By Jennifer J Brown, Ph.D.
The bug that causes 80 percent of gastritis and many ulcers, H pylori, is one of the most common bacterium around, and H pylori infection can even lead to stomach cancer or lymphoma.
But not everyone gets sick from having these bacteria in the gut, and researchers have been working to demystify H pylori and understand what helps some people stay healthy while others get sick. Turns out that some people may be protected from infection by a gene, finds a new study reported in the medical journal JAMA.
To find the gene linked to getting an H pylori infection, Julia Mayerle,MD, and other researchers at the University of Medicine Greifswald in Germany did two large studies, one in Germany and the other in the Netherlands. Together they included 2,763 patients with H pylori infection whose DNA were compared to 8,175 people without infection. They also looked at the activity of the genes in patients’ blood. The differences they found allowed scientists to identify a gene linked to the infection. Called TLR1, the gene is for a receptor on the surface of people’s cells. TLR genes are involved with our immunity against infections. TLR1 may act like a dock for the bacteria’s surface to attach to human cells, which could cause disease. People in whom the TLR1 gene is active are more likely to have an H pylori bacterial infection that can lead to gastritis, ulcers and stomach cancer.
The new study had a strong design because of the large size – over 10,000 people – and it also included two different populations. However, the study linked people’s genes only to a bacterial infection, not specifically to any illness.
“To me this discovery may have greater relevance as to why patients are predisposed to getting this infection we are all exposed to. Mechanistically, it’s fascinating," said Greg Gregory S. Sayuk, MD, MPH, a gastroenterologist and Program Director of the GI Fellowship Program at Washington University School of Medicine.
It is too early to recommend genetic testing for the new gene, but in a JAMA editorial today, Dr. Emad El-Omar of Aberdeen University in the UK, wrote, “the clinical implications and benefits could be tremendous."
Diagnosing and Treating H Pylori Infections
Currently, getting a test for H pylori infection is quick and inexpensive. Treating H pylori ulcers can be complex, said Peter Mannon, M.D., Professor of Medicine in the University of Alabama at Birmingham Division of Gastroenterology and Hepatology. “The challenges doctors face in treating stomach and duodenal ulcers include: confirming the role of H pylori infection so that it can be treated, ensuring the recurrence of ulcers is recognized and/or prevented, making sure the ulcer does not represent a form of cancer if it does not heal, and preventing ulcers when patients need to take medications known to cause them," he explained
Knowing which gene is involved in people who have ulcers may someday lead doctors to better treatments for ulcers. Now, these infections are treated with antibiotics and acid inhibitors. However, antibiotic resistance is on the rise, and you can’t kill the bug if it is resistant to the drug. Dr. Sayuk notes, “There is an increasing issue with antibiotic resistance in H pylori even with the best agents we have available. Certainly if you can find new targets, this would be a huge advance in managing the condition.”
The gene linked to H Pylori infections may be a key to helping scientists discover newer, better drugs. It may even point to new ways to prevent stomach cancer, or provide lead to development of a vaccine against H pylori.
The researchers were cautious about generalizing their results too broadly.
Dr. Mannon noted, “We don’t know if this is a protective or pro-inflammatory effect against H pylori infection or its complications.” The study also did not include people from Africa and South America, where infection is more common; as much as 90 percent of the populations there may be infected.
Despite minor weaknesses, the new study does shine a light on why some people may be at risk for illness from H pylori infection - it may be in their genes.
"Gene Linked to Ulcer-Causing Bacterial Infections" originally appeared on Everyday Health.