Unveiling the Growth Impact of Probiotics in Neonates: To BEgin or Not to BEgin?

Background/Objectives: This study aimed to evaluate the supportive role of probiotic supplementation in neonatal weight gain through a meta-analysis of published studies. Given the conflicting results in the literature, the objective was to determine the overall effect size and assess the influence of regional and intervention-specific factors. Methods: A total of 20 studies published between 2011 and 2022 were included, comprising a combined sample size of 3929 neonates. A random-effects model was used to calculate the pooled standardized mean difference (SMD) in neonatal weight gain attributable to probiotic supplementation. Heterogeneity among studies was assessed using the I² statistic. Subgroup analyses were conducted based on geographic region, probiotic strain, dosage, and treatment duration. Results: The pooled analysis demonstrated a modest but non-significant positive effect on neonatal weight gain (SMD: 0.27; 95% CI: -0.06 to 0.61), with substantial heterogeneity across studies (I² = 91%). Subgroup analyses indicated that regional variations, particularly in studies conducted in China, were associated with a more favorable effect. However, not all studies reported a benefit; some found no difference or even negative effects, particularly in discharge weight outcomes. Conclusions: Probiotic supplementation shows potential for improving neonatal weight gain, but findings remain inconsistent and heterogeneous. Strain selection, dosage, and treatment duration appear to be critical variables influencing outcomes. Future large-scale, multicenter randomized controlled trials are necessary to develop standardized, evidence-based guidelines for probiotic use in neonatal care.