digestion and immune system info

The Digestive – Immune System Connection

It has long been noted that to have a strong immune system, there first must be a healthy digestive system. These two systems used to be thought of as separate entities. Now, through research, an intimate connection between the two has been discovered.

When we think of the digestive system, we think of it as a series of organs that help us digest food. This is partially correct. Actually much more happens within this system. Digestion starts in the mouth and ends in the rectum. When you boil it down, it’s one long “tube." Within that “tube," food is taken in, broken down, and then excreted. Lining this “tube" is a multitude of beneficial bacteria, immune cells, and secretions. Food and liquids spend anywhere from 15-30 hours along any one portion of this system. It’s the only place in the body where the outside world interacts with the inside world. For that reason alone, there has to be a protective mechanism in place to ward off invaders. This is where the immune system comes into play.

Within the mouth live immune factors known as secretory immunoglobulin A (sIGa). These “fighters" await any invader or microbe not welcomed in the body. Once activated, this sIGa contacts other immune mediators and attacks the invader or microbe.

As we make our way down the digestive system to the stomach, we find another host of fighters, the gut flora. This flora or bacteria are natural inhabitants of the digestive system. They help digest food, but also, help keep a close eye on the general environment of the system. It is astounding how many bacteria are found in the digestive system. If you were to weigh the entire flora population in the digestive system, it would weigh upwards of 9 pounds, in a healthy adult. There are actually more bacteria in the digestive system than there are cells in the body. This complex array of bacteria is crucial for healthy maintenance of the digestive lining. Without them, the stomach and the rest of the digestive system may become susceptible to opportunistic bacteria. These opportunistic bacteria, like Candida Albicans, can offset the natural balance of bacteria and cause havoc to the system.

The amount of healthy bacteria in the digestive tract can be reduced by :
  • Exposure to many rounds of antibiotics
  • Limited amounts of fresh fruits and vegetables
  • High amounts of saturated fatty foods
  • Smoking
  • Stress
If you have any of the above challenges, then your digestive system may not be functioning at its optimal level.

Studies have been done linking imbalanced healthy flora to asthma and allergies. Once normal balance has been re-established within the system, optimal health can be attained. Some factors that can help restore this healthy balance are the following:

  • Supplementing with good probiotics
  • Eating a high-quality, low-sugar yogurt
  • Eating fermented foods
  • Eating fresh fruits and vegetables
  • Decreasing stress levels

Comprehensive lab testing and lifestyle counseling from a certified, clinical nutritionist and other healthcare providers can help uncover digestive issues before they become symptomatic. Dietary counseling along with lifestyle counseling can help treat the digestive system and strengthen the whole body.

written by,

Dr. Seth Pearl

© 2009 Hemorrhoid Information Center


Snoeck V, Peters I, Cox E (2006). “The IgA system: a comparison of structure and function in different species”. Vet. Res. 37 (3): 455–67; Psychology Today

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