Science | Worming your way out of allergies
Accumulating evidence suggests that infection with intestinal parasitic worms can protect against allergy. Zaiss et al. investigated how worms reduce allergic reactions, using mice chronically infected with the parasitic wormHeligmosomoides polygyrus. They found that worms could reduce the incidence of allergy in mice harboring an intestinal microbiota but not in mice treated with oral antibiotics. The intestinal microbiota of mice infected with H. polygyrus produced larger amounts of short-chain fatty acids (SCFAs) than did uninfected mice. Moreover, mice had to express the protein receptor for SCFA in order for worms to protect them from developing allergies. Worm-infected pigs and people also had elevated amounts of SCFAs, suggesting that these metabolites may play a similar role in other organisms.