There is an active theory and research regarding the necessity of helminths (parasitic worms). List of peer-reviewed, Journal-published science regarding helminthic therapy and related topics:
asthma
allergies
anaphylaxis
psychiatric disorders
inflammation
ASD
autism
cardiovascular disease
IBD
Chron's
liver disease
MS
diabetes
http://www.helminthictherapy.com/Science.html More research: http:/…