Background Women who are overweight or obese have an increased risk of developing gestational diabetes mellitus. The gut microbiome is an important determinant of metabolic health and contributes to the development of insulin resistance. This study aimed to assess the relationship between gut microbiome composition and glucose metabolism in overweight and obese pregnant women at 16 weeks gestation.
Methods Fecal microbiota profiles from overweight (n=29) and obese (n=41) pregnant women from the SPRING study were assessed by 16S rRNA sequencing and analysed with QIIME software. Fasting insulin and c-peptide levels were correlated to gut microbiome taxa abundance with bootstrapped Spearman rank correlation tests. Validation of the observed microbial-hormonal interaction was performed in an additional 57 overweight and 73 obese SPRING participants.
Results Insulin, c-peptide levels and microbiome profiles differed between overweight and obese women. The relative abundance of the genus Collinsella was positively correlated with insulin (rho=0.36, p=0.003), c-peptide (rho=0.27, p=0.023) and was higher in obese pregnant women (median: 0.0037 vs. 0.0077, p=0.027). The validation cohort further supported the positive association of genus Collinsella with glucose metabolism (Insulin: rho=0.30, p=0.0006, c-peptide: rho=0.20, p=0.050) and abundance was higher in obese women (p= 0.043).
Conclusion This study shows that the composition of the gut microbiome is associated with maternal glucose metabolism in early pregnancy. These results suggest that manipulation of the gut microbiome composition may have the potential to influence metabolism in pregnancy.