A synbiotic containing Heyndrickxia coagulans TBC169 plus dietary fibers significantly improved constipation outcomes including weekly bowel movements, stool consistency, and quality of life compared with dietary fiber alone in middle-aged and elderly adults with chronic constipation.
Key Findings
Results
The TBC169-based synbiotic significantly increased weekly bowel movements (WBMs) compared with dietary fiber alone.
Randomized, double-blind, controlled clinical trial with 140 participants aged ≥45 years with chronic constipation
Participants were assigned to either the synbiotic (H. coagulans TBC169 plus dietary fibers) or dietary fiber control group
Increased WBMs were a primary constipation outcome measure
The trial was registered in the Chinese Clinical Trial Registry (ChiCTR2400085844)
Results
The synbiotic intervention produced higher Bristol Stool Scale (BSS) scores compared with the dietary fiber control group.
Higher BSS scores indicate stool consistency more consistent with normal bowel function
BSS score improvement was one of the key constipation outcome measures evaluated
The effect was attributed to the combined synbiotic product rather than H. coagulans TBC169 alone
Results
The synbiotic group showed reduced Wexner constipation scores compared with the dietary fiber control group.
The Wexner score is a validated clinical measure of constipation severity
Lower Wexner scores indicate improvement in constipation symptoms
This improvement was observed in middle-aged and elderly participants (aged ≥45 years)
Results
The synbiotic intervention reduced Patient Assessment of Constipation Quality of Life (PAC-QOL) scores compared with dietary fiber alone.
Lower PAC-QOL scores indicate better quality of life related to constipation
Quality of life improvement was a secondary outcome measured in the trial
The finding is relevant given that chronic constipation can markedly impair quality of life
Results
Post-intervention gut microbiota profiling showed higher alpha diversity in the synbiotic group compared with the dietary fiber control group.
Higher Shannon diversity indices were observed in the synbiotic group
Higher Faith_PD (phylogenetic diversity) indices were also observed in the synbiotic group
Distinct community composition was found in the synbiotic group compared with the dietary-fiber control group
Because baseline fecal samples were not collected, these microbiota findings are described as 'exploratory between-group associations'
Results
The synbiotic group had higher relative abundance of beneficial bacterial taxa including Blautia, Akkermansia, Faecalibacterium, and Bacillus compared with the dietary fiber control group.
Lower relative abundance of Collinsella was also observed in the synbiotic group
Ecological analyses suggested enhanced microbial stability and metabolic potential in the synbiotic group
Correlations were identified linking key taxa with clinical improvement
Authors caution these are exploratory associations due to lack of baseline fecal samples
Results
The synbiotic formulation was well-tolerated, with only mild, transient adverse events reported.
Safety was a key consideration given the study population's age-related physiological changes and polypharmacy concerns
No serious adverse events were attributed to the intervention
The tolerability profile supports potential use as a safe intervention in middle-aged and elderly populations
What This Means
This research suggests that a synbiotic supplement — combining a specific probiotic strain called Heyndrickxia coagulans TBC169 with dietary fiber — can meaningfully improve chronic constipation in people aged 45 and older. In a clinical trial of 140 participants, those taking the synbiotic had more frequent bowel movements per week, better stool consistency (as measured by the Bristol Stool Scale), and lower scores on standardized measures of constipation severity and constipation-related quality of life, compared to those taking dietary fiber alone. The supplement was well-tolerated, producing only mild and temporary side effects.
The study also found differences in gut bacteria between the two groups after the intervention. People taking the synbiotic had greater bacterial diversity and higher levels of bacteria generally considered beneficial (such as Blautia, Akkermansia, and Faecalibacterium), as well as lower levels of Collinsella. However, because stool samples were not collected at the start of the study, these microbiota differences cannot be definitively linked to the treatment — they represent associations observed at the end of the trial rather than proven changes caused by the supplement. The authors also emphasize that the benefits seen should be credited to the synbiotic combination as a whole, not to the probiotic strain alone.
This research matters because chronic constipation is common in older adults and current treatment options can be problematic due to drug interactions, side effects, and concerns about long-term use. This research suggests that a synbiotic supplement combining probiotics and dietary fiber could offer a safe and effective complementary approach for managing constipation in middle-aged and elderly individuals, though further studies with baseline microbiome measurements would help clarify the biological mechanisms involved.
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Zhou X, Guo C, Hu G, Ding L, Zou T, Wang M, et al.. (2026). Synbiotic Supplementation With Heyndrickxia coagulans TBC169 Improves Chronic Constipation in Middle-Aged and Elderly.. Biotechnology journal. https://doi.org/10.1002/biot.70250