Evidence of Fermented Health Benefits

/ / Health, Science

We’re on the cusp of a new generation of health-promoting foods, foods that will harness the power of microbes present in fermented foods and beverages. 

Paul Cotter, head of Food Bioscience Department at Teagasc Food Research Centre in Ireland, envisions a future system where fermented foods are made with strains having scientifically-proven health-promoting benefits. His lab is integrating microbiome and metabolic data and using DNA sequencing to drill down to specific health benefits.

“We’ve really only scratched the surface as to the real potential of all those different microbes and what they could be doing,” says Cotter, who is also the principal investigator with the APC Microbiome Ireland. “Whether a particular food is health promoting or not will be dictated by what microbe is in there and can only be proved by carrying out the appropriate studies.”

Cotter was a speaker at TFA’s conference FERMENTATION 2021. He made a case for establishing minimum standards for fermented foods and beverages. In his scenario, kombucha or kefir couldn’t be labeled as such without using a scientifically-backed combination of microbial strains.

“That ensures that the kind of pseudo fermented foods — the foods that are fermented but not really with the right microbes — don’t get on the market or can’t be distinguished,” Cotter says.

Not all Fermented Foods are Equal

There is scientific evidence of the health benefits of frequently and regularly consuming fermented foods and beverages. They can prevent illness, provide a source of live and active microbes, improve the digestibility of foods, increase certain vitamins and bioactive compounds and remove or reduce toxic compounds like lactose.

“Ultimately, I’m a scientist and so I want to see proof that underpins the claims associated with a particular food,” Cotter says. “While there’s a lot of good information out there, I think also some of the claims are doing a disservice to the fermented food industry and to those who make fermented foods in their homes because they’re overstating the potential health benefits.”

Problematic, too, are fermented foods made with shortcuts and additives. Cotter’s lab is currently studying kefir, and they found that not all are equal. Traditional kefir has been documented as helping to reduce weight and improve cholesterol and liver triglyceride levels. But some brands of commercial kefir they studied didn’t produce those same health benefits. And they found that some of the kefir on the market was nothing more than watered-down yogurt.

 “Consumer beware: the benefits weren’t the same for each kefir and differ depending on what the microbes present in the kefir were,” says Cotter, a self-described fermented foods nerd. ”I think that’s a problem for lots of other fermented foods too, and I really feel for consumers who don’t have a microbiological background and are reading a label and assuming that they are consuming a fermented beverage or fermented food that has lots of beneficial microbes in there and is made in the artisanal way that that food has been made over hundreds of different years.”

What are the health benefits?

Cotter’s lab has used in-depth analyses to detail the microbial composition of a food, including naming the microorganisms present and their capabilities. They’ve identified “completely novel species that had never been found previously,” Cotter says. An example is African fermented food, which contains a huge diversity of microbes, including ones not typically found in fermented foods in the West.

The highest level of what’s called “Health Associated Gene Clusters” are in fermented foods, specifically those brine- (like sauerkraut and kimchi) or sugar-based (kefir and kombucha). Cotter notes the genes in fermented foods are health promoting because the microbes are closely related to probiotics. 

 “What we can do is to try to harness the microbes that are present and use them in a way that facilitates large-scale production,” Cotter says.