Consuming the wrong kind of kombucha, or too much of it, may produce harmful side effects. These include digestive issues and tooth erosion.

Kombucha is a probiotic drink made from fermenting tea and sugar, sometimes along with other ingredients.

Kombucha may have some possible health benefits when consumed in moderate amounts, but drinking too much may carry some risks.

Other issues such as contamination or over-fermentation may also play a role in the possible side effects of kombucha, and there are some characteristics to look out for when choosing a kombucha drink.

This article explores the possible harmful side effects of kombucha, and how to consume it safely.

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Kombucha is a traditional fermented drink.

At its simplest, kombucha contains brewed tea and sugar. Many manufacturers add other ingredients for flavor, such as fruit, herbs, or juices.

Leaving the combination to ferment in a controlled environment allows healthy bacteria and yeasts to build up in the drink, making kombucha an easy source of beneficial probiotic bacteria.

The drink may also be carbonated, either through natural fermentation or artificially. The result is a bubbly drink that may have some health benefits.

Research posted to the Journal of Chemistry notes that the probiotics and antioxidants in kombucha may have a number of therapeutic benefits, such as helping support a healthy gut microbiome, as well as supporting other organs and body systems such as the liver, heart, and nervous system.

Although kombucha may have health benefits, there is some possibility for side effects from drinking it.

Digestive upset

Some people may experience digestive upset when drinking kombucha, or from drinking too much.

Symptoms such as gas, nausea, and vomiting may occur. These side effects may be more likely in people who drink too much kombucha.

Additionally, some people may not tolerate kombucha well, or have a poor digestive reaction when drinking it.

Excess calories

Some people drink kombucha as a sweet, carbonated alternative to soft drinks.

While kombucha may provide some benefits to the body, it does contain calories. The actual levels of calories in kombucha will vary widely based on manufacturer and additives.

Some manufacturers may add more sugar or sugar-rich juices to their kombucha for flavor. This also adds calories.

People on calorie-restrictive diets may wish to avoid the extra calories from kombucha.

People with diabetes will also need to be aware of the calories and the carbohydrate and sugar content of kombucha.

Added sugars

The fermentation process from kombucha requires sugar to feed the probiotic bacteria in the drink.

Many manufacturers will also add additional sugars or sugar-rich fruits and juices to the drink.

Sugar-sweetened beverages have links to a number of health conditions.

For example, research posted to Circulation notes the association between sugar-sweetened beverage consumption and conditions such as obesity, type 2 diabetes, and cardiovascular disease.

Additional research in the European Journal of Nutrition notes that people who drink more sugar-sweetened beverages have a higher risk for nonalcoholic fatty liver disease.

Opting for kombucha products lower in sugars may provide the same health benefits with fewer of the risks associated with excessive sugar consumption.

Tooth erosion

Drinking too much kombucha may not be good for the teeth.

As research posted to Beverages notes, the fermentation process of kombucha creates acids such as acetic acid. This is the same acid found in vinegar, and gives the kombucha its tangy flavor.

The release of acetic acid during the fermentation process decreases the pH level of the drink, making it acidic.

Research posted to the Journal of Chemistry notes kombucha has a pH lower than 4.2. Because of this, drinking too much kombucha may put the teeth at risk of erosion.

For this reason, drinking water or rinsing the mouth with water after drinking sweetened acidic beverages may help protect tooth enamel.

Infection risk

Kombucha may not be right for people with sensitive immune systems in some situations.

For example, home-brewed or small-batch kombucha may not have gone through the pasteurization process.

A mix of different types of wild bacteria and yeasts may grow in the drink.

While many of these microbes may be beneficial, the same environment during fermentation may also allow some harmful microbes to grow or leave space for these microbes to take root.

For this reason, people who are prone to infection, such as those with a weakened immune system or chronic conditions affecting their immune system, may want to avoid kombucha.

Excess caffeine

Kombucha typically contains tea during the fermentation process.

Depending on the type of tea, this could provide a person with a lot of added caffeine.

For those sensitive to caffeine or who already drink caffeinated beverages, adding kombucha may increase caffeine consumption and cause symptoms such as:

People who are sensitive to caffeine may want to avoid kombucha or look for versions made without caffeine from tea leaves.

Liver toxicity

Although rare, some people may have more severe reactions to kombucha.

Research posted to SD Med attributes some cases of toxicity of the liver and inflammation to kombucha consumption. These may lead to complications such as jaundice or lactic acidosis.

Those with conditions affecting the liver may want to avoid kombucha or ensure it comes from a controlled environment.


As kombucha is a result of natural fermentation, improper handling or poor control of the environment may lead to contamination.

Kombucha contaminated with other bacteria or yeasts may not be as healthy, or may even be dangerous to drink.

Contamination from a container may also be a risk factor. Porous pots, or resins or glazes that contain lead or other contaminants, may leech into the kombucha.

Some plastics may break down into the kombucha as it brews. Contaminants from the container may put the person at risk for side effects or toxicity depending on the chemical.

Safe consumption of kombucha may help reduce some risk factors from the drink.

For small-batch brews or homemade kombucha, ensure the container will not break down or leech chemicals or metals such as lead into the drink.

It is best to brew kombucha in a glass container that can be sanitized before use.

Preventing contamination from other microbes may include proper temperature control and the use of clean equipment during brewing.

For those worried about the possibility of other microbes in the drink, look for pasteurized kombucha. Some manufacturers will pasteurize the drink and then add only beneficial bacteria afterward.

For those concerned with sugar and calorie intake, look for drinks that do not contain too many added sugars or calories.

There is no set recommendation for kombucha consumption.

Individual factors and the type of kombucha may vary greatly.

With this said, drinking one to two 8-ounce servings of kombucha each day may be suitable for average consumers.

Kombucha is a fermented probiotic tea that may be beneficial to the body.

There are some risks to consider, especially when drinking kombucha in excessive amounts.

Some people may want to avoid kombucha, such as those with compromised immune systems and people sensitive to caffeine.

There are no exact guidelines on kombucha consumption, and finding a way to balance individual consumption may be best in each case.