If you pasteurize breast milk (heat to 62°C), and the milk no longer causes BMJ in a test system. However, the fatty acid inhibitors remain. This suggests BMJ is multifactorial – the balance between gut de-conjugation (enzyme-driven) and liver conjugation (inhibition-driven) determines severity. This is why BMJ is benign (rarely causes kernicterus) – the inhibition is partial and reversible.
Newborns have sterile guts that gradually become colonized with bacteria. In formula-fed infants, certain bacteria help break down bilirubin so it cannot be reabsorbed. In breastfed infants, the gut flora is different; the absence of specific bacteria early on may allow more bilirubin to remain in a state where it can be reabsorbed. what causes breast milk jaundice
Mutations in the UGT1A1 gene , which is responsible for bilirubin metabolism, can make some infants more susceptible to prolonged jaundice when exposed to these substances in breast milk. If you pasteurize breast milk (heat to 62°C),