Human Milk Leptin, Insulin and N6/N3 Fatty Acids are associated with Early Differences in Gut Microbiome of Infants Born to Normal Weight and Obese Mothers

Abstract

BACKGROUNDObese mothers deliver offspring with greater risk of developing childhood obesity and the gut microbiome may be an important factor mediating this relationship during infancy.OBJECTIVEDetermine how exposure to human milk (HM) components are associated with the structure and function of infants' gut microbiome delivered to mothers with high vs. low pre‐pregnancy BMI.METHODSMicrobiota was determined from vaginally delivered exclusively breastfed full‐term infant stool samples using targeted 16S gene and whole‐genome shotgun sequencing. Insulin, leptin, total n‐6 and n‐3 fatty acids in fasting mid‐feed HM was measured by GC‐MS.RESULTSTaxa and metagenomes of the infant microbiome did not differ based on maternal BMI. HM insulin, leptin and n‐6/n‐3 fatty acid ratio were positively associated (p<0.01) with maternal BMI. Adjusting for maternal BMI, HM leptin was associated with Firmicutes (p=0.03) and Flavin adenine dinucleotide biosynthesis pathway (p=0.04). HM insulin was associated with Actinobacteria (p=0.02), leucine biosynthesis, lipid transport and metabolism (p<0.05). HM n‐6/n‐3 negatively associated with FAD (p=0.007) and Riboflavin biosynthesis (p=0.007).CONCLUSIONSInfant exposures to HM leptin, insulin, and n‐6/n‐3, all higher in mothers with high BMI, may influence the structure and function of the infant gut microbiota.