Weight loss helps to oust worms

Scientists from The University of Manchester have discovered that weight loss plays an important role in the body's response to fighting off intestinal worms.

The findings have been published in the journal PLOS Pathogens and show that the immune system hijacks the natural feeding pathways causing weight loss. This then drives the defense mechanisms down the correct pathway to expel the worms.

Nearly one quarter of the world's population is infected with gastrointestinal parasites. These prevalent infections often result in a period of reduced appetite resulting in weight loss. However, little is known about the factors controlling these feeding alterations and the reason why they occur.    

Scientists from the Manchester Immunology Group and the Institute of Inflammation and Repair studied the immune response system in mice that were lacking immune cells and feeding hormones. The mice were infected with the round worm parasite Trichinella spiralis.  

They identified that the mouse immune response to the parasite was behind two periods of reduced feeding through two distinct immune mediators.

Interestingly, the immune system was using the hormone cholecystokinin, which usually stops feeding during daily meals to cause a reduction in weight and fat deposits. This then reduced the levels of the fat produced hormone leptin, which can influence the immune response.