# Effect of Infant Formula Made With Milk Free of A1‐Type β‐Casein on Growth and Comfort: A Randomized Controlled Trial

## TL;DR

Infant formula made with milk free of A1-type β-casein improved comfort and reduced crying in mixed-fed infants compared to conventional formula, without affecting growth.

## Contribution

First randomized controlled trial comparing infant formulas made with A1-type β-casein-free milk versus conventional milk in Chinese infants.

## Key findings

- A1PF group had significantly lower gastrointestinal symptom scores and fewer crying episodes at Weeks 2 and 4.
- No significant differences in growth measurements between A1PF and CON groups.
- A1PF was associated with improved digestion and stool characteristics according to parental satisfaction surveys.

## Abstract

Consumption of milk free of A1‐type β‐casein (A1PF) can result in reduced gastrointestinal/inflammatory symptoms versus conventional milk (containing A1‐ and A2‐type β‐casein; CON); however, the comparative effects of infant formula made with these milks are unknown. This study compared growth, gastrointestinal tolerance, and crying frequency/duration in healthy Chinese infants aged 3–4 months who consumed both breastmilk and A1PF or CON infant formula. This open‐label, randomized, controlled trial conducted between July and November 2023 evaluated anthropometric measurements and comfort (Infant Gastrointestinal Symptom Questionnaire [IGSQ] and frequency of crying) of mixed‐fed infants who also consumed A1PF or CON infant formula. Eczema/dermatitis severity, quality of life, satisfaction with the formula, and adverse events were also assessed. In the A1PF (n = 140) and CON groups (n = 140), the mean (standard deviation) ages were 100.83 (15.01) and 99.28 (13.15) days, respectively. There were no significant between‐group differences in any anthropometric measurements. At Weeks 2 and 4, the A1PF group had significantly lower mean daily total IGSQ scores; lower mean stooling, spitting up/vomiting, crying, and fussiness domain scores; and fewer daily crying episodes than the CON group (p < 0.05). From satisfaction surveys, a significantly higher percentage of the A1PF group had relieved gastrointestinal symptoms, reduced vomiting after feeding, improved digestion, and better stool characteristics (p < 0.05). Both formulas were generally well tolerated. Among mixed‐fed infants, those who consumed A1PF infant formula had the same growth as those fed CON infant formula, and improved comfort (including relieved gastrointestinal symptoms and fewer crying episodes).

Trial Registration:
ClinicalTrials.gov, NCT06256094

We compared growth, gastrointestinal tolerance, and crying frequency/duration in healthy Chinese infants aged 3–4 months who consumed both breastmilk and formula free of A1‐type β‐casein (A1PF) or conventional infant formula (CON). At Weeks 2 and 4, the A1PF group had significantly lower mean daily total Infant Gastrointestinal Symptom Questionnaire (IGSQ) scores; lower mean stooling, spitting up/vomiting, crying, and fussiness domain scores; and lower mean number of daily crying periods than the CON group (p < 0.05). Both formulas were generally well tolerated, but infants who consumed A1PF infant formula had improved comfort as measured by relieved gastrointestinal symptoms and fewer crying periods.