Debbie Nicholson

Parasitic worms responsible for many diseases are also a valuable treatment

Parasitic worms (helminths) cause many diseases in developing countries. These worm-like organisms live in and feed on living hosts to get nourishment and protection from their host but disrupts the hosts nutrient absorption, causing weakness and disease. Even though current medications have lessened their threat in some areas but still remain a major threat.

View slideshow: Parasitic worms and health conditions

But now they may serve a useful purpose according to a research team comprised of scientists from the United States, France and China.

In this new study researchers have demonstrated that once the worms are inside the host, many parasitic worms secrete a sugar-based anti-inflammatory molecule that might actually help treat metabolic disorders associated with obesity. Metabolic disease associated with obesity is now at epidemic proportions.

Parasitic worms express host-like glycans (sugar molecule) to adjust the immune response of human hosts. The therapeutic potential of this immunomodulatory mechanism in controlling the metabolic dysfunction that is associated with chronic inflammation remains unexplored, according to the study’s abstract.

Glycan is released by parasites to help them evade the body's immune system. By reducing inflammation, they are better able to hide in tissues and humans experience fewer symptoms that might reveal their presence.

According to the National Council on Strength and Fitness, a common theme that links many diseases and chronic illness is uncontrolled cellular inflammation. It is a factor in diseases including cardiovascular disease, diabetes, cancer, arthritis and many autoimmune-related conditions. Obesity has recently been added to this group of diseases as it is now known to present a low grade inflammatory response within many of the body’s tissues, which cause deleterious effects, often leading to the development of cardiovascular and metabolic disease.

With the fact of obesity being an inflammatory disease researchers hypothesized that glycan may have some effect on complications related to it.

In order to test the hypothesis the researchers used mice who were fed a high-fat diet. Mice in the control group showed many symptoms linked with excessive weight gain such as insulin resistance and high cholesterol.

Mice who received treatment with sugar produced by the worms still gained weight but did not have the same negative health effects as the mice in the control group.

Dr. Donald Harn, PhD, worked on this research while he was an adjunct professor, department of immunology and infectious diseases, Harvard School of Public Health and now at the University of Georgia as a Georgia Research Alliance Distinguished Investigator, stated "All of the metabolic indicators associated with obesity were restored to normal by giving these mice this sugar conjugate. It won't prevent obesity, but it will help alleviate some of the problems caused by it."

The same sugars excreted by the parasites are also found in the developing human fetus and in human breast milk. Dr. Harn assumes that this may provide proper metabolic functions in the newborn infant. But after infancy sugar expression is only found on a few cells, and the only external source for the sugar is parasitic worms.

"Prevalence of inflammation-based diseases is extremely low in countries where people are commonly infected with worms, “says Dr. Harn. "But the minute you start deworming people, it doesn't take too long for these autoimmune diseases to pop up."

Dr. Harn adds that this does not mean that people should actively seek out parasitic infections as treatment however, it is an indication that the compounds secreted by worms may serve as the basis for future therapies.

Besides demonstrating the sugar molecule released by the parasite can help with obesity related disease Dr. Harn notes that along with this colleagues that glycan may relieve several other inflammatory diseases such as psoriasis treatment. It also seems that the sugar could be a strong anti-rejection drug that may one day be used in patients who have received organ transplants.

In closing Dr. Harn comments "We see great promise in this sugar, and we hope that future research and collaborations will eventually lead to marketable therapies for people suffering from disease.”

The researchers note that more research is needed before glycan can be tested in humans. The research team is hopeful that they can develop effective treatments that provide all the benefits of parasitic worms without the worms themselves.

The study is published in the journal Nature Medicine.

The research team was comprised of scientists from Harvard School of Public Health, Department of infectious Diseases, College of Veterinary Medicine, University of Georgia, Centre Hospitalier Régional Universitaire de Tours, Department of Internal Medicine, Nutrition, INSERM U1069, Université François Rabelais, Tours, France and Pharmacogenetics Research Institute, Institute of Clinical Pharmacology, Central South University.


Slideshow; Parasitic worms and health conditions

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