The human body is designed to function optimally when homeostasis (balance) is maintained. SIBO is a prime example of what happens when balance is lost in the GI tract mainly related to disruption of the built-in defense mechanisms that were intended to protect against bacterial overgrowth. These mechanisms include stomach acid, intestinal motility, an intact valve at the junction of the small and large intestines, antimicrobial properties of liver and pancreas secretions, and immunoglobulins (antibodies) within intestinal secretions.
The causes of SIBO are usually multiple factors, each of which in some way impair the protective antibacterial mechanisms. These factors include, but are not limited to, low stomach acid, inadequate pancreatic enzyme production, immune deficiencies, impaired motility of the small intestine, and disruption of the normal bacterial balance in the stomach, small intestine, or colon. There are diseases that predispose a person to SIBO including liver, pancreas, lung, and bowel diseases including atrophic gastritis, cystic fibrosis, cirrhosis and other liver diseases, HIV/AIDS, Crohn’s, diverticulitis, and celiac disease. In addition to this, there are many medical and surgical treatments that further dispose someone to the development of SIBO: antibiotics, proton pump inhibitors (such as Prilosec and the like), prior gastrointestinal surgery, radiation, chemotherapy, oral contraceptives, and the list goes on and on. Furthermore, advancing age itself raises the possibility of developing SIBO.
In the case of the association of some diseases with the presence of SIBO, the big question becomes: Which came first? Did the disease cause the SIBO or did the SIBO cause the disease? This question is being worked out in various ways and some of the preliminary data is fascinating. It is now beginning to appear that there a a number of “disease states” that may be a result of an imbalance in gut bacteria. Hypothetically at this point there appears to be a gradual progression of bacterial imbalances in the gut that at least play a role in the development of diseases such as Alzheimer’s, Parkinson’s, autoimmune diseases, Crohn’s and Ulcerative colitis. That’s not to say that everyone who has one of these diseases will have SIBO, but it is worth looking into. Like old Hippocrates said so long ago (and he wasn’t far off): “All disease begins in the gut.” Focus on getting the gut healthy first, and a lot of other health issues will improve as a result!