Kombucha

Studies in people

• Open question

  Human health evidence²

  Only one study has tested kombucha in people, so its claimed health benefits are not yet proven.

• Concern

  Gut germs and blood sugar³

  In people, drinking kombucha daily for four weeks slightly changed gut germs and raised fasting insulin, but whether this matters is unknown.

• Open question

  Weight loss and inflammation⁴

  In people with excess weight, green tea kombucha did not boost weight loss but may have helped inflammation.

• Benefit

  Heart risk markers⁵

  In people with excess weight on a restricted diet, green tea kombucha lowered cholesterol markers versus their own starting levels.

• Benefit

  Gut comfort and bloating⁶

  In 39 adults, drinking blueberry kombucha daily for 28 days was linked to better bowel function, but authors say results are early.

Animal and lab studies only

• Open question

  Digestive and immune health¹³

  Kombucha has probiotics and antioxidants that may help digestion and immunity, but studies disagree and most were in animals or test tubes.

• Open question

  Sleep and pain in rats¹⁴

  In animal studies, kombucha helped rats sleep better and feel less pain, but some people got sick from drinking it.

• Benefit

  Gut health¹⁵

  Kombucha contains many bacteria and yeasts, and some may help the human gut.

Study type not stated

• Benefit

  Gut health and immunity⁸

  Scientific studies suggest kombucha has antimicrobial, antitumor, anticarcinogenic and immune-related properties, plus probiotic bacteria and yeasts.

• Open question

  Health effects in people⁹

  Scientists do not yet know whether kombucha helps human health, since few studies have tested it in people.

• Benefit

  Gut health and disease prevention¹⁰

  Kombucha's bacteria and yeasts may support gut health, but more studies are needed to confirm this.

• Benefit

  Gut and liver health¹¹

  Kombucha is a fermented tea drink that may help with digestion, liver protection and fighting germs.

• Open question

  Health benefits still unproven¹²

  Kombucha drinkers report many health benefits, but scientists say there is very little evidence to back these claims.

Found in some samples or products

These come from where it was grown, how it was processed or cooked, or what it was made into. They are not about the ingredient itself, so the signal does not count them.

• Lead poisoning from drinks⁷

  A family got lead poisoning from kombucha brewed in ceramic containers, which leaked lead into the drink.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.