Inclusion Criteria:  The gestational age was 37-42 weeks at birth; Birth weight ≥2,500 g and ≤ 4,500 g; Chinese nationality;  Weight and height are within normal range (i.e. WHO Child Growth Standards  2SD); No relocation across provinces/ cities in the past 1 year and no plans to relocate during the study period. Breastfeeding reference: breastfeeding at the time of enrollment, and the mother intends to continue breastfeeding throughout the study period; Intervention arm: formula feeding / habitual milk drinking (formula milk, milk and other dairy products) at the time of enrollment, and willing to change from the original milk powder / dairy product to the study formula, and consume it as instructed during the study period; The child's parent(s) / guardian has access to a mobile phone on which the secure digital WeChat platform can be installed and used, connect to the network, take photographs and record defecation, and complete questionnaires during the study; The child's parent(s) / guardian is of legal age of consent, has sufficient command of Chinese (Mandarin) language to complete the informed consent and other study documents, is willing and able to fulfill the requirements of the study. The child's parent(s) / guardians can be contacted directly by telephone or WeChat;  Exclusion Criteria:  Neonatal asphyxia at birth; Chronic infectious, metabolic, genetic illness or other disease including any condition that impacts feeding or may impact study outcomes; Cognitive and developmental disorders; Antibiotic usage up to 2 weeks before enrollment; Ongoing antibiotic treatment; Taking probiotic supplements or formula with probiotics up to 1 month before enrollment; Participation in other clinical trials; Parent(s)' / guardian's refusal to participate in the study; Known or suspected allergy to cow milk, soy or fish