Common gastrointestinal symptoms in healthy infants receiving goat milk-based formula or cow's milk-based formula: a double-blind, randomized, controlled trial.

Objective: To assess common gastrointestinal symptoms in healthy Brazilian infants receiving goat milk-based formula (GMF) compared to cow's milk-based formula (CMF).

Methods: We performed a 24-weeks double-blind, randomized, controlled study in Brazil, enrolling healthy infants from 3 to 12 months of age. Primary outcome were the gastrointestinal (GI) symptoms stool consistency, regurgitation frequency and crying duration. Secondary outcomes were growth trajectories and hemoglobin levels. Repeated mixed models were used to compare outcomes variables between GMF and CMF groups, while adjusting for age at baseline.

Results: Fifty-six infants were recruited and randomly allocated in the GMF (n = 26) and the CMF (n = 30) group. Scores on all measured GI symptoms were low and similar among the groups throughout intervention period and improved over time. Average age- and sex-adjusted WHO z-scores of weight, length, head circumference, and weight-for-length were all within +/-1 SD and similar between groups, indicating adequate growth. Serum hemoglobin was 11.1 (SD 0.7) g/dL in infants fed GMF and 11.0 (SD 0.8) g/dL in infants fed CMF after the intervention and was similar between groups.

Conclusion: GMF was well tolerated, safe and supported adequate growth in infants. This was shown by the low occurrence of GI symptoms, adequate blood hemoglobin levels and adequate growth within WHO standards.

Trial registration: The clinical trial was approved by the ethics committee of the Federal University of Bahia under number CAAE06923319.5.0000.5577. The study was retrospectively registered in clinicaltrials.gov on 02/05/2024 under identifier NCT06395571.