People interested in Chronic Inflammatory Response Syndrome (CIRS), mold-related illness, and the nasal microbiome have long debated whether MARCoNS (Multiple Antibiotic-Resistant Coagulase-Negative Staphylococci) play an important role in recovery.

A recently published study in Frontiers in Endocrinology adds new data to that discussion. Researchers reported that patients who tested negative for MARCoNS during follow-up had significantly higher levels of alpha-melanocyte stimulating hormone (α-MSH) than those who remained MARCoNS-positive.

Although the study does not establish a cause-and-effect relationship, it provides additional evidence supporting further investigation into the relationship between the nasal microbiome and neuroimmune regulation.

What Are MARCoNS?

MARCoNS (Multiple Antibiotic-Resistant Coagulase-Negative Staphylococci) are a group of bacteria that can colonize the nasal passages. Like many other bacteria, they are capable of forming biofilms—structured microbial communities surrounded by a protective matrix that may make them more resistant to environmental stresses.

Some healthcare practitioners working within the Chronic Inflammatory Response Syndrome (CIRS) framework consider persistent MARCoNS colonization to be a potential factor that may influence recovery in certain patients. However, research in this area remains limited, and many aspects of the relationship continue to be investigated.

What Is Alpha-MSH?

Alpha-melanocyte stimulating hormone (alpha-MSH) is a naturally occurring neuropeptide involved in numerous physiological processes, including immune regulation, inflammatory signaling, barrier function, and pain modulation.

Within the CIRS framework, reduced alpha-MSH levels have been reported in many patients and have been proposed as one of several biomarkers that may reflect altered neuroimmune regulation.

Researchers continue to investigate the broader role of alpha-MSH in both health and disease.

The Study

The study, published in Frontiers in Endocrinology, followed 188 adults receiving care within a Chronic Inflammatory Response Syndrome treatment framework.

Researchers examined changes in three commonly monitored biomarkers:

• Alpha-MSH, a neuroimmune regulatory peptide.
• VIP (vasoactive intestinal peptide), another signaling molecule involved in immune and neurological regulation.
• MMP-9 (matrix metalloproteinase-9), a protein associated with inflammatory processes and tissue remodeling.

Participants received comprehensive care rather than treatment directed solely at MARCoNS. The investigators therefore examined whether MARCoNS status was associated with changes in these biomarkers over time.

The Key Finding

Across the study population, several biomarkers showed improvement during follow-up.

However, one finding stood out.

Patients who no longer tested positive for MARCoNS at follow-up had significantly higher alpha-MSH levels than patients who continued to test positive.

Interestingly, this relationship appeared specific to alpha-MSH.

Although VIP and MMP-9 also changed over time, neither showed a statistically significant association with MARCoNS status.

This selective association suggests there may be a unique relationship between the nasal microbiome and alpha-MSH regulation that warrants further investigation.

Why Is This Finding Interesting?

Alpha-MSH is involved in regulating inflammatory signaling throughout the body and has been studied for its effects on immune responses, epithelial barrier function, and nervous system signaling.

The observation that alpha-MSH—but not the other biomarkers—was associated with MARCoNS status raises several important scientific questions.

For example:

• Does persistent nasal colonization influence neuroimmune signaling?
• Could changes in the nasal microbiome affect systemic inflammatory pathways?
• Or does MARCoNS status simply reflect broader improvements occurring during treatment?

At present, the available data cannot answer these questions definitively, but they provide a strong rationale for future research.

Important Limitations

As with any retrospective observational study, several limitations should be considered.

The study demonstrates an association, not causation.

It does not establish that MARCoNS directly lowers alpha-MSH or that eliminating MARCoNS will increase alpha-MSH levels.

Participants were receiving multiple treatments simultaneously, making it impossible to determine which components of care contributed to the observed biomarker changes.

Additional prospective and randomized clinical studies will be needed to better understand the relationship between MARCoNS, alpha-MSH, and recovery.

What This Means

This study contributes to a growing body of literature exploring how the nasal microbiome may interact with immune and neuroendocrine pathways.

While many questions remain unanswered, the findings suggest that the relationship between nasal microbial communities and systemic physiology may be more significant than previously appreciated.

As interest in the nasal microbiome continues to grow, future research may help clarify how microbial ecology, biofilms, and host immune regulation influence overall health.

Frequently Asked Questions

What is MARCoNS?

MARCoNS stands for Multiple Antibiotic-Resistant Coagulase-Negative Staphylococci, a group of bacteria that can colonize the nasal passages and form biofilms.

Does MARCoNS cause low alpha-MSH?

This study found that patients who tested negative for MARCoNS had higher alpha-MSH levels than those who remained positive. However, the study does not demonstrate that MARCoNS directly causes low alpha-MSH.

What is alpha-MSH?

Alpha-MSH is a naturally occurring neuropeptide involved in immune regulation, inflammatory signaling, barrier function, and several other physiological processes.

Does this study prove that treating MARCoNS improves CIRS?

No. Participants received comprehensive care, and the study was observational. The findings demonstrate an association rather than proving that addressing MARCoNS alone produces clinical improvement.

Why is this study important?

The study provides additional evidence supporting further investigation into the relationship between the nasal microbiome, biofilms, neuroimmune signaling, and biomarkers such as alpha-MSH.

FDA Disclaimer

This article is provided for educational and informational purposes only and summarizes findings from a published scientific study. It is not intended as medical advice and should not be interpreted as evidence that any product, ingredient, or treatment diagnoses, treats, cures, or prevents any disease or medical condition. Individuals with ongoing health concerns should consult a qualified healthcare professional.