Bananas and milk can also be eaten together, but eating bananas and yogurt together can lead to indigestion or diarrhea. Because 80% of protein in milk is casein, when the pH value of milk is lower than 4.6, that is, when milk encounters acid, a large amount of casein will agglutinate and precipitate, which is difficult to digest and absorb, and even lead to indigestion or diarrhea in severe cases.