Faecal and mucosal microbiota in patients with functional gastrointestinal disorders: Correlation with toll-like receptor 2/toll-like receptor 4 expression

AIM To investigate the intestinal luminal microbiota(LM)and mucosa-associated microbiota(MAM)in Chinese patients with functional gastrointestinal disorders(FGIDs)and examine the association between these communities and the expression of toll-like receptor(TLR)2 and TLR4. METHODS Thirty-two Chinese subjects who suffered from symptoms of FGIDs,as confirmed by gastroenterologists,were enrolled in this study.Fresh faecal samples and descending colonic mucosal biopsies were collected from the subjects before(faecal)and during(mucosal) flexible colonoscopy.For analysis of the samples,we performed high-throughput sequencing of the V3-V4region of the 16S rR NA gene and reverse transcription(RT)-PCR to detect the expression of colonic TLR2 and TLR4.Differences in the stool and mucosal microbiota were examined and a correlation network analysis was performed. RESULTS The microbiota of faecal samples was significantly more diverse and richer than that of the mucosal samples,and the LM and MAM populations differed significantly.TLR2 expression showed a significant positive correlation with TLR4 expression.In the MAM samples,the genera Faecalibacterium and Ruminococcus,which belong to the family Ruminococcaceae,were inversely correlated with TLR4 expression(r=-0.45817,P=0.0083 and r=-0.5306,P=0.0018,respectively).Granulicatella,which belongs to Carnobacteriaceae,and Streptococcus,which belongs to Streptococcaceae,were inversely correlated with TLR2 expression(r=-0.5573,P=0.0010 and r=-0.5435,P=0.0013,respectively).In the LM samples,examination at phylum,class,or order level revealed no correlation with TLR4 expression.Faecalibacterium,which belongs to Ruminococcaceae,and Streptococcus,which belongs to Streptococcaceae,were inversely correlated with TLR2 expression(r=-0.5743,P=0.0058 and r=-0.3905,P=0.0271,respectively). CONCLUSION Microbial compositions of LM and MAM in Chinese patients with FGIDs are different.Expression of TLRs may be affected by the type of bacteria that are present in the gut.

Role of intestinal microbiota and metabolites in inflammatory bowel disease

Objective:The metabolites produced by the gut microbiota are of interest to scientists.The objective of this review was to provide an updated summary of progress regarding the microbiota and their metabolites and influences on the pathogenesis of inflammatory bowel disease(IBD).Data sources:The author retrieved information from the PubMed database up to January 2018,using various combinations of search terms,including IBD,microbiota,and metabolite.Study selection:Both clinical studies and animal studies of intestinal microbiota and metabolites in IBD were selected.The information explaining the possible pathogenesis of microbiota in IBD was organized.Results:In IBD patients,the biodiversity of feces/mucosa-associated microbiota is decreased,and the probiotic microbiota is also decreased,whereas the pathogenic microbiota are increased.The gut microbiota may be a target for diagnosis and treatment of IBD.Substantial amounts of data support the view that the microbiota and their metabolites play pivotal roles in IBD by affecting intestinal permeability and the immune response.Conclusions:This review highlights the advances in recent gut microbiota research and clarifies the importance of the gut microbiota in IBD pathogenesis.Future research is needed to study the function of altered bacterial community compositions and the roles of metabolites.

Psychological reactions of healthcare workers deployed to Wuhan from Shanxi province and how they cope during coronavirus disease 2019(COVID-19)outbreak

To the Editor:Since the outbreak of coronavirus disease 2019(COVID-19),a large number of healthcare workers(HCWs)volunteered to leave their familiar working and living environments to travel to Hubei province to undertake emergency response work.For most medical workers who traveled to Hubei province,this was their first time participating in such a crisis situation.Previous studies have reported that HCWs face a double blow of high-intensity work and high psychological pressure,making them particularly prone to mental health difficulties.