Helicobacter pylori and some aspects of gut microbiota in children

Abstract

Helicobacter pylori infection in children differs from infection in adults in many aspects. The rate of infection, epidemiology, clinical presentations and complications, the applicability of diagnostic tests, antibiotic resistance, treatment options, and success rates differ significantly. Due to all these differences, management guidelines for children and adults differ also substantially. In 2017, the Updated ESPGHAN and NASPGHAN Guidelines on the management of H. pylori infection in children were published, emphasizing the differences in clinical presentation and indications for treatment, stating that the primary goal of clinical investigation in children is to identify the cause of upper gastrointestinal symptoms rather than the presence of H. pylori infection. Therefore, the diagnosis should be based on upper endoscopy, and the "test and treat strategy" should not be used in children. Due to an increasing rate of antibiotic resistance worldwide, the updated guidelines recommend broader use of antimicrobial susceptibility testing for H. pylori strains in order to tailor eradication treatment accordingly. Moreover, treatment in children should be prescribed only when indicated and should be based on the rate of eradication in local populations aiming for treatment success above 90%. During the last two decades there has been a steady decrease in the rate of H. pylori infection in both children and adults in the Western world. Two recent publications studying the incidence of H. pylori infection confirmed that early childhood is a time for acquisition of infection both in industrialized and nonindustrialized countries. In addition, they showed that H. pylori could be acquired outside the family. In respect to the inverse association between H. pylori and allergy, a longitudinal study demonstrated that early exposure to H. pylori at any age was inversely associated with atopy and allergic conditions.

Helicobacter pylori virulence genes

“…In children, it is thought that environmental factors, such as smoking, are implicated in disease development to a far lesser degree than in adults. Whereas several factors influence the prevalence rates of H. pylori infection in children ( e.g ., gender, age, low socioeconomic status and family education, poor hygiene, household crowding and certain geographical regions), it has been shown that the infection is acquired in early childhood in both industrialized and non-industrialized countries[7]. The most frequent form of gastritis in children is nodular gastritis, while atrophic gastritis and intestinal metaplasia, which occur more often in adults, are relatively rarely found in children[7].…”

“…Whereas several factors influence the prevalence rates of H. pylori infection in children ( e.g ., gender, age, low socioeconomic status and family education, poor hygiene, household crowding and certain geographical regions), it has been shown that the infection is acquired in early childhood in both industrialized and non-industrialized countries[7]. The most frequent form of gastritis in children is nodular gastritis, while atrophic gastritis and intestinal metaplasia, which occur more often in adults, are relatively rarely found in children[7]. Because the degree of H. pylori colonization and repertoire of virulence genes are comparable in both children and adults, it is thought that the lower levels of gastric inflammation and lower rates of severe clinical outcome in children indicate downregulation of immune responses[8].…”

Phenotypic and Genotypic Analysis of Resistant Helicobacter pylori Strains Isolated from Children with Gastrointestinal Diseases

“…Extragastric complications, such as iron-deficiency anemia and immune thrombocytopenic purpura, may also occur [ 1 , 2 ]. Serious complications—including gastric cancer or mucosa-associated lymphoid tissue (MALT) lymphoma—may occur many years after primary infection and are associated with a chronic inflammation process that leads to angiogenesis and pathologic changes in the gastric mucosa [ 3 , 4 ]. The association between H. pylori infection and gastroesophageal reflux disease (GERD) or inflammatory bowel disease (IBD) is controversial.…”

Lack of association between Helicobacter pylori infection and childhood overweight/obesity

“…H. pylori decreases ghrelin secretion by decreasing the number of ghrelin producing cells in the stomach. Eradication of H. pylori resulted in increased levels of ghrelin in adults and children 13 . A recent study done on Mexican school children aged 5‐13 years found lower levels of leptin in H. pylori ‐infected children—0.54 ng/ml (95% CI −0.98 to −0.09), compared with uninfected children.…”

“…Previous studies investigating the association between H. pylori infection and obesity have shown inconsistent results. Most studies in children have found that H. pylori infection is associated with a decreased risk for obesity 7‐13 . Our aim was to evaluate the association between H. pylori infection and childhood overweight/ obesity in Israeli Children.…”