Human–Microbe Mismatch Boosts Risk of Stomach Cancer

Ed Yong, Nature, January 13, 2014

The Colombian town of Tuquerres, nestled high in the Andes Mountains, has one of the highest rates of stomach cancer in the world: about 150 cases per 100,000 people. Meanwhile in the coastal town of Tumaco, just 200 kilometres away, the equivalent rate is only around 6 in 100,000.

This 25-fold difference is partly due to an evolutionary mismatch between human and microbe, according to a new study.

The main cause of stomach cancer is Helicobacter pylori, a bacterium that infects half the world’s population. It is usually harmless, but occasionally leads to tumours. H. pylori has been infecting humans since our origins in Africa, and diversified with us as we spread around the world. But in places such as South America, the arrival of European colonists has broken this long history of co-evolution, leaving some people with H. pylori strains that do not share their ancestry.

Now, a team of scientists led by Pelayo Correa and Scott Williams at Vanderbilt University Medical Center in Nashville, Tennessee, has shown that this mismatch can turn a normally benign infection into a potentially carcinogenic one. When analysed together, the genomes of hosts and microbes give a better prediction of the risk of disease than when considered alone, the team found. Their results are published in Proceedings of the National Academy of Sciences.

{snip}

The researchers first showed that people from coastal Tumaco trace the majority of their ancestry (58%) and most of their H. pylori strains to Africa, because many are the descendants of freed and escaped slaves. By contrast, the mountain population from Tuquerres is 67% Amerindian and 31% European. Their H. pylori strains are mostly European ones, which were imported by conquistadors and somehow displaced the native Amerindian strains.

The team also found that if the H. pylori strains have a different origin to their hosts, they appear more likely to cause cancerous stomach lesions. For example, strains that originated in Africa seem mostly benign in people with significant African ancestry, but were more likely to lead to lesions in people with a largely Amerindian background.

{snip}

The authors also want to see whether the same trends apply in East Asia, where stomach cancer is unusually common (affecting about 42 in every 100,000 men and 18 per 100,000 women), or in Africa, which has little incidence of stomach cancer despite high levels of H. pylori infection.

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  • Jack Burton

    So miscegenation also causes cancer, how interesting.

    • Spartacus

      All the better for us normal people .

  • bigone4u

    Race mixing causes all sorts of unforeseen consequences doesn’t it. That’s another argument in favor of racial purity.

  • ncpride

    The main cause of stomach cancer is Helicobacter pylori, a bacterium that infects half the world’s population.

    It’s also the main cause of stomach ulcers. And who do we have to thank for discovering this potentially fatal bacteria, and helped millions rid themselves of ulcer forever? Two brilliant Australian scientists who also deservedly won the Nobel Prize. Despite years of ridicule from their colleagues who scoffed at the idea that bacteria could live in the stomach because of the acid it produces, they persevered and got the last laugh.

    • I believe these two noticed that persons who had been prescribed antibiotics for completely unrelated reasons had their ulcer trouble go away.

      • ncpride

        That makes sense, and probably led them to suspect bacteria was the culprit behind ulcers. Whatever led them to that conclusion, many of us who suffered from recurring ulcers for years are beyond grateful for their work and discovery. Ulcers are painful and can be deadly.

  • r j p

    Difference between Colombian mountain areas and Colombian coast?
    Coca plant grows in the mountains.

  • Tim_in_Indiana

    But in places such as South America, the arrival of European colonists has broken this long history of co-evolution, leaving some people with H. pylori strains that do not share their ancestry.

    Never can an article be written that doesn’t take some dig or another at whites or Europeans. Also, never is it mentioned that whites are the ones doing the vast majority of the research to cure the world’s diseases. Can’t give whites any credit for anything now, can we?

  • Lt_Greyman_NVA

    But But But….Social Construct!

  • JackKrak

    I’m sure the Colombian scientists were just about to solve the mystery affecting their own people when the guys from Tennessee beat them to it….

    Slightly OT, but it’s another example of the white man’s science, technology, inquisitiveness and ingenuity saving the day for people who never bothered to wonder about their own problems.

    Even further OT, this kinda reminds me of the fact that Machu Picchu in Peru was abandoned and forgotten until an American found it, cleaned it up, started restoring it and spread the word to the rest of the world.

    “Here you go, Peru, you obviously didn’t know or care about it but I found this iconic place of enormous historical value – that is, your own history that you apparently weren’t terribly concerned about – and got it ready for you to use as a postcard to the world and a cornerstone of your future tourism industry. You’re welcome!”

    • About the American discovery of Machu Picchu, it’s not as simple as you say. A lot of controversy surrounds Hiram Bingham.

      • JackKrak

        Yeah, I know – it’s not so cut and dried but at the same time there’s no denying his key role.

        Can you imagine the Grand Canyon, the Alamo, the Rose Bowl, the Liberty Bell etc. lying in ruins, neglected or reclaimed by the forest until a brown/black man arrived to clean it off and show us what we never saw right under our nose?

        I’ll answer that for you – no, no you can’t.

  • sbuffalonative

    But in places such as South America, the arrival of European colonists has broken this long history of co-evolution

    The take-away from this article: White people cause cancer.

  • Max

    Even germs know that race is not a “social construct” which makes them smarter than David Suzuki.

  • Can we just start boycotting these anti-White publications? Every time they throw in a dig at the Evil White Man(TM) for creating all the world’s problems, cancel your subscription and send a letter to the editor telling them exactly why. I understand that Nature is considered one of the world’s premier science magazines. But that line about Whites wasn’t based in science and clearly exists to uphold The Narrative so that academicians and other cultural Marxists can smugly nod and stroke their scraggly goatee. We need to start being confrontational with these lunatics: to wit, we need to ask the editors directly, “What is this nonsense doing in the article? Cancel my subscription, today.”

    All the mainstream publications, TV channels, movie studios…we need a total media boycott. Why do we not do this?