Transfer of antibiotics and their metabolites in human milk: Implications for infant health and microbiota

Abstract

Antibiotics are an essential tool for perinatal care. While antibiotics can play a life-saving role for both parents and infants, they also cause collateral damage to the beneficial bacteria that make up the host gut microbiota. This is especially true for infants, whose developing gut microbiota is uniquely sensitive to antibiotic perturbation. Emerging evidence suggests that disruption of these bacterial populations during this crucial developmental window can have long-term effects on infant health and development. Although most current studies have focused on microbial disruptions caused by direct antibiotic administration to infants or prenatal exposure to antibiotics administered to the mother, little is known about whether antibiotics in human milk may pose similar risks to the infant. This review surveys current data on antibiotic transfer during lactation and highlights new methodologies to assess drug transfer in human milk. Finally, we provide recommendations for future work to ensure antibiotic use in lactating parents is safe and effective for both parents and infants.

Keywords: antibiotics; breastmilk; human milk; metabolomics.

FIGURE 1

Variables that affect actual infant dose of antibiotics in human milk.

FIGURE 2

Molecular networking allows for identification of novel antibiotic metabolites. (A) Molecular network containing sulfonamide antibiotics and their metabolites in human milk. Reproduced with permission from Thomas et al. Network nodes with chemical identifications from basic computational analysis are shown with black outlines. Numbers next to each node correspond to m/z (or mass-to-charge ratio) of each molecule. Asterisks (*) mark compounds that were identified in solvent controls in at least one dataset; number in circle indicates MS/MS match level (a measure of match certainty). All colored nodes in these networks have been manually annotated by spectral comparison to library compounds and other related spectra. (B) Proposed structure of novel sulfamethazine metabolite. Structures can be proposed by comparing spectra of known compounds (black, top) with the unknown metabolites of interest (green and gray, bottom). Matching peaks (green) indicate where the two structures are identical, unmatched peaks (gray) indicate where they differ.