Probiotic Supplementation for Promotion of Growth in Undernourished Children: A Systematic Review and Meta-Analysis

Objectives: Probiotic supplementation has been proposed as a therapeutic intervention to improve growth outcomes in children with undernutrition. The objective of this review is to synthesize the current evidence on probiotic supplementation for promotion of growth in undernourished children. Methods: We searched MEDLINE, Cochrane CENTRAL, CINAHL, Embase, LILACS, and Scopus for randomized controlled trials (RCTs) that administered probiotics or eligible comparators to undernourished children below 5 years of age. Our primary outcomes of interest were weight-for-age, height-for-age, and weight-for-height at the longest follow-up points reported. Random-effects meta-analysis was used to calculate standardized mean differences (SMD) for continuous outcomes and risk ratios for dichotomous outcomes. The Grading of Recommendations Assessment, Development and Evaluation criteria were used to assess certainty of the evidence. Results: Nine RCTs with 5295 children in total were included. Durations of treatment ranged from 1 month to 1 year. Pooled analyses from 7 studies showed that probiotics may have little to no effect on weight-for-age (SMD 0.05 standard deviation [SD], 95% CI: -0.04 to 0.13, n = 2115 children; low-certainty evidence) and height-for-age (SMD -0.04 SD, 95% CI: -0.14 to 0.07, n = 1357 children; low-certainty evidence). The evidence was very uncertain about the effect on weight-for-height. Conclusions: Probiotics may have little to no effect on anthropometry in undernourished children, though there is considerable heterogeneity among the trials reviewed thus far. The interaction between gut microbiota and human nutrition is complex, and further research is needed to determine how the gut microbiome may contribute to undernutrition and how probiotics may affect growth in this vulnerable population.