Review article: should we kill or should we save Helicobacter pylori?

Results from epidemiological studies and therapeutic clinical trials have s hown that Helicobacter pylori infection causes acute and chronic active gas tritis and is the initiating factor for the majority of peptic ulcer diseas e. Eradication of the infection with antibiotics resolves gastritis and res tores normal gastric physiology, accelerates healing of peptic ulcer diseas e, and virtually eliminates recurrence of duodenal ulcer disease. The infection also plays an important role in the initiation and/or progres sion of gastric atrophy and intestinal metaplasia, which may eventually lea d to the development of distal gastric cancer. Furthermore, almost all pati ents with gastric MALT lymphoma are infected with H. pylori and cure of the infection leads to histological regression of the tumor and maintains the regression in over 80% of patients during long-term follow-up. Preliminary uncontrolled data from Japan show that eradication of the infec tion significantly reduced metachronous intestinal-type gastric cancer foll owing initial endoscopic resection of early gastric cancer and might also p revent the progression of gastric adenoma to gastric dysplasia or gastric c ancer. Although this overwhelming evidence has demonstrated that H. pylori infecti on is bad for humans, some have questioned the wisdom of eradicating the in fection in all those infected. Their arguments are largely based on hypothe sis and circumstantial. evidence: 1) Less than 20% of all H. pylori infecte d persons will develop significant clinical consequences in their lifetime. 2) H. pylori strains are highly diverse at a genetic level and are of diff erent virulence. 3) The antiquity of H. pylori infection in humans and thei r coevolution suggests that H. pylori may be a commensal to humans. Eradica tion of H. pylori may remove some beneficial bacterial strains and may prov oke esophageal disease or gastric cancer at the cardia. However, careful review of the literature confirms that H. pylori infection is a serious pathogen albeit in a minority of those infected. It remains f or carefully designed prospective studies, rather than hypothesis to make c hanges in the current consensus position.