Probiotic trials favored cognitive test scores in older adults with Alzheimer's disease
In older adults with diagnosed Alzheimer's disease, pooled trials favored probiotics over placebo on cognitive tests. Results differed substantially, and the abstract does not establish improved everyday functioning.
Based on the published abstract. The full paper may contain additional methods, results and limitations.
The 30-second takeaway
Across randomized trials in older adults with Alzheimer's disease, probiotic supplementation produced better cognitive test scores than placebo on average. Results varied substantially between studies, and only a limited set of trials was available. The abstract does not establish whether the score differences translated into daily functioning or persisted beyond the study periods.
The abstract omits treatment duration, individual trial results, and everyday-function outcomes. Substantial variation among studies makes the pooled cognitive-score estimate difficult to apply to a particular probiotic product or patient.
What researchers found
Cognitive function in Alzheimer's disease
Compared with placebo across trials of unreported duration: standardized mean difference 0.67 (95% CI 0.14 to 1.19), expressing the score gap on a shared statistical scale.
What improved
The outcome was performance on validated cognitive assessments. Combining different tests requires a standardized statistical scale, so the pooled result cannot be read as a percentage improvement or a specific number of points on any single test.
Differences between trials
Subgroup analyses suggested that formulation, dosage, and initial disease severity might influence results. The abstract does not provide enough detail to establish a preferred formulation or dose, or identify which patients would experience a meaningful change.
The original publication
Efficacy of probiotic supplementation in influencing cognitive function in Alzheimer's disease: A systematic review and meta-analysis.
Liu W, Guo J, Dong Y et al.
J Food Sci · 2025
- PubMed ID
- 40709497
- Record checked
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