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
What this study found
Both probiotic strains improved cognition and anxiety over 12 weeks, with better MMSE, CFT, and IADL outcomes than placebo, but no significant benefit for basic ADL. MMSE and CFT showed significant time-by-group effects (both P < 0.0001); post hoc MMSE differences versus placebo were 4.86 for B. longum and 4.06 for L. rhamnosus, and CFT favored both active arms versus placebo (P < 0.0001). IADL also improved versus placebo for L. rhamnosus (difference 1.05, 95% CI 0.49-1.61; P < 0.0001) and B. longum (difference 1.50, 95% CI 0.93-2.06; P < 0.0001), while ADL was not significant (P = 0.24).…
- Study & population
- Randomized, double-blind, placebo-controlled, multicenter trial in Iran.
- Intervention
- Two oral probiotic regimens were tested for 12 weeks: Lactobacillus rhamnosus HA-114 or Bifidobacterium longum R0175.
- Key limitation
- Per-active-arm sample size was modest (n = 30 each), and follow-up was short at 12 weeks.
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Open PDFOriginal 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 single-strain probiotics on cognition, physical activity, and anxiety in subjects with mild and moderate AD. Eligible patients (n = 90) with AD were randomly assigned to either of two interventions [Lactobacillus rhamnosus HA-114 (1015 CFU) or Bifidobacterium longum R0175 (1015 CFU)] or placebo group, receiving probiotic supplement twice daily for 12 weeks. The primary outcome of the study was cognitive function measured by using the two tests, namely, the Mini-Mental State Examination (MMSE) and the categorical verbal fluency test (CFT). Secondary outcomes included a performance in Activities of Daily Living (ADL), the Lawton Instrumental Activities of Daily Living (IADL) scale, and the Generalized Anxiety Disorder (GAD-7) scale. Linear mixed-effect models were used to investigate the independent effects of probiotics on clinical outcomes. After 12 weeks, MMSE significantly improved cognition (PInteraction < 0.0001), with post hoc comparisons identifying significantly more improvement in the B. longum intervention group (differences: 4.86, 95% CI: 3.91–5.81; P < 0.0001) compared with both the placebo and L. rhamnosus intervention groups (differences: 4.06, 95% CI: 3.11–5.01; P < 0.0001). There was no significant difference between the two intervention groups (differences: −0.8, 95% CI: −1.74 to 0.14; P = 0.09). In conclusion, this trial demonstrated that 12-week probiotic supplementation compared with placebo had beneficial effects on the cognition status of patients with AD.