IDDF2020-ABS-0202 Meta-analysis on the Effect of Probiotics on Neurodegenerative Disorders in Humans Clinical Trials

Background Probiotics have been shown to improve neurocognitive behaviour in animal models via the gut-brain-axis. This meta-analysis aims to evaluate the evidence in human studies on the potential of probiotics as a treatment for age-related neurodegeneration such as Mild Cognitive Impairment (MCI) and Alzheimer’s Disease (AD). Methods A PRISMA meta-analysis was conducted by screening through MEDLINE, Embase, Scopus, Web of Science and Cochrane library for human studies using equivalent combinations of ‘probiotics’, ‘age-related neurodegeneration’, ‘MCI’ and ‘AD’. Studies with Mini-mental State Examination (MMSE), a test for cognitive function with comparable quantitative outcome were meta-analysed using RStudio. The analysis for overall effect (95% CI) and heterogeneity (I2) was performed by Forest Plots and subgroup analysis. We further assessed whether the results varied with age,%female, BMI, dosage and sample size with weighted meta-regression. Probiotic amelioration of neurodegeneration was also evaluated through biomarker analysis. Results 9 human studies were identified, where 5 studies had quantitative results. Meta-analysis demonstrates that there is a 0.9 mark (0.1 to 1.9) improvement in MMSE scores in human RCTs, though the results are quite heterogeneous (I2 = 94%) (figure 1). Subgroup analysis of MCI and AD models were divergent with a difference of -0.1 (-0.3 to 0.2) versus a 1.7 (0.9 to 2.5) difference in MMSE score between the two groups. Studies also report improvement in other cognitive tests, such as CERAD and RBANS. Meta-regression revealed that the improvement in MMSE scores is age-dependent (p Conclusions Human study evidence generally shows an association between probiotic supplementation and improved neurocognitive function, although confounded by age and severity of neurodegeneration. Caution should be applied in the use of probiotics as an intervention for cognitive decline.