For the past seventy years,1 at least, some form of acidified milk has been used by pediatricians in feeding babies. There have been many explanations given for the beneficial results that have been obtained. Most of these explanations were based on some theory of influencing gastric function:
That acidified milk acts by increasing the bactericidal properties of the gastric contents.2
That it causes a greater secretion of gastric juice.3
That it influences pancreatic function, and many other explanations.
In 1875, Uffelmann4 mentioned that the titrable acidity of infant's stomach was much less than that of the adult, and was much lowered, or even absent, in babies with diarrhea. Allaria5 was the first to determine the hydrogen ion concentration of the gastric contents of infants. He records an average of ph 5.3 for bottle fed babies. Davidsohn,4 as well as Marriott and Davidson,6
ARNOLD L. INFLUENCE OF ACIDIFIED MILK ON DUODENAL FUNCTION IN INFANTS. Am J Dis Child. 1926;31(5):668-675. doi:10.1001/archpedi.1926.04130050068006