The bacteria present in the intestine provide information about the quantities of fungi of the potentially disease-causing Candida genus. Among them, and surprisingly, are lactic acid bacteria that are known for their protective effect against fungal infections. The findings of researchers at the Leibniz Institute for Natural Product Research and Infection Biology (Leibniz-HKI) and their collaborative partners from Denmark and Hungary add another piece to the puzzle of understanding the human gut microbiome.