1. Introduction
colorectal cancer, cancers
COLORECTAL CANCER, CANCERS, MINOR, METABOLIC DISEASES, INFLAMMATORY DISEASE, COMPLICATIONS, COLORECTAL POLYPS
The aim of this study was to evaluate the effects of probiotic pretreatment on the alteration and recovery of gut microbiota after bowel preparation and its correlation with minor complications. This was a randomized, double-blind, placebo-controlled pilot trial that included participants 40–65 years of age. Participants were randomly provided probiotics (active group) or placebo (placebo group) for 1 month before the colonoscopy and their feces collected. A total of 51 participants were included in the present study (26 in the active group and 25 in the placebo group). In the active group, the microbial diversity, evenness, and distribution were not significantly changed between before and after bowel preparation, but did change in the placebo group. The number of gut microbiota that decreased after bowel preparation in the active group was lower than in the placebo group. On the seventh day after colonoscopy, the gut microbiota in the active group was restored to almost the same level as before bowel preparation. In addition, we identified that several strains were assumed as key microbiota in early colonization and some taxa were increased only in the active group after bowel preparation. In multivariate analysis, taking probiotics before bowel preparation was identified as a significant factor for decreasing the duration of minor complications (odds ratio 0.13, 95% confidence interval 0.02–0.60, Colonoscopy is an effective screening tool to reduce the incidence of colorectal cancer by detecting and removing colorectal polyps. However, the adherence rate to screening colonoscopy remains low; the overall participation rate for screening colonoscopy was only 38% compared with 67% for a fecal occult blood test [Emerging evidence showed that dysbiosis of the gut microbiome was found in various conditions, including metabolic diseases, inflammatory diseases, and cancers. In several studies, bowel preparation for colonoscopy was shown to change the gut microbial diversity, composition, and metabolome, and these effects could last up to 1 month [Based on these results, we hypothesized that the minor complications after colonoscopy were associated with an initial gut microbial status of the subject, and that the modification of this microbial status before bowel preparation can help reduce the occurrence of complications after colonoscopy. The aim of this study was to investigate the beneficial effects of probiotic pretreatment on the alteration and recovery of gut microbiota after bowel preparation for colonoscopy and its association with minor complications.