12/10/2025
What Is MARCoNS — And Why Does It Matter in Mold Illness?
If you’ve been learning about mold or mycotoxin-related illness, you may have come across a strange acronym: MARCoNS.
It sounds complicated, but here’s the simple version ⬇️
MARCoNS = a type of staph bacteria that hides deep in the nasal passages.
For many people who’ve been dealing with mold exposure, chronic sinus issues, brain fog, fatigue, or ongoing inflammation, MARCoNS can quietly contribute to the problem.
This isn’t the kind of staph infection that causes fevers or urgent symptoms.
Instead, MARCoNS forms a sticky biofilm, a protective layer that helps it stay out of reach of the immune system. Think of it like a shield that lets these bacteria hang out long-term.
Why does this matter for mold-related illness?
Research from physicians who specialize in environmental and biotoxin-related conditions has shown that MARCoNS can:
• Produce toxins that irritate the immune system
• Contribute to sinus inflammation and congestion
• Disrupt certain regulatory hormones involved in energy, sleep, and mood
• Make it harder for the body to calm inflammation after mold exposure
For some patients, this becomes one reason they continue to feel unwell even after leaving a moldy environment.
How do people get MARCoNS?
Anyone can be exposed, but it’s more common in people who have:
• Long-standing inflammation
• Recurrent sinus issues
• Environmental or water-damaged-building exposure
• A history of chronic infections or immune dysregulation
It’s not considered a contagious infection — it’s more of a sign that the immune system has been working overtime.
How do we approach it at PEAK?
At PEAK Integrative Medicine, we include MARCoNS screening in certain cases where patients continue to struggle with sinus symptoms, fatigue, or brain fog long after the initial exposure has resolved.
Identifying and addressing MARCoNS can be an important part of helping the body rebalance and move forward.
It’s one piece of a much larger picture, but for some, it’s a meaningful one.
The big takeaway:
If you feel like you’ve done “all the right things” for mold recovery but symptoms remain, MARCoNS may be one of the hidden factors worth exploring with a trained provider.
If you’re curious whether this might apply to you, or you’re dealing with lingering sinus or inflammatory issues, we’re here to help.
PEAK Integrative Medicine
Patient-Centered • Root-Cause • Science-Driven
