Influence of proton pump inhibitor therapy on intestinal inflammation assessed by fecal calprotectin in pediatric patients

Recently, an increase in the numbers of patients with gastrointestinal symptoms is being observed. To investigate the effects of proton pump inhibitor therapy (PPI) on intestinal inflammation, in children and adolescents as confirmed by clinical manifestations and objectively assessed by measurement of fecal calprotectin (FC) level. Consecutive children (aged 3-18 years), who presented with gastrointestinal symptoms and were treated with or without PPI for at least 1 month, were enrolled. Patients were divided into PPI and non-PPI groups. PPI group was further subdivided based on the treatment duration and type of PPI used. Stool samples were collected for FC evaluation at baseline and after treatment, and clinical data and FC levels were compared between the groups. Fifty-one patients (15 boys and 36 girls) were enrolled in the study. PPI group comprised 37 patients and non-PPI group included 14 patients. Clinical symptoms were not statistically different. FC levels and laboratory results, including C-reactive protein levels, white blood cell count, and absolute neutrophil count were not statistically different before and after PPI treatment. After treatment, FC levels decreased to 8.1 (-575.4 ~ 340.3) mg/kg in the PPI group and increased to 5.6 (-460.0 ~ 186.9) mg/kg in the non-PPI group compared to that before treatment (P = 0.841). The number of patients with increased FC levels was not significantly different between the two groups (48.6% vs. 64.3%, P = 0.363), similar to that observed in patients with FC levels >50 mg/kg (24.3% and 7.1%, P = 0.250). The duration and type of PPI therapy did not affect the FC levels (P= 0.811 and P= 0.502, respectively). We attempted to confirm the evidence of intestinal inflammation due to PPI use in children and adolescents through clinical symptoms and FC measurement; however, no significant changes were observed.