BACKGROUND: Chronic constipation is prevalent in middle-aged and elderly individuals and can markedly impair quality of life and increase comorbidity risk. However, safe and effective therapies for this population remain limited because of age-related physiological changes, polypharmacy, and concerns about long-term medication use. METHODS: We conducted a randomized, double-blind, controlled clinical trial enrolling 140 participants aged ≥45 years with chronic constipation to evaluate a synbiotic containing Heyndrickxia coagulans (H. coagulans) TBC169 plus dietary fibers as an adjunct intervention. RESULTS: Compared with dietary fiber alone, the TBC169-based synbiotic significantly improved constipation outcomes, including increased weekly bowel movements (WBMs), higher Bristol stool scale (BSS) scores, and reduced Wexner and Patient Assessment of Constipation Quality of Life (PAC-QOL) scores. Post-intervention gut microbiota profiling showed higher Shannon and FaithPD diversity indices and distinct community composition in the synbiotic group compared with the dietary-fiber control group, along with higher relative abundance of Blautia, Akkermansia, Faecalibacterium, and Bacillus and lower relative abundance of Collinsella. Because baseline faecal samples were not collected, these microbiota findings should be interpreted as exploratory between-group associations. Ecological analyses suggested enhanced microbial stability and metabolic potential, and correlations linked key taxa with clinical improvement. The intervention was well-tolerated, with only mild, transient adverse events. CONCLUSIONS: The synbiotic formulation containing H. coagulans TBC169 and dietary fiber-related components was well-tolerated and may improve constipation-related outcomes in middle-aged and elderly adults. Because the formulation contained both probiotic and fiber components, the observed effects should be attributed to the combined synbiotic product rather than to H. coagulans TBC169 alone. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2400085844, http: //www. chictr. org. cn/), registered on June 19, 2024.
Zhou et al. (Mon,) studied this question.