**10. Benefits of eradication therapy**

Peptic ulcer disease: Eradication therapy heals most cases of PUD and greatly diminishes the risk of recurrent bleeding. A systematic review found that eradication therapy is more effective than antisecretory therapy without eradication in preventing recurrent bleeding [8, 14].

Uninvestigated dyspepsia: It is one of the indications for the diagnosis and treatment of *H. pylori* infection according to ACG guidelines. Studies have shown that the "test and treat" strategy is cost-effective and useful compared to acid-suppressive treatment in patients with uninvestigated dyspepsia. However, it is not effective in patients aged above 55 with alarm symptoms and is subject to regional *H. pylori* prevalence [14].

Functional dyspepsia or non-ulcer dyspepsia (FD): A Cochrane systematic review published in 2006 showed a small but statistically significant benefit of treating *H. pylori* infection in patients with FD, with a number needed to treat (NNT) of 14 [14].

Chronic atrophic gastritis (CAG): *H. pylori* infection is the most common cause of atrophic gastritis (AG). Multiple studies had demonstrated a strong relationship between *H. pylori* infection and the development of chronic atrophic gastritis [4]. Based on a meta-analysis, the rate ratio of AG incidence in patients with vs. without *H. pylori* infection was 5.0 (95% CI 3.1–8.30), and AG incidence was very low (<1% annually) among *H. pylori* uninfected individuals, supporting the strong relationship between *H. pylori* and AG [4]. CAG is a precancerous condition that can progress to dysplasia, and gastric cancer (GC). The rate of progression of AG to adenocarcinoma is 0.1–0.3% per year but may be higher depending on AG severity, extent, concomitant IM, and other factors The vast majority of patients with AG have evidence of current or past *H. pylori* infection [4]. Therefore, eradication of *H. pylori* is of utmost importance among anyone infected. Successful treatment and eradication of *H. pylori* can lead to the restoration of normal gastric mucosa in some patients [4]. Although not all cases show improvement, numerous studies have demonstrated a significant reduction in the risk of gastric cancer associated with *H. pylori* eradication [4].

MALT lymphoma: MALT lymphoma is now largely supplanted by marginal zone B cell lymphoma of MALT type. For patients with MALT lymphoma who have *H. pylori* infection, studies have shown that the tumor regresses in 60–93% of patients after eradication. However, the response can be inconsistent, with some patients showing a delayed response or experiencing tumor relapse within one year of treatment [14].

Early gastric cancer: Studies have shown that the incidence of metachronous gastric cancer following endoscopic resection of gastric neoplasm was reduced following eradication therapy [14].

NSAIDs: *H. pylori* is an independent risk factor for NSAID-induced ulcers and ulcer-like bleeding. Eradication of *H. pylori* before starting NSAID treatment reduces the development of ulcers and the risk of ulcer bleeding, with a 57% reduction in the incidence of peptic ulcers. The benefits are most prominent in NSAIDnaive patients [14].

Asymptomatic individuals and gastric cancer: Evidence suggests that eradication reverses the gastric premalignant changes of gastric atrophy and intestinal metaplasia, although conflicting findings exist. However, studies have shown that the incidence of gastric cancer among asymptomatic individuals is reduced after eradication therapy vs. placebo or no treatment, with an NNT of 124. The estimated benefit in the population with a high risk of gastric cancer will be higher, with an estimated NNT of 15 [14].

Iron deficiency anemia (IDA): Adults with iron deficiency anemia benefit from combining iron treatment with eradication treatment, resulting in an increase in hemoglobin (Hb), serum iron, and serum ferritin levels (p-value 0.00001) [14].

Idiopathic thrombocytopenic purpura (ITP): There is limited evidence from both randomized and nonrandomized trials that there is sustained improvement in platelet count after eradication of *H. pylori* in a proportion of adults with ITP. The American Society of Hematology suggests screening for *H. pylori* infection in adults with ITP and offering eradication therapy if they test positive for an active infection [14].
