When my son was a toddler he had ear infection after ear infection, like literally as soon as he finished his antibiotics then cleared next day by doctor of his infections (I’m talking both ears), no joke within 2 days I would call the docs office back and say he has ear infections again. The nurse would say “that’s not possible.” We would argue a few minutes until she made an appointment that day, I’d bring him in and sure enough he had infection again. Finally one nurse told me to change his milk. I was surprised, but figured what the heck, it wouldn’t hurt to try, it’s not like he liked milk anyway. As an infant he couldn’t tolerate regular formula, so he drank soy formula. Once he turned 1 and tried to start switching him to whole milk, nope not happening. So the only time he actually drank any amount of milk was in his plain Cheerios, and he would not drink the milk, whatever milk went in was what was on the spoon with the cereal. So changed the whole milk with 2% and he has never had another ear infection since. He’s now 30 yrs old.