This 2017 Spanish article reviewed health benefits of sauerkraut:

“During cabbage shredding and fermentation, a disruption of cabbage cells occurs, and GLS [glucosinolates] are hydrolyzed by myrosinase enzyme to a variety of GLS breakdown products. In particular, glucobrassicin is hydrolyzed into indol-3-carbinol (I3C) by myrosinase.

As the pH decreases during cabbage fermentation, I3C reacts nonenzymatically with ascorbic acid to yield ascorbigen (ABG). Studies have shown that ABG is the main GLS breakdown compound in sauerkraut, and it is present at levels between 3 and 18 μmol/100 g fw.

The antioxidant activity observed for sauerkraut in all studies was higher than that observed in raw cabbage.

It has been reported that doses between 53 and 150 μmol of ITCs [isothiocyanates] are enough to display anticarcinogenic effects. Taking into account that the content of ITCs in sauerkraut is in the range 22 μmol/100 g fw, it could be assumed that a weekly consumption of 200–250 g of sauerkraut would provide effective ITC doses to exert cancer chemopreventive effects.

Many studies reported that LAB [lactic acid bacteria] isolated from sauerkraut are potential probiotics.”

https://www.sciencedirect.com/science/article/pii/B9780128023099000248 “Sauerkraut: Production, Composition, and Health Benefits” (not freely available)

This introductory article presented interesting facts, but oversold sauerkraut. Dose and other conditional dependencies in order to achieve health and disease prevention benefits seemed to be beyond its scope.

A more considered view was offered in Fermented Food and Non-Communicable Chronic Diseases which referenced this article:

“Clinical data about the effects of sauerkraut on the human organism, health and disease are scarce. There is knowledge concerning particular compounds in sauerkraut and their impacts on diseases; however, a literature search revealed mostly cell line or rat experiments with very limited conclusions for humans.”

Earlier this month I started eating refrigerated sauerkraut twice a day with microwaved broccoli sprouts. I mix in three heaping teaspoons each time, and finish a 50 oz (1418 g) container in a week.

The mixture tastes better than just microwaved broccoli sprouts. It requires more chewing, which assists myrosinase hydrolization of broccoli sprout glucosinolates into sulforaphane and other healthy compounds.

Although sauerkraut isn’t a primary source, there may be beneficial amounts of probiotics etc. that increase what I get with broccoli sprouts and supplements.

I also started making my own sauerkraut using the commercial product’s juice as a starter. I add garlic but not salt. No results yet.