Exploring dynamic change and influencing factors of TGF-β1 and MUC1 in human breast milk, and their association with infantile diseases.

Background: Human breast milk, which comprises numerous bioactive compositions, has been well-demonstrated to be benefit to the infants in both short-term and long-term outcomes. We aim to determine the concentration of transforming growth factor beta 1 (TGF-β1) and mucin 1 (MUC1) in human breast milk, identify their influencing factors, and explore their association with infantile diseases. Methods: Ninety paired mother-infants were enrolled in this study, and their demographic and clinical information was collected and analyzed. Paired colostrum and mature milk samples were collected from the healthy mothers within 5 days and at about 42 days after delivery, respectively. The concentrations of TGF-β1 and MUC1 were determined by enzyme-linked immunosorbent assay. Results: The results showed that the concentrations of TGF-β1 and MUC1 in human breast milk dynamically changed during lactation, and their concentrations were significantly higher in colostrum than in mature milk. Advanced maternal age was associated with a significantly increased TGF-β1 concentration in colostrum, and caesarean delivery was significantly associated with an increased MUC1 concentration in colostrum. Finally, a high concentration of TGF-β1 in colostrum was significantly associated with a higher risk of infantile diarrhea within the first 3 months after giving birth, and infantile upper respiratory infection (URI) within the first 6 months after giving birth. Conclusions: To the best of our knowledge, we for the first time showed that a high concentration of TGF-β1 in human breast milk was significantly associated with an increased risk of infantile diarrhea and URI, which helps to give a better understanding of the relationship between the TGF-β1 in human breast milk and infantile diseases.