A small study links the type of bacteria living in people's digestive systems to a desire for chocolate.

Everyone has a vast community of microbes in their guts. But people who crave daily chocolate show signs of having different colonies of bacteria than people who don't.

That may be the case for other foods too. The idea could eventually lead to treating some types of obesity by changing the composition of the trillions of bacteria occupying the intestines and stomach, said Dr Sunil Kochhar, co-author of the study. It appeared yesterday in the peer-reviewed Journal of Proteome Research.

It took the research team a year to find 11 men who do not eat chocolate. The researchers then compared the blood and urine of this group with that of 11 men who ate chocolate daily.

They examined the byproducts of metabolism in the men's blood and urine and found that a dozen substances were significantly different between the two groups.

ASSOCIATED PRESS