Tea Polyphenols Destroy "Unfriendly" But Not "Friendly" Intestinal Bacteria

One of the amazing effects of tea catechins is their ability to destroy disease-causing bacteria like E. coli, Salmonella, Staphylococcus aureus and Clostridium, especially when they reside in the digestive tract. One reason that the catechins can do this is they're not completely absorbed by the body during digestion. Instead, they hang around in the digestive tract for awhile until they’re broken down by the intestinal bacteria. This means that they linger longer than typical food or drink and have more time to exert their health-enhancing effects.

But if tea catechins are strong enough to kill major pathogens, what do they do to the “friendly” bacteria in your intestinal tract – the ones that you actually need in order to digest and absorb your food properly? To find out, scientists from the National University of Singapore looked at the effects of different tea catechins extracted from Yunnan Chinese tea on the growth of 28 kinds of intestinal bacteria, both “friendly” and pathogenic.

As expected, the catechins inhibited the growth of the disease-causing bacteria, especially Clostridium perfringens (a common cause of food poisoning), Clostridium difficile (which is linked to colitis), and Bacteroides (which can cause abscesses if the bacteria escape from the intestines). But the gut’s “friendly” bacteria, including Bifidobacterium and Lactobacillus, were relatively unaffected by the tea catechins.

What does this mean for you? By drinking green tea you may be able to favorably increase the proportion of "friendly" to "unfriendly" bacteria in your intestines. And that could mean better digestion and better intestinal health.