Breast Milk Contributes Significantly to Babies' Bacteria

Thirty percent of bacteria found in babies' guts came from mothers' milk, a study finds.

Written byAshley P. Taylor
| 2 min read

Register for free to listen to this article
Listen with Speechify
0:00
2:00
Share

PIXABAY, WERBEFABRIKThe importance of delivery method for the development of babies’ gut bacteria has come into question in recent months. A new study from University of California, Los Angeles, reports how another aspect of newborn life influences the nascent gut microbiome: breastfeeding. The study, published Monday (May 8) in JAMA Pediatrics, found that 30 percent of babies’ gut bacteria seem to come from the mother’s breast milk and that another 10 percent can be traced to skin around the mother’s nipple.

“Breast milk is this amazing liquid that, through millions of years of evolution, has evolved to make babies healthy, particularly their immune systems,” UCLA’s Grace Aldrovandi, the study’s lead author, said in a press release. “Our research identifies a new mechanism that contributes to building stronger, healthier babies.”

In 107 mother-infant pairs, the study examined the microbial content of the mother’s milk, the skin around the mother’s nipple, and the baby’s stool, whose bacteria represent those of the gut. As Reuters reported, the bacteria in infants’ poop were more similar to the microbes from their own mothers than those from other mothers in the study, suggesting that the bacteria are transferred from mother to child through breastfeeding.

This study did not examine baby health. However, ...

Interested in reading more?

Become a Member of

The Scientist Logo
Receive full access to more than 35 years of archives, as well as TS Digest, digital editions of The Scientist, feature stories, and much more!
Already a member? Login Here

Related Topics

Meet the Author

Share
December digest cover image of a wooden sculpture comprised of multiple wooden neurons that form a seahorse.
December 2025, Issue 1

Wooden Neurons: An Artistic Vision of the Brain

A neurobiologist, who loves the morphology of cells, turns these shapes into works of art made from wood.

View this Issue
Stacks of cell culture dishes, plates, and flasks with pink cell culture medium on a white background.

Driving Innovation with Cell Culture Essentials

Merck
Stacks of cell culture dishes, plates, and flasks with pink cell culture medium on a white background.

Driving Innovation with Cell Culture Essentials

MilliporeSigma purple logo
Abstract wireframe sphere with colorful dots and connecting lines representing the complex cellular and molecular interactions within the tumor microenvironment.

Exploring the Inflammatory Tumor Microenvironment 

Cellecta logo
An image of a DNA sequencing spectrum with a radial blur filter applied.

A Comprehensive Guide to Next-Generation Sequencing

Integra Logo

Products

brandtech logo

BRANDTECH® Scientific Announces Strategic Partnership with Copia Scientific to Strengthen Sales and Service of the BRAND® Liquid Handling Station (LHS) 

Top Innovations 2026 Contest Image

Enter Our 2026 Top Innovations Contest

Biotium Logo

Biotium Expands Tyramide Signal Amplification Portfolio with Brighter and More Stable Dyes for Enhanced Spatial Imaging

Labvantage Logo

LabVantage Solutions Awarded $22.3 Million U.S Customs and Border Protection Contract to Deliver Next-Generation Forensic LIMS