Research Reveals Healthy Soft Drink!
First Peer-Reviewed, Randomised, Controlled Trial of Kombucha Shows Improved Blood Sugar Levels After Meals
The first ever randomised, placebo-controlled, clinical trial of kombucha has been published in Frontiers of Nutrition and shows ‘living kombucha’ reduces the blood sugar spike and improves insulin response after meals compared to soda water or diet soft drink. The research, which was conducted by Prof Jennie Brand-Miller and her team at Sydney University's Glycemic Index Research Service (SUGiRS) and supported by an Australia Innovation Connections Grant, was published in the prestigious peer-reviewed journal Frontiers in Nutrition.
Prof Brand-Miller said; “Rarely do nutritionists have something good to say about soft drinks, but now there’s an exception – we have shown a specific live form of kombucha reduces the blood glucose response to a meal.”
According to study co-author Prof Marc Cohen, “Kombucha originated in ancient China where it was labelled the “Elixir of Life” and “The Tea of Immortality' after it was discovered fermented tea produces a delicious, fizzy and tart drink that makes the drinker feel wonderful.” Prof Cohen adds: “The health effects of kombucha have been extensively studied in animals and kombucha has been shown to assist in detoxification, digestion, antioxidation, energy metabolism and immunity, yet this is the first controlled clinical trial of kombucha in humans, and the first study to show living kombucha reduces post-prandial blood sugar spikes when consumed with a meal”.
“The mechanisms of kombucha’s action on blood sugar are unclear, and not all kombuchas are the same” said Prof Cohen “The kombucha used in the study is produced by The Good Brew Company and was previously reported to contain 200 microbial species and two and a half times the polyphenol content of green tea. This suggests this kombucha is a rich source of probiotics and the kombucha SCOBY (Symbiotic Colony of Bacteria and Yeast) bioactivates the phytochemicals in tea to produce new beneficial nutrients.”
Prof Cohen, added “It’s surprising it’s taken so long to see a published clinical trial of kombucha in humans, considering kombucha is already a multi-billion dollar market, yet large kombucha companies are not interested in the health benefits of their products and do not produce living wild ferments and may pasteurise their kombucha to make it shelf-stable or use vinegar and tea extracts and call it 'kombucha'.”
The 'living kombucha', used in the clinical trial is the base for all Extremely Alive products and was previously shown to contain 200 microbial species and more than twice the polyphenol content of green tea in study that was published last year.
Prof Brand-Miller concludes: “This provides an alternative to both alcoholic and non-alcoholic beverages and is a simple and enjoyable way to improve health.”
The study titled “Glycemic Index and Insulin Index after a Standard Carbohydrate Meal Consumed with Live Kombucha: A Randomised, Placebo-Controlled, Crossover Trial” was published in Frontiers in Nutrition.
The first full metagenomic analysis of kombucha.
The first full metagenomic and physico-chemical analysis of kombucha reveals 200 microbial strains and more than twice the polyphenol content of green tea.
Swapping booze or soft drink for kombucha to kickstart a healthy gut? The first comprehensive microbial analysis of the popular fermented drink has revealed an intriguing picture of its potential benefits. The analysis by researchers from RMIT University shows The Good Brew Kombucha, which is the base for all Extremely Alive Products contains more beneficial bacteria strains than commercial probiotics and more than twice the antioxidant polyphenols than green tea.
The study shows kombucha is packed with a bacterial strain that can help reduce sugar content in the body, suggesting the drink may have a role in helping prevent Type 2 diabetes and obesity. Lead researcher Associate Professor Nitin Mantri said there were many health claims made about kombucha, which has a long history of use as a health tonic, but little robust research on what it contains.
“This is the first deep analysis of the microbial ecosystem in a commercially-available brand of kombucha,” Mantri said. “Previous studies have not been this comprehensive or only looked at kombucha created at lab-scale, rather than examining a real product that is actually sold in shops. We’ve found that kombucha made through commercial proprietary methods contains an array of beneficial microbes, yeasts and antioxidants, which are likely to be good for keeping your gut healthy and balanced. Our study also suggests drinking living kombucha may impact glucose in the body – an exciting finding that we are keen to explore further through clinical research.”
Comprehensive analysis
Kombucha is a fizzy, fermented black or green tea drink that has been growing in popularity in recent years, with a global market estimated to be worth more than 2.5 billion in 2020. The new research, published in the journal Nutrients, examined kombucha produced by Melbourne-based enterprise, The Good Brew Company. The comprehensive analysis included genetic sequencing for a full picture of the kombucha’s microbial composition and biochemical properties. The study found the kombucha contained:
200 different species of friendly bacteria and 16 species of yeast, which is far more than most commercial probiotics which only contain around 7 species
5 dominant bacteria species (Acetobacter, Bacillus, Starmerella, Komagataeibacter and Gluconobacter), which are known to cooperate with beneficial strains in the gut and can inhibit the growth of infectious microorganisms
2.5 times more polyphenols than green tea, suggesting that fermentation helps boost polyphenols (compounds known for their cholesterol-reducing, sugar-reducing, antibiotic and anticarcinogenic properties)
Importantly, one of the most dominant bacteria species – Komagataeibacter – is known to produce gluconic acids, which have a tangy sweet flavour, reduce sugar content in the body and improve insulin sensitivity.
“The high glucose conversion efficiency of this bacteria species and its strong survival rate in the gut suggests kombucha may have a role as a dietary intervention to help prevent diabetes and obesity,” Mantri said. “We can also see that the fermentation process itself leads to the bioactivation of nutrients and phytochemicals and the production of additional compounds that significantly add to the health benefits of kombucha. Our comprehensive analysis suggests kombucha is a source of bioactive compounds, essential microbiota and important functional nutrients that contribute to its role as a dietary supplement and natural probiotic.”
Authenticating kombucha
As well as identifying and fully classifying microbial communities, the study developed the first chemical “fingerprint” for kombucha. In a hotly contested commercial market, a detailed chemical profile is vital as a benchmark for authenticating kombuchas, Mantri explained.
“With many kombucha products now available, it is vital that consumers and regulators can distinguish real, fermented, living kombucha from flavoured, lifeless, fizzy drinks” he said.
The research was funded by The Good Brew Kombucha Company and supported by an Australia Innovation Connections Grant. Study co-author Dr Marc Cohen is co-owner of Extremely Alive Pty Ltd, which produces wellness tonics based on Good Brew Kombucha.
‘Microbial diversity and characteristics of kombucha as revealed by metagenomic and physicochemical analysis’, with first author and PhD researcher Mayank Kaashyap, is published in the high-impact journal Nutrients.
