Is blue cheese an antimicrobial food?

You are no doubt familiar with penicillin — 90 years after its discovery, it is still among the most-prescribed antibiotics. And you probably know that it is a natural product, produced by a bluish mold that grows on bread and also gives blue cheeses their distinctive color and flavor.

Is blue cheese a food you might want to eat for antimicrobial benefits? Or conversely, one that might perturb a healthy gut microbiome by wiping out beneficial bacteria?

This is a blue cheese. Photo by Jez Timms on Unsplash

The genus Penicillium contains over 300 species. Only a few are known to produce penicillins, including P. griseofulvum, P. dipodomys, P. flavigenum, P. nalgiovense, P. chrysogenum and notably P. rubens, the strain with which Fleming made his famous discovery.

Here’s what Fleming’s discovery looked like: no bacteria grew near a contaminating colony of Penicillium. From Penicillium Fungi

The main cheese-making Penicilliums — roqueforti (blue cheese), camemberti, (Camembert and Brie) and glaucum (Gorgonzola) — are not penicillin producers. They do produce other antibacterial metabolites — as well as human toxins and allergens — but no medically useful antibiotics.