Want to control your weight? Intestinal worms could help, say Japanese researchers

If it worked for Maria Callas, maybe it can work for others.

Rumor has it that Callas, one of the most influential soprano singers of the 20th century, used tapeworms to maintain her figure, helping her lose around 50 kg in the 1950s.

Although the truth about the singer’s diet has never been proven, a group of Japanese researchers has for the first time confirmed that slimy, creepy helminths may help improve metabolism and thus suppress weight gain.

In the findings published Monday in the U.S. science journal Infection and Immunity, researchers from Gunma University and the National Institute of Infectious Diseases in Tokyo revealed that intestinal helminths have the ability to increase intestinal cells, which are responsible for the release of neurotransmitters that activate sympathetic nerves and speed up the burning of fat.

The researchers put up to 200 mice on a high-fat diet and then infected some of them with a naturally occurring type of gastrointestinal roundworm. After 28 days, the researchers noticed that the worms helped suppress the increase of the infected mice’s body weight by 20 percent, compared to uninfected mice.

“To be precise, the worms don’t cause weight loss but can suppress weight gain,” Chikako Shimokawa, the assistant professor at the Department of Parasitology at Gunma University’s Graduate School of Medicine who led the study, told The Japan Times on Thursday. “They help maintain health and prevent putting on excess weight.”

Shimokawa laughed off rumors that the researchers were planning to infect humans with parasites and said the study focused on the effects of tapeworms on intestinal cells.

“We believe they release a substance that increases intestinal cells and if we manage to determine what it is, we could use it in dietary supplements and medicines” designed to help people lose weight, Shimokawa said.

“If the findings help us find a way to increase intestinal cells, we may not need tapeworms to do so.”

Shimokawa, who specializes in immunology disorders, said the study was based on a common hypothesis that, due to improved hygiene, tapeworms are no longer lurking in human bodies. It’s a theory that can be closely linked to the rising prevalence of autoimmune diseases, allergies and inflammatory disorders, including obesity, Shimokawa said.

“I thought that tapeworms could give us some tips on how to improve the immune system,” Shimokawa said.

The Infection and Immunity journal, issued by the American Society for Microbiology, focuses on interactions between bacterial, fungal or parasitic pathogens and their hosts.