Kombucha is basically black tea, sugar, and a “mother” culture or mushroom. The culture is a blend of bacteria and yeast that ferments with the tea and sugar. The end result is full of probiotics and B vitamins. It is very fizzy and has a slightly sour but sweet taste. There are several well-known brands and even recipes to brew your own. If you find yourself at a nearby health food store, try a bottle and see what you think. It is supposed to have many more health benefits than I have named here.
Kefir is a fermented milk drink made from kefir grains (mixture of bacteria, yeast, proteins, fats, and sugars) in any kind of milk—cow, goat, coconut. It can be easily made at home with kefir grains starter kits. It is widely available at most health food stores and costs about the same as goats milk and slightly more expensive than organic whole milk. Kefir contains a ton of probiotics as well as folic acid. Many people who are lactose intolerant are able to drink kefir without any side effects. Kefir is like a slightly sour, drinkable yogurt. There are many flavored varieties but check the sugar content.