from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.- n. a genus of helical or curved or straight aerobic bacteria with rounded ends and multiple flagella; found in the gastric mucosa of primates (including humans) Sorry, no etymologies found. I think the heliobacter theory of ulcers is a different story. It helps in fighting harmful bacteria such as listeria monocytogenes and heliobacter pylori, and harmful protozoa such as giardia lamblia.