Probiotic supplements are effective in people with cognitive impairment: a meta-analysis of randomized controlled trials

source extracted confidence: high 2026-04-09
#humans #aged #alzheimer-disease #quality-of-life #randomized-controlled-trials-as-topic

Probiotic supplements are effective in people with cognitive impairment: a meta-analysis of randomized controlled trials

Liu et al., 2023 | Nutr Rev | Meta Analysis

Citation

Liu Nanyang, Yang Di, ... Li Yapeng. Probiotic supplements are effective in people with cognitive impairment: a meta-analysis of randomized controlled trials. Nutr Rev. 2023-Aug-10;81(9):1091-1104. doi:10.1093/nutrit/nuac113

Abstract

CONTEXT: Cognitive function is a significant concern among the elderly and has a major negative effect on their quality of life. Probiotics have a positive effect on improving cognition, but the exact nature of the association between probiotic supplements and cognitive function is poorly understood. OBJECTIVE: The purpose of this systematic review was to evaluate how probiotic supplements improve cognitive function. DATA SOURCES: A systematic search was conducted of the PubMed, Web of Science, the Cochrane Library, Embase, and ClinicalTrials.gov databases for all relevant studies published in English, with no date restrictions. DATA EXTRACTION: The estimated, pooled results were analyzed with a standardized mean difference (SMD) and a corresponding 95% confidence interval (95%CI). Publication bias was analyzed by the Egger's and Begg's tests. Funnel plots were also constructed to assess the probability of publication bias. The robustness of the results was tested using the method of sequential removal and cumulation of each trial. DATA ANALYSIS: Overall, the pooled SMD showed significant differences between the probiotic and placebo groups (SMD = 0.64; 95%CI, 0.15-1.12), with significant heterogeneity (I2 = 92%). Subgroup analyses showed a significant effect of probiotics on cognition in the studies involving populations with Alzheimer's disease and cognitive impairment (SMD = 1.34; 95%CI, 0.51-2.16; P < 0.01). In addition, subgroup analysis showed that single probiotic strains, receiving probiotic supplements over 12 weeks, and doses >1 × 109 CFU/g were more beneficial for improving cognitive impairment. CONCLUSIONS: According to this meta-analysis, probiotic supplementation had a highly significant effect on cognitive function in people with cognitive impairment or Alzheimer's disease. For people without cognitive impairment, probiotic supplementation may be ineffective.

Key Findings

According to this meta-analysis, probiotic supplementation had a highly significant effect on cognitive function in people with cognitive impairment or Alzheimer's disease. For people without cognitive impairment, probiotic supplementation may be ineffective.

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size See abstract
Age Range See abstract
Condition cognitive

MeSH Terms

  • Humans
  • Aged
  • Alzheimer Disease
  • Quality of Life
  • Randomized Controlled Trials as Topic
  • Dietary Supplements
  • Probiotics
  • Cognitive Dysfunction

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Systematic Review, Meta-Analysis, Journal Article, Research Support, Non-U.S. Gov't
  • Vertical: probiotics

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09