Emerging evidence suggests a potential role for the tryptophan-niacin pathway (including the end-product nicotinamide, an isoform of vitamin B3) in decreasing mucosal inflammation and affecting enteral microbiota. At the Tanzania site of MAL-ED, serum levels of tryptophan were related to subsequent linear growth, further suggesting importance of the tryptophan-niacin pathway. What is not clear is whether early childhood growth and development could be improved by targeting enteric infection and the tryptophan-niacin pathway by 1) delivering antibiotics against specific bacteria and/or 2) providing vitamin B3 as nicotinamide/niacinamide.