April 28, 2009
Helicobacter pylori have claimed the human stomach as its own according to a University of Illinois professor who spoke at Indiana State University to educate students how the bacteria affects humans.
H-pylori causes gastric diseases such as ulcers and stomach cancers.
Steven Blanke, associate professor of microbiology at the University of Illinois, said the bacterium has affected many historic people and it continues to do so today.
Stonewall Jackson, Pope John Paul II and Charles Darwin are believed to have had the bacteria during their lifetime, according to Blanke.
"All individuals affected with h-pylori develop a lower level of chronic inflammation of gastritis," Blanke said. "Once a person becomes infected; it can persist for the lifetime of the host in the absence of medical intervention."
He stated that 0.5 percent to 2 percent of people infected with H-pylori would progress into a form of gastric cancer. Dieting, alcohol usage and smoking increase the risk to progress into a disease state.
Scientists aren't sure how people become infected with h-pylori but believe the bacteria spread from person to person through feces and saliva.
In the 1970s, Barry Marshall and Robin Warren, two Australian physicians and scientists, observed H-Pylori in the stomachs of people with gastric ulcer disease.
"They were scorned, they were even ridiculed for putting forth this theory that an infectionate agent could cause this disease," Blanke said.
In lab experiments, Marshall and Warren proved people could get gastritis within a week of ingesting live cultures of H-Pylori bacteria.
Blanke believes that in 5-20 percent of infected individuals, it will progress into either gastric or duodenal disease.
H-pylori can change itself to adapt to host conditions and promote its colonization and persistence.
"Colonization can come at a cost," Blanke said. "Pathogens are able to remodel host cells and tissues as to create a more suitable niche for their own colonization within the host through the productions of a remarkable class of bacteria protein toxins."
H-Pylori, a gram-negative bacteria, was the first infectious organism to be classified as a Type I carcinogen, which places it in the same class as tobacco as a risk factor for cancer, according to Blanke.
When scientists discovered that H-pylori caused gastric ulcers, pharmaceutical companies resisted the idea because they were making money-selling medications that blocked stomach acid.
"H-two Blockers" block histamine receptors in the lining of the stomach so acid wouldn't bind to the stomach wall. Medications include Tagamet, Zantac, Pepcid, and Axid.
"We don't hear a lot about stomach cancer in this country, but it's the fourth leading cause of cancer cases each year and the second leading cause of cancer deaths world wide each year," Blanke said.
Infection rates are thought to be lower in the West largely because of the higher hygiene standards and widespread use of antibiotics.
H-Pylori has a high infectious rate, 100 percent in some developing countries and 20-50 percent in developed countries.
Until 30 years ago, scientists thought the human stomach could not support microbial floral because harsh acidic conditions were found in them.
"This indicates it must have mechanisms that allow it to persist within the acidic environment of the stomach," Blanke said.
Scientists have found evidence that children affected with H-Pylori are protected from childhood asthma.
"In the future H-Pylori may be used to inoculate small children with the intent of preventing the onset of childhood asthma and as that individual gets older and is more at risk of developing gastric cancers and ulcers then to treat that person eradicate that infection," Blanke said.
Contact: Rusty Gonser, Indiana State University, assistant professor, at 812- 237-2395 or email@example.com
Writer: Marcie Brock, Indiana State University, media relations intern, at 812-237-3773.
Cutline: Steven Blanke, associate professor of microbiology at the University of Illinois, speaks during ISU's Hans Christian Gram Microbiology presentation. ISU Photos by Justin Schwab
Helicobacter pylori have claimed the human stomach as its own according to a University of Illinois professor who spoke at Indiana State University to educate students how the bacteria affects humans