Short-chain fatty acids in fecal samples from normal-weight and overweight/obese women with gestational diabetes

Short-chain fatty acids (SCFAs), which are produced by the microbial fermentation of undigested carbohydrates, play an important role in the metabolism and physiology of the host. SCFAs are involved in the regulation of maternal metabolism during pregnancy and influence weight gain, glucose metabolism and metabolic hormones. In 2017, women who were treated for gestational diabetes mellitus (GDM) at the University Medical Centre Ljubljana were invited to participate in a longitudinal study. A total of 45 women were included in the study and comprehensively phenotyped. During the second and third trimester of pregnancy, the GDM women provided fecal samples for SCFA analysis. The samples were analyzed by high-performance liquid chromatography for the simultaneous determination of acetate, propionate, and butyrate. SCFA concentrations in feces differed between overweight/obese and normal weight GDM women. Acetate and propionate concentrations were significantly higher in pregnant women who were overweight or obese before pregnancy compared to normal-weight women, but butyrate concentrations were not. Butyrate was elevated in the third trimester in the group with excessive gestational weight gain. Regardless the conflicting publications on the role of SCFAs, our study showed that higher acetate and propionate levels were associated with overweight or obesity before pregnancy and higher butyrate levels were associated with excessive gestational weight gain. The relationship between SCFAs and obesity is complex, and the association between SCFAs and GDM remains to be clarified.