There is strong medical evidence available that suggests one of the simplest, most natural, and perhaps even most effective ways of dealing with digestive problems such as IBS, candida, acid reflux, Crohn’s Disease, and leaky gut could be fermented foods.
Commercial yogurt in the US is made from pasteurized milk which is inoculated with a select variety of fermenting lactobaccilli, which I suspect is why the author poo-poos it – because it’s not the wild, all-natural, found on your fruits and vegetables wide variety of yeasts and bacteria you’d get elsewhere.
If you eat raw fruit and veg you probably get plenty of said raw, natural microbia. Ever notice that grapes appear to have a sorta dusty appearance ? That’s mostly yeast. Rinsing doesn’t remove most of them. Same for plums, cherries, cabbage, and most any other fruit or vegetable you can think of, it’s just more visible on red grapes. Eat raw fruit and vegetables as well as fermented food, and don’t worry so much about probiotics.