Probiotics treatment improves cognitive impairment in patients and animals: A systematic review and meta-analysis

Neurosci Biobehav Rev. 2021 Jan:120:159-172. doi: 10.1016/j.neubiorev.2020.10.027. Epub 2020 Nov 4.


The gut-brain axis has received considerable attention in recent years, and the "psychobiotics" concept indicates that probiotics have a potential positive effect on cognitive function. Therefore, the aim of this study was to quantitatively evaluate the influence of probiotics on cognition. We conducted a random-eff ;ects meta-analysis of 7 controlled clinical trials and 11 animals studies to evaluate the eff ;ects of probiotics on cognitive function. Probiotics supplementation enhanced cognitive function in both human (0.24 [0.05-0.42]; I2 = 0 %) and animal studies (0.90 [0.47-1.34]; I2 = 74 %). Subgroup analyses indicated that the effects of probiotics on cognitively impaired individuals (0.25 [0.05-0.45]; I2 = 0 %) were greater than those on healthy ones (0.15 [-0.30 to 0.60]; I2 = 0 %). Furthermore, compared with a multiple-probiotic supplement, a single strain of probiotics was more effective in humans. The meta-analysis provided some suggestions for probiotics intervention and tended to support a customized approach for different individuals to ameliorate cognitive disorders. Future additional clinical trials are necessary to evaluate therapeutic effect and influencing factors.

Keywords: Cognitive function; Meta-analysis; Morris water maze test; Novel-object recognition test; Probiotics; Therapy.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Review
  • Systematic Review

MeSH terms

  • Animals
  • Cognition
  • Cognition Disorders*
  • Cognitive Dysfunction* / therapy
  • Dietary Supplements
  • Humans
  • Probiotics* / therapeutic use