It turns out intestinal parasites ( which are called helminths) can be beneficial in reducing allergies and autoimmune diseases, irritable bowel syndrome, MS symptoms and numerous study show helminths protecting lab rats from colon cancer. Lack of mutualistic parasites in in the industrialized world maybe a key contributed to loss of health. https://theconversation.com/they-might-sound-gross-but-intestinal-worms-can-actually-be-good-for-you-49868