Modulating Early-life Nutrition for Childhood Obesity Prevention (NutrOb)

In this study, betaine intake will be increased in formula-fed infants through formula milk supplementation. To do this, a double-blind randomized study has been designed with the supplementation group (infant formula supplemented with betaine) and control group (unsupplemented infant formula). The main objectives of the study are to determine the safety of supplementation and to assess whether there are changes in infant growth.

Childhood obesity is one of the main public health concerns worldwide. Previous results have linked a nutrient called betaine (trimethylglycine) to the risk of childhood obesity. Betaine is a modified amino acid with osmotic properties that participates in the methionine cycle as a methyl group donor. Specifically, previous data demonstrate a link between breast milk betaine content, postnatal growth, and long-term metabolic health, suggesting that betaine supplementation may be an effective strategy for regulating growth trajectories and preventing childhood obesity. This study will assess the effects of increasing betaine intake in formula-fed infants through formula milk supplementation. To do this, a double-blind randomized study has been designed where participants will be randomly assigned to the control group or the supplementation group. The main objectives of the study are to determine the safety of supplementation and to assess whether there are changes in infant growth. Additionally, potential changes in the intestinal microbiome induced by the increase in betaine intake will be analyzed.

Infant formula will be supplemented with betaine to provide a final concentration of 100 µmol/L in the reconstituted milk. The intervention will last for 12 weeks.

Weight and length will be measured at different time-points and combined to calculate weight-for-length z scores.

Differences in features associated with a healthy mucosal layer and metabolic state (e.g. Bifidobacteria and Akkermansia relative amount). Stool samples will be processed to isolate the bacterial DNA. Microbiome composition will be determined by DNA sequencing.

Urine samples will be analyzed to quantify betaine content as well as related metabolites (including dimethylglycine, the product of the betaine demethylation reaction

DNA will be extracted from infant saliva samples. The DNA methylome will be obtained with array technology.

Inclusion Criteria: Maternal age between 17 and 42 years Maternal pre-pregnancy BMI equal or higher than 25 Gestational age at birth > 37 weeks No exclusive breastfeeding at time of recruitment Exclusion Criteria: Presence of disease or malformations in the infant Infant birth weight < -1 SD (standard deviations) Multiple pregnancy Elective c-section