Clinical Research Directory

Inclusion Criteria: * Infants aged 0 to 5 months at enrollment * Full-term birth (gestational age ≥37 weeks) * Birth weight ≥2500 g * Infants with symptoms of gastrointestinal discomfort (e.g., abdominal distension, excessive crying, regurgitation, or feeding intolerance) * Parents or legal guardians able and willing to provide written informed consent and comply with study procedures Exclusion Criteria: * Infants with known or suspected organic gastrointestinal diseases (e.g., congenital malformations, Hirschsprung disease) * History of severe perinatal complications or significant systemic diseases * Known or suspected cow's milk protein allergy or other food allergies * Use of antibiotics, probiotics, or other medications that may affect gastrointestinal function within 2 weeks prior to enrollment * Participation in another clinical study within the past 3 months * Any condition that, in the investigator's judgment, may interfere with study participation or outcome assessment For the reference cohort: healthy breastfed infants without significant gastrointestinal symptoms