Tea polyphenols are also discovered to boost our immunity by increasing and heightening certain functions of white blood vessels.  Tea has been documented to have antiviral and antibacterial properties that help combat bacteria leading to dysentery, diphtheria, cholera, and bacillary as well as preventing inflammation such as gastroenteritis and enteritis.  Research has discovered that tea catechins combat helicobacter, which are a bacterial source for stomach ulcers while also promoting the growth of friendly bifidobacteria in the intestine.