Symbiotic immunomodulation involves deliberately hosting a controlled number of carefully selected, benign intestine-dwelling helminths such as Necator americanus (NA) and Trichuris Trichiura (TTO).
The introduction of NA hookworm requires the larvae to be placed onto the skin, which they normally penetrate within 10 – 20 minutes. They are then carried through the blood vessels to the lungs where they ascend the bronchial tree to the pharynx, and are swallowed and eventually reach the small intestine where they reside and mature into adults. Adult worms live in the lumen of the small intestine, where they attach to the intestinal wall and normally remain alive for 3 – 5 years.
It is often necessary to have at least 3 doses of NA hookworm larvae at a minimum of 12 week intervals to get optimum results.
The life cycle of Trichuris Trichiura – commonly known as whipworm due to their whiplike structure— relies on the eggs being passed in stool and under the right circumstances becoming embryonated before becoming infective. Once the embryonated eggs are consumed by a human host, they hatch in the small intestine, stimulated by exposure to microflora in the gut. The juvenile worms then enter the crypts of Lieberkuhn, a gland found in the epithelium lining of the intestines, where they grow and molt 4 times before making their way to the large intestine. It is thought that whipworm first colonise the cecum area (beginning of the large intestine) and with further exposure the worms make their way down the colon. It takes around 3 months for the worms to fully mature and for the females to begin to lay eggs.
Whipworm live for around 1 – 2 years and are primarily used for the treatment of colitis however recent studies suggest TTO may also help with gut dysbiosis:
“In addition, a study using a primate model of idiopathic chronic diarrhoea (ICD) has demonstrated that the therapeutic ability of T. trichiura whipworms to improve clinical symptoms of inflammation was associated with significant changes in the composition and relative abundance of different gut bacterial species.”
Suppression of inflammation by helminths: a role for the gut microbiota?
Paul Giacomin, John Croese, Lutz Krause, Alex Loukas, Cinzia Cantacessi