Necessarily, exactly the same as from any other fermented milk products. Kefir, sour cream, cottage cheese, cheese, ayran, tan, koumiss, fermented baked milk, varenets, yogurt, yogurt. There are, of course, people with high acidity and certain dietary restrictions due to medical reasons. A bit of history; Herodotus in the 5th century BC. described that the favorite drink of the Scythians was koumiss. In the clinics of the 17th century. kumis and simpleton is mentioned as a medicine in the treatment of tuberculosis and fever. And milk itself from time immemorial was considered more medicine than an ordinary drink. Hypocrates, Aristotle, Pliny, Avicena were successfully treated with milk. Our scientists and doctors S.P. Botkin, G.A. Zakharyin, I.P. Pavlov also treated tuberculosis, heart, liver, kidneys and many other diseases.
Of course there is.
It's food after all.
Without food, people die in three weeks.
Then there is milk, and it is useful.
All sourdoughs are also useful or not harmful at least