Variation in human milk composition is related to differences in milk and infant fecal microbial communities

Research output: Contribution to journalArticle


Previously published data from our group and others demonstrate that human milk oligosaccharide (HMOs), as well as milk and infant fecal microbial profiles, vary by geography. However, little is known about the geographical variation of other milk-borne factors, such as lactose and protein, as well as the associations among these factors and microbial community structures in milk and infant feces. Here, we characterized and contrasted concentrations of milk-borne lactose, protein, and HMOs, and examined their associations with milk and infant fecal microbiomes in samples collected in 11 geographically diverse sites. Although geographical site was strongly associated with milk and infant fecal microbiomes, both sample types assorted into a smaller number of community state types based on shared microbial profiles. Similar to HMOs, concentrations of lactose and protein also varied by geography. Concentrations of HMOs, lactose, and protein were associated with differences in the microbial community structures of milk and infant feces and in the abundance of specific taxa. Taken together, these data suggest that the composition of human milk, even when produced by relatively healthy women, differs based on geographical boundaries and that concentrations of HMOs, lactose, and protein in milk are related to variation in milk and infant fecal microbial communities.


  • Ryan M. Pace
  • Janet E. Williams
  • Bianca Robertson
  • Kimberly A. Lackey
  • Courtney L. Meehan
  • William J. Price
  • James A. Foster
  • Daniel W. Sellen
  • Elizabeth W. Kamau-Mbuthia
  • Egidioh W. Kamundia
  • Samwel Mbugua
  • Sophie E. Moore
  • Andrew M. Prentice
  • Debela G. Kita
  • Linda J. Kvist
  • Gloria E. Otoo
  • Lorena Ruiz
  • Juan M. Rodríguez
  • Rossina G. Pareja
  • Mark A. McGuire
  • And 2 others
  • Lars Bode
  • Michelle K. McGuire
External organisations
  • University of Idaho
  • University of California, San Diego
  • Washington State University
  • University of Toronto
  • Egerton University
  • University of Ghana
  • Complutense University of Madrid
  • King's College London
  • London School of Hygiene and Tropical Medicine
  • Hawassa University
  • CSIC Instituto de Productos Lácteos de Asturias (IPLA)
  • Instituto de Investigación Sanitaria del Principado de Asturias (ISPA)
  • Nutrition Research Institute Lima
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Microbiology in the medical area


  • Bacteria, Breastmilk, Gastrointestinal tract, HMO, Human milk, Infant, Lactose, Microbiome, Oligosaccharides, Protein
Original languageEnglish
Article number1153
Issue number6
Publication statusPublished - 2021 Jun 1
Publication categoryResearch

Bibliographic note

Funding Information: Funding: This research was funded by the National Science Foundation IOS-BIO 1344288; the Ministry of Economy and Competitiveness, Spain (AGL2013-4190-P); the European Commission (624773-FP-7-PEOPLE-2013-IEF, to LR); and in part by National Institutes of Health NICHD R01-HD092297 and COBRE Phase III grant P30GM103324. Sterile, single-use milk collection kits were provided by Medela Inc.