A new study showed that diets lacking in fibre also lack in bacteria that are good for us.
According to the New Scientist, Paolo Lionetti of the University of Florence, Italy, said that short-chain fatty acids (SCFA) are generated by bugs associated with diets containing a very high proportion of vegetables and cereals.
SCFAs kill harmful gut bacteria such as salmonella and help protect against inflammation.
Lionetti compared the gut bacteria of children in Burkina Faso and Italy.
The stools of the African children contained almost three times as many short-chain fatty acids.
Breastfed infants in both countries had the same gut bacteria profiles, so diet rather than other environmental factors or genes seems to dictate which bacteria colonise the gut.
The study is published in the Proceedings of the National Academy of Sciences.