Researchers discovered for the first time how human genes influence the fungi living in our gut and how this connection affects heart disease risk. They found that a yeast called Kazachstania is regulated by a gene called CDH13, and people with certain genetic variants have less of this beneficial yeast and higher risk of heart disease. This groundbreaking study shows that our genetics don’t just affect bacteria in our gut—they also shape our fungal community, which has real implications for heart health.