2.1 Study design
Fecal samples were collected from 1482 children up to 16 years of age who visited the outpatient clinic of the Children’s Hospital of Fudan University and were diagnosed with acute gastroenteritis between January 2020 and December 2022 in Shanghai. All enrolled samples were routinely collected and stored at -70°C before the examination. The definition of AGE was three or more loose, watery, thin, pasty stools or the presence of mucous stools within 24 hours, possibly accompanied by vomiting, abdominal pain, fever, and nausea. This definition excluded the presence of pus or blood regardless of the presence of fever22. Demographic information and clinical diagnoses were obtained from the patients’ medical history. The study proposal was approved by the Institutional Review Board of the Children’s Hospital of Fudan University. All procedures were performed in accordance with relevant guidelines and regulations.