Fecal calprotectin concentrations in fecal extracts are associated with abnormal fecal status and gastrointestinal infection in captive and wild giant pandas

Fecal calprotectin (FC) is widely used as a non-invasive marker of intestinal inflammation in human medicine, but its application in giant pandas remains poorly characterized. This study evaluated FC concentrations in standardized fecal extracts from captive and wild giant pandas and explored their associations with fecal status, age, sex, diet, living environment, and gastrointestinal infection. Fecal samples were classified as normal or abnormal on the basis of fecal consistency, clinical signs, and PCR testing for gastrointestinal pathogens. FC was measured by enzyme-linked immunosorbent assay (ELISA) and reported as ng/mL of fecal extract. The effects of storage at 26 °C and − 80 °C were assessed descriptively. In addition, fecal proteomic profiles from 12 samples (normal, n = 3; abnormal, n = 9) were compared. FC concentrations were generally higher in abnormal than in normal fecal samples. Concentrations also varied among age, diet, and living-environment strata, whereas sex-related differences were limited. Wild giant pandas had higher mean FC concentrations than captive pandas. Proteomic analysis identified calprotectin among the proteins with increased abundance in abnormal samples. FC measured in standardized fecal extracts is associated with abnormal fecal status and gastrointestinal infection in giant pandas. These findings support further evaluation of FC as a non-invasive adjunct for gastrointestinal health assessment, but larger longitudinal studies and species-specific analytical validation are needed before clinical cutoffs can be established.