MARCoNS: Research on Multiple Antibiotic Resistant Coagulase-Negative Staph

MARCoNS is one of those things almost nobody outside the CIRS world has heard of, and it can quietly keep you stuck.

MARCoNS stands for Multiple Antibiotic Resistant Coagulase-Negative Staphylococci. These are staph bacteria that colonize deep in the nasal passages and hide under a sticky protective layer called a biofilm. It isn't usually an "infection" in the way most people think. Many people have no obvious sinus symptoms at all. In the Shoemaker framework, the concern is that MARCoNS is tied to low MSH (alpha-melanocyte stimulating hormone), a master regulatory hormone that's already low in many CIRS patients. Lower MSH can mean more trouble with sleep, pain, the gut, hormones and inflammation.

That's why eradicating MARCoNS is its own step in the Shoemaker Protocol, usually after you're out of exposure and on binders. Research in this hub has looked at whether clearing it is associated with better MSH levels.

This hub holds 13 papers on MARCoNS and CIRS. It's small, but it's focused research on nasal colonization, biofilms, MSH and testing.

For how testing works (the deep nasal swab), treatment options to discuss with your provider, and why timing matters, read my MARCoNS guide.

Educational only, not medical advice. Treatment decisions belong with your Shoemaker-trained provider.

— Lauren Lowenstein, The Biotoxin Lady · Last reviewed October 19, 2026