Altered Gut Microbiota in Irritable Bowel Syndrome and Its Association with Food Components

Abstract

The interplay between diet and gut microbiota has gained interest as a potential contributor in pathophysiology of irritable bowel syndrome (IBS). The purpose of this study was to compare food components and gut microbiota patterns between IBS patients and healthy controls (HC) as well as to explore the associations of food components and microbiota profiles. A cross-sectional study was conducted with 80 young adults with IBS and 21 HC recruited. The food frequency questionnaire was used to measure food components. Fecal samples were collected and profiled by 16S rRNA Illumina sequencing. Food components were similar in both IBS and HC groups, except in caffeine consumption. Higher alpha diversity indices and altered gut microbiota were observed in IBS compared to the HC. A negative correlation existed between total observed species and caffeine intake in the HC, and a positive correlation between alpha diversity indices and dietary fiber in the IBS group. Higher alpha diversity and gut microbiota alteration were found in IBS people who consumed caffeine more than 400 mg/d. Moreover, high microbial diversity and alteration of gut microbiota composition in IBS people with high caffeine consumption may be a clue toward the effects of caffeine on the gut microbiome pattern, which warrants further study.

Crosstalk Between Intestinal Serotonergic System and Pattern Recognition Receptors on the Microbiota–Gut–Brain Axis

“…Actinobacteria Bifidobacteriaceae Coriobacteriaceae Decreased in IBS (247,248) Decreased in IBD (249,250) Decreased in UC and CD (251) Increased in IBS (248) Decreased in IBD (249) Increased in UC and CD (252) Increased in Parkinson's disease (253)(254)(255) Decreased in Alzheimer's disease (251) Decreased in autism spectrum disorder (256,257) Increased in bipolar disorder (258) Decreased in Parkinson's disease (259) Increased in bipolar disorder (258) Increases TPH1 and decreases SERT expression (260) Increases 5-HT in CNS (261) Increases mucosal 5-HT, and expression of SERT; 5-HTR 2 and 5-HTR 4 (237) Bifidobacterium are decreased in SERT -/mouse (262) Correlated with increased levels of serotonin (263) Microbial manipulation: prebiotic and probiotics in GI disorders (264)(265)(266) Probiotic supplementations in neurodegenerative disorders (267,268);…”

“…Reduced in IBD (293,297) Increased in IBS (248,302) Increased in UC (252) and in CD (293) Reduced in CD (252,298) Increased in Parkinson's disease (259) Increased in Alzheimer's disease (300) Decreased in autism spectrum disorder (301) Decreased in bipolar disorder (258) Increases 5-HT levels (232) Correlated with levels of serotonin (303) Veillonellaceae Increased in IBS (304,305) Increased in IBD (305,306) Increased in UC and CD (252) Decreased in autism spectrum disorder (256) Correlated with increased levels of serotonin (307) Lactobacillaceae Increased in IBS (248) Increased in IBD (297) Decreased in IBD (Lactobacillus) (250) Increased in CD and reduced in UC (252) Increased in Parkinson's disease (253,255,308) Decreased in Alzheimer's disease (251) Increased in Alzheimer's disease (300) Increased in autism spectrum disorder (257) Decreases TPH1, 5-THR 3 and 5-HTR 4 expression; and increases SERT expression…”

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

“…In addition, the research group noted the reduced number of bacteria from Prevotella genus in IBS patients compared to healthy subjects. However, Su et al (2018) and Barandouzi et al (2021) found increased abundance of this genus in IBS individuals [ 63 , 64 , 65 ]. What is more, Shukla et al (2015) found a lower abundance of Bifidobacterium and Lactobacillus genus and increased prevalence of Veillonella genus, Clostridium coccoides , Bacteroides thetaiotamicron , Ruminococcus productus , and P. aeruginosa [ 66 ].…”

“…What is more, Shukla et al (2015) found a lower abundance of Bifidobacterium and Lactobacillus genus and increased prevalence of Veillonella genus, Clostridium coccoides , Bacteroides thetaiotamicron , Ruminococcus productus , and P. aeruginosa [ 66 ]. Although several studies have described an increased ratio of Firmicutes to Bacteroidetes in patients with IBS compared to healthy individuals, Barandouzi et al (2021) observed a similar abundance of bacteria belonging to these two phyla, that constitute about 90% of the total microbiota of GIT [ 65 , 67 ]. This research group observed, among IBS patients, a higher prevalence of bacteria belonging to Verrucomicrobia phyla, as well as from Blautia genus, which is acknowledged as a marker of microbiota imbalance [ 65 ].…”

“…Although several studies have described an increased ratio of Firmicutes to Bacteroidetes in patients with IBS compared to healthy individuals, Barandouzi et al (2021) observed a similar abundance of bacteria belonging to these two phyla, that constitute about 90% of the total microbiota of GIT [ 65 , 67 ]. This research group observed, among IBS patients, a higher prevalence of bacteria belonging to Verrucomicrobia phyla, as well as from Blautia genus, which is acknowledged as a marker of microbiota imbalance [ 65 ]. Similarly, Lee et al (2021) found no significant differences in phyla levels in fecal samples of IBS patients and healthy population.…”