whilst in the placebo group, these variables decreased significantly(P =0.001). The observed changes between two groups were statistically significant (P < 0.05). Although WAZ and HAZ of infants increased slightly in the supplemented group (from1.19±0.79 to1.20±0.69 and0.36±0.86 to0.37±0.85 respectively) ,these two parameters decreased in the placebo group which was significant only for WAZ (P = 0.01). Moreover,nosignificant association was found between mineral intake and breast milk mineral contents. It seems,synbiotic supplementation may have positive effects on breast milk mineral contents