Is it a dose of friendly bacteria?
Or the glutathione?
With the Wave of a Wand, Raw Milk Wipes Away the Wheeze: How Our Good Friend Glutathione Protects Against Asthma | Mother Nature Obeyed - Weston A Price Foundation
I don't know that there is, or could be, a definitive answer to that. Maybe a glass or two a day, providing you're not sensitive to it.
Mark's Definitive Guide to Dairy:
The Definitive Guide to Dairy | Mark's Daily Apple