Genes shared with a meal

13 July 2016

Published in Nature: Routine day-to-day human interactions, such as sharing a meal, may lead to changes in the genetic make-up of our microbiome, the total set of bacteria we harbour. And this could ultimately also influence the state of our health, a US-led study found.

PhD candidate Aaron Jenkins from Edith Cowan University took part in the study of microbiomes obtained from people in Fiji and the US.

In addition to the type of bacteria they contain, the researchers also examined their mobile genes, which are genes that can be exchanged between microorganisms across species and thus alter the functions they carry.

They found that people from Fijian villages had a greater diversity of microbes than North Americans, which may be attributed to the more hygienic conditions and greater use of antibiotics in Western societies.

Fijians were also more likely to contain genes that help digesting starch, suggesting that the dietary differences between these populations cause selective pressures on the genetic make-up of their microbiomes.

Even between neighbouring Fijian villages they established differences in the mobile-gene pool, despite their microbiomes being very similar.

The researchers conclude that localised cultural and environmental differences can shape microbial communities through the exchange of mobile genes, rather than a change in the type of bacteria they contain.

Notably, this process could potentially also affect how communities respond to disease, for example by spreading genes that determine resistance to an antibiotic.

However, they say that it will require further studies to assess whether cultural practices indeed influence human health via mobile genetic elements.

The paper by Dr Ilana Brito from MIT and her co-workers is accompanied by a Nature news story from Peter Andrey Smith