SIBO Small Intestine Bacterial Overgrowth

Small Intestinal Bacterial Overgrowth (SIBO) is a condition the occurs, when bacteria and pathogens are allowed to enter the small bowel and proliferate.

In a normal healthy body, nutrients enter the stomach and are mixed with Hydrochloric acid (HCL), Pepsin and a host of other enzymes.  The HCL maintains a sterile environment, in the stomach, by destroying bacteria and pathogens, before they can enter the small bowel.  The strong acid also breaks down nutrients, into a thick sticky mass, called Chyme.  The strong acid also assists the Peptic enzymes, in the conversion of proteins.  Pepsin breaks down proteins into proteoses and peptones, which are the building blocks for the Amino acids.  Pepsin is most active in the conversion, of proteins, when the strength of the acid is at 1.0 pH. The sterilized and converted nutrients now, pass into the duodenum (upper small bowel), where the excess acid is neutralized, by fluids from pancreas and liver.  Because the nutrients are sterilized, broken down and converted, bacteria in the small bowel is kept in check. Now vitamins, minerals and micro-nutrients are readily absorbed in the small bowel. This is a basic illustration of how the body maintains a proper balance and keeps bacteria in check.

When the strength of the hydrochloric acid diminishes, there is less sterilization and less protein conversion, in the stomach.  The weak hydrochloric acid prevents the Peptic enzymes from properly converting the incoming proteins. The reduction in the strength of the hydrochloric acid is called Hypochlorhydria, or in extreme cases it is called Achlorhydria.  When nutrients enter the stomach, they are not completely broken down, as they were in a healthy body.  There is reduced sterilization and bacteria are not completely destroyed. Pepsin is no longer converting all the proteins, because the HCL is not strong enough. Many proteins are allergens and will cause allergic reactions, when they enter the small bowel. Bacteria that are normally destroyed in a healthy body, will enter the alkaline fluids of the small bowel and start to proliferate, causing bacterial overgrowth.

What causes of Bacterial Overgrowth in the small bowel? Malabsorption is the primary cause of bacterial overgrowth and diminished vitamin and mineral absorption.   Hypochlorhydria and Achlorhydria are caused by aging, the use of antibiotics, antihistamines, Proton Pump Inhibitors (PPI), excessive alcohol consumption and a host of other chemical medications. Use of these medications stop the acid producing cells (parietal cells), in the stomach, from producing acid. The lack of strong hydrochloric acid (hypochlorhydria), in the stomach, will cause malabsorption, and allow bacterial overgrowth, in the digestive tract.  Hypochlorhydria and Achlorhydria can also be caused by certain viruses, like HIV.  Hypochlorhydria and Achlorhydria can be easily diagnosed with a pH diagnostic test, pH gastrogram, or pH capsule test.  For more info go to