Maternal dairy intake and infant formula feeding practices in food protein–induced allergic proctocolitis

Background: Food protein–induced allergic proctocolitis (FPIAP) is a nonimmunoglobulin E–mediated food allergy in infancy, most often triggered by cow’s milk protein. Maternal and infant dietary exposures may be associated with its occurrence. This study aimed to evaluate the associations between maternal dairy product consumption during lactation, infant formula feeding practices, and FPIAP. Methods: We conducted a retrospective case–control study including mothers of infants diagnosed with FPIAP related to cow’s milk protein between 2019 and 2024 and control mothers of healthy infants aged 9 to 24 months. Maternal dairy intake frequency and infant formula use were compared between groups. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Results: The study included 97 case mothers and 100 control mothers. Increased maternal dairy intake during breastfeeding was significantly associated with FPIAP (OR, 2.2; 95% CI, 1.0–4.8; P < 0.05). Early exposure to cow’s milk–based formula within the first week after birth was also significantly associated with FPIAP (OR, 7.7; 95% CI, 3.5–17.1; P < 0.05). Conclusion: Increased maternal dairy consumption during breastfeeding and exposure to cow’s milk–based formula within the first week of life were associated with FPIAP in infants. However, given the observational design, these findings should be interpreted with caution and do not support specific clinical recommendations.