People with gastroesophageal reflux disease (GERD) often suffer recurrent chest distress and commonly experience asthma symptoms. Normally, stomach acid forms a barrier between bacteria in your intestines and your esophagus, lungs and sinuses because bacteria are killed by stomach acid. Acid reflux can surpass this protective mechanism, especially if stomach acid is neutralized. When acid neutralizing you could look here drugs are used (PPIs, H2 blockers and even antacids), bacteria from the intestines are more likely to overgrow and survive in the small intestine and stomach. Reflux can cause these bacteria to enter the esophagus and potentially the lungs and sinuses. People on acid blocking meds are more susceptible to respiratory infections most likely from bacteria originating in their own intestines.
The prevalence of GERD in IBS patients (39%) and IBS in GERD patients (49%) is much higher than the prevalence of GERD (19%) or IBS (12%) in the general population indicating a relationship between the two conditions (17). IBS has been clearly linked to small intestinal bacterial overgrowth via hydrogen breath testing and, like GERD, has been treated successfully with carbohydrate restriction as well as antibiotics (18,19,20,21,22). This evidence is consistent with SIBO playing a role in both conditions.
Half of GERD patients taking PPI drugs showed evidence of SIBO by glucose breath testing compared to only 25% of IBS patients not taking PPIs. Eighty-seven to ninety percent of SIBO-positive patients (with GERD or IBS) showed improvement after antibiotic treatment (23). I believe the SIBO-positive results in both groups would have been higher if the study employed the lactulose breath test instead of the glucose breath test. Lactulose is not digested or absorbed in the small intestine and can detect bacteria (fermenting the lactulose and producing hydrogen) throughout the entire length of the small intestine. Glucose is rapidly absorbed in the first part of the small intestine and will only detect bacteria if they are present in this region. Dr. Pimentel found that 78 percent of IBS patients tested at the Cedars-Sinai Medical Center had SIBO as indicated by a positive lactulose breath test (18).
While a large diverse population of bacteria is healthy in the large intestine, relatively few bacteria should be present in our small intestine where our own critical nutrient absorption takes place. Normally, the numbers range from zero in the stomach and first part of the small intestine to about one million bacteria per milliliter (mL) in the last part of the small intestine where the large intestine begins. One million bacterial cells is actually a very small amount compared to the trillions in the large intestine.