CHICAGO, May 31 (Xinhua) -- Bacterium Helicobacter pylori, a major contributor to gastritis, ulcers and stomach cancer, resists the body's immune defenses by shutting down energy production within the cells of the stomach lining that serve as a barrier to infection.

The study was posted on University of Illinois (UI)'s website on Wednesday and the findings have been published in the journal Cell Host and Microbe.

Using stomach cells and tissues, UI researchers found that H. pylori manipulates the cell from the outside by sending in a toxin to directly target the mitochondria, which serves as the powerhouse where the cell's energy is produced.

"The toxin disables the mitochondria, resulting in a loss of energy production," said UI microbiology professor Steven Blanke, who led the research. "When the cell tries to compensate by reallocating resources from other parts of the cell, a signal is triggered directing the cell to stop production and start breaking things down."

Disabled but still alive, the cell eventually loses its ability to fend off infection.

According to Blanke, H. pylori infects and causes gastritis in half the world's population, and the human stomach is the only known environment where H. pylori exists.

The findings will aid efforts to better understand and combat H. pylori infections, the researchers said.