(P07-005-23) Associations of Human Milk Metabolomics and Infant Growth in Rural Bangladesh

Objectives: To identify human milk (HM) metabolomic profiles associated with infant growth from birth to 6 months.

Methods: We conducted a longitudinal cohort study following 92 mother-infant dyads from the Projahnmo pregnancy cohort in Sylhet, Bangladesh. We measured infant anthropometrics from birth through six months. Mothers self-collected HM samples mid-feed at one month postpartum which were stored at -80°C until time of analysis. We quantified HM metabolomics using untargeted mass-spectrometry and used principal component analysis to consolidate the 567 annotated metabolites into eight factors, which accounted for 46.5% of variance in the original metabolomics dataset. We used linear regression to determine associations between factors and change in infant weight, length, and body mass index (BMI) z-scores from birth to 6 months to capture growth during the period of exclusive breastfeeding. A Bonferroni-corrected alpha level of < 0.05/8 was used to account for multiple comparisons.

Results: Median maternal age was 24 (interquartile range (IQR) 20-27) years. Median gestational age at birth was 39.6 (38.8-40.6) weeks, birthweight was 2730 (2505-2980) grams, and 50.6% of infants were female. In unadjusted analyses, we observed a positive association between factor 2, composed of long-chain fatty acids, and change in infant BMI z-score (β 0.23; p=0.081). We also found positive associations of factor 5, composed of higher levels of xenobiotics and lower levels of branched-chain amino acids (BCAAs), with change in weight (β 0.19; p=0.071) and BMI (β 0.22; p=0.087) z-scores. These associations did not meet the corrected threshold for significance.

Conclusions: Our exploratory analysis suggests that future studies should examine the role of HM fatty acids, xenobiotics, and BCAAs in child growth trajectories in low-middle income countries.

Funding Sources: This research was funded by the National Institute of Child Health and Human Development, Brigham & Women's Hospital, and the Massachusetts Life Sciences Center.