Microbiota manipulation for weight change

We identified and included 13 adult, 17 children, and 23 infant RCTs. Effects were opposite among adults and children, showing weight loss among adults (SMD −0.54 [−0.83, −0.25)) and minor weight gains among children (SMD 0.20 [0.04, 0.36]) and infants (SMD 0.30 [−0.01, 0.62]) taking mainly Lactobacillus probiotic supplements. Heterogeneity was substantial in the adult and infant analyses and could not be explained by intervention or patient characteristics. Azithromycin administration in children with pulmonary disease was associated with weight gain (SMD 0.39 [0.24, 0.54]), without heterogeneity. A high risk of selective reporting and attrition bias was detected across the studies, making it difficult to draw firm conclusions. Overall, our meta-analysis suggests that there may be a role for probiotics in promoting weight loss in adults and weight gain in children, however additional studies are needed. Though we cannot recommend antibiotic administration for weight manipulation, its use provides advantageous weight gain in children with cystic fibrosis and bronchiectasis.