How our gut bacteria may have influenced evolution

body dna

[Editor’s note: Susan Erdman is a research scientist and assistant director of MIT’s Division of Comparative Medicine.]

Lately I’ve been wondering if microbes helped drive the bus…I’ve been studying the microbiome for more than 20 years…Several findings from our work make me think that microbes helping steer the evolution of humans isn’t such a far-fetched idea.

For starters, in our “glow of health” study, we fed to mice bacteria extracted from human breast milk. This dietary addition gave them thicker skin, more lustrous fur, and, in females, more acidic vaginal mucus. That change in mucus is correlated with increased fertility in mice — and in humans.

[Similarly], testosterone levels in mice soar after eating these bacteria. Such microbe-treated mice display larger testicles with higher sperm counts and also build extra muscle. The resulting “mouse swagger” would give these mice a competitive edge in combat and romance, letting them spread their genes and microbes more widely and for a longer time.

Interestingly, mouse moms consuming probiotic bacteria from human breast milk actually take better care of their infants — and are less likely to eat them — compared with untreated mice or those eating other types of diets. Following this line of reasoning, the bacteria help make more mice and thus more future microbe hosts.

The GLP aggregated and excerpted this blog/article to reflect the diversity of news, opinion, and analysis. Read full, original post: Did the microbiome help drive human evolution?

{{ reviewsTotal }}{{ options.labels.singularReviewCountLabel }}
{{ reviewsTotal }}{{ options.labels.pluralReviewCountLabel }}
{{ options.labels.noReviewsLabel }}
{{ options.labels.newReviewButton }}
{{ userData.canReview.message }}

Related Articles

Infographic: Global regulatory and health research agencies on whether glyphosate causes cancer

Infographic: Global regulatory and health research agencies on whether glyphosate causes cancer

Does glyphosate—the world's most heavily-used herbicide—pose serious harm to humans? Is it carcinogenic? Those issues are of both legal and ...

Most Popular

Picture1
Hiroshima at 81: America’s new nuclear bomb, a buried Iranian target, and a question no one wants to ask
ChatGPT-Image-Mar-10-2026-01_39_01-PM
Viewpoint—“Miracle molecule” debunked: Why acemannan supplements don’t work
Screenshot-2026-07-31-at-10.10.55-AM
Viewpoint: ‘Misinformation' about the effects of offshore wind turbines on marine life could derail offshore wind farm projects 
ChatGPT Image Jul 29, 2026, 06_26_01 PM 2
Facts & Fallacies podcast: Organic food myths make a comeback on Instagram, with Dr. Kevin Folta
ChatGPT-Image-Jul-10-2026-09_42_12-AM-1
Peptides, patient autonomy, and the limits of medical freedom
ChatGPT-Image-Jul-10-2026-12_21_03-PM
Viewpoint: Is there new evidence that the animal deworming drug ivermectin decreases the risk of Covid and cancer? Don’t waste your money.
ChatGPT Image Jul 29, 2026, 10_17_59 AM
Viewpoint: What does it mean when critics of conventional agriculture say many fruits and vegetables are “linked” to pesticide poisoning?
ChatGPT Image Jul 31, 2026, 08_05_37 AM
With trust in RFK, Jr.'s CDC vaccine advice collapsing, physicians scramble to fill the information gap
Screenshot-2026-07-09-at-1.09.25-PM
Anti-vaccine myths rattle health care
ChatGPT-Image-Jul-31-2026-07_35_35-AM
Wikipedia has assembled an informative list of fake news websites from across the ideological spectrum
Screenshot-2026-07-31-at-9.37.42-AM
Obsessing about ultra-processed foods but ignoring what matters far more: A balanced diet
ChatGPT-Image-Jul-22-2026-09_13_07-AM
Viewpoint—The Strategic Litigation boom: Understanding the tightening coalition among NGOs, foundations, journalists, and tort lawyers
glp menu logo outlined

Get news on human & agricultural genetics and biotechnology delivered to your inbox.