Maternal diet during the perinatal period has a significant impact on her offspring’s risk for metabolic diseases, including obesity and diabetes, via direct and indirect influence from the gut micorbiome. Studies have assessed the influence of maternal diet and microbiota composition on offspring health outcomes, but the relative impact of maternal diet during pregnancy vs. lactation has not been determined.


Pregnant Sprague-Dawley rats were fed high fat (HF) or low fat chow (CH) diets throughout pregnancy. All offspring were cross-fostered on postnatal day (P)1 to a different dam consuming CH or HF diet resulting in 4 offspring diet groups: CH-CH, CH-HF, HF-CH, and HF-HF (n=6 litters each, 1 male pup from each litter was used). Offspring body weight (BW) was measured weekly. Dam fecal and offspring colon samples were collected at P21 for microbiota analysis by 16S rRNA sequencing.


There was an overall significant effect (P<0.05) of maternal HF diet during lactation in increasing BW of pups at P21, independent of the maternal diet during gestation. Alpha diversity did not differ among the offspring groups. Analyses of the overall microbiota compositions characteristic of the 4 groups indicated that maternal diet during lactation, rather than gestation, had a greater influence on offspring gut microbiota profile and BW at P21. Turicibacter, Staphylococcus, and Ruminococcus were characteristic of CH diet during lactation and inversely associated with offspring BW. Lactococcus, Streptococcus, and Parabacteroides were characteristic of HF diet during lactation and positively correlated with offspring BW.


Maternal diet during the lactation period determined offspring microbiota composition at P21, independent of maternal diet during gestation. These data may have greater implications on proper establishment and maturation of gut-brain connections during the perinatal period that may predispose offspring to metabolic disorders.