Patients with COVID-19 present with low plasma citrulline concentrations that associate with systemic inflammation and gastrointestinal symptoms

While gastrointestinal symptoms are more and more recognized, the exact etiopathogenesis of SARS-CoV-2-associated diarrhea is still unknown [1]. It also remains unclear whether SARS-CoV-2 directly impacts enterocytes. The amino acid citrulline is not incorporated into proteins and is involved in intermediary metabolism. In humans, plasma citrulline is almost exclusively produced by enterocytes. Therefore, citrulline is used as a biomarker of small bowel enterocyte mass and function. For example, it is decreased in total villous atrophy as well as in short bowel syndrome with generally accepted thresholds of 10 μmol/L and 20 μmol/L, respectively [2].
Source: Digestive and Liver Disease - Category: Gastroenterology Authors: Source Type: research