Gut bacteria which can lead to obesity and allergies are found more in children in industrialised countries than Africa because of Western diets rich in fat and sugar, research has suggested.
There were striking differences found in the composition of bug populations inhabiting the digestive systems of groups of children aged one to six in Italy and rural Africa.
Scientists claim this is why "Western" children are so prone to problems such as obesity and allergy, because they believe the different diets to hold the key to disparities in bug populations.
There was a lower proportion of microbes associated with obesity in adults and higher numbers of bugs linked to leanness, amongst the African children from Burkina Faso.
Other types of bacteria found in the guts of African, but not Italian, children assisted the digestion of plant foods. These bugs generated fatty acids that are known to protect against inflammation, and may help to prevent the over-active immune reactions that lead to allergies.
African children had fewer of the bacteria that cause common stomach upsets and diarrhoea, such as Shigella and Escherichia, the E.coli bug.
While the African children ate a diet consisting mainly of cereals, pulses and vegetables, their Italian counterparts consumed much higher amounts of meat, fat and sugar.
Overall, the African children had a far more diverse population of bacteria in the foecal samples analysed by the researchers.
The scientists, led by Dr Paolo Lionetti, from the University of Florence in Italy, reported their findings in the journal Proceedings of the National Academy of Sciences. They wrote:
"Our results suggest that diet has a dominant role over other possible variables such as ethnicity, sanitation, hygiene, geography, and climate in shaping the gut microbiota."
"I think in the West all foods have additives and also refined. I do think allowing nature do its job may be the best way to allow our children to enjoy healthier lives" - Julia L G Basu, South Yorkshire