Worms relieve zoo diarrhea in monkeys

Therapeutic Helminth Infection of Macaques with Idiopathic Chronic Diarrhea Alters the Inflammatory Signature and Mucosal Microbiota of the Colon

By Broadhurst, MJ et al. in PLoS Pathogens, Nov 15, 2012  doi:10.1371/journal.ppat.1003000  (open access)

Only 5 subjects!  But dramatic results, nonetheless.

Author’s Summary> Young macaques kept in captivity at Primate Research Centers often develop chronic diarrhea, which is difficult to treat because it is poorly understood. This disease shares many features with ulcerative colitis, which is an autoimmune disease affecting the intestinal tract of humans. Recently, parasitic worms have been used in clinical trials to treat inflammatory bowel diseases in humans with positive results, but very little is known about how worms can improve symptoms. We performed a trial where we treated macaques suffering from chronic diarrhea with human whipworms, collecting gut biopsies before and after treatment. We found that 4 out of the 5 treated macaques improved their symptoms and studied the changes in their gut immune responses, as they got better. We found that after treatment with worms, the monkeys had less bacteria attached to their intestinal wall and a reduced inflammatory response to the gut bacteria. Additionally, the composition of gut bacteria was altered in the sick macaques and was restored close to normal after treatment with whipworms. These results provide a potential mechanism by which parasitic worms may improve the symptoms of intestinal inflammation, by reducing the immune response against intestinal bacteria.