A special issue on Helicobacter pylori has been published by Landes Bioscience (Austin, TX USA). The articles contained in this special issue of the journal Gut Microbes have been authored by world-class investigators and provide new insights into the pathophysiology, diagnosis, prevention, and treatment of this microbe.

Helicobacter pylori is a gram-negative, microaerophilic bacterium found in the stomach. Identified in the early 1980s, it was shown to be present in patients with chronic gastritis and gastric ulcers, conditions that were not previously believed to have a microbial cause. It is also linked to the development of duodenal ulcers and stomach cancer. However, in over 80% of carriers, H. pylori does not cause symptoms and it has been suggested that the bacterium may play an important role in the natural stomach ecology. H. pylori is the most common bacterial infection worldwide, with more than half of the world's population harboring the bacterium in the upper gastrointestinal tract. While incidence is decreasing in Western countries, H. pylori infection is highly prevalent in developing countries. In the absence of targeted antimicrobial therapy, colonization typically lasts for decades.

Dr Richard Peek from Vanderbilt-Ingram Cancer Center and Cancer Biology (Nashville, TN USA) has worked with the editorial team of Gut Microbes to organize this special issue on H. pylori. Papers in the issue discuss the role of childhood infection in the sequelae of H. pylori disease (Guillermo Perez-Perez), how glyco-conjugates promote virulence of H. pylori (M Stephen Trent), interplay of various H. pylori factors with host protein receptors (Steffen Backert), the role of chronic inflammation and oxidative stress in H. pylori induced gastric cancer (Keith T Wilson), diet, microbial virulence, and H. pylori induced gastric cancer (Timothy L Cover), consequences of H. pylori infection in children in developing countries (Jean E Crabtree), role of the gastrointestinal microbiome in H. pylori pathogenesis (James G Fox), biomarkers of H. pylori associated gastric cancer (Jay V Solnick), H. pylori therapies in light of evolving resistance (Francis Mégraud), benefits of H. pylori treatment in childhood (Karen J Goodman), vaccination against H. pylori (Steven J Czinn), and a study investigating the influence of H. pylori on hepatitis C virus-associated liver cancer.

In an accompanying editorial, Dr Peek highlights the importance of understanding the relationship between H. pylori infection and carcinogenesis. He writes, "Delineation of bacterial, host, and environmental mediators that augment gastric cancer risk has profound ramifications for both physicians and biomedical researchers, as such findings will not only focus prevention approaches that target H. pylori-infected human populations at increased risk for stomach cancer, but will also provide mechanistic insights into inflammatory carcinomas that develop beyond the gastric niche."