Is Kombucha Good For You? The Surprising Benefits of Fermented Tea

Evan Leafy

Is kombucha actually healthy? Or is it simply another health fad, like coconut oil, kale, or acaí? Humans have enjoyed this fermented tea for thousands of years, starting in China and moving throughout the world. Surprisingly, given this long history of kombucha consumption, little scientific research has looked into the health effects of this drink. 

Clinical Studies on Kombucha Health Effects Don’t Exist 

A 2019 meta-study of all English-language medical articles containing the word ‘kombucha’ determined that no clinical trials have examined the effect of kombucha on humans. This means that the gold standard of scientific study hasn’t yet confirmed the health benefits (and potentially dangers) of regular kombucha drinking. 

That being said, there are numerous studies on the effects of kombucha on non-human mammals. Other studies look at the chemicals contained within fermented teas. These studies can give us an idea of how kombucha may interact with humans. 


Photo by Sidcley via Pixabay

Potential Benefits of Drinking Kombucha

While we don’t know exactly how kombucha as a whole affects humans, we do know a fair amount about the chemicals and bacteria contained within kombucha. 


Photo by Alicia Harper via Pixabay

The Probiotic Effect

The most commonly claimed health benefit of kombucha is due to probiotics. Probiotics are beneficial bacteria that humans eat or drink. These bacteria are incorporated into the human microbiome. This microbiome is the diverse assortment of bacteria contained within our bodies. Most of these bacteria live within our guts, where they help with digestion.

Studying the human microbiome is trending in science right now. The National Institute of Health recently completed the Human Microbiome Project. This project completed the genomes of all the microbes living within the human body. They found that the average human body has 2-6 pounds of bacteria! The number of bacterial cells within the human body are 10 times more than the actual human cells than make up that body! Moreover, the bacteria in our bodies contain about 1,000 more genes than our human bodies themselves. Fascinating, isn’t it?

Scientists currently think imbalances in our microbiome may cause many diseases. These associated diseases cover almost the entire body. They include the stomach, lungs, intestines, heart, and nervous system.  

The idea behind probiotics is that they add beneficial bacteria to our gut microbiomes. These beneficial bacteria may restore some balance within the human microbiome. While probiotic dairy products such as cottage cheese, kefir, and yogurt are well studied, kombucha is not. 

Fermented foods have the highest concentration of probiotics. In order to expose your gut to the widest array of beneficial bacteria species, it is best to consume a variety of probiotic foods. Don’t rely solely on kombucha!

A worker harvests green tea leaves. Photo by Free-photos via Pixabay

Anti-inflammatory Chemicals

Tea in general is an effective antioxidant. This is due primarily to the polyphenol chemicals within the tea leaves. Polyphenols are special chemicals in tea that scour the human body looking for bad molecules. Since green tea is cooked less than black tea during processing, it contains a higher concentration of polyphenols. This means that fermented teas made with green tea will have more antioxidant effects than fermented teas made with black tea. 

Fermenting kombucha changes the types and concentrations of different kinds of polyphenols. It can also increase the total amount of polyphenols in the tea, making it a more effective anti-oxidant than regular tea.   


Antioxidants are effective in preventing cancer-causing cells. As mentioned above, kombucha contains a good amount of these antioxidants. 

Liver Disease

Kombucha contains some chemicals known to decrease the potential for liver disease. In a study done on rats, scientists found that regular consumption of kombucha significantly reduced liver inflammation and other liver dangers. 

homebrew kombucha

Home bottled kombucha. Photo by Melanie Rodriguez via Pixabay

Some People Should Avoid Kombucha

Regardless of the supposed health benefits, kombucha is a powerful drink. It has a pH of about 3, which is similar to soda. Drinking too much acidic liquid can be unhealthy.

Pregnant women should avoid fermented tea since it contains alcohol. For the same reason, people recovering from alcohol use disorder should also avoid this fermented tea. Even small amounts of alcohol can trigger addictive responses in such folks.

People with kidney and lung diseases have more difficulty regulating their body’s pH. For these people, drinking a highly acidic beverage can be dangerous.  

Kombucha has a decent amount of sugar. People watching their sugar intake should compare different brands of kombucha because some brands have much more sugar than others. 

Since kombucha contains large amounts of bacteria, immunosuppressed individuals should avoid this drink.

Lastly, please don’t drink copious amounts of kombucha. As stated above, it is an intense, highly acidic, probiotic drink. Fermented teas are best in moderation.

Kombucha Is Big Business

Have you noticed the kombucha selection in your grocery store growing recently? Just a decade ago it was difficult to find this drink in supermarkets. In the last few years, however, the popularity of fermented tea has skyrocketed. Some stores have an entire section devoted to kombucha! In 2017, U.S. consumption of fermented teas was nearly 40% higher than the previous year. Experts predict the global kombucha market will grow almost 20% annually through 2025. Even beverage giant Pepsi has taken notice. In 2016, Pepsico bought KeVita kombucha for 200 million U.S. dollars!

Much of the increased demand for this fermented tea is due to its claimed health benefits. When big money and mega-corporations are involved, we must be diligent about examining such claims. 

For example, KeVita, Brew Dr., Health-Ade, and other large kombucha companies are all facing class action lawsuits for false advertising. Some brands claim to have more probiotic bacteria than they actually contain.

fermented tea on tap

Kombucha on tap. Photo by Christopher Backer via Pixabay

Not All Kombucha is Created Equal

These lawsuits center around the authenticity of commercial kombucha. Some companies, like Kevita, aren’t ‘raw’. Instead, these drinks have been pasteurized to remove all bacteria. After pasteurization, the company allegedly adds ‘probiotic bacteria’ back into the drink. Pasteurization helps prevent the further fermentation of kombucha post-bottling. It also helps with distribution. But the whole point is that fermented tea is a living drink. Some brands may taste just like kombucha but deliver few of the desired bacteria due to pasteurization. 

Other well-known brands, such as GT Kombucha and Brew Dr. are raw, meaning they are never pasteurized. These brands probably contain hefty amounts of live probiotics, but it’s hard to say how much they actually contain. The big takeaway here is that commercial fermented teas vary wildly in quality. 

If fermented tea has health benefits, the raw varieties of these drinks are more likely to deliver such benefits. Since most of the health benefits are supposed to come from the probiotic bacteria, it seems silly to kill off all that bacteria, only to re-add some assorted mixture of ‘probiotics’.

Homemade kombucha, or small-batch, locally brewed kombucha, almost certainly contains more beneficial bacteria than either pasteurized or raw store-bought varieties. Since it is easy and economical to make at home, avid kombucha drinkers should consider this option. Homemade fermented tea will vary significantly in alcohol content, pH, and bacteria content due to environmental factors, different SCOBYs, and human error. 

Kombucha is a Delightful Drink

Taking everything above into account, kombucha is a complex drink that is a great alternative to sodas or sugary juices. Kombucha carries delightful flavors that are unusual in other drinks, such as rose and sage. However, unless some big scientific studies come out saying otherwise, we should probably think of kombucha as a tasty drink rather than a cure-all superfood.

Featured image via Wikimedia

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