Probiotics are the good bacteria that everyone has living in their gastrointestinal tract. Your digestive tract is home to over 500 different species of bacteria, some are good and some are bad. A good healthy balance is 80% beneficial bacteria with the remaining 20% being of a mix of the innocuous or potentially bad ones. Of the trillions of bacteria dwelling in your tract most of them live in the large intestine.

The two most common probiotics are Lactobacilla, who constitute the majority of the probiotics living in your small intestine, and the Bifidobacteria which are the most prevalent probiotic in your large intestine. About 70% of your immune system is located in your digestive tract. Therefore a thriving community of benevolent bacteria is very important to your overall health. Any overgrowth of the bad bacteria can lower or overwhelm your immune system. So, how do you go about keeping your bacteria in balance?

Although we don't realise it everyone consumes potentially harmful bacteria on a daily basis. Even your supposedly 'clean' cutlery will have the less benign forms of bacteria living on them. Bad bacteria are all around. They are in your home, your office, your car, etc. However clean you strive to be these bacteria will still be lurking.

However for the most part this isn't a problem for a healthy individual. The good bacteria help keep the bad bacteria under control. You can ingest good bacteria through your diet. Fermented dairy products such as live yogurt as well as fermented vegetables like sauerkraut are both types of food high in the right sorts of bacteria.

If you want to increase your levels of good bacteria, consume those foods mentioned above and in addition eat a high fibre diet. This is because good bacteria love to eat fibre. With a plentiful supply of soluble fibre they will multiply and when they multiply, they crowd out the bad bacteria and so conserve the right balance within your gut. Lactobacilli

Lactobacilli not only help to regularise the immune system they also break down proteins, carbohydrates and milk sugar into forms the human body can use. In addition they produce compounds and acids that help create an environment that is unfriendly for possibly harmful bacteria.

Lactobacilli are also the most prevalent probiotic that are found in the vagina. Here the acidic compounds they create help keep other organisms, including Candida, in check. Bifidobacteria

In a healthy large intestine the most common probiotics are Bifidobacteria. Because the passage of solids through the large intestine is slower than the small intestine, it is easier for potentially harmful bacteria to thrive. It is the Bifidobacteria that are your best protection against these bad bacteria. The Bifidobacteria overwhelm the bad bacteria simply by virtue of being so numerous. At the same time they produce acidic compounds that help reduce the unwanted bacteria's capacity to multiply.

Bifidobacteria have another important function. They ferment soluble fibre, breaking it down so that it can be used by the human body. The fermenting process produces compounds including short chain fatty acids, Vitamin B and Vitamin K.

Something to remember is that studies have shown that the numbers of Bifidobacteria in our gut decreases with age. Researchers are now looking at the link between the decline of the bacteria and the adverse effects of aging such as the increase in colon polyps and colon cancer. So as you get older you might like to take a high potency Lactobacilli and Bifidobacteria supplement.