MADISON, Wis. -- Valerie Stull was 12 when she ate her first insect.
"I was on a trip with my parents in Central America and we were
served fried ants," she says. "I remember being so grossed out
initially, but when I put the ant in my mouth, I was really surprised
because it tasted like food -- and it was good!"
Today, Stull, a recent doctoral graduate of the University of
Wisconsin-Madison Nelson Institute for Environmental Studies, is the
lead author of a new pilot clinical trial published in the journal
Scientific Reports that looks at what eating crickets does to the human microbiome.
It shows that consuming crickets can help support the growth of
beneficial gut bacteria and that eating crickets is not only safe at
high doses but may also reduce inflammation in the body.
"There is a lot of interest right now in edible insects," Stull
says. "It's gaining traction in Europe and in the U.S. as a sustainable,
environmentally friendly protein source compared to traditional
livestock."
More than 2 billion people around the world regularly consume
insects, which are also a good source of protein, vitamins, minerals and
healthy fats. The research team was interested in documenting for the
first time via clinical trial the health effects of eating them.
"This study is important because insects represent a novel component
in Western diets and their health effects in human populations haven't
really been studied," says co-corresponding author Tiffany Weir, a
professor of food science and human nutrition at Colorado State
University. "With what we now know about the gut microbiota and its
relationship to human health, it's important to establish how a novel
food might affect gut microbial populations. We found that cricket
consumption may actually offer benefits beyond nutrition."
Raising insects for protein not only helps protect the environment,
but also offers a more healthful option than meat in many wealthy
countries with high-meat diets, says co-author Jonathan Patz, director
of the UW-Madison Global Health Institute, where Stull will begin a
postdoctoral research position in the fall.
Crickets, like other insects, contain fibers, such as chitin, that
are different from the dietary fiber found in foods like fruits and
vegetables. Fiber serves as a microbial food source and some fiber types
promote the growth of beneficial bacteria, also known as probiotics.
The small trial probed whether insect fibers might influence the
bacteria found in the gastrointestinal tract.
For two weeks, 20 healthy men and women between the ages of 18 and
48 ate either a control breakfast or a breakfast containing 25 grams of
powdered cricket meal made into muffins and shakes. Each participant
then ate a normal diet for a two-week "washout period." For the
following two weeks, those who started on the cricket diet consumed a
control breakfast and those who started on the control diet consumed a
cricket breakfast.
Every participant served as their own control for the study and the
researchers were blinded with respect to which diet each participant was
on at any given time.
The researchers collected blood samples, stool samples and answers
to gastrointestinal questionnaires immediately before the study began,
immediately following the first two-week diet period and immediately
after the second two-week diet period.
Participants' blood samples were tested for a host of health
measures, like blood glucose and enzymes associated with liver function,
and also for levels of a protein associated with inflammation. The
fecal samples were tested for the byproducts of microbial metabolism in
the human gut, inflammatory chemicals associated with the
gastrointestinal tract, and the overall makeup of the microbial
communities present in the stools.
Participants reported no significant gastrointestinal changes or
side effects and the researchers found no evidence of changes to overall
microbial composition or changes to gut inflammation. They did see an
increase in a metabolic enzyme associated with gut health, and a
decrease in an inflammatory protein in the blood called TNF-alpha, which
has been linked to other measures of well-being, like depression and
cancer.
Additionally, the team saw an increase in the abundance of
beneficial gut bacteria like Bifidobacterium animalis, a strain that has
been linked to improved gastrointestinal function and other measures of
health in studies of a commercially available strain called BB-12.
But, the researchers say, more and larger studies are needed to
replicate these findings and determine what components of crickets may
contribute to improved gut health.
"This very small study shows that this is something worth looking at in
the future when promoting insects as a sustainable food source," says
Stull.
Stull is co-founder of an award-winning startup and research
collaboration called MIGHTi, the Mission to Improve Global Health
Through Insects. In the future, MIGHTi hopes to provide home-use
insect-farming kits to communities that already consume insects,
including many in southern Africa. Insects require far less water to
farm than traditional livestock and can help improve food security in
impoverished communities while providing economic opportunities to
women.
"Most of the insects consumed around the world are wild-harvested
where they are and when they are available," says Stull, who has eaten
insects -- including caterpillars, cicadas, grasshoppers and beetle
larvae -- all over the world. "People love flying termites in Zambia,
which come out only once or twice a year and are really good; they taste
like popcorn and are a crunchy, oily snack."
She hopes to promote insects as a more mainstream food in the United
States, and though the industry is currently small, the rise of edible
insect producers and companies using insects in their food products may
make this possible.
"Food is very tied to culture, and 20 or 30 years ago, no one in the
U.S. was eating sushi because we thought it was disgusting, but now you
can get it at a gas station in Nebraska," she says.
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The study was funded by a multistate Hatch project (W3122:
Beneficial and Adverse Effects of Natural Chemicals on Human Heath and
Food Safety), the Karen Morris-Fine New Investigator Success Fund, the
Climate Quest competition, and the Clinical and Translational Science
Award program of the NIH National Center for Advancing
Translational Sciences (UL1TR000427). Entomo Farms donated a portion of
the cricket powder used in the study.
