How Helicobacter pylori identifies and colonizes sites of small injury in the stomach

July 17, 2014, Public Library of Science

Helicobacter pylori infection promotes stomach ulcers and cancer. How H. pylori initially interacts with and irritates gastric tissue is not well understood. An article published on July 17th in PLOS Pathogens now describes that H. pylori rapidly identifies and colonizes sites of minor injuries in the stomach, almost immediately interferes with healing at those injury sites, and so promotes sustained gastric damage.

Smoking, alcohol, excessive salt intake, and non-steroidal anti-inflammatory drugs cause damage to the tissue lining the stomach, and are associated with . A team of scientists led by Marshall Montrose, from the University of Cincinnati, USA, asked whether H. pylori can sense and respond to such damage and so contribute to disease development.

The researchers induced small stomach lesions in anesthetized mice and observed that H. pylori bacteria can rapidly detect the injury site and navigate toward it. Within minutes, accumulation of bacteria interferes with repair of the —and these results are the earliest indication showing H. pylori causing disease.

To examine how the bacteria accomplish this, the researchers also studied mice with larger stomach lesions (ulcers) that were subsequently infected with H. pylori. They found that H. pylori preferentially colonizes stomach tissue at injured ulcer sites, and there impairs healing of the damaged tissue. Selective colonization requires both bacterial motility and chemotaxis (the ability to change direction of movement in response to environmental cues), and higher levels of bacterial accumulation cause slower healing. However, when extremely high levels of immotile or chemotaxis-deficient bacteria are added to damaged tissue, they can also slow healing. As the researchers explain, "it's like a tag team race. Chemotactic machinery guides H. pylori into the damage site to colonize, and then other virulence factors take over to make sure the site stays just as tasty in the long term by slowing repair of any damage".

While the signals that attract H. pylori (but not benign stomach bacteria) toward injured tissue are not yet known, the researchers hope that their ability to rapidly measure H. pylori accumulation at the injured site now provides an experimental set-up to determine the factor(s) involved.

"The broader implications of our work", the researchers say, "are that even subclinical insults to the stomach that occur in daily life (damage from grinding of food, ingestion of alcohol, taking an aspirin) can potentially attract H. pylori and not only slow repair of any existing damage, but maybe also provide an initiation site that can start the pathogenic sequence of more severe diseases caused by H. pylori".

Explore further: Does your stomach bacteria protect you from obesity?

More information: Aihara E, Closson C, Matthis AL, Schumacher MA, Engevik AC, et al. (2014) Motility and Chemotaxis Mediate the Preferential Colonization of Gastric Injury Sites by Helicobacter pylori. PLoS Pathog 10(7): e1004275. DOI: 10.1371/journal.ppat.1004275

Related Stories

Does your stomach bacteria protect you from obesity?

June 2, 2014
The germ Helicobacter pylori is the cause of most stomach ulcers, but new research in Alimentary Pharmacology & Therapeutics suggests that treating the bacteria is linked to weight gain.

Stomach bacteria switch off human immune defences to cause disease

September 1, 2013
Helicobacter pylori is a bacterium that establishes a life-long stomach infection in humans, which in some cases can lead to duodenal ulcers or stomach cancer. New research, presented at this week's Society for General Microbiology ...

Other stomach microbiota modulate resistance to H. pylori-driven ulcers

March 25, 2013
Mice with different naturally occurring stomach bacteria have distinct susceptibilities to disease caused by Helicobacter pylori, the well-known cause of ulcers in humans, according to a study published online ahead of print ...

Some bacteria may protect against disease caused by stomach infection

March 12, 2013
Half of the world's human population is infected with the stomach bacteria called Helicobacter pylori, yet it causes disease in only about 10 percent of those infected. Other bacteria living in the stomach may be a key factor ...

Researchers discover novel protein complex with potential to combat gastric cancer caused by bacterial infection

July 4, 2014
A team of scientists from the Cancer Science Institute of Singapore (CSI Singapore) at the National University of Singapore (NUS) discovered that a protein named IL23A is part of our stomach's defence against bacterial infection ...

Recommended for you

Researchers illustrate how muscle growth inhibitor is activated, could aid in treating ALS

January 19, 2018
Researchers at the University of Cincinnati (UC) College of Medicine are part of an international team that has identified how the inactive or latent form of GDF8, a signaling protein also known as myostatin responsible for ...

Bioengineered soft microfibers improve T-cell production

January 18, 2018
T cells play a key role in the body's immune response against pathogens. As a new class of therapeutic approaches, T cells are being harnessed to fight cancer, promising more precise, longer-lasting mitigation than traditional, ...

Weight flux alters molecular profile, study finds

January 17, 2018
The human body undergoes dramatic changes during even short periods of weight gain and loss, according to a study led by researchers at the Stanford University School of Medicine.

Secrets of longevity protein revealed in new study

January 17, 2018
Named after the Greek goddess who spun the thread of life, Klotho proteins play an important role in the regulation of longevity and metabolism. In a recent Yale-led study, researchers revealed the three-dimensional structure ...

The HLF gene protects blood stem cells by maintaining them in a resting state

January 17, 2018
The HLF gene is necessary for maintaining blood stem cells in a resting state, which is crucial for ensuring normal blood production. This has been shown by a new research study from Lund University in Sweden published in ...

Magnetically applied MicroRNAs could one day help relieve constipation

January 17, 2018
Constipation is an underestimated and debilitating medical issue related to the opioid epidemic. As a growing concern, researchers look to new tools to help patients with this side effect of opioid use and aging.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.