The reason why Sauerkraut is good for you and your gut is due to its richness in good live beneficial bacteria such as : Leuconostoc mesenteroides, Lactobacillusbrevis, Pediococcus pentosaceus, and Lactobacillus plantarum which are formed during the fermentation process.
It contains more of the good Lactobacillus than Yogurt.
Most of the canned sauerkraut are pasteurized which kills the good bacteria, so homemade is the best option to get all the benefits from this bacteria.
Some scientist says that it may be more than 3 billion (CFUs- Colony forming Units) in only 1 cup of Sauercraut.