Short-chain fatty acids as novel therapeutics for gestational diabetes

Gestational diabetes mellitus (GDM) affects up to 16% of pregnant women and is associated with significant long-term health detriments for the mother and her offspring. Two central features of GDM are low-grade inflammation and maternal peripheral insulin resistance, therefore therapeutics which target these may be most effective at preventing the development of GDM. Short-chain fatty acids (SCFAs), such as butyrate and propionate, are metabolites produced from the fermentation of dietary fibre by intestinal microbiota. SCFAs possess anti-inflammatory, anti-obesity and anti-diabetic properties. Therefore, this study aimed to investigate the effect of SCFAs on inflammation and insulin signalling defects in an in vitro model of GDM. Human placenta, visceral adipose tissue (VAT) and s.c. adipose tissue (SAT) were stimulated with either the pro-inflammatory cytokine TNF or bacterial product lipopolysaccharide (LPS). The SCFAs butyrate and propionate blocked TNF- and LPS-induced mRNA expression and secretion of pro-inflammatory cytokines and chemokines in placenta, VAT and SAT. Primary human cells isolated from skeletal muscle were stimulated with TNF to assess the effect of SCFAs on inflammation-induced defects in the insulin signalling pathway. Butyrate and propionate were found to reverse TNF-induced increases in IRS-1 serine phosphorylation and decreases in glucose uptake. Butyrate and propionate exerted these effects by preventing ERK activation. Taken together, these results suggest that the SCFAs may be able to improve insulin sensitivity and prevent inflammation induced by sterile or bacterial inflammation. Future in vivo studies are warranted to investigate the efficacy and safety of SCFAs in preventing insulin resistance and inflammation associated with GDM.