Can indigenous fermented beverages play a prominent role in a healthy diet? Biochemists studied four commercial  products – kefir and ryazhenka  from Russia, amasi and mahewu from South Africa. Their research was published in the journal Foods

Researchers from the Institute of the Research Center of Biotechnology of the Russian Academy of Science (RAS)  and South Africa’s Durban University of Technology discovered key elements of the fermented drinks. The three that are milk-based had more antioxidants than the corn-based one, while the corn drink (mahewu) was “better at suppressing the angiotensin-converting enzyme.” Kefir and ryazhenka, meanwhile, have a more diverse composition of fatty acids.

“Usually, food is considered only as a source for sustenance. However, more and more people (are starting) to believe that it also should preserve and improve health,” Konstantin Moiseenko, co-author of the study and a research fellow at RAS in Moscow. He notes modern science allows “mankind to look differently at the usefulness of traditional, centuries-old foods. Our research focuses on fermented products, which regular consumption can potentially prevent atherosclerosis, hypertension and thrombosis.”

Read more (Lab Manager and Foods)

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.

Renowned professor, epidemiologist and author of The Diet Myth and Spoon Fed Tim Spector is encouraging people to eat the 4k’s: kefir, kombucha, kimchi and kraut. His studies found diet plays a role in preventing severe symptoms of Covid.

Spector is a leading expert on long Covid, the symptoms that can continue for extended periods after an initial infection. He leads the ZOE Covid Study, created by scientists and doctors at King’s College London (where he is based), Stanford, Harvard, Massachusetts General Hospital and health science company ZOE. Last year Spector helped research the attributes and predictors of long Covid, the results of which were published in the journal Nature Medicine.

A microbiome researcher, Spector advocates for people to eat a diverse diet to improve the trillions of microbes in the gut. 

“We know from Covid now that your gut health is crucial for your immune system,” he told ITV. “If we can focus on our gut health…gut microbiome is really crucial.”

Diet must be high-quality to improve immunity, he stresses. In the ZOE Covid study, researchers have found eating “the right things and avoiding feeding (the gut) the bad things, that’s what made the difference to getting long Covid,” he said. Fermented foods have proven health benefits, but Spector says many people opt for cheaply-made yogurts and cheeses prevalent in the grocery store to get their daily dose of fermented foods. This dairy is full of sugar and artificial ingredients, which thwart the positive effects of fermentation.

“The other fermented foods that many people don’t know about are what I call the 4 k’s,” Spector says: kefir, kombucha, kimchi and kraut (sauerkraut). He encourages “small shots a day” of a fermented food or beverage. “That really is a powerful enhancer of your microbes. And all these things are going to be cheaper actually than taking multivitamins every day of your life.”

Spector is not a fan of supplements, like pill forms of vitamins and nutrients. Many are proven not to work, he explained. In his studies on the effects of supplements on long Covid, there were minimal benefits for women and none for men. 

“People are much better off getting all their vitamins and nutrients by having a diverse diet,” Spector said.

SCOBY as Water Filter?

Can you use bacteria to eliminate bacteria? Commercial water filters remove contaminants from water, but the pores eventually clog, causing water to filter more slowly. Now researchers are studying a living membrane to filter water: a kombucha SCOBY.

Researchers at Montana Technological University (MTU) and Arizona State University (ASU) found the films of cellulose that make up a SCOBY are 19-40% more effective than commercial filtration systems at preventing the formation of bacterial biofilms. The SCOBY filter also maintained a fast rate of filtration for a longer period of time. Though a biofilm did eventually form on top of the SCOBY, it contained fewer bacteria than in a commercial filter.

“The scientists couldn’t use the wild yeasts typically used in kombucha because the yeasts are difficult to modify genetically,” reads an article in Wired. “Instead, the researchers used lab-grown yeast, specifically a strain called Saccharomyces cerevisiae, or brewer’s yeast. They combined the brewer’s yeast with a bacteria called Komagataeibacter rhaeticus (which can create a lot of cellulose) to create their ‘mother’ SCOBY.”

Researchers engineered the cells in the yeast to produce glow-in-the-dark enzymes, which sense pollutants and break them down. SCOBY-based filters are not only inexpensive to make, they biodegrade when discarded.

Their research was published in the American Chemical Society journal ACS ES&T Water.

Read more (Wired)

Tastier Apple Spirits

Thanks to their high sugar content and strong flavor, apples have been a great base for spirits like cider, calvados and applejack for hundreds of years. But “many decisions about their processing are still subjectively determined.” When to stop distillation for the most flavorful liquor, for example, is open to question. But new research has identified the best conditions for making apple-based spirits with the most desirable qualities and taste.

Researchers with the American Chemical Society fermented apples into a mash, then distilled it in a German-style batch column. Heat concentrates the alcohol and “removes unpleasant fermentation byproducts, such as carboxylic acids that can impart unclean, rancid, cheesy and sweaty flavors.” The researcher’s mash was continuously monitored during heating, and the levels of the nine carboxylic acids measured. 

Heating the mash too quickly yielded unwanted flavor compounds and a bland aroma. But raising the temperature of the cooling tower slightly produced a good fragrance intensity, and reduced carboxylic acid levels.

Read more (American Chemical Society)

Yogurt Alters Gut Microbiome

It’s widely appreciated that consuming high-quality yogurt can aid a healthy diet. Now new research shows eating yogurt changes the composition of the human gut microbiome.

In a new human study published in BMC Microbiology, researchers studied the microbiome of European twins. Results found those regularly eating yogurt had less visceral fat mass, reduced insulin levels and an increase of bacterial species in the gut. Strains S. thermophilus, B. animalis subsp. lactis., S. thermophilus and B. animalis subsp. lactis were all present in yogurt eaters.
The study also found the yogurt bacteria are “transient members of the gut microbiome and do not durably engraft within the gut lumen.”

Read more (BMC Microbiology)

Thyme and oregano possess an anti-cancer compound that suppresses tumor development, but adding more to your tomato sauce isn’t enough to gain significant benefit. The key to unlocking the power of these plants is in amplifying the amount of the compound created or synthesizing the compound for drug development.

And exciting for the field of fermentation: extracting those beneficial compounds from the plant is done through fermentation. 

“The fermentation process is so important to food and beverage, pharmaceutical and biofuels production that Purdue now offers a fermentation science major,” reads a press release from Purdue University. 

Researchers at Purdue took the first step in using the compound in pharmaceuticals by mapping its biosynthetic pathway, a sort of molecular recipe of the ingredients and steps needed. 

“These plants contain important compounds, but the amount is very low and extraction won’t be enough,” said Natalia Dudareva, distinguished professor of biochemistry in Purdue’s College of Agriculture and director of Purdue’s Center for Plant Biology, who co-led the project. “By understanding how these compounds are formed, we open a path to engineering plants with higher levels of them or to synthesizing the compounds in microorganisms for medical use. “It is an amazing time for plant science right now. We have tools that are faster, cheaper and provide much more insight. It is like looking inside the cell; it is almost unbelievable.”

Thymol, carvacrol and thymohydroquinone are flavor compounds in thyme, oregano and other plants in the Lamiaceae family. They have antibacterial, anti-inflammatory, antioxidant and other properties beneficial to human health. Thymohydroquinone has been shown to have anti-cancer properties and is particularly of interest, said Dudareva..

In collaboration with scientists from Martin Luther University Halle-Wittenberg in Germany and Michigan State University, the Purdue team uncovered the entire biosynthetic pathway to thymohydroquinone, including the formation of its precursors thymol and carvacrol, and the short-lived intermediate compounds along the way.

The findings alter previous views of the formation of this class of compounds, called phenolic or aromatic monoterpenes, for which only a few biosynthetic pathways have been discovered in other plants, she said. The study results were published in the Proceedings of the National Academy of Sciences. 

“These findings provide new targets for engineering high-value compounds in plants and other organisms,” said Pan Liao, co-first author of the paper and a postdoctoral researcher in Dudareva’s lab. “Not only do many plants contain medicinal properties, but the compounds within them are used as food additives and for perfumes, cosmetics and other products.”

Now that this pathway is known, plant scientists could develop cultivars that produce more of the beneficial compounds, or it could be incorporated — using fermentation — into microorganisms like yeast for production. 

A $5 million grant from the National Science Foundation supported the research. Using RNA sequencing and correlation analysis, the team screened more than 80,000 genes from plant tissue samples and identified the genes needed for thymohydroquinone production. Based on what was known about the compound structure and through metabolite profiling and biochemical testing, the team identified the biosynthetic pathway.

“The intermediate formed in the pathway was not what had been predicted,” Liao said. “We found that the aromatic backbone of both thymol and carvacrol is formed from γ-terpinene by a P450 monooxygenase in combination with a dehydrogenase via two unstable intermediates, but not p-cymene, as was proposed.”

More pathways are now being discovered, thanks to the availability of RNA sequencing to perform high-throughput gene expression analysis, according to Dudareva.

“We, as scientists, are always comparing pathways in different systems and plants,” Dudareva said. “We are always in pursuit of new possibilities. The more we learn, the more we are able to recognize the similarities and differences that could be key to the next breakthrough.”

Fermentation is cloaked in mystery for many — it’s bubbly, slimy, stinky and not always Instagram-ready. In The Fermentation Association’s recent member survey, this lack of

understanding of fermentation and its flavor and health attributes among consumers was cited by 70% of producers as a major obstacle to increased sales and acceptance of fermented products.

“We get so many questions from our readers about fermentation. People are very interested, but have very, very little knowledge about it,” says Anahad O’Connor, reporter for The New York Times. O’Connor has written about fermented foods multiple times in the last few months, and those articles were among The Times’ most emailed pieces of 2021. “I think there’s a huge opportunity to educate consumers about fermented foods, their impact on the gut and health in general.”

O’Connor spoke on consumer education as part of a panel of experts during TFA’s conference, FERMENTATION 2021. Panelists — who included a producer, retailer, scientist, educator and journalist — agreed consumer education is lacking. But the methods of how to fill that gap are contested.

How to Tell Consumers “What is a Fermented Food?”

There are differences between what is a fermented product and what is not — a salt brine vs. vinegar brine pickle, or a kombucha made with a SCOBY or one from a juice concentrate, for example.

“I can tell you that the majority of our customers do not even know [what is a] fermented item,” says Emilio Mignucci, vice president of Philadelphia gourmet store Di Bruno Bros., which specializes in cheese and charcuterie. When customers sample products at the store, they can easily taste the differences between a fermented and a non-fermented product, Mignucci says. But he feels the health benefits behind that fermented product are not the retailer’s responsibility to communicate. “I need you guys [producers] to help me deliver the message.” 

“Retailers like myself, buyers, we want to learn more to be able to champion [fermented foods] because, let’s face it, fermented foods is a category that’s getting better and better for us as retailers and we want to speak like subject matter experts and help our guests understand.”

Now — when fermentation tops food lists and gut health is mainstream — is the time for education.

“This microbiome world that we’re in right now is sort of a really opportune moment to really help the public understand what fermented foods are beyond health,” says Maria Marco, PhD, professor of food science at the University of California, Davis (and a TFA Advisory Board Member).

Kombucha Brewers International (KBI) created a Code of Practice to address confusion over what is or is not a kombucha. KBI is taking the approach that all kombucha is good, pasteurized or not, because it’s moving consumers away from sugar- and additive-filled sodas and energy drinks. 

“That said, consumers deserve the right to know why is this kombucha at room temperature and this kombucha is in the fridge and why does this kombucha have a weird, gooey SCOBY in it and this one is completely clear,” says Hannah Crum, president of KBI. “They start to get confused when everything just says the word ‘kombucha’ on it.”

KBI encourages brewers to be transparent with consumers. Put on the label how the kombucha is made, then let consumers decide what brand they want to buy.

Should Fermented Products Make Health Claims?

Drew Anderson, co-founder and CEO of producer Cleveland Kitchen (and also on TFA’s Advisory Board), says when they were first designing their packaging in 2013, they were advised against using the term “crafted fermentation” on their label because it would remind consumers of beer or wine. But nowadays, data shows 50% of consumers associate the term fermentation with health.

“In the last five to six years, it’s changed dramatically and people are associating fermentation as being good for them, which is good for my products,” he says.

Cleveland Kitchen, though, does not make health claims on their fermented sauerkraut, kimchi and dressings. Anderson says, as a small startup, they don’t have the resources to fund their own research. They instead attract customers with bold taste and striking packaging.

“We’re extremely cautious on what we say on the package because we don’t have an army of lawyers like Kevita (Pepsi’s Kombucha brand), we don’t have the Pepsi legal team backing us here,” Anderson says. Cleveland Kitchen submits new packaging designs in advance to regulators, to make sure they’re legally acceptable before rolling them out. 

O’Connor says taste is the No. 1 driver for consumers. This is why healthful but sticky and stinky natto (fermented soybeans) is not a popular dish in America, but widely consumed in Japan. 

“Many American consumers, unfortunately, aren’t going to gravitate toward that, despite the health benefits,” he says. 

Crum disagrees. “Health comes first,” she says. As more and more kombucha brands emphasize lifestyle, and don’t even advertise their health benefits, she feels they are doing a disservice to the consumer. “Why pay that much money for kombucha if you don’t know it’s good for you too?”

Microbes on our bodies outnumber our human cells. Can we improve our health using microbes?

“(Humans) are minuscule compared to the genetic content of our microbiomes,” says Maria Marco, PhD, professor of food science at the University of California, Davis (and a TFA Advisory Board Member). “We now have a much better handle that microbes are good for us.” 

Marco was a featured speaker at an Institute for the Advancement of Food and Nutrition Sciences (IAFNS) webinar, “What’s What?! Probiotics, Postbiotics, Prebiotics, Synbiotics and Fermented Foods.” Also speaking was Karen Scott, PhD, professor at University of Aberdeen, Scotland, and co-director of the university’s Centre for Bacteria in Health and Disease.

While probiotic-containing foods and supplements have been around for decades – or, in the case of fermented foods, tens of thousands of years – they have become more common recently . But “as the terms relevant to this space proliferate, so does confusion,” states IAFNS. 

Using definitions created by the International Scientific Association for Postbiotics and Prebiotics (ISAPP), Marco and Scott presented the attributes of fermented foods, probiotics, prebiotics, synbiotics and postbiotics.  

The majority of microbes in the human body are in the digestive tract, Marco notes: “We have frankly very few ways we can direct them towards what we need for sustaining our health and well being.” Humans can’t control age or genetics and have little impact over environmental factors. 

What we can control, though, are the kinds of foods, beverages and supplements we consume.

Fermented Foods

It’s estimated that one third of the human diet globally is made up of fermented foods. But this is a diverse category that shares one common element: “Fermented foods are made by microbes,” Marco adds. “You can’t have a fermented food without a microbe.”

This distinction separates true fermented foods from those that look fermented but don’t have microbes involved. Quick pickles or cucumbers soaked in a vinegar brine, for example, are not fermented. And there are fermented foods that originally contained live microbes,  but where those microbes are killed during production — in sourdough bread, shelf-stable pickles and veggies, sausage, soy sauce, vinegar, wine, most beers, coffee and chocolate. Fermented foods that contain live, viable microbes include yogurt, kefir, most cheeses, natto, tempeh, kimchi, dry fermented sausages, most kombuchas and some beers. 

“There’s confusion among scientists and the public about what is a fermented food,” Marco says.

Fermented foods provide health benefits by transforming food ingredients, synthesizing nutrients and providing live microbes.There is some evidence  they aid digestive health (kefir, sourdough), improve mood and behavior (wine, beer, coffee), reduce inflammatory bowel syndrome (sauerkraut, sourdough), aid weight loss and fight obesity (yogurt, kimchi), and enhance immunity (kimchi, yogurt), bone health (yogurt, kefir, natto) and the cardiovascular system (yogurt, cheese, coffee, wine, beer, vinegar). But there are only a few studies on humans  that have examined these topics. More studies of fermented foods are needed to document and prove these benefits.

Probiotics 

Probiotics, on the other hand, have clinical evidence documenting their health benefits. “We know probiotics improve human health,” Marco says. 

The concept of probiotics dates back to the early 20th century, but the word “probiotic” has now become a household term. Most scientific studies involving probiotics look at their benefit to the digestive tract, but new research is examining their impact on the respiratory system and in aiding vaginal health.

Probiotics are different from fermented foods because they are defined at the strain level and their genomic sequence is known, Marco adds. Probiotics should be alive at the time of consumption in order to provide a health benefit.

Postbiotics

Postbiotics are dead microorganisms. It is a relatively new term — also referred to as parabiotics, non-viable probiotics, heat-killed probiotics and tyndallized probiotics — and there’s emerging research around the health benefits of consuming these inanimate cells. 

“I think we’ll be seeing a lot more attention to this concept as we begin to understand how probiotics work and gut microbiomes work and the specific compounds needed to modulate our health,” according to Marco.

Prebiotics

Prebiotics are, according to ISAPP, “A substrate selectively utilized by host microorganisms conferring a health benefit on the host.”

“It basically means a food source for microorganisms that live in or on a source,” Scott says. “But any candidate for a prebiotic must confer a health benefit.”

Prebiotics are not processed in the small intestine. They reach the large intestine undigested, where they serve as nutrients for beneficial microorganisms in our gut microbiome.

Synbiotics

Synbiotics are mixtures of probiotics and prebiotics and stimulate a host’s resident bacteria. They are composed of live microorganisms and substrates that demonstrate a health benefit when combined.

Scott notes that, in human trials with probiotics, none of the currently recognized probiotic species (like lactobacilli and bifidobacteria) appear in fecal samples existing probiotics.

“There must be something missing in what we’re doing in this field,” she says. “We need new probiotics. I’m not saying existing probiotics don’t work or we shouldn’t use them. But I think that now that we have the potential to develop new probiotics, they might be even better than what we have now.”

She sees great potential in this new class of -biotics. 

Both Scott and Marco encouraged nutritionists to work with clients on first  improving their diets before adding supplements. The -biotics stimulate what’s in the gut, so a diverse diet is the best starting point.

“Human civilization simply would not have been possible without fermented foods and beverages…we’re here today because fermented foods have been popular for humans for at least 10,000 years,” says Bob Hutkins, professor of food science at the University of Nebraska (and a recent addition to TFA’s Advisory Board). 

Hutkins was the opening keynote speaker at FERMENTATION 2021, The Fermentation Association’s first international conference. His presentation explored the history, definition and health benefits of fermented foods.  

Cultured History

The topic of fermentation extends to evolution, archaeology, science and even the larger food industry. 

“The discipline of microbiology began with fermentation, all the early microbiologists studied fermentation,” Hutkins says. 

Louis Pasteur patented his eponymous  process, developed to improve the quality of wine at Napoleon III’s request. The microbes studied back then — lactococcus, lactobacillus and saccharomyces — remain the most studied strains.

“What interested those early microbiologists — namely how to improve food and beverage fermentation, how to improve their productivity, their nutrition — are the very same things that interest 21st century fermentation scientists,” Hutkins says. 

Hutkins is the author of one of the books considered gospel in the industry, “Microbiology and Technology of Fermented Foods.” He says that fermented foods defined the food industry. In its early days, it was small-scale, traditional food production that “we call a craft industry now.” At the time, food safety wasn’t recognized as a microbiological problem.

Today’s modern food industry manufactures on a large-scale in high throughput factories withmany automated  processes. Food safety is a priority and highly regulated. And, thanks to developments in gene sequencing, many fermented products are made with starter cultures selected for their individual traits. 

“But I would say that there’s been kind of a merging between these traditional and modern approaches to manufacturing fermented foods, where we’re all concerned about time sensitivity, excluding contaminants, making sure that we have consistent quality, safety is a vital concern and extensive culture knowledge,” Hutkins says.

Defining & Demystifying

Fermentation — “the original shelf-life foods” — is experiencing a major moment. “Fermented foods in 2021 check all the topics” of popular food genres: artisanal, local, organic, natural, healthy, flavorful, sustainable, entrepreneurial, innovative, hip and holistic. “They continue to be one of the most popular food categories,” Hutkins continues.

Interest in fermentation is reaching beyond scientists, to nutritionists and clinicians. But Hutkins says he’s still surprised to learn how many professionals don’t understand fermentation. To address  the confusion, a panel of interdisciplinary scientists created a global definition of fermented foods in March 2021

“Fermentation was defined with these kind of geeky terms that I don’t know that they mean very much to anybody,” he says. 

The textbook biochemical definition of fermentation that a microbiologist learns in Biochemistry 101 doesn’t work for a nutritionist or clinician focusing on fermentation’s health benefits. The panel, which spent a year coming to a consensus, wanted a definition that would simply illustrate “raw food being converted by microbes into a fermented food.” The new definition, published in the the journal Nature and released in conjunction with the International Scientific Association for Probiotics and Prebiotics (ISAPP), reads: “Foods made through desired microbial growth and enzymatic conversions of food components.” 

Fermentation in 2022

Hutkins predicts 2022 will see more studies addressing whether there are clinical health benefits from eating fermented foods. The groundbreaking study on fermented foods at Stanford was important. It found that a diet high in fermented foods increases microbiome diversity, lowers inflammation, and improves immune response. But research like this is  expensive, so randomized control trials are few.

Fermented foods could also make their way into dietary guidelines.

“Fermented foods, including those that contain live microbes, should be included as part of a healthy diet,” Hutkins says.