It looks like the whole process of fermentation has implications for digestion.
The UC Davis April release tells that sauerkraut could soothe the inflamed lining of the intestine while definitely not hurting the cause of spooning hot dog tops.
While they did not directly trigger the inflammation attack, the testing groups did monitor the effects of sauerkraut through bathing the injured cells with different liquids: juices made of cabbage, brine, various home-fermented cabbages, and a refrigerated version of the store brand sauerkraut. Whenever fermented cabbage was there, the authors stated, only that standard "intestinal" lining could gain a protective edge. Everything else, plain cabbage and the brine, had no effect whatsoever.
Fermentation does something extra to the cabbage: the voracious bacteria consume all the sugar and produce a little cocktail of organic acids and a few amino acids, with the only important one being lactic acid, which gives sauerkraut its characteristic sour flavor.
"Intestinal barrier protective compounds are consistently enriched during cabbage fermentation, irrespective of scale or microbial additions," it says in the paper. The tests with the individual molecules failed too, since the authentic magic is in the whole fermented product.
For all the sauerkraut lovers, this is a good thing: the slight setback is that this study was done on cell cultures; a whole other saga of scientific investigation awaits. It may even lend support to barrier function and improved digestion with its fermented counterparts.
But we will gladly share recipes if you want some pointers for making it yourself; however, if you buy from the store, be sure to buy a live refrigerated product—sauerkraut that has been made shelf-stable with heat cannot hold any of the compounds that this study indicated protect the gut lining.