Gut microbiome signatures reflect different subtypes of irritable bowel syndrome

ABSTRACTIrritable bowel syndrome (IBS) is a heterogeneous condition with multifactorial pathogenesis. We studied deeply phenotyped individuals with microbiota sequencing enrolled in the American Gut Project. The IBS subjects were matched by age, gender, body mass index, geography, and dietary patterns with non-IBS controls. A total of 942 subjects with IBS-Diarrhea (IBS-D), IBS-Constipation (IBS-C), unclassified IBS (IBS-U), and 942 non-IBS controls were included. We compared taxonomic and functional composition of gut microbiota based on 16S sequencing data and linked them with clinical characteristics and dietary factors. Subjects with IBS-D or IBS-U but not IBS-C showed significantly reduced bacterial diversity (Shannon; p < .01). Distinct bacterial signatures were associated with different IBS subtypes, and the related functional changes were related to IBS pathogenesis, such as the increased hydrogen sulfide production pathway in IBS-D and the increased palmitoleate biosynthesis pathway in IBS-C. IBS subjects with depression showed lower abundance of Bifidobacterium, Sutterella, Butyricimonas and higher abundance of Proteus than those without depression. The relative abundance of microbial short-chain fatty acid production pathways was significantly lower in IBS patients with depression than those without depression in all three subtypes. Female, younger age in IBS-D, and older age in IBS-C were associated with more severe microbiota dysbiosis, and distinct dietary factors had significant effects on the gut microbiota in different IBS subtypes. Our analysis identified the compositional uniqueness of gut microbiota in different IBS subtypes. Distinct associations of the gut microbiota with depression in IBS provide insights into shared pathways in disease pathogenesis. These findings highlight the importance of personalized gut microbiome modulation approaches in different subtypes for optimal therapeutic effects

Geography influences susceptibility to SARS-CoV-2 serological response in patients with inflammatory bowel disease : multinational analysis from the ICARUS-IBD Consortium

Background: Beyond systematic reviews and meta-analyses, there have been no direct studies of serological response to COVID-19 in patients with inflammatory bowel disease (IBD) across continents. In particular, there has been limited data from Asia, with no data reported from India. The ICARUS-IBD (International study of COVID-19 Antibody Response Under Sustained immunosuppression in IBD) consortium assessed serological response to SARS-CoV-2 in patients with IBD in North America, Europe, and Asia. Methods: The ICARUS-IBD study is a multicenter observational cohort study spanning sites in 7 countries. We report seroprevalence data from 2303 patients with IBD before COVID-19 vaccination between May 2020 and November 2021. SARS-CoV-2 anti-spike and anti-nucleocapsid antibodies were analyzed. Results: The highest and lowest SARS-CoV-2 anti-spike seropositivity rates were found in Asia (81.2% in Chandigarh and 57.9% in Delhi, India; and 0% in Hong Kong). By multivariable analysis, country (India: odds ratio [OR], 18.01; 95% confidence interval [CI], 12.03-26.95; P < .0001; United Kingdom: OR, 2.43; 95% CI, 1.58-3.72; P < .0001; United States: OR, 2.21; 95% CI, 1.27-3.85; P = .005), male sex (OR, 1.46; 95% CI, 1.07-1.99; P = .016), and diabetes (OR, 2.37; 95% CI, 1.04-5.46; P = .039) conferred higher seropositivity rates. Biological therapies associated with lower seroprevalence (OR, 0.22; 95% CI, 0.15-0.33; P < .0001). Multiple linear regression showed associations between anti-spike and anti-nucleocapsid titers with medications (P < .0001) but not with country (P = .3841). Conclusions: While the effects of medications on anti-SARS-CoV-2 antibody titers in patients with IBD were consistent across sites, geographical location conferred the highest risk of susceptibility to serologically detectable SARS-CoV-2 infection. Over half of IBD patients in India were seropositive prior to vaccination. These insights can help to inform shielding advice, therapeutic choices, and vaccine strategies in IBD patients for COVID-19 and future viral challenges