January 23, 2014

Human and Helicobacter co-evolution

by Denise Anthony


A Vanderbilt University-led research team has solved a long-standing riddle: Why do people of mostly Amerindian ancestry in the Andes have a gastric cancer rate that is 25 times higher than that of fellow Colombians of mostly African descent only 124 miles away on the coast?

The answer is disruption of co-evolution of the humans and of Helicobacter pylori, the bacterium that infects their stomach lining and is the leading cause of gastric cancer throughout the world.

In a report in the Proceedings of the National Academy of Sciences, Barbara Schneider, Ph.D., and colleagues conclude that the interaction between host and pathogen ancestries completely accounts for the difference in the severity of gastric lesions in two regions of the same country. An evolutionary mismatch between human and microbe is the reason for this difference.

Understanding the role of co-evolutionary relationships in gastric disease may inform prevention efforts to eradicate H. pylori infection in those at greatest risk, the researchers conclude.

The research was supported in part by grants from the National Institutes of Health (RR024975, TR000445, CA028842, CA077955, CA116087, DK058404, DK053620, DK058587, GM103534, AI039657, AI068009 and AI007474).

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