Fruit flies are being used by University of Cambridge researchers are using to help understand aspects of human metabolism, including why pregnant women suffer from bloating and constipation, and even the link between a low calorie diet and longevity.
The researchers, led by Irene Miguel-Aliaga, have used the fruit fly, Drosophila melanogaster, to investigate the function of these intestinal neurons.
The fly has simpler versions of our nervous and digestive systems, which lend it to genetic manipulation.iguel-Aliaga and colleagues found that these intestinal neurons have very important and specialized functions, such as regulating appetite or adjusting intestinal water balance during reproduction.
Female flies in their reproductive stage get constipated-their gut emptying rate is reduced even though they are eating more food; at the same time, they retain more water and the contents of their intestines become more concentrated.
The researchers showed that these intestinal changes are triggered by the sex peptide, a hormone that males inject into the female during copulation, which activates of a small group of gut neurons.
"Humans and fruit flies reproduce in very different ways, yet the associated symptoms of constipation and bloating and their cause - a reproductive hormone - are the same," explained Miguel-Aliaga.
"This suggests that this mechanism has been conserved through evolution. These intestinal changes may provide a benefit at a time of high nutritional demand by maximizing nutrient absorption," he said.
The research has also provided tantalising clues about the link between calorie intake and longevity.
Intestinal changes that help maximize nutrient absorption would likely be active all the time, as they would provide a selective advantage when food is scarce.
The findings were published in the journal Cell Metabolism.