12.2021 | THE SCIENTIST 27© ISTOCK.COM, CHRISTOPH BURGSTEDT
I
n the middle of 2020, Alex Loukas deliberately infected him-
self with intestinal worms. The procedure was pretty straight-
forward: he used a Band-Aid to press a few larvae of the
New World hookworm (Necator americanus) gently onto his
forearm, and waited for the microscopic critters to burrow on
in. Although it wasn’t painful, exactly, he describes a tingly feel-
ing like “little tiny electric shocks as these guys go through your
skin,” he says. “It’s intensely itchy for a number of days and then
that resolves.” Some people who undergo this process experience
stomach discomfort when the worms arrive in the gut, where they
will grow up to 1 cm long, but many “will then never have any
other clue that they’re infected.”
There were several reasons that Loukas wanted the parasitic
worms, or helminths, on board. For one thing, his research at
James Cook University in Australia focuses on multiple aspects
of N. americanus biology, and as obligate human parasites, these
intestinal worms just don’t grow very well outside of people. Rear-
ing a few in his own gut and then collecting eggs via a bathroom
visit would be a lot simpler than trying to maintain a population in
the lab, Loukas explains. (Judging by how many eggs he’s currently
shedding—he estimates it’s around 20,000 per day—his worms
seem to be doing just fine.)
Loukas has also, in the course of his research, developed the
view that infection with N. americanus and other intestinal hel-
minths, which together are thought to inhabit at least 2 billion
people worldwide, isn’t always harmful. In fact, he argues, work
by his group and others indicates that there could be some unique
benefits to controlled, low-level infection with certain worm
species, particularly for combating so-called Western diseases,
including allergies, autoimmune disorders, and various other
inflammation-related conditions. As an advocate for exploring
helminth infection as a potential therapy against such conditions,
Loukas realized he had to give it a go. “I’m sitting there telling the
world how great this is,” he recalls thinking. “I should probably
experience it for myself.”
Often referred to as immunoregulators, helminths secrete and
excrete vast quantities of proteins and other molecules that influ-