Sauerkraut doesn’t just have a unique, tart, tangy flavor; it also provides a number of health benefits. One big benefit is that sauerkraut contains good bacteria (probiotics) to help balance your gut microbiome and increase the number of good bacteria compared to opportunistic bacteria throughout your digestive system. This is especially helpful if you’ve taken antibiotics or been under a lot of stress.
The bacteria in your intestines affects your mood, metabolism, energy levels, hormone production, immune system, and more. When these microorganisms are out of balance, you’ll likely feel the effects in more ways than one. Eating sauerkraut supplies live advantageous bacteria to your gut. But there are lots of other benefits of eating sauerkraut on the keto diet.
What Is Sauerkraut?
Sauerkraut is a fermented cabbage believed to have originated in China over 2,000 years ago, although the word sauerkraut is German, and this side dish is especially popular in Germany. Some researchers believe sauerkraut has been part of the European diet since the 4th century BC. It’s a favored food on the paleo diet because of its long history. 
Because sauerkraut is just fermented cabbage, it’s low in carbs, like many other cruciferous vegetables, and suitable for your ketogenic diet. One cup of sauerkraut only has around 2 grams of net carbs. 
What sets sauerkraut apart from regular cabbage is the fermentation process. Before freezers and refrigerators, humans often used fermentation to preserve their foods. Fermentation is a preservation method that naturally changes the chemical structure of food to make it more resistant to spoilage and rich in probiotics (beneficial bacteria).
During fermentation, bacteria and yeast convert carbs, such as starch and sugar, into alcohol or acids, which are natural preservatives that also give fermented foods their tart flavor. Sauerkraut involves a type of fermentation called lactic acid fermentation, where lactic acid is produced that prevents harmful yeast and bacteria from growing and increases the bioavailability of nutrients.