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

July 17, 2014

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

A sodium surprise: Engineers find unexpected result during cardiac research

July 20, 2017
Irregular heartbeat—or arrhythmia—can have sudden and often fatal consequences. A biomedical engineering team at Washington University in St. Louis examining molecular behavior in cardiac tissue recently made a surprising ...

Want to win at sports? Take a cue from these mighty mice

July 20, 2017
As student athletes hit training fields this summer to gain the competitive edge, a new study shows how the experiences of a tiny mouse can put them on the path to winning.

Engineered liver tissue expands after transplant

July 19, 2017
Many diseases, including cirrhosis and hepatitis, can lead to liver failure. More than 17,000 Americans suffering from these diseases are now waiting for liver transplants, but significantly fewer livers are available.

Lunatic Fringe gene plays key role in the renewable brain

July 19, 2017
The discovery that the brain can generate new cells - about 700 new neurons each day - has triggered investigations to uncover how this process is regulated. Researchers at Baylor College of Medicine and Jan and Dan Duncan ...

'Smart' robot technology could give stroke rehab a boost

July 19, 2017
Scientists say they have developed a "smart" robotic harness that might make it easier for people to learn to walk again after a stroke or spinal cord injury.

New animal models for hepatitis C could pave the way for a vaccine

July 19, 2017
They say that an ounce of prevention is worth a pound of cure. In the case of hepatitis C—a disease that affects nearly 71 million people worldwide, causing cirrhosis and liver cancer if left untreated—it might be worth ...

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.