Gut microbiota and metabolic signatures of anxiety in ulcerative colitis: a cross-sectional study

Abstract

Background: Patients with ulcerative colitis (UC) usually experience anxiety symptoms that seriously affect their quality of life, treatment, and prognosis. Dysbiosis of the gut microbiota plays an important role in UC and mental illness. However, little is known about the role of the gut microbiota in UC patients with anxiety. Objectives: To identify the gut-microbiome and fecal metabolome profiles uniquely associated with comorbid anxiety in UC patients and to explore potential biomarkers for diagnosis. Design: A cross-sectional, two-group comparative study. Methods: To study the underlying association between them, we recruited 126 UC patients in this study, including 78 with anxiety and 48 without anxiety. A total of 102 fecal samples were collected for metagenomic sequencing and metabolome sequencing. Microbial diversity, differential gut microbiota, functional pathways, and metabolites were analyzed. Multivariable logistic regression was used to identify independent risk factors associated with anxiety in UC patients, while Spearman correlation was employed to explore microbe-metabolite interactions and the performance of potential biomarkers. Results: We found that disease severity, steroid usage, and abdominal pain may promote the occurrence of anxiety. Compared to UC patients without anxiety, UC patients with anxiety had low fecal microbial community diversity, with an increase in the species Haemophilus sp. HMSC71H05 and Corynebacterium durum, and a decrease in the species Roseburia intestinalis (RI), Bifidobacterium longum (BL), and Enterococcus hirae. The metabolic pathways driven by the gut microbiota were disrupted. Moreover, the levels of most metabolites (such as L-kynurenine) were increased in the feces, while the levels of a few metabolites decreased, including indole-2-carboxylic acid, N-demethylmirtazapine, and tauroursodeoxycholic acid. Conclusion: Our research further revealed that these gut microbiota and metabolites are highly correlated. This study provides a new perspective for understanding the occurrence and development of anxiety in UC patients, suggesting that RI and BL may serve as potential candidate biomarkers to diagnose UC patients with anxiety.