In a randomized controlled clinical trial, individuals with functional dyspepsia who received Bifidobacterium animalis subspecies lactis BL-99 (BL-99) displayed remarkably higher clinical response rates when compared to the control group after 8-week treatment. This effect continued for two weeks after the treatment but waned by the 8-week mark. The research, which involved 200 functional dyspepsia patients, compared the efficacy of placebo, Rabeprazole (a positive-drug control), and BL-99 in two different doses over an 8-week period.

The key endpoint ascertained was the clinical response rate of functional dyspepsia score after the treatment period, with secondary endpoints including responses at other time points, as well as various physiological indicators such as serum biomarkers, fecal microbiota composition, and metabolite levels. The findings were striking. The group receiving the high dose of BL-99 exhibited a remarkable clinical response rate of 90.0%, markedly surpassing the placebo (58.0%), low-dose BL-99 (74.0%), and positive-drug control (70.0%) groups after the eight-week treatment period.

Notably, this effect was sustained for up to 2 weeks post-treatment, demonstrating the sustained potential of BL-99 in alleviating functional dyspepsia symptoms. Further analysis utilizing metagenomic and metabolomic techniques unveiled the underlying mechanisms behind BL-99's effectiveness. It was found that BL-99 promoted the proliferation of short-chain fatty acid-producing microbiota, leading to a rise in short-chain fatty acid levels in both stool and serum.

This escalation in short-chain fatty acid levels was correlated with elevated serum gastrin levels, suggesting a potential mechanism for BL-99's therapeutic effect on functional dyspepsia. The potential use of BL-99 (probiotic) as a sustainable and effective treatment for functional dyspepsia marks a paradigm shift in the management of this challenging condition.