When to use probiotics and which probiotic to use continue to be under scientific debate. Many people are taking daily probiotics, without much benefit. A course of probiotics can help some patients recover from GI symptoms. Fermented foods like sauerkraut, kombucha, kimchi, yogurt, cottage cheese, tempeh, miso, and gouda cheese may be more beneficial in adding to your regular diet, and are all mentioned in this Washington Post article: https://wapo.st/482ues0
In Japan, natto, a type of fermented soy, is eaten at breakfast. Some even enjoy it! Many cultures have fermented foods as part of their regular diet.
Here is a sauerkraut recipe: https://www.daringgourmet.com/how-to-make-sauerkraut/