Antibiotic use and multiple sclerosis: A systematic review and meta-analysis

•There is the controversy between the results of studies that have investigated the relationship between antibiotic use and multiple sclerosis.•Five individual studies with 47,491 participants included in this meta-analysis.•There was no significant association between antibiotic use and the risk of MS.•There was no significant association between penicillin use and the risk of MS. : Epidemiological studies have shown conflicting results between antibiotic use and multiple sclerosis (MS) risks. The present systematic review and meta-analysis were conducted to assess the association between antibiotic use and the risk of MS. : PubMed, Scopus, Embase, Web of Science, and Google Scholar as well as reference lists of retrieved studies were searched systematically to identify studies were assessed the relationship between antibiotic use and MS up to September 24, 2022. Random-effects model was used for the calculation of pooled Odds ratio (OR) and 95% confidence intervals (CI). : Five independent studies containing 47,491 participants were included in the meta-analysis. The overall results of included studies showed a non-significant positive association between antibiotic use (OR overall=1.01, 95%CI: 0.75–1.37) and a non-significant negative association between penicillin use (OR overall= 0.83; 95%CI: 0.62–1.13) and MS risk. Heterogeneity was (I2=90.1, P heterogeneity < 0.001) and (I2=90.7, P heterogeneity < 0.001) in antibiotics and penicillin use groups respectively. : Our meta-analysis did not show a significant association between antibiotic or penicillin use with the risk of MS. However, due to the limitations of this study, further well-designed studies are required to confirm our findings.