Summary: In Thai adults with type 2 diabetes on metformin, six weeks of the probiotic strain BA-2591 attenuated the rise in fasting glucose, limited worsening of insulin resistance, and improved beta-cell indices versus placebo in a crossover trial, with some immune and lipid changes and no serious harm.
PICO Summary
| Element | Detail |
|---|---|
| Population | 44 Thai adults aged 35–65 with type 2 diabetes on metformin monotherapy (crossover). |
| Intervention | Bifidobacterium animalis subsp. lactis TISTR 2591 (BA-2591) 1×10⁹ CFU/g/day for 6 weeks. |
| Comparison | Placebo under identical conditions, with 4-week washout before crossover. |
| Outcome | Smaller fasting glucose rise (Δ +1.1 vs +12.6 mg/dL; p<0.001), less HOMA-IR worsening (p=0.006), improved HOMA-beta (Δ +6.8% vs -8.3%; p<0.001), higher IgM/IgG, lower LDL-C and cathepsin D. No change in IL-6, adiponectin, hs-CRP, or body composition. No serious adverse effects. |
Probiotic BA-2591 in type 2 diabetes
Crossover RCT · type 2 diabetes · 6 weeks
A specific probiotic strain blunted the rise in fasting glucose and improved beta-cell indices versus placebo over 6 weeks. Signals are surrogate-based and strain-specific, not a glycaemic treatment.
Expert Commentary
I like the crossover design here, because letting each patient serve as their own control is a genuine strength in a small study, and the metabolic signals point consistently in a favourable direction. What keeps my verdict cautious is the nature of those signals. The benefit was largely attenuation of a rise, glucose climbed in both arms and simply climbed less on the probiotic, which makes me wonder about temporal or dietary influences over the six weeks, and everything rests on surrogate HOMA indices rather than HbA1c or any clinical endpoint. The study also measured a long list of immune and oxidative markers, which raises the odds that some positive findings are chance, and the effect is strain-specific, so it tells me nothing about the probiotic on a shop shelf. Can I use this with my patients? Only as a low-risk adjunct for a well-informed patient who wants to try it, with modest expectations and the clear message that it does not replace metformin or lifestyle. Guidelines do not endorse probiotics for glycaemic control, and this small, short, surrogate-based trial does not change that. I would want a longer trial with HbA1c endpoints.
References
Khiaolaongam W, Boonyapranai K, Sitdhipol J, et al. Bifidobacterium animalis subsp. lactis TISTR 2591 improves glycemic control and immune response in adults with type 2 diabetes mellitus: a randomized, double-blind, placebo-controlled crossover clinical trial. Nutrients. 2025;17(19):3097. doi:10.3390/nu17193097