Gut microbiota composition and functional prediction in diarrhea-predominant irritable bowel syndrome

Abstract

Background Irritable bowel syndrome (IBS) is common and difficult to treat and its pathogenesis is closely related to gut microbiota. However, differences in gut microbiota of patients in different regions make it more difficult to elucidate the mechanism of IBS. We performed an analysis of gut microbiota composition and functional prediction in Chinese patients with diarrhea-predominant IBS (IBS-D). Methods Fecal samples were obtained from 30 IBS-D patients and 30 healthy controls (HCs) in Nanchang, China. Using 16S gene sequence profiles, we analyzed the abundance of dominant microbiota at different taxonomy levels. Based on 16S information, Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) was used to predicting the function of gut microbiota. Results Compared to HCs, gut microbiota richness but not diversity was decreased in IBS-D patients. The abundant phyla Firmicutes, Fusobacteria and Actinobacteria decreased significantly, and Proteobacteria increased significantly in IBS-D patients. PICRUSt indicated that function expression of gut microbiota in IBS-D patients was up-regulated in metabolism of cofactors and vitamins, xenobiotics biodegradation and metabolism, and down-regulated in environmental adaptation, cell growth and death. Conclusions Compared with the normal population in China, IBS-D patients are characterized by complex and unstable gut microbiota, which may influence inflammation and metabolism of the host.

Metabolic Influences of Gut Microbiota Dysbiosis on Inflammatory Bowel Disease

“…Moreover, it is noteworthy fecal (stool) and mucosal sampling is critical during the determination of the microbial dysbiosis in IBD ( Lo Presti et al, 2019 ). The IBD stool samples are characterized by reduced diversity of microbiota in comparison to IBS and healthy population ( Mei et al, 2021 ). IBD cases are characterized by decreased Verrucomicrobia and Bacteroidetes than healthy population ( Lo Presti et al, 2019 ; Mei et al, 2021 ).…”

“…The IBD stool samples are characterized by reduced diversity of microbiota in comparison to IBS and healthy population ( Mei et al, 2021 ). IBD cases are characterized by decreased Verrucomicrobia and Bacteroidetes than healthy population ( Lo Presti et al, 2019 ; Mei et al, 2021 ). On the other hand, in case of IBS Bacteroidetes are increased in comparison to healthy population.…”

“…On the other hand, in case of IBS Bacteroidetes are increased in comparison to healthy population. Moreover, IBD are reported to harbor less population of Bacteroidetes and Verrucomicrobia, and higher abundance of Actinobacteria in comparison to IBS ( Lo Presti et al, 2019 ; Ryan et al, 2020 ; Mei et al, 2021 ). Lactobacillus , Ruminococcus , and Streptococcus are significantly higher in IBD than healthy population, while Oscillospira , Lachnospiraceae , Ruminococcaceae , and Rikenellaceae as well as Akkermansia muciniphila are diminished in IBD ( Lo Presti et al, 2019 ; Ryan et al, 2020 ; Mei et al, 2021 ).…”

“…Moreover, IBD are reported to harbor less population of Bacteroidetes and Verrucomicrobia, and higher abundance of Actinobacteria in comparison to IBS ( Lo Presti et al, 2019 ; Ryan et al, 2020 ; Mei et al, 2021 ). Lactobacillus , Ruminococcus , and Streptococcus are significantly higher in IBD than healthy population, while Oscillospira , Lachnospiraceae , Ruminococcaceae , and Rikenellaceae as well as Akkermansia muciniphila are diminished in IBD ( Lo Presti et al, 2019 ; Ryan et al, 2020 ; Mei et al, 2021 ). In case of IBS, Pseudomonas and Lactococcus are decreased in comparison to healthy population, while Parabacteroides distasonis is relatively increased ( Forbes et al, 2016 ; Lo Presti et al, 2019 ).…”

Probiotics, Prebiotics, and Synbiotics in the Irritable Bowel Syndrome Treatment: A Review

“…Additionally, the article mentioned the increased number of bacteria belonging to Firmicutes phyla, including Lactobacillus and Ruminococcus genus, as well as a decreased abundance of Erysipelotrichaceae and methanogens in IBS patients [61]. Mei et al (2021), who analyzed only IBS-D patients in China, also observed elevated abundance of bacteria belonging to Enterobacteriaceae family, as well as Proteobacteria phyla, and decreased prevalence of Firmicutes, Fusobacteria phyla, and Alloprevotella, Fusobacterium genus in contrast to the healthy population [62]. Tap et al (2017) observed the correlation between the severity of IBS and the number of Methanobacteriales capable of producing methane, which is linked to the occurrence of constipation [63].…”