Authors: Abdul Hannan Siddiqui, Hassan Waseem, Jamir Pitton Rissardo, Zain Abideen, Ana Leticia Fornari Caprara, Vishnu Byroju, FNU Maria, Saba Yaqoob, Zulfiqar Jogezai, Muhammad Moosa, Asma Saif, Muhammad Bilal, Fizza Batool, Areeba Ehsan, Muhammad Shoaib, and Sania Aimen
Conference: 2025 AAN Annual Meeting, San Diego, CA
Objective
This study aims to analyze the probiotic’s effect on neurocognitive function and markers of oxidative stress in Alzheimer’s disease (AD) patients.
Background
AD, being a progressive neurodegenerative disease, constitutes nearly 70% of all the cases related to dementia. Different oxidative stress reduction therapies are being discussed for AD including probiotics.
Design/Methods
PubMed, Cochrane Central, and ScienceDirect were searched till September 2024. The cognitive outcome of interest was the Mini-Mental State Examination (MMSE) score while the metabolic and oxidative outcomes of interest were levels of glutathione (GSH), nitric oxide (NO), malondialdehyde (MAD), total antioxidant capacity (TAC), homeostatic model of assessment for insulin resistance (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), triglycerides (TAG) and total cholesterol. Statistical analysis was performed on Review Manager version 5.4.1 employing a random effects model. The Cochrane RoB 2.0 tool was used for quality assessment.
Results
Five randomized clinical trials were included in the final analysis. The results depict that the MMSE score (MD = 2.49; 95% CI: [0.44,4.53] ; p = 0.02; I2 = 85%) and GSH levels (MD = 17.78 μmol/L, 95% CI: [3.07,32.50]; p=0.02; I2=0%) were significantly higher in the probiotics group. Probiotics also resulted in reduced MAD (MD = −1.54 μmol/L, 95% CI;[−2.31,−0.78] ; p<0.0001; I2 =95%), HOMA-IR (MD =−0.30, 95% CI:[−0.55,−0.05]; p=0.02; I2 =0%) and an increase in QUICKI (MD =0.01, 95% CI:[0.00,0.01]; p=0.03; I2 =0%) levels compared to placebo. Other outcomes like TAC (MD =−0.80 mmol/L, 95% CI:[−101.78,100.19]; p=0.99; I2 =84%), NO (MD =−0.64 μmol/L, 95% CI:[−2.92,1.63]; p=0.58; I2 =31%), TAG (MD =−14.55 mg/dL, 95% CI:[−30.73,1.63]; p=0.08; I2 =0%), total cholesterol (MD =−3.98 mg/dL, 95% CI:[−15.68,7.71]; p=0.50; I2 =0%) were comparable between two groups.
Conclusions
Probiotics improved neurocognitive function in AD patients. They also increased antioxidants like GSH, reduced inflammatory markers like MAD, and lowered insulin resistance.
Citation
Siddiqui AH, Waseem H, Rissardo JP, Abideen Z, Caprara AL, Byroju V, Maria FN, Yaqoob S, Jogezai Z, Moosa M, Saif A. Effect of Probiotics on Oxidative, Cognitive and Metabolic Outcomes in Alzheimer’s Disease: A Systematic Review and Meta-analysis of Randomized Clinical Trials (P12-3.014). Neurology 2025;104(7_Supplement_1):48. doi: 10.1212/WNL.0000000000208368.
Figure. Forest plots showing the effect of probiotics on oMMSE, glutathione, and malondialdehyde in patients with Alzheimer's disease.