Melatonin Mitigates Oxazolone-Induced Colitis in Microbiota-Dependent Manner.

Levels of type 2 cytokines are elevated in the blood and intestinal tissues of ulcerative colitis (UC) patients in the active phase; this phenomenon indicates the participation of type 2 immune response in UC progression. The beneficial effects of melatonin in dextran sodium sulfate (DSS) and 2,4,6-trinitrobenzene sulfonic acid (TNBS) colitis models have been illustrated, but its role in the oxazolone (Oxa)-induced colitis model (driven by type 2 immune response) remains relatively unknown. We investigated the relationship between melatonin concentration and the severity of UC, revealing a significantly negative correlation. Subsequently, we investigated the effects of melatonin in Oxa-induced colitis mice and the potential underlying mechanisms. Administration of melatonin significantly counteracted body weight loss, colon shortening, and neutrophil infiltration in Oxa-induced colitis mice. Melatonin treatment mitigated Oxa-induced colitis by suppressing type 2 immune response. In addition, melatonin attenuated intestinal permeability by enhancing the expression of ZO-1 and occludin in colitis mice. Interestingly, the protective effect of melatonin was abolished when the mice were co-housed, indicating that the regulation of gut microbiota by melatonin was critical in alleviating Oxa-induced colitis. Subsequently, 16S rRNA sequencing was performed to explore the microbiota composition. Decreased richness and diversity of intestinal microbiota at the operational taxonomic unit (OTU) level resulted from melatonin treatment. Melatonin also elevated the abundance of Bifidobacterium, a well-known probiotic, and reduced proportions of several harmful bacterial genera, such as Desulfovibrio, Peptococcaceae, and Lachnospiraceae. Fecal microbiota transplantation (FMT) was used to explore the role of microbiota in the function of melatonin in Oxa-induced colitis. Microbiota transplantation from melatonin-treated mice alleviated Oxa-induced colitis, suggesting that the microbiome participates in the relief of Oxa-induced colitis by melatonin. Our findings demonstrate that melatonin ameliorates Oxa-induced colitis in a microbiota-dependent manner, suggesting the therapeutic potential of melatonin in treating type 2 immunity-associated UC.

Endocuff-assisted colonoscopy versus cap-assisted colonoscopy for adenoma detection rate: A meta-analysis of randomized controlled trials.

BACKGROUND AND AIMS: Add-on devices have been widely used in clinical practice. The aim of this meta-analysis was to compare the adenoma detection rate between Endocuff-assisted colonoscopy (EAC) and cap-assisted colonoscopy (CAC). METHODS: PubMed, EMBASE, SCOPUS, and Cochrane databases were searched. Outcomes included adenoma detection rate, cecal intubation rate, cecal intubation time, and withdrawal time. Dichotomous data were pooled to obtain the odds ratio or risk ratio. Continuous data were pooled using the mean difference. RESULTS: Of the 240 articles reviewed, six randomized controlled trials were included, with a total of 1994 patients. In the meta-analysis, no statistical difference in adenoma detection rate was detected between EAC and CAC (47.0% vs 45.1%; P = 0.33). EAC significantly improved detection rate of diminutive adenomas/polyps compared with CAC (P = 0.01). Cecal intubation was achieved in 96.5% in EAC group and 97.9% in CAC group (P = 0.04). Besides, no statistical difference was found in cecal intubation time (P = 0.86), withdrawal time (P = 0.88), small adenomas/polyps (P = 0.60), or large adenomas/polyps (P = 0.95). CONCLUSION: EAC and CAC have their respective merits. EAC significantly improve the detection of diminutive adenomas/polyps. CAC was better in cecal intubation rate.

EndoCuff-assisted colonoscopy could improve adenoma detection rate: A meta-analysis of randomized controlled trials.

OBJECTIVE: This meta-analysis aimed to evaluate whether EndoCuff-assisted colonoscopy (EAC) could improve adenoma detection rate (ADR) compared with standard colonoscopy (SC). METHODS: PubMed, EMBASE, Scopus, Cochrane Library, and Google Scholar databases were searched for articles published up to March 2019. All pure randomized controlled trials comparing ADR between EAC and SC groups were included. Dichotomous data were pooled to obtain the odds ratio with a 95% confidence interval (CI), whereas continuous data were pooled using a mean difference with 95% CI. Review Manager Version 5.3 was used for data analysis. RESULTS: Thirteen randomized controlled trials consisting of 9038 patients (EAC: 4574; SC: 4464) were included. The EAC group showed significant superiority over the SC group in ADR (odds ratio 1.37, 95% CI 1.15-1.62). However, there were no differences between the EAC and SC groups in adverse events, cecal intubation rate, and cecal intubation time. CONCLUSIONS: EAC could significantly improve ADR without increasing adverse events, especially for operators with low ADRs. In addition, no significant difference was observed in cecal intubation time and cecal intubation rate between EAC and SC.

The efficacy of vonoprazan for management of post-endoscopic submucosal dissection ulcers compared with proton pump inhibitors: A meta-analysis.

OBJECTIVE: Artificial ulcers after endoscopic submucosal dissection (ESD) are usually treated by proton pump inhibitors (PPIs) in clinical setting. Vonoprazan, a newly developed potassium-competitive acid blocker, has recently been used to treat post-ESD ulcers. We aimed to evaluate the efficacy and safety of vonoprazan on the healing of post-ESD artificial ulcers compared with those of proton pump inhibitors (PPIs) using a meta-analysis. METHODS: EMBASE, MEDLINE, Scopus and Cochrane Library databases were searched for all studies comparing the efficacy and safety of vonoprazan with those of PPIs in the treatment of post-ESD ulcers. RESULTS: Fourteen articles with 1328 patients were included in this meta-analysis. When comparing ulcer shrinkage rate, vonoprazan showed a better efficacy than PPIs (mean difference 0.56, 95% confidence interval [CI] 0.18-0.93). Vonoprazan also led to a higher scar formation rate (odds ratio [OR] 1.58, 95% CI 1.00-2.47) and showed a potential superiority on reducing the risk of post-ESD bleeding compared with PPIs, with a pooled OR of 0.69, although there was no statistically significant difference. CONCLUSIONS: Compared with PPIs, vonoprazan showed a better efficacy in ulcer shrinkage rate and achieved more complete healing in the treatment of post-ESD ulcers. Vonoprazan did not induce any incremental risk of post-ESD bleeding as well. It may be an appropriate choice in the management of artificial ulcers after ESD.