ClostraBio, a Chicago startup creating a drug that aims to prevent allergic reactions to food, has raised a $3.5 million seed round.

Born out of the University of Chicago, ClostraBio is creating some of the first drugs to prevent and treat food allergies. The startup’s goal is to make drugs that boost the body’s natural intestinal barrier, stopping the reaction before it starts. It’s initially working to solve peanut and milk allergies.

Investors in the round include Morningstar founder Joe Mansueto and the University of Chicago. Additionally, two families—based in Chicago and Virginia—that have children who suffer from severe food allergies, also invested in ClostraBio’s round.

Here’s how it works: People have microbes in their gut that help maintain the strength of the gut’s lining. But when certain microbes are missing, this barrier function is weakened, making someone more susceptible to food allergies. ClostraBio is making a drug that strengthens that barrier and prevents allergens from passing out of the gut and into the bloodstream, the company says.

It has so far tested the therapy on mice, and it plans to use the new round of funding to conduct additional animal testing.

“It is estimated that two children in every classroom now have a food allergy that requires strict dietary avoidance,” Cathryn Nagler, ClostraBio’s cofounder and president, said in a statement. “And we believe the key to preventing these allergies is in your gut, specifically in the bacteria of your gut.”

ClostraBio, which was recently a finalist for the prestigious UChicago New Venture Challenge, was also one of Chicago Inno’s 18 startups to watch in 2018.