Pomegranates and other superfoods are known to improve brain functions such as memory and cognition, and now, researchers have discovered a clue as to how.

The answer may lie not with the foods themselves, but with the way they interact with the body’s microflora—a discovery that could lead to breakthroughs in protecting against Alzheimer’s.

Navindra Seeram, associate professor of biomedical and pharmaceutical sciences, says anti-inflammatory and neuroprotective compounds are created when gut bacteria break down pomegranate extract. “We asked a simple question: What is it within the extract that is really working?” relates Seeram. “And that’s where it became interesting.”

His team isolated and identified 21 compounds, mostly polyphenols, from pomegranate extract. None were able to cross the blood-brain barrier, but after gut microflora broke them down, the resulting urolithins could.

Before you stain your hands red, there’s a catch. Not everyone is able to produce these useful urolithins—each person’s gut microflora is different.