes in blood and liver tissues were evaluated. Results. Mice treated with ConA for 7 weeks developed advanced liver fibrosis, while splenectomy suppressed liver fibrosis. Although the populations of macrophages/monocytes and M1 macrophages decreased after splenectomy, the inflammatory factors associated with M2 macrophages increased after splenectomy. Furthermore, the population of circulating CD11b+Ly6Chigh myeloid-derived suppressor cells (MDSCs) increased after splenectomy. After ConA treatment, elevated levels of activated and total NF-kBp65/p50 combined with DNA were observed in hepatic tissues. In contrast, the levels of NF-κB p65/p50 decreased after splenectomy. Conclusions. Splenectomy may promote the polarization of CD11b+Ly6Chigh MDSCs and the differentiation of M2 macrophages while restricting the level of NF-κB p65-p50 heterodimers. These factors may suppress the progression of liver fibrosis.

Background: Gut microbiota dysbiosis is closely involved in intestinal carcinogenesis. A marked reduction of butyrate-producing bacteria has been reported in patients with colorectal cancer (CRC), nevertheless, the potential benefit of supplement of butyrate-producing bacteria against intestinal tumor development has not been fully investigated. Methods: The effects of Clostridium butyricum (C. butyricum, one of the clinically commonly used butyrate-producing bacteria) on CRC cells were examined. Apcmin/+ mice were fed a basal diet (BD) or high-fat diet (HFD) with or without C. butyricum (2×109 CFU 3-times a week) by gavage for 12 weeks. Human colonic tissues were collected to evaluate butyric acid recognition receptors, namely G-protein coupled receptors (GPRs) in relation to CRC. Findings: C. butyricum significantly inhibited HFD-induced intestinal tumor development in Apcmin/+ mice. Moreover, decreased proliferation and increased apoptosis were found in intestinal tumor cells treated with C. butyricum. Additionally, C. butyricum suppressed Wnt/β-catenin signaling pathway. C. butyricum modulated gut microbiota composition, which decreased some pathogenic bacteria and bile acids (BAs)-biotransforming bacteria, and increased some beneficial bacteria including short-chain fatty acids (SCFAs)-producing bacteria as shown by Illumina 16S rRNA sequencing. Accordingly, C. butyricum decreased fecal secondary BAs contents, increased caecal SCFAs quantities, and activated butyric acid recognition receptors, GPR43 and GPR109A. Clinically, we also observed that the expression of GPR43 and GPR109A was gradually down-regulated from human normal colonic tissue, adenoma, to carcinoma. Interpretation: Our results showed that C. butyricum could inhibit intestinal tumor development via modulating Wnt signaling and gut microbiota, suggesting the potential efficacy of butyrate-producing bacteria against CRC. Funding Statement: This study is supported by the grants (81570478, 81741075, and 81700456) from the National Natural Science Foundation of China, the grant (17JCYBJC24900) from Natural Science Foundation of Tianjin, the grant (2019M651049) from Postdoctoral Science Foundation of China, and the grant (2018242755) from Medical and Health Science and Technology Project of Zhejiang. Declaration of Interests: The authors declare no conflicts interest. Ethics Approval Statement: The written informed consents were obtained from all individuals prior to participation, and the study was approved by the Ethics Committee of General Hospital, Tianjin Medical University, China.

Background: Accumulating evidence points to a close relationship between gut dysbiosis and colorectal cancer (CRC). As more than 90% of CRC develop from adenoma, we aimed to investigate the crucial role of imbalanced gut microbiota on the progression of intestinal adenoma. Methods: The Apcmin/+ mice gavage with phosphate-buffered saline (PBS), feces from healthy controls or CRC patients after antibiotic cocktails. The intestinal tissues were isolated for histopathology, western blotting, and RNA-seq. The microbiota of feces and short-chain fatty acids (SCFAs) were analyzed by 16S rDNA Amplicon Sequencing and gas chromatography. Results: The Apcmin/+ mice gavaged by feces from CRC patients had more intestinal tumors compared with those fed with feces from healthy controls or PBS. Administration of fecal from CRC patients increased tumor proliferation and decreased apoptosis in tumor cells, accompanied by impairment of gut barrier function and up-regulation the pro-inflammatory cytokines profile. Abnormal expression of genes related to Wnt-protein binding and lipid metabolic process was observed. The upregulated the expression of β-catenin and cyclinD1 further indicating the activation of Wnt signaling pathway. The abundance of pathogenic bacteria was increased after FMT, while SCFAs producing bacteria and SCFAs production were decreased. Conclusion: Gut microbiota of CRC patients disrupted intestinal barrier, induced low-grade inflammation and dysbiosis. The altered gut microbiota enhanced the progression of intestinal adenomas in Apcmin/+ mice, suggesting that a new strategy to target gut microbiota against CRC could be noted. Funding Statement: This study is supported by the grants (81741075, 81570478, and 81700456) from the National Natural Science Foundation of China, the grants (17JCYBJC24900, 17ZXMFSY00210) from Tianjin Research Program of Application Foundation and Advanced Technology of China, the grant (2019M651049) from China Postdoctoral Science Foundation. Declaration of Interests: The authors state: "No potential conflicts of interest." Ethics Approval Statement: All experimental procedures have been approved by the Ethics Committee of Tianjin Medical University.

Serotonin (5-HT) and the serotonin transporter (SERT) have earned a tremendous amount of attention regarding the pathogenesis of irritable bowel syndrome (IBS). Considering that enteric 5-HT is responsible for the secretion, motility and perception of the bowel, the involvement of altered enteric 5-HT metabolism in the pathogenesis of IBS has been elucidated. Higher 5-HT availability is commonly associated with depressed SERT mRNA in patients with IBS compared with healthy controls. The expression difference of SERT between IBS patients and healthy controls might suggest that SERT plays an essential role in IBS pathogenesis, and SERT was expected to be a novel therapeutic target for IBS. Progress in this area has begun to illuminate the complex regulatory mechanisms of SERT in the etiology of IBS. In this article, current insights regarding the regulation of SERT in IBS are provided, including aspects of SERT gene polymorphisms, microRNAs, immunity and inflammation, gut microbiota, growth factors, among others. Potential SERT-directed therapies for IBS are also described. The potential regulators of SERT are of clinical importance and are important for better understanding IBS pathophysiology and therapeutic strategies.

Colorectal cancer (CRC) is the third leading cause of cancer-related mortality in the United States. Recent cancer genome-sequencing efforts and complementary functional studies have led to the identification of a collection of candidate 'driver' genes involved in CRC tumorigenesis. Tripartite motif (TRIM3) is recently identified as a tumour suppressor in glioblastoma but this tumour-suppressive function has not been investigated in CRC.In this study, we investigated the potential role of TRIM3 as a tumour suppressor in CRC development by manipulating the expression of TRIM3 in two authentic CRC cell lines, HCT116 and DLD1, followed by various functional assays, including cell proliferation, colony formation, scratch wound healing, soft agar, and invasion assays. Xenograft experiment was performed to examine in vivo tumour-suppressive properties of TRIM3.Small-interfering RNA (siRNA) mediated knockdown of TRIM3 conferred growth advantage in CRC cells. In contrast, overexpression of TRIM3 affected cell survival, cell migration, anchorage independent growth and invasive potential in CRC cells. In addition, TRIM3 was found to be down-regulated in human colon cancer tissues compared with matched normal colon tissues. Overexpression of TRIM3 significantly inhibited tumour growth in vivo using xenograft mouse models. Mechanistic investigation revealed that TRIM3 can regulate p53 protein level through its stabilisation.TRIM3 functions as a tumour suppressor in CRC progression. This tumour-suppressive function is exerted partially through regulation of p53 protein. Therefore, this protein may represent a novel therapeutic target for prevention or intervention of CRC.