Microbiome-derived metabolites in early to mid-pregnancy and risk of gestational diabetes: a metabolome-wide association study

Abstract

Background: Pre-diagnostic disturbances in the microbiome-derived metabolome have been associated with an increased risk of diabetes in non-pregnant populations. However, the roles of microbiome-derived metabolites, the end-products of microbial metabolism, in gestational diabetes (GDM) remain understudied. We examined the prospective association of microbiome-derived metabolites in early to mid-pregnancy with GDM risk in a diverse population.

Methods: We conducted a prospective discovery and validation study, including a case-control sample of 91 GDM and 180 non-GDM individuals within the multi-racial/ethnic The Pregnancy Environment and Lifestyle Study (PETALS) as the discovery set, a random sample from the PETALS (42 GDM, 372 non-GDM) as validation set 1, and a case-control sample (35 GDM, 70 non-GDM) from the Gestational Weight Gain and Optimal Wellness randomized controlled trial as validation set 2. We measured untargeted fasting serum metabolomics at gestational weeks (GW) 10-13 and 16-19 by gas chromatography/time-of-flight mass spectrometry (TOF-MS), liquid chromatography (LC)/quadrupole TOF-MS, and hydrophilic interaction LC/quadrupole TOF-MS. GDM was diagnosed using the 3-h, 100-g oral glucose tolerance test according to the Carpenter-Coustan criteria around GW 24-28.

Results: Among 1362 annotated compounds, we identified 140 of gut microbiome metabolism origin. Multivariate enrichment analysis illustrated that carbocyclic acids and branched-chain amino acid clusters at GW 10-13 and the unsaturated fatty acids cluster at GW 16-19 were positively associated with GDM risk (FDR < 0.05). At GW 10-13, the prediction model that combined conventional risk factors and LASSO-selected microbiome-derived metabolites significantly outperformed the model with only conventional risk factors including fasting glucose (discovery AUC: 0.884 vs. 0.691; validation 1: 0.945 vs. 0.731; validation 2: 0.987 vs. 0.717; all P < 0.01). At GW 16-19, similar results were observed (discovery AUC: 0.802 vs. 0.691, P < 0.01; validation 1: 0.826 vs. 0.780; P = 0.10).

Conclusions: Dysbiosis in microbiome-derived metabolites is present early in pregnancy among individuals progressing to GDM.

Keywords: Gestational diabetes; Metabolomics; Microbiome; Pregnancy; Risk prediction.

Fig. 1

Study flow chart for discovery set and validation sets 1 and 2

Fig. 2

ChemRICH plots depicting the pathways and key metabolites significantly associated with risk of gestational diabetes. A 10–13 weeks and (B) 16–19 weeks of gestation. ^*P-value for pathway <0.05 after false discovery rate adjustment

Fig. 3

Incremental prediction value of multi-metabolite panels beyond conventional risk factors for gestational diabetes. A 10–13 weeks and (B) 16–19 weeks of gestation. Receiver operating characteristic (ROC) curves and area under the curve (AUC) statistics were estimated without cross-validation for GDM risk prediction using conventional risk factors (age at delivery, race/ethnicity, pre-pregnancy body mass index, nulliparity, pre-existing hypertension, family history of diabetes, gestational age and fasting status at the respective clinic visit, and fasting serum glucose values; Model 1, red curves); a multi-metabolite panel (Model 2, green curves) selected by least absolute shrinkage and selection operator (LASSO) regression at (A) 10–13 weeks and (B) 16–19 weeks of gestation; and the selected multi-metabolite panel in addition to conventional risk factors (Model 3, blue curves). P values for differences in AUC statistics between models were derived by DeLong’s test