A study by investigators from New England suggests that a mother’s diet during pregnancy and lactation may have an impact on the microbiome in her infant’s gut. The association, the authors said, may vary depending on whether the infant is delivered vaginally or by cesarean.
The findings, published in Microbiome, are from analysis of infant stool samples and data on maternal diet during pregnancy collected via questionnaire. The mother-infant dyads who participated were enrolled in the New Hampshire Birth Cohort Study. The authors examined the association between maternal diet during pregnancy and the infant gut microbiome 6 weeks post-delivery.
Stool samples were collected from 145 infants at age 6 weeks and a validated food frequency questionnaire was administered to their mothers at 24 to 28 weeks’ gestation. The women were aged 22 to 44 and most were first-time mothers who had at least a college degree. Approximately two-thirds of the infants (66.9%) were born vaginally and 70.3% were exclusively breastfed at age 6 weeks.
The most abundant microbial species found in the stool samples was Enterobacteriaceae(20%) followed by Bifidobacterium(18.4%), Bacteroides(10.4%), and Streptococcus(8.10%) overall and in the vaginally delivered infants. In the infants delivered by cesarean, the findings were somewhat different: high abundance of Bifidobacterium, high Clostridium, low Streptococcusand Ruminococcusgenera, and high abundance of Enterobacteriaceae.Maternal dairy intake was associated with increased odds of high Clostridium in infants born by cesarean.
After adjustment for infant feeding method, maternal body mass index, parity, and batch, maternal fruit consumption was associated with infant stool microbiome composition (P= 0.028). That effect persisted in babies born vaginally when the analysis was restricted to infants who were exclusively breastfed (P= 0.022). The results were unchanged by exclusion of infants who may have received antibiotics or whose births were premature.
The researchers noted that maternal fish consumption has been associated with child development outcomes including decreased risk of asthma and improved cognition. Their study found a positive relationship between maternal fish and seafood consumption and Streptococcusin the infant gut. Also seen was a decrease in presence of Clostridium neonatalein the stool samples of infants born by cesarean to mothers with increased fish and seafood in their diets, which the authors said was beneficial to the microbiome.
The beneficial microbe Bifidobacteriumwas found to be decreased in the stool samples of infants born vaginally to mothers with increased fruit consumption. However, it was increased in infants born by cesarean to mothers with higher intake of red and processed meat.
Commenting on the strengths and weaknesses of the research, the authors said the generalizability of the results may be limited in that the sample was drawn from Northern New England, which has a relatively homogenous population. They said the effects observed may be due in part to maternal diet during lactation and it is not possible to determine whether the associations between diet and the infant microbiome occur only in breastfed babies, also in those mostly fed formula, or in those fed a combination of formula and breast milk.
The authors said that future studies of the relationship between maternal diet, components of breast milk and their effects on the fetal microbiome are warranted. “Determining the impact of changes in the gut microbiome of infants due to maternal diet on infant health and development,” the researchers concluded, “is an opportunity to refine dietary recommendations for pregnant and lactating women to support infant health.”