Probiotics and cognitive test scores: promising results with substantial uncertainty
A review in older adults found better cognitive test scores with probiotics than placebo, but differences across studies leave the practical meaning uncertain.
Based on the published abstract. The full paper may contain additional methods, results and limitations.
The 30-second takeaway
Probiotics were associated with better scores on cognitive tests in this review, with the authors highlighting studies that enrolled people with cognitive impairment. However, the studies differed substantially, and the abstract does not establish how these test changes translate into everyday functioning. The findings leave the clinical relevance of supplementation uncertain.
Substantial differences across studies and limited biomarker evidence reduce certainty. The abstract does not specify treatment durations or establish whether cognitive score changes were meaningful in daily life.
What researchers found
Mini-Mental State Examination cognitive score
Probiotics versus placebo; standardized mean difference across studies. Treatment duration was not reported.
What was pooled
The researchers combined study results for cognition and also examined markers related to inflammation, oxidative stress and brain-derived neurotrophic factor. These laboratory measures were secondary outcomes, distinct from the cognitive tests.
What the score means
The central estimate expresses the difference on a standardized scale, rather than a change in raw test points. It does not show how many people noticed better memory or maintained greater independence.
The original publication
Probiotics and aging: Impacts on cognitive function, brain-derived neurotrophic factor, inflammation, and antioxidant activity. A systematic review and meta-analysis.
Handajani YS, Turana Y, Hengky A et al.
J Alzheimers Dis · 2026
- PubMed ID
- 41630163
- Record checked
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