Calprotectin: What It Means for Gut Health
Introduction
Digestive symptoms are among the most common health complaints—ranging from occasional bloating and discomfort to persistent abdominal pain, diarrhea, or constipation. While many of these issues are mild or temporary, some are signs of deeper inflammation within the gut. One of the most reliable and widely used tools for detecting gut inflammation is the calprotectin test.
Calprotectin is a protein found in stool that reflects the activity of white blood cells in the gastrointestinal (GI) tract. Elevated levels of calprotectin often point toward underlying inflammation, making it a valuable biomarker in both conventional and functional medicine.
This biomarker can be ordered through normal labs such as Quest Diagnostics or DLO, and it is also included in advanced functional medicine testing panels like the Gut Zoomer, which provides a broader look at the gut microbiome and intestinal health.
In this article, we’ll break down everything you need to know about calprotectin: what it is, why it matters, how it is tested, and how results can be used to optimize patient health.
What is Calprotectin?
Calprotectin is a calcium- and zinc-binding protein that makes up about 60% of the cytosolic proteins in neutrophils, a type of white blood cell involved in inflammation. When neutrophils migrate to areas of inflammation in the gastrointestinal tract, they release calprotectin, which is then excreted in stool.
This makes calprotectin a direct marker of intestinal inflammation. Unlike blood markers of inflammation (such as C-reactive protein), stool calprotectin specifically reflects processes happening within the gut lining.
Why Calprotectin Matters in Gut Health
Inflammation in the gut is a root cause of many health conditions, both gastrointestinal and systemic. Measuring calprotectin helps identify and monitor:
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Inflammatory bowel diseases (IBD): Crohn’s disease and ulcerative colitis.
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Irritable bowel syndrome (IBS) vs. IBD differentiation: IBS typically does not cause elevated calprotectin.
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Gut infections: Bacterial or parasitic infections can raise levels.
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NSAID-induced enteropathy: Nonsteroidal anti-inflammatory drugs (like ibuprofen) can increase intestinal inflammation.
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Colorectal cancer and polyps: In some cases, higher calprotectin levels may suggest advanced pathology.
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Subclinical gut inflammation: Even before severe symptoms appear, elevated calprotectin can reveal ongoing immune activity in the gut lining.
For patients in functional or integrative medicine, calprotectin is particularly useful because it bridges conventional lab testing with advanced microbiome-based insights.
How Calprotectin Is Tested
Testing calprotectin is straightforward:
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Sample type: Stool.
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Availability: Can be ordered through standard clinical labs (Quest, DLO, LabCorp, etc.).
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Advanced testing: Also included in comprehensive gut health panels like the Gut Zoomer, which measures hundreds of markers related to the microbiome, leaky gut, and inflammation.
Because it is non-invasive and relatively inexpensive, calprotectin has become a go-to marker for clinicians who want to assess gut inflammation objectively.
Interpreting Calprotectin Results
Normal or Low Calprotectin
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Suggests absence of significant intestinal inflammation.
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Helps rule out inflammatory bowel disease (IBD).
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In functional medicine, a normal level may reassure patients with IBS-like symptoms that inflammation is not the main driver.
Moderately Elevated Calprotectin
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May indicate mild or localized inflammation.
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Could be due to infection, early IBD, recent NSAID use, or even intense exercise.
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Warrants further evaluation and possibly repeat testing.
Significantly Elevated Calprotectin
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Often seen in Crohn’s disease, ulcerative colitis, or advanced GI pathology.
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Requires further diagnostic imaging or colonoscopy.
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May also indicate a flare in patients with known IBD.
Calprotectin in Conventional Medicine
In gastroenterology, calprotectin has three primary uses:
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Differentiating IBS from IBD:
Patients with irritable bowel syndrome typically have normal calprotectin, while patients with Crohn’s disease or ulcerative colitis show elevations. This helps avoid unnecessary colonoscopies. -
Monitoring IBD activity:
Fluctuations in calprotectin levels often track with disease activity. A rise may predict a flare, while falling levels suggest remission. -
Assessing treatment response:
Whether on biologics, steroids, or dietary therapy, calprotectin can serve as a non-invasive tool to gauge progress.
Calprotectin in Functional & Integrative Medicine
While conventional medicine often uses calprotectin mainly in the context of IBD, functional medicine expands its utility:
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Detecting hidden inflammation: Even “moderately elevated” calprotectin can be a clue to subtle gut issues before major disease develops.
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Guiding microbiome therapies: Elevated levels may prompt interventions like targeted antimicrobials, probiotics, or anti-inflammatory nutrients.
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Monitoring healing: As gut-focused therapies are implemented, calprotectin levels can help track whether the gut lining is improving.
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Optimizing systemic health: Because gut inflammation can drive autoimmune disease, skin conditions, metabolic dysfunction, and mood disorders, calprotectin becomes a gateway marker for whole-body health.
Factors That Influence Calprotectin
Understanding what can raise or lower calprotectin helps clinicians interpret results correctly:
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Medications: NSAIDs, aspirin, and proton pump inhibitors (PPIs) may increase levels.
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Infections: Acute bacterial or parasitic infections often elevate calprotectin.
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Exercise: Very intense exercise may cause temporary increases.
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Age: Levels can be higher in infants and elderly adults.
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Diet and lifestyle: Chronic poor diet, alcohol, and gut dysbiosis contribute to persistent elevations.
Using Calprotectin Results to Guide Treatment
1. If Calprotectin is Elevated
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Identify and address the cause: ruling out infection, IBD, or medication effects.
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Functional strategies may include:
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Anti-inflammatory nutrients: Curcumin, omega-3 fatty acids, quercetin, zinc carnosine.
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Probiotics and postbiotics: Certain strains help lower inflammation and improve gut barrier function.
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Elimination diets: Identifying food triggers such as gluten, dairy, or FODMAPs.
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Gut-healing peptides: Such as BPC-157 or KPV, which support intestinal integrity.
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Stress reduction: Since stress worsens gut permeability and inflammation.
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2. If Calprotectin is Normal
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Suggests functional issues like IBS, SIBO, or dysbiosis rather than overt inflammation.
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Treatment focuses more on motility, microbiome balance, and digestive enzyme support.
3. Monitoring Over Time
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Repeating the test helps track healing. For example, if calprotectin falls after treatment, it validates the therapeutic approach.
Calprotectin and the Gut Zoomer
At our clinic, we use the Gut Zoomer test, which includes calprotectin as part of its comprehensive analysis. While Quest or DLO can provide a standalone calprotectin measurement, the Gut Zoomer offers additional insights into:
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Microbiome diversity.
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Dysbiotic bacteria, yeast, and parasites.
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Markers of leaky gut and gut barrier integrity.
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Immune balance in the GI tract.
By including calprotectin alongside this broader panel, we gain a 360-degree view of gut health—allowing us to create personalized treatment plans that go beyond symptom management to truly optimize patient health.
Calprotectin and Whole-Body Health
Gut inflammation doesn’t just stay in the gut—it has systemic effects:
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Autoimmunity: Chronic gut inflammation can trigger autoimmune diseases (e.g., Hashimoto’s thyroiditis, rheumatoid arthritis).
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Metabolic health: Elevated gut inflammation is linked with insulin resistance and obesity.
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Neurological health: The gut-brain axis means calprotectin elevations may correlate with anxiety, depression, or cognitive issues.
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Skin health: Psoriasis, eczema, and acne can be worsened by gut inflammation.
This makes calprotectin not just a GI marker, but a window into broader patient wellness.
Future Directions for Calprotectin Testing
As research expands, calprotectin may become even more valuable:
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Predicting relapses in IBD before symptoms begin.
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Stratifying patients for targeted therapy (who will respond best to biologics, diet, or microbiome modulation).
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Combining with other biomarkers like lactoferrin, zonulin, or microbiome sequencing for more precise diagnostics.
Conclusion
Calprotectin is a powerful, non-invasive biomarker that helps identify, monitor, and manage gut inflammation. Whether ordered through standard labs like Quest or DLO or as part of the advanced Gut Zoomer panel, it provides actionable insight into gastrointestinal and systemic health.
For patients, calprotectin offers clarity: it helps explain symptoms, differentiates between functional and inflammatory conditions, and guides personalized treatment strategies. For clinicians, it is both a conventional diagnostic tool and a functional medicine biomarker that supports whole-body optimization.
By integrating calprotectin testing into routine practice, we can move beyond symptom suppression and toward a root-cause approach to health—helping patients achieve lasting relief and improved well-being.
References
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Tibble JA, et al. Use of surrogate markers of inflammation and Rome criteria to distinguish organic from nonorganic intestinal disease. Gastroenterology. 2002.
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Mosli M, et al. C-reactive protein, fecal calprotectin, and stool lactoferrin for detection of endoscopic activity in symptomatic inflammatory bowel disease patients: a systematic review and meta-analysis. Am J Gastroenterol. 2015.
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Lasson A, et al. Fecal calprotectin in colorectal cancer: a systematic review. Scand J Gastroenterol. 2014.
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Walsham NE, Sherwood RA. Fecal calprotectin in inflammatory bowel disease. Clin Exp Gastroenterol. 2016.
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Gisbert JP, McNicholl AG. Questions and answers on the role of fecal calprotectin as a biological marker in inflammatory bowel disease. Dig Liver Dis. 2009.