This review concerns important pediatric studies published from April 2013 to March 2014. New data on pathogenesis have demonstrated that Th1 type cytokine secretion at the gastric level is less intense in children compared with adults. They have also shown that the most significant risk factor for Helicobacter pylori infection is the parents' origin and frequency of childcare in settings with a high prevalence of infection. A new hypothesis on the positive relationship between childhood H. pylori infection and the risk of gastric cancer in adults has been suggested which calls for an implementation of preventive programs to reduce the burden of childhood H. pylori infection in endemic areas. Several studies have investigated the role of H. pylori infection in iron-deficiency anemia, and results support the role of the bacterium in this condition. Antibiotic resistance is an area of intense research with data confirming an increase in antibiotic resistance, and the effect of CYP2C19 genetic polymorphism on proton-pump inhibitor metabolism should be further investigated as cure rates are lower in extensive metabolizers. Studies confirmed that probiotic supplementation may have beneficial effects on eradication and therapy-related side effects, particularly diarrhea in children. PathophysiologyIn numerous studies, the influence of Helicobacter pylori virulence on the development of various diseases has been studied. Alvarez et al. [1,2] studied methylation of some genes predisposing to gastric cancer. They observed that THBS1 and GATA-4 were methylated already in the early stage of infection and are downregulated. HIC-1 demonstrated the lowest level of methylation and therefore, the main mechanism of downregulation has to be different. On the other hand, methylation of promotor regions of MGMT and MLH 1 depended on the duration of the infection. Nodular gastritis was very frequently associated with H. pylori infection in childhood. Nodular gastritis associated with H. pylori infection can commonly occur in childhood and is regarded as benign with no clinical significance. Yang et al. [3] analyzed gastric mucosa-associated lymphoid tissue (MALT) to clarify the significance of nodular gastritis in 80 H. pylori-infected children; histopathologic grading of MALT and immunohistochemistry were evaluated by CD3, CD20, cytokeratin, and Ki-67. On endoscopy, severe nodular gastritis was observed in 47% of the cases and mild gastritis in 34%; gastritis was absent in 19%. Density of H. pylori and lymphocyte infiltration differed among the 3 groups (p = .022 and .025, respectively) and histologic grading for gastric lymphoid infiltrates was compatible, with grade 1 in 59%, grade 2 in 26%, grade 3 in 9%, and grade 4-5 in 5%. The degree of nodular gastritis, density of H. pylori, neutrophil activity, and gastritis score in the antrum varied with MALT grades (p = .003, p = .042, p = .028, and p = .006, respectively). This study suggests that nodular gastritis may present as a significant gastric manifestation and that tho...