Lactobacillus rhamnosus Used in the Perinatal Period for the Prevention of Atopic Dermatitis in Infants: A Systematic Review and Meta-Analysis of Randomized Trials

Background Numerous systematic reviews and meta-analyses have examined the effects of probiotics used perinatally on prevention or treatment of atopic disease in infants and children. However, to date, no review has examined randomized controlled trials of Lactobacillus rhamnosus , specifically, administered both prenatally and postnatally and its effect over a long period of time. Objective The objective was to determine if L. rhamnosus either used solely or in conjunction with other probiotics demonstrates a long-term preventive effect on atopic disease in pediatric patients when used perinatally. Methods A systematic review was undertaken to identify those studies where L. rhamnosus was used (either solely or in conjunction with other probiotics). The following databases were searched from the year 2000 through December 8, 2021: PubMed, Cochrane Reviews and Cochrane Central Database of Controlled Trials; systematic reviews were hand searched to identify randomized controlled trials (RCTs). Meta-analytic statistical techniques were then employed. Evaluation of the incidence of atopic eczema was also examined longitudinally based on timeframe. Grading of Recommendations, Assessment, Development and Evaluations (GRADE) assessments were employed to determine the quality of the evidence. Results Eleven randomized controlled trials were identified which examined L. rhamnosus in its effect on atopy. Risk of bias was low on the majority of the domains assessed. Meta-analysis of the timeframes ≤ 2 years (RR 0.60, 95% CI 0.47–0.75; p < 0.00001) and 6–7 years (RR 0.62, 95% CI 0.50–0.75; p < 0.00001) demonstrated statistically significant reductions in atopic eczema with use of L. rhamnosus . For the 4 to 5-year (RR 0.74, 95% CI 0.55–1.00; p = 0.05) and 10–11-year (RR 0.68, 95% CI 0.37–1.27; p = 0.23) timeframes there was no statistically significant reduction. GRADE assessment for each timeframe was considered moderate in two, owing to high attrition rates in all of the studies, and low in two due to imprecision. Conclusion Based on the meta-analysis and GRADE assessments, the use of L. rhamnosus with or without other probiotics appears to have a positive effect in reducing the incidence of atopic eczema in pediatric patients at least out to 7 years. Attrition rates temper these findings.