Adding fermented pickles to sour cream increases the health benefits of the cream, lowering cholesterol and increasing antioxidant properties, according to new research.
Scientists from the Poznań University of Life Sciences in Poland based their research on the French paradox, “the observation that… reduced heart disease is associated with a diet high in saturated fat and cholesterol.” They picked sour cream because of its high levels of saturated fat and cholesterol.
“The results also show that the health-promoting potential of sour cream is enhanced by the presence of metabolically active LAB,” continues the study, published in the Journal of Dairy Science.
The scientists note future work will revolve around characterizing the properties of specific lactic acid bacteria produced by spontaneous fermentation.
Read more (Medical and Life Sciences)
Doctors and microbiologists warn: despite what the latest social media trends proclaim, there’s no quick fix for better gut health. More influencers are promoting their “cures” — from drinking aloe vera juice to boiling apples — on TikTok. Their videos are getting millions of views — and are raising concerns from medical and scientific authorities.
“If somebody is claiming to have something that will immediately turn gut health around, you should be skeptical of that,” says Justin Sonnenburg, a professor of microbiology and immunology at Stanford. The article in The New York Times notes Sonnenburg advocates for “long-term lifestyle habits that can benefit the gut — ones that rarely go viral or make their way to social media acclaim.”
Sonnenburg’s groundbreaking study last August showed fermented foods — like yogurt, kimchi, kefir, sauerkraut and kombucha — can increase the diversity of gut bacteria. “His research found that people who ate six servings of fermented foods each day saw these benefits — the equivalent of consuming one cup of yogurt, one 16-ounce bottle of kombucha and one cup of kimchi in a day,” the article continues.
The Times interviewed a panel of experts that included a dietitian, sociologist, gastroenterologist and Sonnenburg. They say, to improve your gut, change your lifestyle. They encourage eating more fiber, eating fermented foods, limiting processed foods and lowering stress levels.
Read more (The New York Times)
More and more food and beverages are labeling their product with -biotics – probiotics, prebiotics and postbiotics — confusing consumers as to what a -biotic is and its potential health benefit.
There’s an “overuse of the term probiotic as referring to any live microbe,” says Bob Hutkins, professor of food microbiology and the University of Nebraska (and a Science Advisor on TFA’s Advisory Board). Probiotics, according to the International Scientific Association of Probiotics and Prebiotics (ISAPP), require documentation of both a health benefit and the strain.
“It’s a high bar to call something a probiotic,” he continues. “I read labels that say ‘contains probiotics’ and I’d say, the vast majority of the time, they’re incorrectly named if they’re named at all.”
Hutkins was part of a panel hosted by Food Navigator on “Feeding the Gut Microbiome: From Pre-, Pro-, and Postbiotics.” Speakers included leaders of food brands and -biotic supplement brands.
Is a Fermented Food Probiotic?
The issues surrounding probiotics and fermented foods have long been debated. TFA hosted a webinar on the topic in 2021, and it was the focus of a keynote session at TFA’s FERMENTATION 2021 conference.
Using the example of kimchi, Hutkins explains the fermented cabbage may contain live microbes that closely resemble a probiotic strain. But, according to scientific-backed definitions by ISAPP and the World Health Organization (WHO), “you can’t call that kimchi probiotic unless you isolated the strain, characterized the strain, done a clinical study and then that kimchi is going to be different from the kimchi you’ll make tomorrow. So it’s a challenge for companies that are producing fermented foods that probably have live microbes that can provide some benefits, but you can’t call them probiotics.”
Hutkins encourages fermentation producers to use the term “rich in live microbes” on their label instead. If the product does include clinically tested probiotics (like in yogurt), “I really applaud the company that puts the genus and species on their package.”
Miguel Freitas, PhD, vice president of health scientific affairs at Danone North America, says the conversation in the industry needs to change from just probiotics to strain specificity.
“There are many consumers that are just seeking the word probiotic on the packaging. And they believe that probiotics will [help] everything from immune health to gut health,” Freitas says. “This is where I believe it can start to get tricky because there are so many products out there.”
Though the science around -biotics has evolved tremendously in the past two decades, consumers are overwhelmed and confused by all the choices.For example, he points to a new clothing brand that alleges the probiotics in their clothes are activated by heat.
This is why the food and beverage industry needs to play an active role in consumer education, says Todd Beckman, president of Verb Biotics.
“They have a platform to talk about health, these specific ingredients and health benefits,” he says. “They have the megaphone to talk to consumers in a true and authentic way.”
But Beckman warns: “the brands that don’t really know what they’re doing or don’t stand for anything or don’t stand for science, they’re not going to be there tomorrow.” Consumers will abandon brands with unsubstantiated health claims.
“If all of a sudden consumers aren’t believing in probiotics or what they can do, then it’s quite damaging,” he says.
Tom First, founder and CEO of Culture Pop probiotic soda, says that, though their brand has the clinical benefits of a verified and shelf-stable probiotic strain, they don’t lead with this complicated information in their marketing. Instead, they focus on flavor and it “being a fun drink,” figuring consumers can look to the Culture Pop website if they want to dive deeper.
Adding to consumer confusion: products on grocery shelves may now contain one of three -biotics – probiotics, prebiotics or postbiotics. Justin Green, PhD, director of scientific affairs at Cargill Health Technologies, says many think of -biotics as a daily supplement with a simple health benefit, like vitamin C.
“We really have to drive home there’s going to be different [-biotics] from different organisms, different fermentation techniques and most importantly different health benefits,” he says.
Probiotics are live bacteria; prebiotics are food for the bacteria; and postbiotics are metabolites produced by the probiotics.
Though non-alcoholic drinks are growing in popularity, alcohol-free beer has been a laggard. These brews lack the flavorful aroma of hops, with the resulting beverage flat and watery.
Mimicking beer’s flavor profile has been challenging for brewers hoping to appeal to dry drinkers. Some producers add aroma hops in the final stages of brewing, but it’s expensive and wasteful.
“When you remove the alcohol from the beer, for example by heating it up, you also kill the aroma that comes from hops. Other methods for making alcohol-free beer by minimizing fermentation also lead to poor aroma because alcohol is needed for hops to pass their unique flavor to the beer,” says Sotirios Kampranis, a professor in University of Copenhagen’s department of plant and environmental sciences who led the research.
Now researchers from the university have found a possible solution. Their innovation uses baker’s yeast that’s grown in fermenters and releases an aroma of hops. Results of their study were published in the journal Nature.
“After years of research, we have found a way to produce a group of small molecules called monoterpenoids, which provide the hoppy-flavor, and then add them to the beer at the end of the brewing process to give it back its lost flavor. No one has been able to do this before, so it’s a game changer for non-alcoholic beer,” Kamprani says. “When the hop aroma molecules are released from yeast, we collect them and put them into the beer, giving back the taste of regular beer that so many of us know and love. It actually makes the use of aroma hops in brewing redundant, because we only need the molecules passing on the scent and flavor and not the actual hops,” explains Kampranis.
Their discovery represents a potential breakthrough for the overall beer industry because, researchers point out, it could improve beer’s sustainability.
Aroma hops require an enormous amount of water. Over 713 gallons are needed to grow one kilogram of hops. And sourcing fresh hops involves a carbon-heavy supply chain. Hops are farmed mainly on the U.S. West Coast, so trucks and refrigeration units are needed for transportation .
By using baker’s yeast, researchers can create a hoppy flavor without wasting gallons of water and creating carbon emissions.
“With our method, we skip aroma hops altogether and thereby also the water and the transportation. This means that one kilogram of hops aroma can be produced with more than 10.000 times less water and more than 100 times less CO2,” Kampranis says. “Long term, we hope to change the brewing industry with our method – also the production of regular beer, where the use of aroma hops is also very wasteful.”
Kampranis and colleague Simon Dusséaux plan to have the process ready for the brewing industry by this October. The two have founded the biotech company EvodiaBio.
A new study found fermented dairy products reduce memory loss. The study, published in Nutritional Neurosciences, confirms there is a connection between the gut microbiome and the nervous system, known as the gut-brain axis
The adults in the test regularly consumed a dairy-based fermented drink, containing 25-30 billion colony forming units (CFUs). Drinking fermented dairy — like yogurt, kefir or fermented whey — “increased the presence of certain microorganisms in the gut and improved relational memory in healthy adults.”
Read more (Nutritional Neurosciences)
A new study aims to profile consumer habits with fermented foods and beverages. Researchers want to know the types of fermented products that are most popular — and why. To TFA’s knowledge, this is the first major study probing consumer perceptions of fermented foods.
“With this survey we hope to gain a better understanding of the types of fermented foods people are consuming and what motivates them to incorporate fermented foods into their diet,” says Erin DiCaprio, PhD, a food safety expert and extension specialist at UC Davis. “We also want to gather data on the trends related to in-home fermentation and the sources of information the public turns to related to fermented foods. The data we collect will help inform future areas of focus for research and education on fermented foods.”
The study is conducted by the EATLAC project at the University of California, Davis, Department of Food Science and Technology. EATLAC (Evaluating And Testing Lacto-ferments Across the Country), funded by California’s agricultural department, aims to provide accurate information and resources to the public. EATLAC’s directors are DiCaprio and Maria Marco, PhD, microbiologist and professor in the department of food science and technology at the university (and member of TFA’s Advisory Board).
To participate in the 10-minute anonymous survey, follow the link: https://ucdavis.co1.qualtrics.com/jfe/form/SV_0CzKfHUWgX2HHVj
New research has explored how lactic acid bacteria (LAB) in sauerkraut and tibicos survive digestion and change gut microbiota composition.
This work, published in Frontiers in Microbiology, investigated how a fermentation production process affects LAB and yeast microbial viability and probiotic potential. Though there are studies that demonstrate health benefits of fermented foods, few “explore how being part of a whole fermented food matrix affects microbial viability during fermentation, storage and gastrointestinal (GI) transit.”
The study focused on non-dairy, botanical fermented foods, defined as “microbially transformed plant products rich in health-promoting components.” Tibicos and sauerkraut were chosen because recent research had found the microbial diversity of the two ferments “far exceeded that of dairy-based ferments, as well as containing the largest numbers of potential health-promoting gene clusters.” The tibicos studied was sugar-based while the sauerkraut was brine-based, and both contained various strains of LAB and bioactive components.
Ginger, cayenne pepper and turmeric added to tibicos were all found to have different survival rates in the digestion tract. These functional spices are often added to fermented products for their anti-inflammatory and sensory properties, but their microbial proliferation had never been adequately explored. Cayenne was the clear winner, as adding it to tibicos “significantly improved the survival rate of LAB during simulated gastric and small intestinal digestion compared to ginger and turmeric.” Ginger in tibicos had a higher rate of LAB survival than turmeric, though neither had a significantly higher LAB survival rate than plain tibicos. But adding ginger significantly increased and sustained microbial viability of LAB.
The research team — from University of Melbourne — did not perform the study on human subjects, but simulated upper gastrointestinal digestion and colonic fermentation tests using pig feces.
Some other significant findings:
- For an optimal microbial survival rate of 70-80%, tibicos should be consumed within 28 days, and sauerkraut within 7 weeks.
- Sauerkraut made with different salt concentrations did not show any significant variation in LAB counts.
- Inoculating sauerkraut with a starter culture increased LAB counts during fermentation and storage. But, by the end of storage, the LAB counts in the inoculated sauerkraut “dropped to undetectable levels.”
- Spontaneously-fermented sauerkraut LAB counts remained stable through the storage period.
“Botanical fermented foods are cheap, easily made, and consumed globally,” the study concluded. “This makes them excellent candidates for the dietary management of pro-inflammatory noncommunicable diseases, such as type 2 diabetes and metabolic syndrome.
Microbiologists have long considered that there are two distinct categories of energy conservation in microorganisms: fermentation and respiration. Lactic acid bacteria (LAB) use fermentation, making it central to food and drink production and preservation since the dawn of man.
But researchers at the University of California, Davis, and Rice University discovered a LAB species that uses a hybrid metabolism, combining both fermentation and respiration.
“These are two very different things, to the extent that we classify bacteria as basically one or the other,” said Caroline Ajo-Franklin, a bioscientist at Rice University and co-author of the study. “There are examples of bacteria that can do both, but that’s like saying I can ride a bicycle or I can drive a car. You never do both at the same time.”
“What we discovered is a LAB that blends the two, like an organism that’s not warm- or cold-blooded but has features of both,” she said. “That’s the big surprise, because we didn’t know it was possible for an organism to blend these two distinct metabolisms.”
The species — lactiplantibacillus plantarum — is what scientists call a bacterial bully because it takes advantage of two distinct metabolic processes, according to a press release from Rice on the study. These systems were “not previously known to coexist to acquire the fuel they burn for energy.”
“Using this blended metabolism, lactic acid bacteria like L. plantarum grow better and do a faster job acidifying its environment,” said Maria Marco, a professor in the food science and technology department at UC Davis and the study’s co-author [and a TFA Science Advisor].
The discovery is significant for food and chemical production. New technologies that use LAB could now produce healthier and tastier ferments, minimize food waste and change the flavors and textures of fermented food.
“We may also find that this blended metabolism has benefits in other habitats, such as the digestive tract,” Marco said. “The ability to manipulate it could improve gut health.”
The study began with a puzzle: the realization that genes responsible for the electron transfer pathway in mainly respiratory organisms also appear in the LAB genome. “It was like finding the metabolic genes for a snake in a whale,” Ajo-Franklin said. “It didn’t make a lot of sense, and we thought, ‘We’ve got to figure this out.’”
While the Davis lab studied the genome, the team at Rice carried out fermentation experiments on kale.
“It wasn’t our first choice,” said Rice alumna and co-lead author Sara Tejedor-Sanz (now a senior scientific engineer in the Advanced Biofuels and Bioproducts Process Development Unit at Lawrence Berkeley National Lab).
“We performed some initial experiments with cabbage, since that’s a known fermented food — sauerkraut and kimchi — in which lactic acid bacteria are present,” she said. “But there were technical difficulties and it didn’t turn out so well. So we looked for another food to ferment where LAB could be found in its ecological niches.
“Kale has compounds like vitamins and quinones that lactic acid bacteria use as cofactors in their metabolism, and are also involved in interacting with the electrodes,” she said. “We also found fermenting kale to make juice was a trend. It sounded perfect for our biochemical reactors.”
The study showed LAB enhances metabolism through a FLavin-based Extracellular Electron Transfer (FLEET) pathway that expresses two genes (ndh-2 and pp1A) associated with iron reduction, a step in the process of stripping and incorporating electrons into ATP (adenosine triphosphate (ATP), energy-carrying molecule).
Because LAB’s genome has evolved to be small, thus requiring less energy to maintain, the wide conservation of FLEET must serve a purpose, Ajo-Franklin said.
“Our hypothesis is this helps bacteria get established in new environments,” she said. “It’s a way to kick-start their metabolisms and outcompete their neighbors by changing the environment to be more acidic. It’s being a bully.”
That the FLEET pathway can be triggered with electrodes offers many possibilities, she said. “We found we can use the hybrid metabolism in food fermentation,” Ajo-Franklin said. “Now we have a way to change how food may taste and avoid failed food fermentations by using electronics.”
“We may also find that this blended metabolism has benefits in other habitats, such as the digestive tract,” Marco said. “The ability to manipulate it could improve gut health.”
Ajo-Franklin noted LAB are commonly found in the microbiomes of many organisms, including humans. “You can already buy it in health food stores as a probiotic,” she said. “The human gut is an anaerobic environment, so LAB have to keep a redox balance. If it oxidizes carbon to gain energy, it has to figure out a way to reduce carbon somewhere else.
“Now we think if we provide another electron donor or acceptor, we could promote the growth of positive bacteria over negative bacteria.”
UC Davis graduate student Eric Stevens is co-lead author of the study. Co-authors are Rice graduate student Siliang Li; at UC Davis, graduate students Peter Finnegan and James Nelson, and Andre Knoesen, a professor of electrical and computer engineering, at UC Davis; and Samuel Light, the Neubauer Family Assistant Professor of Microbiology at the University of Chicago.
Ajo-Franklin is a professor of biosciences and a CPRIT Scholar. Marco is a professor of food science and technology.
The National Science Foundation, Office of Naval Research, the Department of Energy Office of Basic Energy Sciences and a Rodgers University fellowship supported the research.
The study results were published in the journal eLife.
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.”
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.