An in vitro study has found that the popular fermented cabbage product, sauerkraut, can benefit gut health by eliciting a protective effect on the intestinal barrier.
The research, which was published in Applied and Environmental Microbiology, found that sauerkraut can protect against the disruption of the intestinal barrier via inflammatory cytokines through the metabolites produced during the fermentation process.
This effect was not seen when the Caco-2 monolayer model was exposed to raw cabbage or the brine left over from the fermentation process, suggesting that the fermented product itself can promote gut health and tackle localised inflammation — highlighting their potential use in both nutraceutical products and functional foods.
Similar findings were made with the fermented Korean delicacy kimchi, which been proven to reduce body fat by modulating the gut microbiome and its activity.
Fermentation metabolites: the key to gut health benefits?
Fermented products have become a highly popular choice for gut health, as they are packed with probiotic bacteria that can help balance the microbiome.
Recent research has also revealed the key role that gut bacterial metabolites play in supporting health, so scientists at the University of California, Davis looked into how and why the metabolites produced in the fermentation process could benefit gut health.
To assess the true scope of sauerkraut's gut health benefits, researchers compared raw cabbage, fermented cabbage produced in the laboratory, sauerkraut bought in the shop and liquid brine left from the fermentation process.
They then exposed an in vitro model of the intestinal barrier to cytokine-induced inflammation and assessed if any of the above conditions could mitigate it.
During the study, researchers found that sauerkraut was the only tested substance that could help to maintain the integrity of the intestinal cells, with raw cabbage and brine exhibiting no protective effects.
Interestingly, there was no discernible difference between sauerkraut bought from the supermarket and the laboratory-made version.
“Many of the metabolites found in sauerkraut are similar to those we'd find being produced by the gut microbiome," stated Maria Marco, lead author of the paper and professor with the Department of Food Science and Technology at UC Davis.
"It doesn't seem to matter if we make our own fermented cabbage, as the supermarket version worked just as well," she added.
Sauerkraut's nutraceutical potential
During the fermentation process, Marco and her team found that sauerkraut was enriched with beneficial metabolites such as amino acids, lactic acid and plant-based polyphenols commonly linked to gut health.
"We identified hundreds of different metabolites produced during fermentation, and we're now working to determine which ones play a key role in supporting long-term gut health," she stated.
By putting more fermented foods into the average consumer's diet, both the supplement and functional food industries can help mitigate long-term gut-localised inflammation, which could potentially improve quality of life for many.
This comes at a time where findings from a US consumer health survey reveal that 4 in 10 Americans experience gastrointestinal discomfort and bloating — suggesting the need for efficacious natural ingredients to support gut health.
By incorporating fermented food products into supplements and better-for-you food products, brands could stand out from the crowd and cater to the growing demand for natural gut health solutions.