Competition between 'good bacteria' important

Competition between "good bacteria" in our gut is important for our health, say researchers from Oxford University.

The vital ecosystem of bacteria in the human gut operates like a jungle, with competition between microbes helping maintain the stability necessary to keep us healthy.

The Oxford researchers used mathematical modelling to work out how hundreds of bacteria species are able to co-exist successfully.

They found that -- contrary to popular assumption -- cooperation between species has the effect of destabilising the system.

Instead, a competitive environment between "good bacteria" helps to maintain stability via negative feedback loops that counteract the destabilising effect of high species diversity.

The researchers go on to speculate that people -- or hosts -- may help maintain this natural stability in the gut by acting as "ecosystem engineers" who intervene in a number of ways.

"The assumption has always been that because these bacteria are doing us good, the communities must be cooperating with one another. What our work suggests is that competition may be key to a healthy gut," said study's corresponding author professor Kevin Foster.

"Rather than cooperating like plants and bees, whereby a reduction in one species will drag down the other, we think that the bacteria act more like trees competing in a dense jungle," Foster added.

Microbes inside us provide us with many benefits, including the breakdown of food, protection from pathogens, and maintaining a healthy immune system.

Different people may carry different microbial species, but any one individual tends to carry the same key set of species for long periods. This stability is considered critical for host health and well-being.

The study was published in the journal Science.