Year: 2022
Type: dissertation
Study design: Observational Study
Abstract: This longitudinal study was designed to elucidate whether gut microbiota is associated with relapse and treatment response in ulcerative colitis (UC) patients.Fifty-one patients with UC were enrolled between 2012 and 2017, and followed up through 2020.Colon mucosal biopsy were obtained at enrollment, and 16S ribosomal RNA sequencing was performed using extracted RNA.Of the 51 patients, 24 were in remission and 27 had active UC at enrollment.Of the 24 patients in remission, 17 maintained remission and 7 developed relapse during follow-up.The 7 patients with relapse showed lower diversity, with a lower proportion of Clostridiales (p = 0.0043), and a higher proportion of Bacteroides (p = 0.047) at enrollment than those without relapse.The 27 patients with active UC were classified into response (n = 6), refractory (n = 13), and non-response (n = 8) groups according to their treatment response in 6 months.The refractory and non-response groups showed lower diversity with a lower proportion of Prevotella (p = 0.048 and 0.043) at enrollment than the response group.This study is the first demonstration that reduced diversity and particular microbes are associated with the later clinical course of relapse events and treatment response in UC.Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease, is characterized by chronic relapsing inflammation of the gastrointestinal tract.Although its exact etiology remains unknown, IBD has been reported to result from an exaggerated T-cell response to environmental factors in a genetically predisposed host [1][2][3] .The incidence of IBD has rapidly increased worldwide, especially in the Asia-Pacific area; this suggests that alternations of environmental factors, including changes in the composition of the gut microbiota, might play a role in the pathogenesis of IBD 1,2,4 .Studies have shown significant differences in the composition of gut microbiota between patients with IBD and healthy controls 1,3,5 .Notably, reduced diversity of microbiota, characterized by a decrease in Bacteroides and an increase in Gammaproteobacteria, has been reported during the active phase of UC 3,5 .However, it remains controversial whether alterations of gut microbiota composition are involved in the pathogenesis of UC.In clinical practice, it is critical to assess the risk of relapse and to predict long-term treatment response in patients with UC.However, it remains unclear how gut microbiota affect the disease progress in these patients.Thus far, few studies have examined the effects of alteration of gut microbiota composition on the clinical course of IBD, and most studies have been cross-sectional in nature with assessment at a single time point.Moreover, the method of examination of the gut microbiota has been limited.Indeed, the optimal method to analyze the gut microbiota remains unclear.The DNA extracted from fecal samples is usually used to analyze the gut microbiota, but such analysis cannot exclude either dead or dormant microbes, and is easily affected by the stool and mucosal inflammation 6,7 .In contrast, the use of RNA extracts from the gut mucosa can focus on live and active microbes that adhere to the gut mucosa [8][9][10][11][12] .
Author: NISHIHARA, Yuichiro
Institution: Kyushu University
Language: English
Topic: Inflammatory Bowel Disease
Subfield: Gastroenterology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7208120360