Effect of a Multinutrient-Optimized Infant Formula Supplemented With Human Milk Oligosaccharides on Infant Growth and Development: A Multicenter, Randomized, Controlled Trial

Effect of Adding Breast Milk Oligosaccharides and Multinutrient Optimized Infant Formula on the Growth and Development of Infants Aged 0 to 1 Years: a Multicenter, Double-blind, Randomized, Controlled Trial

This study aims to learn about a newly developed infant formula that adds two special ingredients found in breast milk (human milk oligosaccharides, HMOs) and improves other nutrients. We will compare the effects of this new formula, a currently available standard formula, and breastfeeding on babies' growth and development during their first year of life. We plan to enroll about 240 healthy newborn babies, who will be divided into three groups: about 80 babies will be fed the new formula with added breast milk ingredients, about 80 will receive the standard infant formula, and about 80 will be breastfed by their mothers. Assignment to the formula groups will be done randomly by computer, while families who wish to and are able to breastfeed will join the breastfeeding group. The study will last about 12 months, during which our research team will have 4 visits with the babies at 28 days, 3 months, 6 months, and 12 months of age. At these visits, we will measure the baby's growth (like height, weight, and head size), use internationally recognized tests to check mental and motor development, collect small samples of stool and blood to understand gut health and immune function, and ask parents to fill out short questionnaires about feeding, sleep, fussiness, and the baby's health. Both formulas used in the study meet national food safety standards, and the entire study follows strict ethical rules to protect the privacy and rights of babies and families. Families in the formula groups will receive all study formula for free and receive regular health check-ups from a professional team. The results will help scientists and doctors better understand how to improve infant formula to support healthy baby growth.

This multicenter, randomized, double-blind, controlled, parallel-group clinical trial is designed to evaluate the effects of an investigational infant formula. The formula is supplemented with two key human milk oligosaccharides (HMOs), and further optimized with a nutrient profile, comparing its effects against a standard infant formula. A breastfed reference cohort is included for contextual comparison. The primary objective is to compare the test and control formulas' impact on infant gut health, specifically assessed through gut microbiota composition (via 16S rRNA sequencing) and short-chain fatty acid profiles in stool samples. Secondary objectives involve comparing groups across a range of outcomes: growth parameters (weight, length, head circumference); immune function (serum hsCRP, lymphocyte subsets; fecal sIgA); bone development markers (osteocalcin, alkaline phosphatase); cognitive development (Bayley Scales of Infant and Toddler Development, 4th Edition); metabolic markers (serum amino acids, albumin); and measures of gastrointestinal tolerance, sleep patterns, fussiness, and the incidence of diarrhea and upper respiratory infections. The study will enroll 240 healthy, term infants aged 0-28 days, with key eligibility criteria including singleton birth, gestational age of 37-42 weeks, and birth weight of 2500-4000g. Of these, 160 infants will be centrally randomized (1:1, stratified by site and infant sex) to receive either the test or control formula under double-blind conditions, while the remaining infants will form a non-randomized, open-label breastfed group. The intervention period spans 360 days, with protocol-defined minimum daily feeding requirements for each group. Outcomes will be assessed during scheduled visits at Day 28, Day 90±3, Day 180±5, and Day 360±7, encompassing anthropometry, neurodevelopmental testing (final visit), biosample (stool/blood) collection, and questionnaires.

Inclusion Criteria： Breastfed Group

Infants eligible for the breastfed reference group must meet all of the following criteria:

• Aged 0 to 28 days after birth (inclusive).
• Singleton birth.
• Gestational age between 37 and 42 weeks (inclusive).
• Birth weight between 2500 and 4000 grams (inclusive).
• Parent(s) or legal guardian(s) agree that the infant will not participate in any other interventional clinical studies for the duration of this trial.
• Parent(s) or legal guardian(s) agree to feed the infant according to the trial protocol (i.e., breastfeeding).

Formula-fed Group

Infants eligible for the randomized formula-fed groups must meet all of the following criteria:

• Aged 0 to 28 days after birth (inclusive).
• Singleton birth.
• Gestational age between 37 and 42 weeks (inclusive).
• Birth weight between 2500 and 4000 grams (inclusive).
• Parent(s) or legal guardian(s) agree that the infant will not participate in any other interventional clinical studies for the duration of this trial.
• Parent(s) or legal guardian(s) agree to feed the infant according to the trial protocol.
• For objective or subjective reasons, the mother is unable to provide exclusive breastfeeding.

Exclusion Criteria：

Infants will be excluded from the trial if they meet any of the following criteria:

• Conceived through assisted reproductive technology.
• Maternal history of any condition during pregnancy known to compromise intrauterine growth.
• Maternal history of gestational diabetes, significant metabolic disease, or chronic disease during pregnancy.
• Presence of congenital malformations, genetic disorders, chronic diseases, or congenital conditions that could interfere with the study participation or outcome assessments.
• Known IgE-mediated cow's milk protein allergy, or presence of factors that increase the risk of cow's milk protein allergy.
• Active acute infection or gastroenteritis at the time of enrollment.
• History of functional gastrointestinal disorders, such as gastroparesis.
• Concurrent participation in another clinical trial.
• Any condition that, in the investigator's judgment, could compromise the parent's willingness or ability to comply with the protocol requirements.