All diseases come from the gut.​
- Hippocrates 460-370 BC

Hippocrates said it before more than 2,000 years, but we are only now
understand how right he was.
And not only Hippocrates, but also an old saying more centuries before both Traditional Chinese Medicine (TCM) and the ayurvedic medicine of India, said that:

The root of good and poor health resides in the gut.

Surveys over the past two decades have revealed that gut health is critical to overall health, and that an unhealthy gut contributes to a wide range of diseases such as diabetes, obesity, rheumatoid arthritis, autism, spectrum disorder, depression and chronic fatigue syndrome.

In fact, many researchers (including myself) believe that support intestinal health and restoring the integrity of the intestinal barrier is one of the most important goals of medicine of the 21st century.
There are two closely related variables that determine the health of our gut: the intestinal microflora, or "intestinal flora", and the barrier of the intestine.

Let's discuss each of these in turn.

The flora of the intestine: a healthy garden needs healthy soil.

In our gut is home to about 100,000,000,000,000 (100,000,000,000,000) microorganisms.
This is such a large number of the human brain, we can not understand it really.
An Account trillion if we wanted him stretch from one end to the other, would stretch from the earth to the sun - again-back to earth.
Do this by 100 times and you start to get a least vague idea of ​​how much is the 100 trillion.

The human gut contains 10 times more bacteria from all human cells, which are in the whole body, with over 400 known species of bacteria varied.
In fact, you could say that we are more bacteria than human.
Consider this one for a minute.