Chronic constipation is common among older adults, significantly reducing quality of life and increasing healthcare burden. While dietary fiber is a traditional intervention for constipation, its efficacy in elderly populations remains inconclusive. The purpose of this study was to investigate the effects of dietary fiber on stool frequency, frequency of laxative or enema use, intestinal bifidobacteria concentration, stool dry weight, and adverse events in elderly patients with chronic constipation through a systematic review and meta-analysis of randomized controlled trials (RCTs). A comprehensive search of Embase, Web of Science, PubMed, Scopus, and The Cochrane Library databases was performed to identify eligible studies. Seven RCTs involving 187 participants were included. The meta-analysis found no significant improvement in stool frequency with dietary fiber supplementation (SMD = 0.25, 95% CI [-0.488, 0.988], p = 0.507). However, dietary fiber significantly reduced the frequency of laxative or enema use (SMD = -1.224, 95% CI [-1.786, -0.662], p = 0.000) and increased fecal bifidobacteria concentrations (SMD = 5.142, 95% CI [3.716, 6.568], p = 0.000). These findings suggest that dietary fiber supplementation may reduce reliance on laxatives and enhance intestinal microbiota in elderly individuals with chronic constipation. Further robust and clear randomized controlled trials are needed to more accurately determine the most effective dosage and duration of use.
Keywords: chronic constipation; dietary fiber; elderly; gut microbiota; meta-analysis.