Weight loss following infection with intestinal worms is the body's way of fighting off the parasites, University of Manchester researchers have said.

曼彻斯特大学的研究人员称，人体感染肠蠕虫后通过减轻体重这种方式对抗寄生虫。

The immune system hijacks a hormone that controls when to stop eating, their study of mice suggests.

This then triggers the type of immune response needed to expel the worms from the gut, PLoS Pathogens reports.

The finding could lead to new ways to treat people with intestinal worms, researchers say.

Researchers first saw a potential link when they were measuring levels of a hormone called cholecystokinin（肠促胰酶肽） in volunteers after they had been fed a meal.

One man had incredibly high levels and on further investigation it was found he had an intestinal worm infection he had picked up on holiday.

Joining forces with a team specialising in gut worm infections the researchers did a study in mice infected with a worm called Trichinella spiralis.

They found that immune cells called T-cells responded to the worm infection by driving up levels of cholecystokinin.

This increase has a knock-on effect of driving down another hunger hormone, leptin, which influences what type of immune response the body needs to produce.

When they artificially added leptin back into the infected mice, the immune system mounted the wrong response and the intestinal worms remained in the gut for longer.