Charting the Maternal and Infant Microbiome: What Is the Role of Diabetes and Obesity in Pregnancy?

Abstract

Purpose of Review The purpose of this review is to summarize the evidence on whether diabetes, obesity, and related metabolic derangements during pregnancy are associated with the maternal and infant microbiomes, and to identify gaps in the literature and offer guidance on future research on this topic. Recent Findings We found circumstantial evidence from four observational studies that the maternal gut microbiome was associated with either pre-pregnancy body mass index, gestational weight gain, gestational diabetes, and/or related metabolic biomarkers in pregnancy; we did not identify any studies that examined whether the vaginal microbiome varied according to these metabolic parameters. Maternal diabetes (in one study) and pregnancy weight status (in three studies) were found to be associated with the infant offspring gut microbiome, although some associations only appeared in certain cohort strata. Patterns of association across both maternal and infant microbiome studies, however, lacked consistency, which may owe to biologic or technical differences, or to the lack of control for important confounders or effect modifiers (e.g., delivery mode in infant microbiome studies). Summary Metabolic diseases in pregnancy, such as diabetes and obesity, may be associated with the maternal and infant microbiomes, but there is a need for large prospective studies of mother-child dyads from diverse racial and ethnic backgrounds to determine the direction and potential causal nature of these associations. These studies should include serially collected biospecimens, standardized workflows that conserve microbial DNA and RNA, and rich data on clinical outcomes and environmental, lifestyle, and genetic risk factors for obesity and diabetes.

Chicory fibre improves reproductive performance of pregnant rats involving in altering intestinal microbiota composition

“…Likewise, intestinal microbiota imbalance leads to inflammation and blood glucose disorders during pregnancy, which may be caused by decreased short‐chain fatty acids, disregulated secretion of related hormones, and decreased tight junctions between intestinal epithelial cells (Singh et al . 2017). Indeed, the composition of intestinal microbiota in the offspring of mothers with different physical conditions (e.g., malnutrition or overnutrition during or after pregnancy) also varies.…”

Pregestational overweight and obesity are associated with differences in gut microbiota composition and systemic inflammation in the third trimester

“…Reduced levels of Desulfovibrio , Bacteroides , and Methanobrevibacter have been reported in obese subjects [ 30 , 34 , 35 , 57 ]. Few studies have reported differences in microbiota composition during pregnancy and the influence of pre-BMI and weight gain [ 13 , 46 , 58 ]. Recent studies have revealed the importance of the maternal microbial environment in infants’ health both early and later in life, suggesting that the transfer of the altered gut microbiota from obese pregnant women to their infants may lead to metabolic disorders [ 59 , 60 ].…”

Infant diet and maternal gestational weight gain predict early metabolic maturation of gut microbiomes

“…Maternal weight variables represented a special case, with multiple potential confounding variables 15,31,32,35,51–53 . GWG would ideally be classified as normal, inadequate, or excessive according to maternal pre-pregnancy BMI and estimated gestational age of delivery, according to Institute of Medicine guidelines 54 .…”