Helicobacter pylori infection causes both protective and deleterious effects in human health and disease

Abstract

Infection with Helicobacter pylori (H. pylori) is necessary but not sufficient for the development of gastric cancer, the third leading cause of cancer death globally. H. pylori infection affects over half of people globally; however, it does not affect populations uniformly. H. pylori infection rates are declining in Western industrialized countries but are plateauing in developing and newly industrialized countries where gastric cancer is most prevalent. Despite H. pylori infection being the primary causative agent for gastric cancer, H. pylori infection can also cause other effects, detrimental or beneficial, throughout an individual’s life, with the beneficial effects often being seen in childhood and the deleterious effects in adulthood. H. pylori is an ancient bacterium and its likelihood of affecting disease or health is dependent on both human and bacterial genetics that have co-evolved over millennia. In this review, we focus on the impact of infection and its genetic bases in different populations and diseases throughout an individual’s lifespan, highlighting the benefits of individualized treatment and argue that universal eradication of H. pylori in its host may cause more harm than good for those infected with H. pylori .

Gastrointestinal microbiome and Helicobacter pylori: Eradicate, leave it as it is, or take a personalized benefit–risk approach?

“…We join the opinion of Chen et al [ 7 ] that the decision to eradicate H. pylori should be based on an assessment of the benefit–risk ratio for the individual patient. We also support the position of Miller and Williams[ 44 ] that “universal eradication” of H. pylori may cause more harm than good for the infected persons. Thus, the current guidelines based on the unconditional “test-and-treat” strategy[ 31 ] should be revised, including to reduce the excessive number of indications for eradication and to avoid empirical eradication therapy without a previous diagnostic test for H. pylori infection.…”

Evolutionary Medicine Perspectives: Helicobacter pylori, Lactose Intolerance, and 3 Hypotheses for Functional and Inflammatory Gastrointestinal and Hepatobiliary Disorders

“…Some extragastric disorders are associated with infection with variable levels of evidence, including iron and vitamin B 12 deficiency anemias, immune thrombocytopenia, and some skin and neurological diseases. However, inverse associations of infection include gastroesophageal reflux disease, Barrett's esophagus, esophageal and esophagogastric junction adenocarcinoma, childhood allergic conditions, and inflammatory bowel disease (IBD) (13)(14)(15)(16). The possibility of unmeasured confounders notwithstanding, these diverse associations suggest evolutionary trade-offs.…”

Advances in the Aetiology & Endoscopic Detection and Management of Early Gastric Cancer

“…Holcombe paid attention to the high prevalence of Helicobacter pylori infection in countries with low gastric cancer rates, which he called “African Enigma” [ 103 ]. The so-called “African enigma” (African, Asian, Mid-East, Indian, Malaysian, Costa Rican, Colombian enigmas) stated that gastric Helicobacter pylori infection is common in Africa, Mid-East Asia and some parts of Central and South America, but the pattern of infection, age of acquisition, environmental, dietary, and genetic influences are different from those observed in the West, and therefore the role of Helicobacter pylori is altered in this population [ 103 , 104 , 105 , 106 ]. One of the explanations for this was the Th1-Th2 CD4+ T-lymphocytes shift due to a high prevalence of parasitic infections [ 107 , 108 , 109 ].…”