Fig. 5

Environmental chemicals in breast milk associate with short-chain fatty acids at 1 month. Exposure units are ng/g lipid except for PFOA and PFOS (ng/L). All models adjusted for proportion of feeding from breast milk, gestational age, and C-section (yes/no). The point indicates the β estimate, the horizontal line the 95% CI, as percentage change relative to the mean of the SCFA, per 1 SD increase in exposure. ENET selected exposures (SDs in above units): p,p′-DDE (54), PCB-167 (0.7), PCB-170 (4.4), PCB-194 (1.1), PCB-209 (0.1), PBDE-28 (0.5), PBDE-47 (5.0), PFOA (34.0). ENET (green triangle) indicates chemical selected by and estimate derived from penalized elastic net using the minimum CV-MSE. Multipollutant model estimate (blue circle) from unpenalized linear regression with exposures selected via elastic net. For propionic acid, we excluded PCB-194, the exposure collinear with PCB-170 that had the lowest ENET estimate. Substitution of PCB-170 with PCB-194 did not materially affect results. Single pollutant models (orange circle) are unadjusted for other toxicants