Nairobi study: the bacteria around you shape antibiotic resistance

Nairobi — Why do some people carry drug-resistant bacteria and others don't? Research in a densely populated informal settlement in Nairobi points to an answer beyond antibiotic use: the community of microbes around you. Eric Ng'eno, a PhD candidate at the University of Kansas, describes the findings, published in PLOS ONE, in The Conversation.

What the team did

They mapped the "background" gut bacteria of people living in different parts of the settlement, using E. coli from stool samples, and built models comparing three factors: antibiotic use, the spread of bacteria between people, and those background microbial communities.

What they found

• The local microbial community largely decided which resistant E. coli strains people carried.
• Where resistant bacteria were common in the community, people were more likely to carry them, whatever their own antibiotic use.
• Antibiotics matter in combination: drugs that badly disrupt the gut let surrounding microbes take over quickly; milder ones leave more of the original gut bacteria in place to compete.

What it means

Strategies against antibiotic resistance should fit the local microbial setting:

• Use antibiotics only when needed, and choose ones that disturb the gut least.
• Prevent infections in the first place with vaccines and hygiene.
• Help the gut recover with probiotics after a course of antibiotics.
• In the long run, look after healthy gut bacteria, for example through fermented foods.

Source: The Conversation, 15 October 2026.