A research team has successfully helped children with Prader-Willi Syndrome, a kind of hereditary obesity, lose weight by improving the bacterial flora in their gastrointestinal tract.

Prader-Willi Syndrome is a complex genetic disease that is caused by the absence of some genes that function in a particular part of chromosome 15.

Children with PWS are called "angels who never get the sense of being full", because they develop an insatiable appetite when entering into childhood, which leads to chronic overeating and obesity, then on to bulimia. The disease is rare, but deadly.