Biological Systems Engineering


Effects of triclosan in breast milk on the infant fecal microbiome

Candace S. Bever, University of California, Davis & Foodborne Toxin Detection and Prevention Research Unit
Amy A. Rand, University of California, Davis & Carleton University, Ontario
Malin Nording, University of California Davis & Umeå University
Diana Taft, University of California Davis
Karen M. Kalanetra, University of California Davis
David Mills, University of California, Davis
Melissa A. Breck, University of California, Davis
Jennifer T. Smilowitz, University of California, Davis
J. Bruce German, University of California, Davis

Document Type Article

U.S. government works are not subject to copyright.


Triclosan is frequently used for its antimicrobial properties and has been detected in human serum, urine, and breast milk. Animal and molecular studies have shown that triclosan exerts a wide range of adverse health effects at both high (ppm) and low (ppb) concentrations. Since triclosan is of growing concern to human and environmental health, there is a need to improve extraction procedures and to study additional effects from triclosan exposure. In this study, we have improved triclosan extraction from breast milk by using salt (MgSO4) to reduce emulsion formation and increase water polarity and water (~80%) to enhance the overall extraction efficiency (~3.5 fold). This extraction method was applied to breast milk samples collected from donors who i) recorded their use of triclosan-containing personal care products and ii) provided matching infant stool samples. Of the participants who had detectable amounts of triclosan in their breast milk, nine (75%) of them reported daily use of triclosan-containing personal care products. Levels of triclosan in breast milk were compared to the donor's infant's fecal microbiome. We found that the bacterial diversity in the fecal microbiome of the infants exposed to breast milk with detectable triclosan levels differed compared to their peers exposed to milk containing non-detectable amounts. This finding implies that exogenous chemicals are impacting microbiome diversity.