A recently published study in Frontiers in Endocrinology examined an important question in the Chronic Inflammatory Response Syndrome (CIRS) community: is there a relationship between persistent MARCoNS colonization and low α-Melanocyte Stimulating Hormone (α-MSH) levels?
The findings suggest there may be.
What Are MARCoNS?
MARCoNS (Multiple Antibiotic Resistant Coagulase-Negative Staphylococci) are bacteria that can colonize the nasal passages. Unlike an acute infection, colonization does not necessarily cause obvious symptoms such as fever or tissue damage. However, some researchers believe persistent colonization may contribute to ongoing immune dysregulation in susceptible individuals.
MARCoNS has been discussed extensively within the CIRS literature, particularly in patients with a history of exposure to water-damaged buildings and biotoxin illness.
The Study
Researchers analyzed data from 188 adults who were being treated within a CIRS-informed clinical framework. All participants tested positive for MARCoNS at the beginning of the study and underwent treatment directed at reducing nasal colonization.
The investigators then compared patients who successfully cleared MARCoNS with those who remained culture-positive.
The primary biomarker of interest was α-MSH, a neuroimmune regulatory peptide involved in inflammation, immune signaling, epithelial barrier function, and other aspects of physiological regulation.
What Did They Find?
The most interesting finding was that patients who were MARCoNS-negative at follow-up showed significantly higher α-MSH levels than patients who remained MARCoNS-positive.
Average α-MSH levels increased:
- From 8.6 pg/mL to 20.1 pg/mL in patients who cleared MARCoNS
- From 8.4 pg/mL to 16.6 pg/mL in patients who remained positive
Interestingly, this relationship appeared to be specific to α-MSH. Other commonly measured biomarkers, including VIP and MMP-9, improved over time but did not show the same association with MARCoNS clearance status.
Why Does This Matter?
Low α-MSH has long been reported in many patients diagnosed with CIRS. Previous researchers, including Dr. Ritchie Shoemaker and colleagues, observed associations between MARCoNS colonization and reduced α-MSH levels. This new study adds quantitative evidence supporting that observation.
While the study cannot prove that MARCoNS directly causes low α-MSH, it strengthens the hypothesis that persistent nasal colonization may play a role in ongoing neuroimmune dysregulation.
What Treatments Were Used?
The study included a variety of MARCoNS-directed nasal protocols. According to the authors, formulations used in clinical practice contained ingredients such as:
- Xylitol
- EDTA
- Grapefruit Seed Extract (GSE)
- Colloidal Silver
These ingredients were used individually or in combination depending on the patient's treatment plan.
Because multiple treatment approaches were used, the study was not designed to determine which specific formulation performed best.
The Bottom Line
This study provides further evidence that successful reduction of MARCoNS colonization may be associated with improvements in α-MSH, a biomarker frequently discussed in the CIRS community. While additional prospective research is still needed, the findings highlight the growing scientific interest in the relationship between the nasal microbiome, immune regulation, and chronic inflammatory illness.
As our understanding of MARCoNS continues to evolve, research like this helps shed light on the complex connections between nasal health, immune signaling, and overall wellness.
References: DiTulio M, Navarro-Torres CA. Clearance of multiple antibiotic-resistant coagulase-negative staphylococci is selectively associated with higher circulating α-melanocyte stimulating hormone in patients evaluated for chronic inflammatory response syndrome. Frontiers in Endocrinology. 2026.
