Calprotectin is one of the most important inflammatory markers on the GI-MAP because it tells you whether the gut lining is irritated, inflamed, or under immune stress. Unlike many other markers, calprotectin comes directly from neutrophils — a type of immune cell — which makes it a reliable indicator of actual physical irritation in the intestinal lining. You can explore how we read this clinically on the GI-MAP PAGE.

When calprotectin is elevated, the gut is signaling that something is triggering an immune response. This may come from dysbiosis, yeast overgrowth, parasites, food reactivity, or impaired bile flow. Elevated calprotectin often correlates with symptoms that worsen throughout the day — bloating, pressure, swelling, or post-meal fatigue. These timing-based changes resemble the patterns described in Blog Post — What calprotectin really tells us about gut symptoms.

One meaningful part of interpreting calprotectin is understanding its relationship with fermentation pressure. When the gut is inflamed, motility slows and fermentation increases, which amplifies afternoon and evening symptoms. This fermentation-driven pattern aligns with the physiology described in Blog Post — Why calprotectin rises and what makes it fluctuate.

Calprotectin doesn’t tell you the cause — it tells you the gut is reacting.

By pairing calprotectin with other markers, you can determine the likely driver.
For example: