the disruption of gut bacteria in early life plays a role in food allergies and intolerances. say a kid gets an infection and is treated with antibiotics. not only is the infection killed off, the bacteria in the gut is also disrupted. when that kid then eats, food is not properly digested. this could be a result of non-ideal bacterial growth in the gut, and/or the improperly-digested food itself ending up in the bloodstream leading to the initial autoimmune response and subsequent allergy formation. at least, this is what i think speaking from experience. i don't believe i had issues with food prior to the use of antibiotics. thankfully, the issues i have aren't life threatening, although they are a huge inconvenience.
Australia