Effects of probiotic supplements on cognition, anxiety, and physical activity in subjects with mild and moderate Alzheimer’s disease: A randomized, double-blind, and placebo-controlled study

Frontiers in Aging Neuroscience
Q2
Oct 2022
Citations:58
Influential Citations:4
Interventional (Human) Studies
90
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Enhanced Details

Methods
12-week multicenter, randomized, parallel, double-blind, and placebo-controlled trial conducted in Iran; 90 older adults (aged 50–90) with mild-to-moderate Alzheimer’s disease; diagnosed by NINDS-ADRDA criteria and FAST score 4–6B; three groups (placebo, L. rhamnosus HA-114, and B. longum R0175); primary outcomes: MMSE and CFT; secondary outcomes: ADL (Barthel Index), IADL, and GAD-7; linear mixed-effects model for analysis.
Intervention
Two capsules daily for 12 weeks; Lactobacillus rhamnosus HA-114, each capsule containing 10^15 CFU; Bifidobacterium longum R0175, each capsule containing 10^15 CFU; placebo capsules identical in appearance; capsules taken orally, one after lunch and one after dinner.
Results
Probiotic supplementation for 12 weeks improved cognitive status and anxiety in older adults with Alzheimer’s disease. B. longum R0175 produced the largest MMSE improvement versus placebo (≈4.86 points; 95% CI 3.91–5.81), while L. rhamnosus HA-114 also outperformed placebo (≈4.06 points; 95% CI 3.11–5.01). CFT improved, IADL improved, while ADL did not change significantly; GAD-7 anxiety decreased with probiotics. Conclusion: probiotics may serve as a beneficial adjuvant therapy to enhance cognition and daily function and reduce anxiety in AD; longer-term trials are needed to confirm durability and mechanisms.
Limitations
Small sample size (n=90; 30 per group) and 12-week duration; did not assess gut microbiota changes to elucidate mechanisms; results limited to older adults with mild-to-moderate Alzheimer’s disease in Iran; no long-term follow-up.

Abstract

Probiotics have been suggested as an effective adjuvant treatment for Alzheimer’s disease (AD) due to their modulating effect on the gut microbiota, which may affect the gut-brain axis. Therefore, we aimed to evaluate the effects of two different sin...