Researchers discover how worms promote healing

December 01, 2010

New York (Dec. 1, 2010) - A new study involving a man who swallowed worm eggs to relieve symptoms of ulcerative colitis sheds light on how worms promote healing in the intestine. The study, published today in Science Translational Medicine, also identifies potential targets for more conventional ways of treating colitis, an inflammatory bowel disease.

"The idea for treating colitis with worms is not new, but how this therapy might work remains unclear," says the study's senior corresponding author, P'ng Loke, PhD, assistant professor of medical parasitology at NYU Langone Medical Center. "Our findings suggest that infection with this particular parasite increases or restores mucus production in the colon, providing symptomatic relief."

A chronic disease, ulcerative colitis is characterized by open sores or ulcers in the lining of the colon. The disease is estimated to affect 600,000 Americans, according to the Crohn's & Colitis Foundation of America, and the most common symptoms are abdominal pain and bloody diarrhea. The cause is unknown, but studies points to defects in immune regulation. Disruption of mucus production is often associated with severe symptoms.

Colitis is common in North America and Northern Europe, where helminth (parasitic worm) infections are rare. Conversely, the disease is rare in Asia, Africa, and Latin America, where helminth infections are endemic, leading researchers to hypothesize that the worms offer protection against this inflammatory bowel disease. In animal models of autoimmunity these worms have suppressed inflammation, and clinical trials indicate that helminth therapy can be beneficial in relieving symptoms of inflammatory bowel diseases.

To gain a better understanding of how such therapy works, Dr. Loke and his colleagues analyzed a series of blood and tissue samples taken from a 34-year-old man living in California with ulcerative colitis who ingested Trichuris trichiura eggs (a roundworm that infects the lower intestine) after having researched the scientific literature. After several months, his condition improved dramatically and he remained in remission for almost three years. A subsequent cycle of self-treatment with the worm eggs achieved similar results.

Tissues samples taken when the patient had active disease were found to contain high numbers of a type of immune cell (CD4+ T cells) that produces an inflammatory protein called interleukin-17. Tissue samples taken after exposure to the worms, when the disease was in remission, contained an abundance of T cells that produce interleukin-22 (IL-22), a protein important in mucosal healing. To expel the worm, the researchers note, the immune system appears to activate specialized cells that increase mucous production in the entire colon.

"In essence, the worms trigger a big sneeze of the gut, which may have a beneficial side effect for ulcerative colitis," says Dr. Loke, who does not advocate helminth therapy. "The problem is that these worms themselves can cause harm and damage the gut. The individual in this study is lucky to have responded so well, but for other people the worm infection may exacerbate bowel inflammation," he says.

It is impossible right now to predict who might be helped and who might be harmed by infection with these worms. Studies are underway, adds Dr. Loke, using a worm that infects pigs (T. suis) to treat colitis, which should be less risky.
-end-
Dr. Loke's co-investigators include Mara J. Broadhurst, Joseph M. McCune, Uma Mahadevan, and James H. McKerrow of the University of California, San Francisco; and Jacqueline M. Leung and Vikram Kashyap of NYU Langone Medical Center.

About NYU Langone Medical Center

NYU Langone Medical Center is one of the nation's premier centers of excellence in healthcare, biomedical research, and medical education. For over 170 years, NYU physicians and researchers have made countless contributions to the practice and science of health care. Today the Medical Center consists of NYU School of Medicine, including the Smilow Research Center, the Skirball Institute of Biomolecular Medicine, and the Sackler Institute of Graduate Biomedical Sciences; and the NYU Hospitals Center, including Tisch Hospital, a 705-bed acute-care general hospital, Rusk Institute of Rehabilitation Medicine, the first and largest facility of its kind, and NYU Hospital for Joint Diseases, a leader in musculoskeletal care, a Clinical Cancer Center and numerous ambulatory sites.

NYU Langone Medical Center / New York University School of Medicine

Related Ulcerative Colitis Articles from Brightsurf:

Researchers identify enzyme linked to colitis
An enzyme that usually stops bacterial growth in the large intestine stimulates inflammation in some people, resulting in ulcerative colitis - a chronic digestive disease.

Using artificial intelligence to assess ulcerative colitis
Researchers from Tokyo Medical and Dental University (TMDU) have developed an artificial intelligence system with a deep neural network that can effectively evaluate endoscopic data from patients with ulcerative colitis, which is a type of inflammatory bowel disease, without the need for biopsy collection.

Stanford scientists link ulcerative colitis to missing gut microbes
About 1 million people in the United States have ulcerative colitis, a serious disease of the colon that has no cure and whose cause is obscure.

New AGA guideline outlines treatment best practices for ulcerative colitis patients
An increasing number of drugs are available for long-term management of moderate to severe UC, leading to questions about treatment strategies for optimal patient care.

Colorectal cancer risk remains despite modern treatment for ulcerative colitis
Patients with the inflammatory bowel disease ulcerative colitis have a higher risk of dying from colorectal cancer, despite modern therapy, even though the risk has declined in recent years.

Drug decreases gut leakiness associated with ulcerative colitis
A research team led by biomedical scientists at the University of California, Riverside, has found that a drug approved by the FDA to treat rheumatoid arthritis and ulcerative colitis can repair permeability defects in the gut's epithelium.

Scientists are developing a way to counter ulcerative colitis
Ulcerative colitis (UC) is a long-term condition that results in inflammation and ulcers of the colon and rectum.

Walnuts show protection against ulcerative colitis in early study
Through their complex array of natural compounds and phytochemicals, walnuts provide a multitude of health benefits.

The impacts of smoking on patients with ulcerative colitis
Because smokers are less likely to develop ulcerative colitis (UC), a type of inflammatory bowel disease, patients with UC may be tempted to start smoking to lessen their symptoms.

New method divides patients with ulcerative colitis in groups
Researchers at Karolinska Institutet in Sweden have found a way of using gene expression conserved across species to divide patients with the inflammatory bowel disease ulcerative colitis into two distinct groups.

Read More: Ulcerative Colitis News and Ulcerative Colitis Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.