Helicobacter heilmannii (H heilmannii) infection may be the underlying cause of chronic gastritis among patients with dyspepsia, especially those in close contact with domestic animals, according to study findings published in Microbial Pathogenesis.

Iranian researchers conducted a systematic review and meta-analysis of the literature, searching PubMed, Scopus, Embase, Google Scholar, and ISI Web of Science up until February 2022. Out of 617 articles identified, the researchers selected 27 studies performed globally between 1991 and 2020 for inclusion in the analysis.

The primary objective was to ascertain the frequency of H heilmannii colonization in patients with gastritis and dyspepsia. Additionally, researchers analyzed the histological characteristics of patients who exhibited concurrent Helicobacter pylori (H pylori) and H heilmannii colonization.


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Following statistical analysis, patients with upper gastrointestinal symptoms demonstrated a 1.9% overall prevalence of H heilmannii infection (95% CI, 0.8-4.2; I2=99.11; P =.01). When analyzing H heilmannii infection by location, the researchers observed an increased prevalence of 3.1% in Asian populations (95% CI, 1.2-7.5; I2=98.14; P =.01) compared with 1.2% prevalence in Western populations (95% CI, 0.3-4.8; I2=99.41; P =.01).

Most patients infected with H heilmannii reported a history of contact with dogs and cats, reinforcing the evidence that animals transmit these bacteria to humans. Around 5% to 6% of patients with gastritis were likely to have H heilmannii infection, unlike patients with peptic ulcers or gastric MALT lymphoma (P =.01).

Coinfection with H heilmannii and H pylori occurred at a frequency of 15.4% (95% CI: 5.2-37.6; I2=64.01; P =.01). In these studies, while both H pylori and H heilmannii colonized the antrum, H pylori patterns were more diffuse with greater density, causing increased lymphocytic infiltration of the gastric lumen compared with H heilmannii. Correspondingly, patients with H heilmannii gastritis typically exhibited a less severe, more chronic course of infection than H pylori gastritis.

Although typically used to treat H pylori infections, standard triple therapy (consisting of amoxicillin, either levofloxacin or clarithromycin, and a proton pump inhibitor) also proved effective in resolving H heilmannii infections without recurrence.

“These findings are useful in all aspects of the epidemiology, diagnosis, and pathogenesis of H heilmannii infection,” the study authors wrote. “However, future investigation is essential to determine the role of H heilmannii specific virulence factor as well as expression of genes involved in pathogenesis.”

Study limitations included small population size, small number of studies, heterogeneity, lack of access to raw data, and differing methods to detect H heilmannii infection.

Reference

Keikha M, Karbalaei M. Clinical aspects of Helicobacter heilmannii-associated gastritis in patients with dyspepsia: A systematic review and meta-analysis. Microb Pathog. 2022;166:105518. doi:10.1016/j.micpath.2022.105518

This article originally appeared on Gastroenterology Advisor