Helicobacter pylori: microbiology and interactions with gastrointestinal microflora.

Helicobacter pylori causes substantial morbidity and mortality, and the course of infection results from complex interactions between host, environmental and bacterial factors. It is generally accepted that H. pylori eradication is the best method of treatment for peptic ulcer disease and prevention of its complications. However, the antimicrobial agents used in eradication regimens cause various alterations in gastrointestinal microflora, which can lead to side effects affecting the patient's compliance. Moreover, antimicrobial therapy is responsible for increasing resistance not only in H. pylori but also in colonising microflora, and, therefore, alternative approaches to the treatment and prevention of H. pylori infection have been investigated.