Editorial
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 21, 2021; 27(47): 8040-8046
Published online Dec 21, 2021. doi: 10.3748/wjg.v27.i47.8040
Progress in elucidating the relationship between Helicobacter pylori infection and intestinal diseases
Shunji Fujimori
Shunji Fujimori, Department of Gastroenterology, Chiba Hokusoh Hospital, Nippon Medical School, Chiba 270-1694, Japan
Author contributions: Fujimori S contributed to the writing of this paper.
Conflict-of-interest statement: The author declares no conflict of interest.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Shunji Fujimori, AGAF, MD, PhD, Director, Department of Gastroenterology, Chiba Hokusoh Hospital, Nippon Medical School, 1715, Kamagari, Inzai, Chiba 270-1694, Japan. s-fujimori@nms.ac.jp
Received: May 26, 2021
Peer-review started: May 26, 2021
First decision: June 17, 2021
Revised: June 30, 2021
Accepted: December 7, 2021
Article in press: December 7, 2021
Published online: December 21, 2021
Processing time: 204 Days and 20.1 Hours
Abstract

Helicobacter pylori (H. pylori) infection causes changes to the intestinal flora, such as small intestinal bacterial overgrowth, and increases gastric acid secretion-stimulating gastrointestinal hormones, mainly gastrin, due to a decrease in gastric acid caused by atrophic gastritis. In addition, the cellular components of H. pylori travel through the intestinal tract, so the bacterial infection affects the immune system. Therefore, the effects of H. pylori infection are observed not only in the stomach and the proximal duodenum but also in the small and large intestines. In particular, meta-analyses reported that H. pylori-infected individuals had an increased risk of colorectal adenoma and colorectal cancer. Moreover, a recent study reported that the risk of developing colorectal cancer was increased in subjects carrying H. pylori vacuolating cytotoxin A antibody. In addition, it has been reported that H. pylori infection exacerbates the symptoms of Fabry’s disease and familial Mediterranean fever attack and is involved in irritable bowel syndrome and small intestinal ulcers. On the other hand, some studies have reported that the frequency of ulcerative colitis, Crohn’s disease, and celiac disease is low in H. pylori-infected individuals. Thus, H. pylori infection is considered to have various effects on the small and large intestines. However, few studies have reported on these issues, and the details of their effects have not been well elucidated. Therefore, additional studies are needed.

Keywords: Helicobacter pylori; Intestine; Colorectal cancer; Intestinal bacterial overgrowth; Inflammatory bowel disease; Intestinal ulcer

Core Tip: Helicobacter pylori (H. pylori) infection causes abnormalities in the intestinal flora and increases gastric acid secretion-stimulating gastrointestinal hormones. In addition, the cellular components of H. pylori travel through the intestinal tract, causing an effect of bacterial infection on the immune system. Meta-analyses reported that colorectal adenoma and cancer increase in H. pylori-infected individuals, and this bacterium has also been reported to be involved in several other diseases. On the other hand, H. pylori infection is considered to suppress inflammatory bowel disease. However, few studies have reported on these issues, and further elucidation is required.