2.2. Study Design
weight gain, chronic illness, breast milk, allergies
CHRONIC ILLNESS, SYSTEMIC DISEASE, ALLERGIES, PROTEIN ALLERGY
A randomized, double-blinded controlled study with three study groups was used to investigate the safety of Infants meeting the following criteria were included in this study. First, informed consent was correctly signed by the parent or legal guardian. Second, the infants were healthy without any medical conditions, full term (≥36 weeks of gestation at birth), and born with a birth weight ≥ 2500 g. Their age was between 7 days and 2 months (60 ± 7 days) at enrollment.Infants were excluded from the study if they were developmental delayed (weight gain <100 g/week average from birth to the last recorded weight), had major acute or chronic illness (e.g., significant cardiac, respiratory, hematological, gastrointestinal or other systemic diseases, a major developmental or genetic abnormality), cow’s milk protein allergy, history of any allergies to maltodextrin, feeding difficulties, and any use of substances that alter gut microbiota (antibiotics, prebiotics, probiotics, or gastric acid inhibitors) within 2 weeks prior to the study initiation. The breastfed infants were excluded if their mother used antibiotics, prebiotics, or probiotics.Sample size was estimated by previous studies, which had mentioned growth as the primary outcome variable of the safety study. Therefore, weight gain was selected as the primary outcome [In these three different groups, each infant was given the content of one capsule (mixed in infant formula, breast milk, or water) twice daily (morning and evening) for 4 months. The placebo capsules contained maltodextrin, while the probiotic capsules contained 