Parasitic worms live inside the intestines of more than 1 billion people worldwide, feeding off of the nutrients and blood of their hosts. But the effects of the worms aren’t always entirely bad, and, according to a new discovery from scientists at the University of California, can even help to promote pregnancy. The Tsimane are a people who live in prime parasite country within the Amazon rainforest of Bolivia. Roughly 20 percent of them harbor Ascaris lumbricoides, a giant roundworm that survives by stealing a portion of the host’s food, and 56 percent host hookworms that puncture the lining of the intestine to drink their host’s blood. Tsimane women infected with hookworms suffer minor health defects and are less fertile than healthy counterparts, but women infected with Ascaris give birth to two more children during their lifetimes than the average healthy Tsimane, becoming pregnant more frequently and at earlier ages. The team attributes the result to the worm’s need to interfere with the immune system to survive, a process which can reduce inflammation and potentially promote conception and implantation of the embryo in the womb. Researchers do not consider Ascaris a viable infertility treatment but the result sheds light on the immune system’s role in pregnancy, presenting the possibility for drugs that reproduce a similar immune response.
Read the full story at Science Magazine.