In a systematic review of six in-person trials in Asian populations, the Cochrane Upper GI and Pancreatic Diseases Group showed that antibiotics given to individuals testing positive for Helicobacter pylori decreased the likelihood of those individuals developing gastric neoplasias (cancers).

Early gastric cancer in the gastric body, stained with indigo carmine Public domain image/Med_Chaos
Early gastric cancer in the gastric body, stained with indigo carmine
Public domain image/Med_Chaos

H.pylori is a gastric bacterium that can cause peptic ulcers and cancers in many individuals.  First discovered in humans by Dr. Robin Warren in 1979, H. pylori was shown by Dr. Barry Marshall in 1981 to cause not only ulcers but gastric tumors, both of which could be relieved by a single course of general antibiotics (ridiculed for this seeming hoax, Dr. Marshall gave himself an H. pylori-induced peptic ulcer and cured it with antibiotics to prove his point; the doctors would end up sharing the 2005 Nobel Prize in Physiology or Medicine for their work).

These current trials recruited 6,497 Asian individuals who tested positive for an H. pylori infection, but were otherwise healthy.  Of the 3,294 people randomly assigned to take antibiotics, only 51 developed gastric cancers, whereas 76 of the 3,203 assigned placebo developed gastric cancers.  Translated, the results mean individuals receiving treatment, which included acid suppressant therapies, were 34% less likely to develop H. pylori-induced cancers.  In another trial looking at esophageal cancers, patients receiving placebo were twice as likely to develop cancer compared to those receiving treatment.

While this points to a positive effect by antibiotics, “[t]he review highlights the need for further trials in different populations to provide more evidence, and these should report both the benefits and harms of such an approach,” said lead author Alexander Ford, MBChB, MD, from St. James’s University Hospital and Leeds University in the United Kingdom.  Though eradication of H. pylori has been clinically proven to reduce gastric ulcers and cancers, a maintained infection actually decreases the likelihood of children developing allergies and asthma, as well as the severity of Barrett’s esophagus and gastroesophageal reflux disease.  Plus, the addition of broad spectrum antibiotics to a maintained system could decrease the prevalence of beneficial bacteria, allowing pathogens such as Clostridium difficile to gain a foothold in the gastrointestinal tract.

Though much maligned, H. pylori infection is asymptomatic in the majority of cases.  Since more than 50% of the world’s population is infected more research is still needed to determine when to eliminate the infection and when to leave the patient, and their gastrointestinal system, alone.

Edward Marks is a PhD student at the University of Delaware.  His research involves the healing of myocardial tissue after major cardiac events using nanomedicine techniques, with the goal of pushing any advancement directly into the clinic.  Edward received his BS from Rutgers University and Masters from the University of Delaware.