BL-99 shortens intestinal transit in a small older-adult trial
A peer-reviewed trial of 73 older adults with constipation found that BL-99 shortened intestinal transit compared with placebo over four weeks. Some bowel-movement measures improved, while constipation scores and quality of life showed no significant final difference between groups. Mouse and cell experiments explored a possible mechanism that remains unconfirmed in humans.
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Transit time falls in a four-week trial
A single peer-reviewed placebo-controlled trial tested the bacterial strain BL-99 in 73 older adults with functional constipation in Beijing. The average participant was 67.8 years old, and entry required a whole-gut transit time of 59 hours or longer. BL-99 was given to 37 participants, while 36 received placebo. All completed four weeks. After adjustment, the final assessment put the BL-99 group’s transit time 28.6 hours below placebo. The 95 per cent confidence interval ranged from a 20.4-hour reduction to 36.8 hours.[1]
Bowel movements improve more than other outcomes
The between-group difference was 2.58 spontaneous bowel movements per week and 1.17 complete spontaneous bowel movements. The final constipation-score comparison was not statistically significant, and the quality-of-life scale showed no significant difference. These outcomes distinguish faster transit and more frequent bowel movements from a broader improvement in daily wellbeing. A separate part of the research used aged mice and cells to investigate a possible connection between bile acids and regulatory proteins in intestinal smooth muscle. Some steps of the proposed pathway remain unconfirmed in humans.[1]
A small, selective sample limits generalisation
Participants came from one geographical setting, 72.6 per cent were women, and people with some accompanying illnesses were excluded. The small sample and short follow-up limit application to a wider older population. No adverse events were reported during the four weeks, but that observation cannot determine long-term safety. The findings concern Bifidobacterium animalis subsp. lactis BL-99 specifically. They support further testing of this strain and the proposed biological pathway, while leaving the effects of other probiotics to separate investigations.[1]
