Green Tea and Your Gut Microbiome

A Matcha Made In Heaven?

Green tea is a truly unique beverage with qualities that are similar but distinct from coffee, not least of which for the fact it contains about half the amount of caffeine per serving.

Like coffee, the major health-promoting benefits of green tea are tied to its rich and varied polyphenol content.

Tea is the third richest source of polyphenol antioxidants in the average American diet, contributing 7.5% while sitting only behind coffee (~40%) and beans (~10%).

The significant role that tea and coffee play in this regard speaks both to their incredibly rich polyphenol content as it does to the relative lack of abundant intake of other polyphenol-rich foods (fruits, veggies, nuts, seeds, whole grains) in the average American diet.

But wait a minute, what the heck is a polyphenol?

Polyphenols are a family of antioxidant compounds which may have the propensity to act as “prebiotics” in the human digestive tract – which brings us to the topic of today’s article.

Let’s get to the good stuff.

Green Tea Polyphenols & Your Gut Microbiome

One of the primary and most notable polyphenol compounds found in green tea is ECG (epigallocatechin-3-gallate) which belongs to a polyphenol subgroup known as catechins.

Among polyphenol compounds that have been examined for their prebiotic potential, the catechin subgroup is supported by the strongest evidence.

The term prebiotic, by the way, refers to food components with the potential of stimulating the growth of beneficial bacteria in the digestive tract.

You can learn more about prebiotics in my previous piece on the topic.

While polyphenols are not yet fully acknowledged to be prebiotic compounds, the evidence is mounting.

A 2012 study published in Microbiology and Immunology looked at the effects of green tea consumption on the gut microbiome in a novel way.

The researchers in this study evaluated the effect of green tea consumption on the gut microbiome (via analysis of fecal samples) over a 10-day period in volunteers who did not usually consume green tea.

They found that green tea consumption increased the proportion of beneficial Bifidobacterium species over this period and concluded that their study offered up initial human evidence of the prebiotic potential of green tea. 

Years later Nutrients published a review paper looking at studies involving green tea and the microbiome, concluding that:

“Overall, given the totality of the evidence, it seems logical to suggest that tea drinking, but especially green tea, could help to improve the profile of gut microbiota and even exhibit prebiotic effects.”

Green tea intake up to 1,000 ml daily (~ 4 cups) may be required to optimize this effect, but such recommendations are limited by the relatively small amount of human data available thus far. 

For those curious/concerned about the caffeine intake in that amount of green tea, it will likely fall in the 125-200 mg range total – which is well below the FDA’s formal caffeine recommendation of 400mg or less to avoid adverse consequences in most people.

Green Tea & Gut Health - Beyond The Microbiome

Don’t care too much about the gut microbiome but still want an excuse to drink more green tea for your gut and overall health?

This next section is for you.

As per the dietary inflammatory index (DII), green tea is considered among the most potent anti-inflammatory products in our food system.

I know just how much people resonate with this concept – and of course, the connection between gut health and inflammation needs little introduction here. 

Case in point, green tea intake has also been associated with a reduced risk of both stomach cancer and gastritis, the latter having been covered at great length in a previous article by yours truly.

Even supplemental green tea extract (1 gram daily) has been recently demonstrated in a clinical setting to reduce intestinal inflammation. 

Quite a bit to swallow right?

You might as well drink up because I’ve got a bit of a gut feeling you might look at green tea differently after today’s post.

Hope you enjoyed reading it as much as I enjoyed writing it.

---Until next time

1. _{Huang, Q., Braffett, B. H., Simmens, S. J., Young, H. A., & Ogden, C. L. (2020). Dietary Polyphenol Intake in US Adults and 10-Year Trends: 2007-2016. Journal of the Academy of Nutrition and Dietetics, 120(11), 1821–1833.}
2. _{Alves-Santos, Aline & Sugizaki, Clara & Lima, Glaucia & Naves, Maria. (2020). Prebiotic effect of dietary polyphenols: A systematic review. Journal of Functional Foods. 74. 104169.} 
3. _{Jin, Jong-Sik & Touyama, Mutsumi & Hisada, T. & Benno, Yoshimi. (2012). Effects of green tea consumption on human fecal microbiota with special reference to Bifidobacterium species. Microbiology and immunology. 56. 729-39.} 
4. _{Bond, T., & Derbyshire, E. (2019). Tea Compounds and the Gut Microbiome: Findings from Trials and Mechanistic Studies. Nutrients, 11(10), 2364.}
5. _{Shivappa, N., Steck, S. E., Hurley, T. G., Hussey, J. R., & Hébert, J. R. (2014). Designing and developing a literature-derived, population-based dietary inflammatory index. Public health nutrition, 17(8), 1689–1696.}
6. _{Setiawan, V. W., Zhang, Z. F., Yu, G. P., Lu, Q. Y., Li, Y. L., Lu, M. L., Wang, M. R., Guo, C. H., Yu, S. Z., Kurtz, R. C., & Hsieh, C. C. (2001). Protective effect of green tea on the risks of chronic gastritis and stomach cancer. International journal of cancer, 92(4), 600–604.}
7. _{Hodges, J., Zeng, M., Cao, S., Pokala, A., Rezaei, S., Sasaki, G., Vodovotz, Y. & Bruno, R. (2022) Catechin-Rich Green Tea Extract Reduced Intestinal Inflammation and Fasting Glucose in Metabolic Syndrome and Healthy Adults: A Randomized, Controlled, Crossover Trial. Current Developments in Nutrition, 6(1) 981.}