Cognitive test scores favored probiotics, while everyday benefits remain unclear
A trial meta-analysis found better cognitive scores with probiotics than placebo; their practical meaning and the best formulation or duration remain uncertain.
Based on the published abstract. The full paper may contain additional methods, results and limitations.
The 30-second takeaway
The pooled trial results favored probiotics on cognitive tests. However, the abstract leaves the practical meaning of that difference unclear and describes subgroup analyses that include people with and without cognitive impairment. These findings do not establish which product works best, whether benefits persist, or whether supplementation changes disease progression.
This abstract-based summary cannot resolve the mix of diagnoses or assess everyday functioning and safety, which are not detailed.
What researchers found
Cognitive test scores: standardized mean difference
Probiotics versus placebo across trials; overall assessment timeframe not reported. Scores favored probiotics by 0.57 standard deviations, with a 95% confidence interval of 0.19–0.94.
Reading the standardized difference
Standard deviations express differences relative to how much scores vary, allowing different tests to be combined. These are neither ordinary test points nor percentages. The confidence interval gives a range of plausible average effects.
Subgroups do not establish an optimum
Results varied across analyses of strains, dose and duration, with greater variability for strain mixtures. The abstract does not report direct comparisons establishing that a particular formulation, higher dose or longer course was superior.
The original publication
Effectiveness of probiotic supplements on cognitive function in mild cognitive impairment and Alzheimer's disease: A meta-analysis of randomized controlled trials.
Peng TR, Lin HH, Tseng TL et al.
Gen Hosp Psychiatry · 2025
- PubMed ID
- 41237466
- Record checked
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