It’s called “the gut,” also known as the gastrointestinal (GI) tract or the digestive tract. It is essentially a long tube made up of layers of muscle lined by cells and glands imbedded in a mucous lining. The job of the gut is to ingest food, digest it, absorb nutrients, and to excrete waste products. The digestive system works hard. It is pressed into service every time we eat. In fact, over the course of a lifetime, it will digest some 23,000 pounds of solid food.
There are numerous organs involved in the digestive process: mouth, esophagus, stomach, small and large intestines, anus, gallbladder, liver and pancreas. These last three organs are located outside the digestive tube or tract, but still play an important role in digestion. Should something go wrong with any of the digestive organs, the process of digestion becomes impaired. Nutritional status and overall health are then adversely affected.
This happens more often than we might suspect. More people are hospitalized for GI disorders than for any other, and more than 100 million Americans are reported to have digestive disorders. The health of the digestive system impacts the health of the rest of the body. When digestion is not optimal, whether from a recognized digestive disorder, inadequate diet, or even a silent digestive imbalance, the rest of the body not only misses out on vital nutrients, but it also receives toxins that can adversely affect many different areas of the body. The many gut connections to overall health highlighted in this book illustrate just how important digestive health is.
In the process of digestion, food is converted into fuel, or energy, to run the body. Large pieces of food are broken down physically (through chewing) and chemically (through enzyme activity) into microscopic particles, so that they are small enough to cross the cell membranes of the gut and enter the bloodstream. Any glitch in the digestive conversion process short-circuits the body’s energy supply, and can have far-reaching effects on health.
Before looking at what can go wrong in the process, let’s look at what a properly functioning system does and how it works.