What Hunter-Gatherer Skin Reveals About Our Modern Microbiome

In 2018, researchers swabbed the foreheads, forearms, and hands of the Hadza people—one of the last hunter-gatherer populations on Earth, living in northern Tanzania. What they found was a microbial zoo. Compared to city dwellers in the United States, Hadza skin hosted significantly greater bacterial diversity, with entire families of microbes that have all but vanished from Western skin. The difference wasn't subtle: the researchers identified distinct microbial signatures tied to lifestyle, particularly exposure to soil, smoke, and animal contact. These weren't just different strains of the same bacteria. They were fundamentally different ecosystems.

The study, published in 2018 by Jochum and colleagues, offered a rare snapshot of what human skin might have looked like for most of our species' history—and what most of us have lost in just a few generations.

What makes hunter-gatherer skin different?

The Hadza don't use soap. They don't shower daily. They sleep in huts made of grass and branches, cook over open fires, butcher animals with their hands, and dig tubers from the dirt. All of this microbial exposure shows up on their skin. The researchers found higher abundances of Proteobacteria, a diverse phylum associated with environmental contact, and Actinobacteria, which includes soil-dwelling species. Meanwhile, the bacteria that dominate Western skin—like Cutibacterium acnes and Staphylococcus epidermidis—were present but didn't monopolize the landscape.

This isn't just about dirt. It's about equilibrium. The Hadza microbiome appears more stable, with no single species dominating. Western skin, by contrast, tends toward monoculture: a few well-adapted bacteria thrive in the low-diversity conditions created by indoor living, daily bathing, and synthetic skincare.

(For a deeper dive into the key bacteria on modern skin, see our overview of the skin microbiome.)

What happened when we moved indoors?

The shift didn't happen overnight. Urbanization, industrialization, and modern hygiene practices gradually reshaped the microbial landscape of human skin. Soap became widespread in the early 20th century. Indoor plumbing followed. Air conditioning. Antibacterial everything. Each innovation reduced our contact with environmental microbes—the ones we evolved alongside for millennia.

The result is what some researchers call "microbial extinction." We didn't just reduce diversity; we lost entire lineages. Studies comparing rural and urban populations worldwide show the same pattern: the more Westernized the lifestyle, the lower the skin microbial diversity. And this loss isn't benign. Lower diversity correlates with higher rates of inflammatory skin conditions like eczema, psoriasis, and certain types of acne. The hygiene hypothesis, originally applied to the gut and immune system, increasingly applies to skin as well.

Is this actually a problem?

That depends on what you mean by "problem." The Hadza don't have acne at the rates Westerners do, but they also face environmental challenges—parasites, infections, limited medical care—that most of us wouldn't trade for clearer skin. Still, the loss of microbial diversity seems to matter. A 2016 study by Oh and colleagues found that microbial diversity on healthy skin acts as a buffer against pathogenic invasion. More species means more competition, more chemical signaling, more redundancy. Monocultures are fragile.

The question isn't whether we should abandon soap and live in huts. It's whether we can identify which lost microbes—or microbial functions—actually contributed to skin resilience, and whether there are ways to reintroduce or support them without sacrificing hygiene. (If you're curious about the broader pattern of microbial loss, explore which microbes we lost when we moved indoors.)

Why this matters for your skin

The Hadza microbiome isn't a blueprint, but it is a baseline. It shows us what diversity looks like in the absence of industrial hygiene, and it suggests that our modern routines—while effective at killing pathogens—may have overshot the mark. Understanding what we lost helps clarify what we might need to protect or restore.

References

• Byrd AL, Belkaid Y, Segre JA. The human skin microbiome. Nat Rev Microbiol. 2018.
• Oh J, Byrd AL, Park M, et al. Temporal stability of the human skin microbiome. Cell. 2016.
• Nakatsuji T, Chen TH, Narala S, et al. Antimicrobials from human skin commensal bacteria protect against Staphylococcus aureus and are deficient in atopic dermatitis. Sci Transl Med. 2017.
• Prescott SL, Larcombe DL, Logan AC, et al. The skin microbiome: impact of modern environments on skin ecology, barrier integrity, and systemic immune programming. World Allergy Organ J. 2017.