Roundworm quells obesity and related metabolic disorders

April 25, 2013

Researchers at the University of Maryland School of Medicine, Baltimore, have shown in a mouse model that infection with nematodes (also known as roundworms) can not only combat obesity but ameliorate related metabolic disorders. Their research is published ahead of print online in the journal Infection and Immunity.

Gastrointestinal nematodes infect approximately 2 billion people worldwide, and some researchers believe up until the 20th century almost everyone had worms. In developed countries there is a decreasing incidence of nematode infection but a rising prevalence of certain types of , suggesting a relationship between the two. Nematode infection has been purported to have therapeutic effects and currently clinical trials are underway to examine worms as a treatment for diseases associated with the relevant cytokines, including , multiple sclerosis, and allergies.

In the study researchers tested the effect of nematode infection on mice fed a high-fat diet. Infected mice of normal girth gained 15 percent less weight than those that were not infected. Mice that were already obese when infected lost roughly 13 percent of their body weight within 10 days. Infection also drastically lowered fasting , a risk factor for diabetes, and reduced , decreasing liver fat by ~25 percent, and the weight of the liver by 30 percent.

The levels of insulin and leptin also dropped, "indicating that the mice restored their sensitivities to both hormones," says corresponding author Aiping Zhao of the University of Maryland School of Medicine, Baltimore. Leptin moderates appetite. As with too much insulin, too high a level of leptin results in insensitivity, thus contributing to obesity and metabolic syndrome, Zhao explains.

The mechanism of the moderation of these hormones "was associated with a parasite-induced reduction in glucose absorption in the intestine, reduced liver triglycerides, and an increase in the population of cells called "alternatively activated macrophages," which regulate glucose metabolism and inflammation," says coauthor Joe Urban of the United States Department of Agriculture. Some of these changes involved "a protein called interleukin-13 and related intracellular signaling mechanisms," he says. "This suggests that there are immune related shifts in metabolism that can alter expression of obesity and related metabolic syndrome."

The incidence of obesity has been climbing dramatically, worldwide. It is a key risk factor for many metabolic diseases, including diabetes, hypertension, and heart disease. Recent studies indicate that it is accompanied by chronic low-grade inflammation in adipose tissues, causing the release of proinflammatory cytokines and chemokines that contribute to the development of cardiovascular disease and .

Parasitic nematode infection induces a marked elevation in host immune Th2-cells and related type 2 cytokines which, besides combating the infection, also have potent anti-inflammatory activity, according to the report.

Explore further: Substance in tangerines fights obesity and protects against heart disease

More information: Z. Yang, V. Grinchuk, A. Smith, B. qin, J.A. Bohl, R. Sun, L. Notari, Z. Zhang, H. Sesaki, J.F. Urban, Jr., T. Shea-Donohue, A. Zhao, 2013. Parasitic nematode-induced modulation of body weight and associated metabolic dysfunction in mouse models of obesity. Infect. Immun. Published ahead of print 18 March 2013, doi:10.1128/IAI.00053-13

Related Stories

Substance in tangerines fights obesity and protects against heart disease

April 6, 2011
New research from The University of Western Ontario has discovered a substance in tangerines not only prevents obesity, but also offers protection against type 2 diabetes, and even atherosclerosis, the underlying disease ...

Study reveals how high-fat foods impact diabetes and metabolic syndrome

May 22, 2012
A University of Michigan Health System study provides new clues about the health-damaging molecular changes set in motion by eating high-fat foods.

Adding intestinal enzyme to diets of mice appears to prevent, treat metabolic syndrome

April 8, 2013
Feeding an intestinal enzyme to mice kept on a high-fat diet appears to prevent the development of metabolic syndrome – a group of symptoms associated with type 2 diabetes, cardiovascular disease and fatty liver – and ...

Recommended for you

Genetic immune deficiency could hold key to severe childhood infections

July 18, 2017
A gene mutation making young children extremely vulnerable to common viruses may represent a new type of immunodeficiency, according to a University of Queensland researcher.

What are the best ways to diagnose and manage asthma?

July 18, 2017
What are the best ways to diagnose and manage asthma in adults? This can be tricky because asthma can stem from several causes and treatment often depends on what is triggering the asthma.

Study finds molecular explanation for struggles of obese asthmatics

July 17, 2017
A large, bouquet-shaped molecule called surfactant protein A, or SP-A, may explain why obese asthma patients have harder-to-treat symptoms than their lean and overweight counterparts, according to a new study led by scientists ...

Large multi-ethnic study identifies many new genetic markers for lupus

July 17, 2017
Scientists from an international consortium have identified a large number of new genetic markers that predispose individuals to lupus.

Team identifies potential cause for lupus

July 14, 2017
Leading rheumatologist and Feinstein Institute for Medical Research Professor Betty Diamond, MD, may have identified a protein as a cause for the adverse reaction of the immune system in patients suffering from lupus. A better ...

Immunosuppression underlies resistance to anti-angiogenic therapy

July 14, 2017
A Massachusetts General Hospital (MGH) research team has identified a novel mechanism behind resistance to angiogenesis inhibitors - drugs that fight cancer by suppressing the formation of new blood vessels. In their report ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

neversaidit
not rated yet Apr 26, 2013
or, you can just follow a low carb diet and get similar results.
http://www.youtub...embedded

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.