The study, led by the Sydney Brenner Institute for Molecular Bioscience at the University of the Witwatersrand and published in Nature, analysed stool samples from about 1,800 women in Kenya, Ghana, Burkina Faso and South Africa. Scientists used genetic sequencing to map the gut microbiome and identified more than 1,000 new bacterial species and over 40,000 new viruses, reporting in total more than 40,000 previously unknown gut microbes in African populations.
A striking result was a unique microbial signature linked to HIV. This was the largest study yet of women living with HIV, and researchers found bacterial patterns in people with HIV in Africa that were completely different from those reported in wealthier countries. The authors say these differences could inform new approaches to detect, monitor and treat HIV in African settings and help design medicines that work better for local populations.
The team also found clear rural–urban contrasts. Rural participants had richer, more diverse gut bacteria, while urban residents often lacked the bacterium Treponema, a change possibly related to lower-fibre diets and increased antibiotic use. Charissa Naidoo, co-director of the African Microbiome Institute, warned that beneficial gut bacteria are disappearing with urban lifestyles and growing antibiotic use and called for urgent nutritional interventions to preserve diversity.
Researchers noted that diversity varied not only by rural or urban status but also between cities and regions, reflecting local diets, environment and cultural practices. The study fills gaps left by earlier work such as the 2007 Human Microbiome Project and the team plans to expand research into links with sleep problems, menopause, brain diseases and tuberculosis.
Difficult words
- microbiome — community of microorganisms living in the gut
- sequence — process of determining the order of DNAsequencing
- signature — distinctive pattern used to identify something
- antibiotic — medicine that kills or stops bacteria growth
- intervention — actions taken to improve a situationinterventions
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- What are possible reasons why urban lifestyles and antibiotic use might reduce beneficial gut bacteria in people? Give two examples from the article.
- How could the study's finding that bacterial patterns in people with HIV differ by region affect the way medicines are designed or used locally?
- What nutritional interventions could help preserve gut microbiome diversity in urban populations? Mention practical steps or policies suggested by the study.
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