Green tea is perhaps one of the oldest beverages in the world. In addition to its well-known antioxidant properties, it also has a direct impact on gut health, which in turn is directly linked to immunity, psyche, metabolism and even longevity. Below we will list all the scientifically proven gut health benefits of green tea.
Bioactive compounds
The main benefit of green tea is provided of course by the substances catechins, particularly powerful ones are:
– EGCG (epigallocatechin-3-galate) – the main active ingredient
– gallic acid
– polyphenols
These are the ones that act as antioxidants, active anti-inflammatory agents, and modulators of the gut microbiota.
How exactly does green tea affect the intestines?
1. Improves barrier function
In an Ohio State University clinical study on people who consumed 1 g of green tea extract (890 mg of catechins) daily, a reduction in intestinal permeability, a key marker of ‘leaky gut’, was reported: ‘A confection rich in green tea extract in healthy adults and adults with metabolic syndrome reduces small intestinal permeability due to lower intestinal inflammation,’ Journal of Advanced Nutrition, https://www.sciencedirect.com/science/article/pii/S2475299123133622.
This means that green tea reduces the risk of all sorts of toxins, allergens and bacteria entering the bloodstream through the damaged intestinal mucosa.
2. Reduces inflammation in the intestines
The same clinical study recorded a reduction in inflammatory markers such as calprotectin and myeloperoxidase in the faeces of both healthy and metabolic individuals.
3. Balances the microbiota
In two scientific studies, ‘Microbe-transmitted metabolites and enhancement of the biological activity of green tea catechins by the human intestinal microbiota,’ in the Journal of Food, https://www.mdpi. com/2304-8158/13/5/5/792, and ‘The intestinal microbiota of mice administered green tea polyphenols improves intestinal epithelial homeostasis and alleviates experimental colitis’ in the journal Microbiome, https://microbiomejournal.biomedcentral.com/articles/10.1186/s40168-021-01115-9 show that green tea alters the composition of the intestinal microbiota, specifically manifested as follows:
– increases the number of beneficial bacteria (Akkermansia, Lactobacillus)
– reduces the number of pathogenic microorganisms
– Stimulates the production of short-chain fatty acids (SCFAs), key metabolites for the nutrition of intestinal cells.
How does all this affect gut health?
Through the above mechanisms, green tea has these effects:
- Reduces the risk of irritable bowel syndrome and inflammatory diseases (e.g. colitis).
- Improves blood sugar levels by reducing insulin resistance associated with endotoxins (study ‘Epigallocatechin galate, but not catechin, prevents non-alcoholic steatohepatitis in mice similar to green tea extract while differentially affecting the gut microbiota’, Journal of Nutritional Biochemistry, https://www.sciencedirect.com/science/article/abs/pii/S0955286320304873.
- Reduces the risk of metabolic syndrome and even obesity due to effects on the microbiota and inflammation (‘Metabolic benefits of green tea catechins at the gut level: mechanistic evidence from preclinical and clinical studies,’ Phytomedicine Publishing. https://www.sciencedirect.com/science/article/abs/pii/S0944711323005664).
Expert conclusions.
Dr Priyankar Dey (Ohio University) states that: ‘Green tea catechins act not only as antioxidants – they have a direct positive effect on intestinal wall integrity and microbiota profile.’
Professor Jiangchao Zhao (Nanjing Agricultural University), as a result of his study ‘The intestinal microbiota of mice injected with green tea polyphenols improves intestinal epithelial homeostasis and alleviates experimental colitis’, https://microbiomejournal.biomedcentral.com/articles/10.1186/s40168-021-01115-9, published in Microbiome, is confident that: ‘Green tea is a powerful natural prebiotic that promotes the growth of bacteria that protect against colitis and dysbiosis.’
What is the right way to drink green tea to heal the gut?
1-2 cups a day, ideally in the morning or after meals, brewed at 70-80°C to preserve catechins, consumed without sugar – to retain maximum probiotic benefits.
Additional probiotics (such as Lactobacillus plantarum) can enhance the effects of green tea.
Overall, we can conclude that green tea is not only a source of antioxidants, but also a powerful modulator of intestinal health.
