Battle of the Bloat

Researchers at the University of Cambridge are looking to the fruit fly to learn about human intestinal neurons and have uncovered some startling findings in the process.

The scientists have found, for instance, that the more than 500 million nerve cells in our gut help regulate appetite and adjust intestinal water balance during reproduction. (Fruit flies share remarkably similar nervous and digestive systems to humans, although much less complex and thus, easier to study.)

Female fruit flies become constipated during pregnancy, causing them to retain water and the contents of their intestines to become more concentrated, as in humans. The researchers found this process was triggered by the sex peptide, a hormone injected by male fruit flies into females when they mate, which activates of a small group of gut neurons. The effect is similar to the same functions of sex hormones in humans, including progesterone, oxytocin and estrogen.

A reproductive hormone causes constipation and bloating in fruit flies as in humans, said study leader, Dr. Miguel-Aliaga.

The study was funded by the Wellcome Trust and the Biotechnology and Biological Sciences Research Council.