How Worms May Fight Obesity
You may squirm at the thought of using worms to fight obesity, but researchers are serious about the possibility. It appears that roundworm infections offer a number of potential health benefits, including fighting obesity, diabetes, and autoimmune diseases.
What are roundworms?
Roundworms are a type of gastrointestinal nematode, of which there are six of major importance in human health. The other five include whipworm, pinworm, threadworm, and two distinct species of hookworm.
According to a previous article in the International Journal of Experimental Pathology, gastrointestinal nematode infections are among the most common type of infection in the world, and their prevalence has remained largely unchanged in more than 50 years, although there has been some progress in reducing the numbers in recent years.
Despite their prevalence, roundworm infections often do not cause symptoms and so they are often undiagnosed. In addition, the majority of people who have roundworm or other GI nematode infections live in developing countries, with those living in the poorest conditions being most at risk.
Some good news about roundworms comes from researchers at the University of Maryland School of Medicine, who report that a roundworm infection in mice resulted in some important results, namely:
- 13 percent loss of body weight in 10 days among obese mice
- 15 percent less weight gained among normal weight mice fed a high-fat diet
- Decline in insulin and leptin levels, suggesting the animals “restored their sensitivities to both hormones,” according to Aiping Zhao, one of the study’s authors. High levels of insulin and/or leptin can contribute to obesity and metabolic syndrome
- Significant decline in fasting blood glucose levels, a risk factor for type 2 diabetes
- Decrease in liver fat by about 25 percent, which can reduce fatty liver disease
What role did the roundworms have in these positive results? The authors noted that the worms were associated with the reduction in the amount of glucose absorbed in the intestinal tract, a decline in the level of triglycerides in the liver, and an increase in the number of cells responsible for regulating glucose metabolism and inflammation.
On a more scientific level, what the researchers found was that a roundworm infection resulted in an increase in immune cells called Th2 cells and type 2 cytokines which both fight infection and inflammation. Obesity, as well as related conditions such as diabetes and heart disease, also involves inflammation and proinflammatory cytokines.
You don’t need to worry your doctor will prescribe roundworms to fight obesity or related conditions anytime soon. However, clinical trials are currently underway to determine whether worms can be used to treat conditions associated with certain cytokines.
For now, researchers note that “parasitic nematode infection has both preventive and therapeutic effects against the development of obesity and associated features of metabolic dysfunction in mice.” Who knows what investigators will find as they continue exploring how worms may fight obesity.
Stepek G et al. Human gastrointestinal nematode infections: are new control methods required? International Journal of Experimental Pathology 2006 Oct; 87(5): 325-41
Yang Z et al. Parasitic nematode-induced modulation of body weight and associated metabolic dysfunction in mouse models of obesity. Infection and Immunity 2013; doi:10.1128/IAI.00053-13