This is fascinating considering my ongoing medical indoctrination. We have just been taught what a bad guy H. pylori is. Allopathic medicine say that if someone tests positive for it, the bug should be immediately destroyed using antibiotics. Dr. David Johnson of Eastern Virginia Medical School (on Medscape) informed me today that H. pylori is beneficial to the host in at least 3 ways. In the last SIX WEEKS three articles have been published in GUT that indicate that H. pylori 1) decreases risk of Barrett's esophagus by 70% 2) decreases risk of adenocarcinoma by 50%, and 3) is inversely correlated with atopy in children, especially asthma (NYU Langone Med Ctr study). Another study questions the possibility that introducing the bacteria might confer improved resistance to influenza.
H. pylori has been living in human guts for at least 50,000 years, and we have a well established relationship with the bug. Yes, it is correlated with ulcers and gastric cancer in adults over 30---in people with terrible diets and generally poor health, ie, Americans. Not that long ago 70-90% of children had H. pylori growing in their bellies. Now the number is more like 5-10%. Considering the inverse relationship with atopy, it is no surprise that childhood asthma numbers are climbing. Asthma rates in the US for kids under 17 jumped from 3.6% in 1980 to 8.9% in 2005.
The NY researchers report in The Journal of Infectious Diseases that kids aged 3-13 are 59% less likely to have asthma and 69% less likely to have hay fever and other childhood allergies if they test positive for H. pylori. They're thinking about introducting the bacteria to kids who don't have it!
H. pylori is normally acquired from close contact with parents and siblings. In the atopy study (in the US) only 5% of kids under 10 tested positive for H. pylori, while the majority of kids in developing nations test positive. This difference is probably due to many factors including cleaner water and living conditions, and the widespread juse of antibiotics.
Another study found that kids with IBS are less likely to have H. pylori.