The Following is a guest post by Mari Hoiland

By now, most health-conscious consumers are somewhat familiar with the bubbly, vinegary beverage known as kombucha. Lining the shelves of every decent health store refrigerated section and touted as a “miracle tonic”, the ancient fermented drink has made a comeback in the 21st century thanks to an impressive list of purported health benefits and immune boosting properties. Kombucha has enjoyed a long history — over 2000 years, and yet the recipe for the drink has stayed relatively similar throughout. Kombucha was originally developed in Northeast China, (1) and is made from a combination of black tea, sugar and a living culture called a SCOBY (Symbiotic Colony Of Bacteria and Yeast).

The SCOBY resembles a large mushroom – the solid you may have seen floating in many of the commercially available kombuchas. A kombucha SCOBY is made up of Acetobacter sp. (which convert ethanol to acetic acid), and one or more yeast species. Black tea provides nitrogen, minerals, and ideal (low) pH necessary for the health of the SCOBY, while the yeast feeds on the sugar, creating ethanol and carbonation (2). During the fermentation stage, the SCOBY produces a potent detoxifying substances such as glucuronic acid (3).

Glucuronic acid is normally produced in the liver to neutralize toxins and clear unwanted excess chemicals, but when our livers become overburdened, our natural cleansing process can become sluggish and less effective. The glucuronic acid in kombucha is thought to ease the burden of the liver aid in the overall detoxifying process. In addition to this powerful detoxifying agent, consuming the living microbes present in kombucha may help contribute to the health of our gut’s microbiome. Humans historically ate a diet rich in fermented foods– however, since the appearance of processed foods in the last century or so, the consumption of these probiotic-rich foods has steadily declined. Researchers have theorized that a lack of beneficial bacteria in our foods compounded with the heavy use of antibiotics has resulted in a lack of diversity in the microbial population in the human gut and and impaired immune function. When ingested, the beneficial bacteria produced during kombucha’s fermentation may help combat the overgrowth of aggressive unwanted bacteria, resulting in a more balanced gut microbe population and better GI function. Skeptics argue that the eubacteria found in living foods are unlikely to survive the varying pH of the human GI tract, however, kombucha’s SCOBY is known to thrive at the pH found in the stomach, which is deadly to many microbes.

Recent research has explored another compound present in kombucha, glucaric acid, as a cancer preventing agent (4).While proponents of the ancient drink claim that kombucha contains properties that assist in curing everything arthritis and depression to cancer, these strong claims remain limited to studies of individual compounds found in kombucha and anecdotal evidence. There has not yet been a definitive, controlled study on the specific effects of drinking kombucha. Regardless, we know for a fact that kombucha does contain a wide array of enzymes and antioxidants that have positive effects on overall health.

Mari Hoiland is currently a Food Policy Intern at the Bureau of Planning and Sustainability in Portland, Oregon. In her spare time she enjoys pickling and fermenting all kinds of weird stuff and geeking out on bizarre nutrition facts.

Links to Studies Referenced in this article:

1. http://pubs.acs.org/doi/abs/10.1021/jf991333m

2. http://www.culturesforhealth.com/kombucha

3. hhttp://www.ncbi.nlm.nih.gov/pubmed/11119158

4. http://www.ncbi.nlm.nih.gov/pubmed/2208084?dopt=Abstract