The leading cause of morbidity in captive rhesus monkeys is a condition called idiopathic chronic diarrhea (ICD), a condition similar to the inflammatory disease ulcerative colitis in humans. Since parasitic worms have recently been used to treat inflammatory bowel diseases in humans, researchers Broadhurst et al., decided to try this therapy in infected monkeys. Young rhesus macaques were administered 1000 human whipworm eggs (Trichuris trichiura) orally (don’t worry, they are microscopic). The results: 4 out of 5 of the treated monkeys had reduced diarrhea and began gaining weight.
Broadhurst MJ, Ardeshir A, Kanwar B, Mirpuri J, Gundra UM, Leung JM, Wiens KE, Vujkovic-Cvijin I, Kim CC, Yarovinsky F, Lerche NW, McCune JM, Loke P. Therapeutic Helminth Infection of Macaques with Idiopathic Chronic Diarrhea Alters the Inflammatory Signature and Mucosal Microbiota of the Colon. PLoS Pathogens. 8(11): e1003000. doi:10.1371/journal.ppat.1003000