Significant improvement of physicians' knowledge and clinical practice: an opportune, effective, and convenient continuing medical education program on functional dyspepsia.

Aims: This cohort study aimed to explore the effect of a one-day online continuing medical education (CME) on the improvement of physicians' knowledge and clinical practice on functional dyspepsia (FD). Methods: Physicians were invited to participate in this CME via medical education applications. FD training videos made in advance were sent to participants via a weblink. Before and after training, participants were required to finish the FD knowledge test and provide case information of FD patients. McNemar test, Wilcoxon rank-sum test, Freidman test, Chi-square test, quantile regression, and generalized estimating equations (GEE) were used to perform statistical analysis. Results: There were 397 of 430 (92.33%) physicians finished this CME program. The total score of the FD knowledge test after training was significantly higher compared with before training [488.3 (468.3-510.0) vs. 391.7 (341.7-450.0), p < 0.001]. Particularly, physicians from primary hospitals show more increase in total scores than physicians from secondary and tertiary hospitals. According to the GEE model, receiving this online training was an independent predictor of physicians' choice of upper gastrointestinal endoscopy in patients with FD [OR 1.73, 95%CI (1.09-2.73), p = 0.020], especially in PDS. Also, it was an independent predictor of physicians' choice of acid-suppressive drugs in patients with FD [OR 1.30, 95%CI (1.03-1.63), p = 0.026], especially in EPS and PDS overlapping EPS. Conclusion: This one-day online CME program effectively and conveniently improved physicians' knowledge and clinical practice, providing new ideas for future CME and facilitating precise clinical management of FD patients with different subtypes especially in primary hospitals.

Identifying MS4A6A+ macrophages as potential contributors to the pathogenesis of nonalcoholic fatty liver disease, periodontitis, and type 2 diabetes mellitus.

Purpose: Concrete epidemiological evidence has suggested the mutually-contributing effect respectively between nonalcoholic fatty liver disease (NAFLD), type 2 diabetes mellitus (T2DM), and periodontitis (PD); however, their shared crosstalk mechanism remains an open issue. Method: The NAFLD, PD, and T2DM-related datasets were obtained from the NCBI GEO repository. Their common differentially expressed genes (DEGs) were identified and the functional enrichment analysis performed by the DAVID platform determined relevant biological processes and pathways. Then, the STRING database established a PPI network of such DEGs and topological analysis through Cytoscape 3.7.1 software along with the machine-learning analysis by the least absolute shrinkage and selection operator (LASSO) algorithm screened out hub characteristic genes. Their efficacy was validated by external datasets using the receiver operating characteristic (ROC) curve, and gene expression and location of the most robust one was determined using single-cell sequencing and immunohistochemical staining. Finally, the promising drugs were predicted through the CTD database, and the CB-DOCK 2 and Pymol platform mimicked molecular docking. Result: Intersection of differentially expressed genes from three datasets identified 25 shared DEGs of the three diseases, which were enriched in MHC II-mediated antigen presenting process. PPI network and LASSO machine-learning analysis determined 4 feature genes, of which the MS4A6A gene mainly expressed by macrophages was the hub gene and key immune cell type. Molecular docking simulation chosen fenretinide as the most promising medicant for MS4A6A+ macrophages. Conclusion: MS4A6A+ macrophages were suggested to be important immune-related mediators in the progression of NAFLD, PD, and T2DM pathologies.

Psychological factors may affect the quality of life in irritable bowel syndrome patients more than the gut itself? A multicenter cross-sectional study.

Background and Aim: Both intestinal symptoms and comorbidities exist in irritable bowel syndrome (IBS) patients and influence their quality of life (QOL). More research is needed to determine how these variables impact the QOL of IBS patients. This study aimed to determine which specific factors had a higher influence on QOL and to further compare the effects of intestinal symptoms and comorbidities on QOL. Methods: IBS patients were recruited from six tertiary hospitals in different regions of China. QOL, gastrointestinal symptoms, and comorbidities were assessed by different scales. Correlation analysis, multiple linear regression, and mediation model were used for statistics. Results: Four hundred fifty-three IBS patients (39.7% women, mean age 45 years) were included and no significant differences in QOL were found across demographic characteristics. Abnormal defecation (r = -0.398), fatigue (r = -0.266), and weakness (r = -0.286) were found to show higher correlation with QOL. More than 40% of IBS patients were found to suffer from varying degrees of anxiety or depression, and anxiety (r = -0.564) and depression (r = -0.411) were significantly negatively correlated with QOL (P < 0.001). Psychological factors showed the strongest impact (ß' = -0.451) and play a strong mediating role in the impact of physiological symptoms on QOL. Anxiety was found to be the strongest factor (ß' = -0.421). Conclusion: Compared with other symptoms, psychological symptoms, particularly anxiety, are more common and have a more negative influence on QOL. The QOL of IBS patients is also significantly impacted by abnormal defecation, abdominal distension, and systemic extraintestinal somatic symptoms. In the treatment of IBS patients with unhealthy mental status, psychotherapy might be prioritized.

Fut2 Deficiency Promotes Intestinal Stem Cell Aging by Damaging Mitochondrial Functions via Down-Regulating α1,2-Fucosylation of Asah2 and Npc1.

Fut2-mediated α1,2-fucosylation is important for gut homeostasis, including the intestinal stem cell (ISC). The stemness of ISC declines with age, and aging-associated ISC dysfunction is closely related to many age-related intestinal diseases. We previously found intestinal epithelial dysfunction in some aged Fut2 knockout mice. However, how Fut2-mediated α1,2-fucosylation affects ISC aging is still unknown. On this basis, the herein study aims to investigate the role of Fut2-mediated α1,2-fucosylation in ISC aging. Aging models in ISC-specific Fut2 knockout mice were established. ISCs were isolated for proteomics and N-glycoproteomics analysis. ISC functions and mitochondrial functions were examined in mice and organoids. Ulex europaeus agglutinin I chromatography and site-directed mutagenesis were used to validate the key target fucosylated proteins of Fut2. As a result, Fut2 knockout impaired ISC stemness and promoted aging marker expression in aged mice. Proteomics analysis indicated mitochondrial dysfunction in Fut2 knockout ISC. More injured mitochondria, elevated levels of reactive oxygen species, and decreased levels of adenosine 5'-triphosphate (ATP) in Fut2 knockout ISC were found. Moreover, respiratory chain complex impairment and mitophagy dysfunction in Fut2 knockout ISC were further noted. Finally, Fut2 was demonstrated to regulate mitochondrial functions mainly by regulating the α1,2-fucosylation of N-acyl sphingosine amidohydrolase 2 (Asah2) and Niemann-Pick type C intracellular cholesterol transporter 1 (Npc1). In conclusion, this study demonstrated the substantial role of Fut2 in regulating ISC functions during aging by affecting mitochondrial function. These findings provide novel insights into the molecular mechanisms of ISC aging and therapeutic strategies for age-related intestinal diseases.

Identification of CXC Chemokine Receptor 2 (CXCR2) as a Novel Eosinophils-Independent Diagnostic Biomarker of Pediatric Eosinophilic Esophagitis by Integrated Bioinformatic and Machine-Learning Analysis.

Background: Eosinophilic esophagitis (EoE) is a complex allergic condition frequently accompanied by various atopic comorbidities in children, which significantly affects their life qualities. Therefore, this study aimed to evaluate pivotal molecular markers that may facilitate the diagnosis of EoE in pediatric patients. Methods: Three available EoE-associated gene expression datasets in children: GSE184182, GSE 197702, GSE55794, along with GSE173895 were downloaded from the GEO database. Differentially expressed genes (DEGs) identified by "limma" were intersected with key module genes identified by weighted gene co-expression network analysis (WGCNA), and the shared genes went through functional enrichment analysis. The protein-protein interaction (PPI) network and the machine learning algorithms: least absolute shrinkage and selection operator (LASSO), random forest (RF), and XGBoost were used to reveal candidate diagnostic markers for EoE. The receiver operating characteristic (ROC) curve showed the efficacy of differential diagnosis of this marker, along with online databases predicting its molecular regulatory network. Finally, we performed gene set enrichment analysis (GSEA) and assessed immune cell infiltration of EoE/control samples by using the CIBERSORT algorithm. The correlations between the key diagnostic biomarker and immune cells were also investigated. Results: The intersection of 936 DEGs and 1446 key module genes in EoE generated 567 genes, which were primarily enriched in immune regulation. Following the construction of the PPI network and filtration by machine learning, CXCR2 served as a potential diagnostic biomarker of pediatric EoE with a perfect diagnostic efficacy (AUC = ~1.00) in regional tissue/peripheral whole blood samples. Multiple infiltrated immune cells were observed to participate in disrupting the homeostasis of esophageal epithelium to varying degrees. Conclusion: The immune-correlated CXCR2 gene was proved to be a promising diagnostic indicator for EoE, and dysregulated regulatory T cells (Tregs)/neutrophils might play a crucial role in the pathogenesis of EoE in children.

Tongue Biting Event in Patients with Sleep-Related Facial Mandibular Myoclonus: A Case Series Study.

Background: Sleep-related facial mandibular myoclonus (SRFMM) remains rare in clinical practice. The aim of this study was to provide a comprehensive understanding of the electroclinical manner, therapeutic regimen, and prognosis of SRFMM. Methods: Twenty-three patients who were diagnosed with SRFMM by clinical manifestation, video-electroencephalography (EEG) and electromyography over bilateral masseter and temporalis muscles were enrolled. Clinical and electrophysiological evaluation as well as follow-up information were recorded and analyzed. Results: The cohort involved 4 infants and 19 adults with a mean onset age of 43.5 years for SRFMM, among whom 19 were male. Twenty-one patients complained of tongue injuries and disturbed night-time sleep. SRFMM in 4 patients were ascribed to oral aripiprazole, brainstem ischemia and brain trauma. In 62 SRFMM episodes, 93.5% occurred in NREM sleep and 6.5% in REM sleep, and all events were associated with EEG arousals. In 13 patients with or without clonazepam, the motor events gradually disappeared, and the rest turned to be sporadic. Conclusion: SRFMM is a characteristic parasomnia manifested by tongue biting and accompanying facial mandibular myoclonus, leading to disrupted sleep. Besides adults, infants can also experience SRFMM with spontaneous remission. Most patients respond well to clonazepam, eventually with favorable prognosis.

EphB2 promotes enteric nitrergic hyperinnervation and neurogenic inflammation in DSS-induced chronic colitis in mice.

BACKGROUND: Enteric nervous system (ENS) has been closely associated with the neuro-immune response and is currently considered a reliable target for intestinal inflammation. Neuronal nitric oxide synthase (nNOS) nerves are involved in inflammatory diseases by releasing nitric oxide (NO). EphB2 expression and density of innervation of the mucosal layer are positively correlated with the severity of intestinal inflammatory responses. In this study, we hypothesized that a EphB2-mediated mechanism may regulate enteric immunity through modulation of nNOS nerves. METHODS: Firstly, the Western blot (WB) method was employed to quantify EphB2 expression in the intestinal mucosal layer of DSS mice and assess alterations in nerve fiber activation and density. Immunofluorescence (IF) double staining with nNOS and neuronal marker PGP9.5 was conducted to measure nNOS nerve fiber density within the intestinal mucosal layer of mice. Subsequently, in vivo experiments were performed to investigate the inhibitory or activatory effect of EphB2Fc or EphrinB2Fc on EphB2 expression and activation. Immunoprecipitation experiments confirmed the interaction between EphB2 and nNOS nerves. WB and IF experiments were carried out to evaluate both inflammatory conditions of mouse colonic mucosa following intervention with EphB2Fc/EphrinB2Fc as well as changes in nNOS nerve fibers expression. Finally, in vitro experiments, neurally-mediated inflammation was assessed in the organ bath system by activating intestinal mucosal innervation through Veratridine (VER) and electrical field stimulation (EFS) techniques for 3 h. The activation of nNOS nerves was inhibited by nitroindazole (7NI). WB was employed to detect changes in the expression of inflammatory factors in the intestinal mucosal layer in EphB2Fc/EphrinB2Fc treated mice and control group. KEY RESULTS: We found that the expression of EphB2 and density nNOS nerve fibers in the intestinal mucosa were positively correlated with the colitis response. Blocking (EphB2Fc)/activating (EphrinB2Fc) EphB2 in vivo significantly reduced/increased the density of nNOS nerve fibers and expression of inflammatory factors in colonic mucosa of DSS treated mice. In vitro, blocking nNOS nerves activation attenuated the inflammatory reaction induced by either EFS or EphB2. CONCLUSIONS: Our findings provided evidence that EphB2 mediated regulation of innate immunity-ENS crosstalk might represent an attractive target for novel therapeutic strategies in ulcerative colitis.

Lymphocyte and neutrophil count combined with intestinal bacteria abundance predict the severity of COVID-19.

IMPORTANCE: The 2019 coronavirus disease (COVID-19) patients had a unique profile of gut bacteria. In this study, we characterized the intestinal bacteria in our COVID-19 cohorts and found that there was an increased incidence of severe cases in COVID-19 patients with decreased lymphocytes and increased neutrophils. Levels of lymphocytes and neutrophils and abundances of intestinal bacteria correlated with the severity of COVID-19.

Different dosages of vonoprazan for gastroesophageal reflux disease: study protocol for a pragmatic, crossover-cluster, randomized controlled trial with patient preference arms.

BACKGROUND: Vonoprazan results in more potent acid suppression for gastroesophageal reflux disease (GERD) than proton pump inhibitors. It has only been approved for treating erosive esophagitis in China, but 30-40% of GERD patients cannot achieve the goal of treatment with vonoprazan 20 mg daily. This study aims to investigate whether vonoprazan could relieve the symptoms of Chinese patients with non-erosive reflux disease (NERD) and whether increased dosage or different times of dosing could increase the response rate of GERD. METHODS: This study is a pragmatic, open-label, crossover-cluster, randomized controlled trial with patient preference arms. Two thousand eight hundred eighty patients with GERD from 48 hospitals in China will be enrolled. These hospitals will be divided into a compulsory randomization cluster (24 hospitals) and a patient preference cluster (24 hospitals). Patients in the compulsory randomization cluster will be randomized to three regimens according to the crossover-cluster randomization. Patients in the patient preference cluster may choose to receive any regimen if they have a preference; otherwise, patients will be randomly assigned. The three treatment regimens will last 4 weeks, including (1) vonoprazan 20 mg p.o. after breakfast, (2) vonoprazan 20 mg p.o. after dinner, and (3) vonoprazan 20 mg p.o. after breakfast and after dinner. Patients will attend a baseline visit, a 4-week e-diary, a fourth-week visit, and a sixth-month visit online. The primary outcome is the symptom relief rate of all patients after 4-week therapy. Secondary outcomes include the healing rate of EE patients, the severity of symptoms, compliance with the therapy at the fourth-week follow-up visit, recurrent symptoms, and the frequency of self-conscious doctor visits at the sixth-month follow-up visit. DISCUSSION: This trial will explore the effectiveness of different regimens of vonoprazan that will be implemented with GERD patients in China. The randomization with patient preferences considered and the crossover-cluster component may improve the robustness and extrapolation of study conclusions. TRIAL REGISTRATION: https://www.chictr.org.cn ChiCTR2300069857. Registered on 28 March 2023. PROTOCOL VERSION: February 18, 2023, Version 2.

Sudden unexpected death in epilepsy disclosure causes anxiety in patients with epilepsy: a Chinese questionnaire survey.

Background and objective: Sudden unexpected death in epilepsy (SUDEP) has been regarded as a leading cause of premature death in patients with epilepsy (PWE). Although patients, relatives and caregivers have the right to be informed of SUDEP, neurologists prefer not to release the facts for fear of associated anxiety. In the study, a Chinese questionnaire survey was carried out to elucidate effect of SUDEP disclosure on anxiety in PWE and variables determining the anxiety of patients and provided suggestions for SUDEP disclosure. Methods: A survey study in China was conducted. We recruited 305 PWE from 3 tertiary epilepsy centers who attended outpatient clinic from December 2021 to February 2022. Two hundred and thirty-two PWE completed the screening evaluation, survey and Hamilton anxiety rating scale (HAMA) twice with 171 PWE completing third HAMA at follow-up. HAMA scores at baseline, T1, T2 were compared using analysis of variance and dependent samples t-test. The variables related to anxiety were screened out by univariate analysis and used for multivariate logistic regression. Result: We found 127 (54.7%) among the 232 participants experienced anxiety after SUDEP disclosure. HAMA scores at T1 were significantly higher than at baseline and T2, while there was no statistical difference between baseline and T2. Medical insurance, seizure severity, and whether the PWE supported SUDEP being disclosed to their relatives and caregivers only were associated with the occurrence of anxiety. Conclusion: SUDEP disclosures may cause short-term acute anxiety, but have no long-term effects in PWE. Acute anxiety caused by SUDEP disclosure may be more common in PWE with NCMI and severe seizures. Meanwhile, compared with indirect SUDEP disclosure to their relatives and caregivers, direct SUDEP disclosure to PWE reduces the risk of anxiety. Recommendations are provided to avoid anxiety caused by SUDEP disclosure.

Insights into the liver-eyes connections, from epidemiological, mechanical studies to clinical translation.

Maintenance of internal homeostasis is a sophisticated process, during which almost all organs get involved. Liver plays a central role in metabolism and involves in endocrine, immunity, detoxification and storage, and therefore it communicates with distant organs through such mechanisms to regulate pathophysiological processes. Dysfunctional liver is often accompanied by pathological phenotypes of distant organs, including the eyes. Many reviews have focused on crosstalk between the liver and gut, the liver and brain, the liver and heart, the liver and kidney, but with no attention paid to the liver and eyes. In this review, we summarized intimate connections between the liver and the eyes from three aspects. Epidemiologically, we suggest liver-related, potential, protective and risk factors for typical eye disease as well as eye indicators connected with liver status. For molecular mechanism aspect, we elaborate their inter-organ crosstalk from metabolism (glucose, lipid, proteins, vitamin, and mineral), detoxification (ammonia and bilirubin), and immunity (complement and inflammation regulation) aspect. In clinical application part, we emphasize the latest advances in utilizing the liver-eye axis in disease diagnosis and therapy, involving artificial intelligence-deep learning-based novel diagnostic tools for detecting liver disease and adeno-associated viral vector-based gene therapy method for curing blinding eye disease. We aim to focus on and provide novel insights into liver and eyes communications and help resolve existed clinically significant issues.

Slowed Intestinal Transit Induced by Less Mucus in Intestinal Goblet Cell Piezo1-Deficient Mice through Impaired Epithelial Homeostasis.

Mucus secreted by goblet cells (GCs) may play an important role in intestinal transit function. Our previous study found that Piezo1 protein is essential for GC function; however, the effect of GC Piezo1 on intestinal transit function is unclear. Our study aimed to investigate the effect of Piezo1 in GCs on intestinal transit and the potential mechanism. We compared intestinal mucus, fecal form, intestinal transit time, intestinal epithelial cell composition, and stem cell function in WT and GC-specific Piezo1-deficient (Piezo1ΔGC) mice. Our results revealed a correlation between mucus and intestinal transit: the less mucus there was, the slower the intestinal transit. Piezo1 deficiency in GCs led to decreased mucus synthesis and also disrupted the ecological niche of colon stem cells (CSCs). Through organoid culture, we found that the capacity of proliferation and differentiation in Piezo1ΔGC mouse CSCs was significantly decreased, which also led to a reduced source of GCs. Further studies found that the reduced Wnt and Notch signals in colon crypts might be the potential mechanism. These results indicated the importance of GC Piezo1 in intestinal transit function, which acts by maintaining the homeostasis of intestinal epithelial cells and mucus.

Exploring the relationship between urinary phthalate metabolites and Crohn's disease via oxidative stress, and the potential moderating role of gut microbiota: A conditional mediation model.

OBJECTIVE: Interactions between phthalic acid esters (PAEs) exposure and Crohn's disease (CD) were unknown. This study aims to examine the association between exposure to PAEs and CD activity and to explore the roles of oxidative stress and microbiota. METHODS: A cross-sectional study with 127 CD patients was conducted. The disease activity was evaluated based on symptoms (Harvey-Bradshaw index, HBI), endoscopy findings (Simple Endoscopic Score for CD, SES-CD), and computed tomography enterography (CTE-scores). Ten urinary PAEs metabolites (mPAEs), two urinary oxidative stress biomarkers, including 8-hydroxydeoxyguanosine (8-OHdG) and 8-iso-prostaglandin-F2α (8-iso-PGF2α), as well as 16S rRNA sequencing of stool samples were determined. Multiple linear regression models and Hayes's PROCESS macro for SPSS were used to evaluate the interplays between urinary PAEs metabolites, CD activities, oxidative stress, and microbiota diversity. RESULTS: There were positive associations between most mPAEs and HBI. Oxidative stress mediated 20.69-89.29% of the indirect associations between low molecular weight (LMW) mPAEs and HBI, while the majority of the high molecular weight (HMW) mPAEs were directly associated with HBI. In addition, microbiota diversity moderated the indirect associations of LMW mPAEs on HBI. CONCLUSIONS: PAEs exposure was related to CD activity, and the association could be mediated by oxidative stress and reversed or alleviated by rich gut microbiota.

Piezo1 in Digestive System Function and Dysfunction.

Piezo1, a non-selective cation channel directly activated by mechanical forces, is widely expressed in the digestive system and participates in biological functions physiologically and pathologically. In this review, we summarized the latest insights on Piezo1's cellular effect across the entire digestive system, and discussed the role of Piezo1 in various aspects including ingestion and digestion, material metabolism, enteric nervous system, intestinal barrier, and inflammatory response within digestive system. The goal of this comprehensive review is to provide a solid foundation for future research about Piezo1 in digestive system physiologically and pathologically.

Glucocorticoid receptor-mediated Nr1d1 chromatin circadian misalignment in stress-induced irritable bowel syndrome.

Stress-elevated glucocorticoids cause circadian disturbances and gut-brain axis (GBA) disorders, including irritable bowel syndrome (IBS). We hypothesized that the glucocorticoid receptor (GR/NR3C1) might cause chromatin circadian misalignment in the colon epithelium. We observed significantly decreased core circadian gene Nr1d1 in water avoidance stressed (WAS) BALB/c colon epithelium, like in IBS patients. WAS decreased GR binding at the Nr1d1 promoter E-box (enhancer box), and GR could suppress Nr1d1 via this site. Stress also altered GR binding at the E-box sites along the Ikzf3-Nr1d1 chromatin and remodeled circadian chromatin 3D structures, including Ikzf3-Nr1d1 super-enhancer, Dbp, and Npas2. Intestinal deletion of Nr3c1 specifically abolished these stress-induced transcriptional alternations relevant to IBS phenotypes in BALB/c mice. GR mediated Ikzf3-Nr1d1 chromatin disease related circadian misalignment in stress-induced IBS animal model. This animal model dataset suggests that regulatory SNPs of human IKZF3-NR1D1 transcription through conserved chromatin looping have translational potential based on the GR-mediated circadian-stress crosstalk.

Exploring the Relationship between the Gut Mucosal Virome and Colorectal Cancer: Characteristics and Correlations.

The fecal virome has been reported to be associated with CRC. However, little is known about the mucosal virome signature in CRC. This study aimed to determine the viral community within CRC tissues and their contributions to colorectal carcinogenesis. Colonic mucosal biopsies were harvested from patients with CRC (biopsies of both neoplasia and adjacent normal tissue (CRC-A)) and healthy controls (HC). The shot-gun metagenomic sequencing of virus-like particles (VLPs) was performed on the biopsies. Viral community, functional pathways, and their correlations to clinical data were analyzed. Fluorescence in situ hybridizations (FISH) for the localization of viruses in the intestine was performed, as well as quantitative PCR for the detection of Torque teno virus load in human mucosal VLP DNA. A greater number and proportion of core species were found in CRC tissues than in CRC-A and HC tissues. The diversity of the mucosal virome in CRC tissues was significantly increased compared to that in HC and CRC-A tissues. The mucosal virome signature of CRC tissues were significantly different from those of HC and CRC-A tissues at the species level. The abundances of eukaryotic viruses from the Anelloviridae family and its sub-species Torque teno virus (TTV) were significantly higher in CRC patients than in HC. Furthermore, increased levels of TTV in the intestinal lamina propria were found in the CRC group. Multiple viral functions of TTV associated with carcinogenesis were enriched in CRC tissues. We revealed for the first time that the mucosal virobiota signature of CRC is characterized by a higher diversity and more eukaryotic viruses. The enrichment of TTV species in CRC tissues suggests that they may play an oncogenic role in CRC. Targeting eukaryotic viruses in the gut may provide novel strategies for the prevention and treatment of CRC.

Fucose promotes intestinal stem cell-mediated intestinal epithelial development through promoting Akkermansia-related propanoate metabolism.

Intestinal stem cells (ISCs) are critical for the development and rapid turnover of intestinal epithelium. The regulatory effects of gut microbiota and their metabolites on ISCs stemness remain elusive. Fucose has been demonstrated to mediate host-microbe interactions in the intestine. However, the association between fucose, gut bacteria, and ISCs stemness remains unclear. To investigate the effects of fucose on ISCs-mediated intestinal epithelial cells (IECs) development, we administered fucose to 4-week-old mice for 4 weeks. ISCs stemness, IECs proliferation, and differentiation were examined. Variations in gut microbes and metabolism were detected using 16S rDNA sequencing and metabolomic analysis. Fucose was added to the bacterial culture medium to further study its effects on metabolism. Crypts were isolated from the mouse ileum for organoids culture in vitro to evaluate the effects of metabolites and the underlying mechanism. The results showed that fucose accelerated ISCs proliferation and secretory lineage differentiation in mice, whereas antibiotics eliminated these effects. The composition and functions of gut bacteria were altered by fucose treatment, while significant increases in Akkermansia and propanoate metabolism were noted. Propionic acid and propionate have been shown to promote organoid development. Fucose fermentation increases the production of propionic acid in Akkermansia muciniphila and enhances its ability to increase the stemness of ISCs. Moreover, ileal contents from fucose-treated mice promoted organoid development in a Gpr41/Gpr43-dependent manner. Fucose administration activates the Wnt signaling pathway in ISCs, and Wnt inhibitors suppress the effects of fucose. We conclude that fucose accelerates ISC-mediated intestinal epithelial development by promoting Akkermansia-related propanoate metabolism. These findings provide new insights into the promotion of gut homeostasis and the application potential of fucose as a prebiotic.

Gut microbiota-derived tryptophan metabolites alleviate liver injury via AhR/Nrf2 activation in pyrrolizidine alkaloids-induced sinusoidal obstruction syndrome.

BACKGROUND AND AIMS: Hepatic sinusoidal obstruction syndrome (HSOS) is caused by toxic injury, such as pyrrolizidine alkaloids, to the liver sinusoidal endothelial cells, and the gut microbiota may be involved. However, the specific role and underlying mechanism of gut microbiota in HSOS is unknown. METHODS: HSOS model was established by gavage of monocrotaline (MCT) in rats. Fecal microbiota transplantation (FMT) with HSOS-derived or healthy gut flora was also conducted to validate the role of gut microflora in MCT-induced liver injury. The microbial 16 s rRNA analysis and untargeted metabolomics analysis in the faeces were performed to identify HSOS-related flora and metabolites. Finally, by supplementation with specific tryptophan metabolites, such as indole-3-acetaldehyde (IAAld) and indole acetic acid (IAA), we further confirmed the role of tryptophan metabolism in HSOS and the role of the AhR/Nrf2 pathway in MCT-induced liver injury. RESULTS: MCT induced HSOS-like liver injury in rats with significantly altered gut microbiota. Particularly, some tryptophan-metabolizing bacteria reduced in MCT-treated rats, such as Bacteroides, Bifidobacterium, Lactobacillus and Clostridium, and accompanied by a decrease in microbial tryptophan metabolic activity and a series of tryptophan derivatives. Restoring the gut microbiota via FMT improved MCT-induced liver damage, while HSOS-derived gut microbiota aggravated the liver injury induced by MCT. Supplementation with microbial tryptophan derivatives (IAAld or IAA), or 6-formylindolo(3,2-b)carbazole (Ficz, an AhR agonist) could activate the AhR/Nrf2 signaling pathway, thereby attenuating the MCT-induced liver oxidative stress and liver sinusoidal endothelial cells injury. CONCLUSIONS: Gut microbiota plays a critical role in MCT-induced HSOS, with inadequate microbial tryptophan metabolism in the gut and consequently a lower activity of the AhR/Nrf2 signaling pathway in the liver, which should be a potential target for the management of HSOS.

The Novel Role of Phage Particles in Chronic Liver Diseases.

The gut microbiome is made up of bacteria, fungi, viruses and archaea, all of which are closely related with human health. As the main component of enterovirus, the role of bacteriophages (phages) in chronic liver disease has been gradually recognized. Chronic liver diseases, including alcohol-related liver disease and nonalcoholic fatty liver disease, exhibit alterations of the enteric phages. Phages shape intestinal bacterial colonization and regulate bacterial metabolism. Phages adjoining to intestinal epithelial cells prevent bacteria from invading the intestinal barrier, and mediate intestinal inflammatory response. Phages are also observed increasing intestinal permeability and migrating to peripheral blood and organs, likely contributing to inflammatory injury in chronic liver diseases. By preying on harmful bacteria, phages can improve the gut microbiome of patients with chronic liver disease and thus act as an effective treatment method.

Contribution of gut microbiota to drug-induced liver injury.

Drug-induced liver injury (DILI) is caused by various drugs with complex pathogenesis, and diverse clinical and pathological phenotypes. Drugs damage the liver directly through drug hepatotoxicity, or indirectly through drug-mediated oxidative stress, immune injury and inflammatory insult, which eventually lead to hepatocyte necrosis. Recent studies have found that the composition, relative content and distribution of gut microbiota in patients and animal models of DILI have changed significantly. It has been confirmed that gut microbial dysbiosis brings about intestinal barrier destruction and microorganisms translocation, and the alteration of microbial metabolites may cause or aggravate DILI. In addition, antibiotics, probiotics, and fecal microbiota transplantation are all emerging as prospective therapeutic methods for DILI by regulating the gut microbiota. In this review, we discussed how the altered gut microbiota participates in DILI.