Kombucha is a drink traditionally made by fermenting sweet, herbal tea with a scoby (symbiotic culture of bacteria and yeast).
During the fermentation process, the yeast converts the sugar in the tea to alcohol and the bacteria then convert the alcohol to organic acids (e.g. acetic acid). Leaving a refreshing, crisp drink with a slightly sour taste. Kombucha has recently been available on the commercial market in a range of tastebud-tingling flavours, think; pink lemonade, crisp apple, ginger & lemon.
What about those health claims?
Firstly, yes. kombucha does have some positive points...
1. It contains a live culture of bacteria and yeast, which can act as a probiotic. Probiotics are live microorganisms which have been found to improve digestion, help protect against disease and enhance immune function.
2. Fermentation creates organic acids (including acetic acid), these acids have been shown to inhibit the growth of pathogenic bacteria.
3. It's a tea based product. Tea is looked upon favourably for a number of reasons, one of which is the particular variety of polyphenols (naturally occurring plant chemicals) known as catechins which are found in brewed tea. The strong antioxidant properties from catechises have been shown to assist with brain health and continued, regular consumption has been linked to lowered levels of depression & anxiety.
Yes, kombucha does hold potential, but the composition and nutritional value of the product varies ridiculously from one brand to the next. Plus. whilst these bioactive components are there, where they are in sufficient numbers to have a beneficial impact on the large bowel (a.k.a "the gut") is up for debate.
Ultimately, the studies which look into this are currently limited. There's a lack of scientific evidence from human clinical trials to support the claims, and more research is needed.