Serum Versus Fecal Calprotectin Levels in Patients with Severe Obesity Before and 6 Months After Roux-Y-Gastric Bypass: Report of the Prospective Leaky-Gut Study.

FC is a surrogate marker of systemic and intestinal inflammation and adiposity, whereas SC only tends to correlate with systemic inflammation. At 6 months after RYGB, SC-based systemic inflammation decreased, whereas FC-based intestinal inflammation increased. FC and SC levels follow different trajectories and are unrelated to improvements following bariatric surgery.