Article Text

Download PDFPDF

Probiotic L. gasseri strain (LG21) for the upper gastrointestinal tract acting through improvement of indigenous microbiota
  1. Yasuhiro Koga1,
  2. Toshihiro Ohtsu2,
  3. Katsunori Kimura2,
  4. Yukio Asami2
  1. 1Gastroenterology, Tokai University School of Medicine, Isehara City, Japan
  2. 2Food Microbiology Research Laboratories, Meiji, Hachiouji City, Japan
  1. Correspondence to Yasuhiro Koga; jpn.probio1998{at}


Objective To describe probiotics including a Lactobacillus gasseri strain LG21 used for the upper gastrointestinal tract, which are considered to act through improvement of indigenous microbiota inhabiting there.

Background and design Because the early definition of probiotics emphasized their effects on improving the intestinal microbial ecology, their effects on the intestinal tract and its immunity have been considered common general benefits associated with probiotics. This conclusion was also based on a body of successful clinical trials whose endpoints were the prevention or treatment of intestinal diseases. In contrast to intestinal microbiota, our understanding of the role of gastric microbiota in human health and physiology remains poor, as the bacterial load in the stomach is considered too small to exert a significant effect due to the highly acidic environment of the human stomach. Therefore, the intervention using probiotics in the stomach is still limited at present.Results:In this article using representative 38 quoted articles, we first describe the gastric microbiota, as the indigenous microbiota in the stomach is thought to be significantly involved in the pathophysiology of this organ, since probiotics exert their beneficial effects through improving the resident microbiota. We then review the present status and future prospects of probiotics for the treatment of upper gastrointestinal diseases by quoting representative published articles, including our basic and clinical data.

Conclusions Probiotics have been demonstrated to suppress Helicobacter pylori in the stomach, and are also expected to improve functional dyspepsia through the correction of dysbiotic gastric microbiota.

  • bacterial pathogenesis
  • gastric diseases
  • gastric function
  • helicobacter pylori
  • probiotics

This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (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, appropriate credit is given, any changes made indicated, and the use is non-commercial. See:

View Full Text

Statistics from


  • Contributors YK wrote the outline for the Introduction, Gastric microbiota and Future aspect sections, and is responsible for the overall content as the guarantor. TO wrote the section on Use for functional dyspepsia. KK wrote the sections on Development of a probiotic Lactobacillus strain for the suppression of H. pylori in human and on Gastric microbial community associated with the occurrence of gastric cancers. YA constructed the ground design of this article and wrote the section on Biological role of indigenous gastric microbiota.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient consent for publication Nor required.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement There are no data in this work. No data are available.

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.