Effect of Probiotic Bifidobacterium breve in Improving Cognitive Function and Preventing Brain Atrophy in Older Patients with Suspected Mild Cognitive Impairment: Results of a 24-Week Randomized, Double-Blind, Placebo-Controlled Trial
What this study found
Total ADAS-Jcog and MMSE scores did not differ between probiotic and placebo. Orientation improved at 24 weeks with MCC1274 (ADAS-Jcog orientation, p=0.021); MMSE orientation in time improved in participants with baseline MMSE <25 (p=0.006). In MMSE <25, ADAS-Jcog orientation improved (p=0.022). In MMSE ≥25, minor improvements in ADAS-Jcog construction (p=0.021) and MMSE writing (p=0.036). A modified MMSE (excluding Serial-7) showed total MMSE improvement at week 16 in MMSE <25 (p=0.011). MRI (VSRAD) indicated slower brain atrophy progression with MCC1274; GM extent difference between groups…
- Study & population
- Randomized, double-blind, placebo-controlled trial in older adults with suspected MCI; 130 participants aged 65–88 years; DSM-5 criteria for MCI; MMSE 22–26; CDR 0.5; conducted in Tokyo, Japan; outcomes included ADAS-Jcog, MMSE, and MRI with VSRAD.
- Intervention
- Bifidobacterium breve MCC1274, 2×10^10 CFU per sachet, taken once daily for 24 weeks; oral administration.
- Key limitation
- COVID-19 reduced the planned sample size (from 140 to 130); 115 completed the Full Analysis Set; many findings are subgroup analyses and may be underpowered; generalizability limited to Japanese older adults with MCI; RBANS was not used; long-term effects unknown.
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Open PDFOriginal abstract
Background: Probiotics have been reported to ameliorate cognitive impairment. Objective: We investigated the effect of the probiotic strain Bifidobacterium breve MCC1274 (A1) in enhancing cognition and preventing brain atrophy of older patients with mild cognitive impairment (MCI). Methods: In this RCT, 130 patients aged from 65 to 88 years old with suspected MCI received once daily either probiotic (B. breve MCC1274, 2×1010 CFU) or placebo for 24 weeks. Cognitive functions were assessed by ADAS-Jcog and MMSE tests. Participants underwent MRI to determine brain atrophy changes using Voxel-based Specific Regional Analysis System for Alzheimer’s disease (VSRAD). Fecal samples were collected for the analysis of gut microbiota composition. Results: Analysis was performed on 115 participants as the full analysis set (probiotic 55, placebo 60). ADAS-Jcog subscale “orientation” was significantly improved compared to placebo at 24 weeks. MMSE subscales “orientation in time” and “writing” were significantly improved compared to placebo in the lower baseline MMSE (< 25) subgroup at 24 weeks. VSRAD scores worsened in the placebo group; probiotic supplementation tended to suppress the progression, in particular among those subjects with progressed brain atrophy (VOI Z-score ≥1.0). There were no marked changes in the overall composition of the gut microbiota by the probiotic supplementation. Conclusion: Improvement of cognitive function was observed on some subscales scores only likely due to the lower sensitiveness of these tests for MCI subjects. Probiotics consumption for 24 weeks suppressed brain atrophy progression, suggesting that B. breve MCC1274 helps prevent cognitive impairment of MCI subjects.