Sea Monsters Lurk in Your Gut

When we picture monsters from the deep, most envision colossal sea beasts ready to drag the unsuspecting sailor to abyss. In actuality the sea beasts are at the other end of the size spectrum. Those viscous, nasty bacteria that line your digestive tract that could send you to your grave originated from deep-sea bacteria. A Japanese group report in PNAS that the two groups of bacteria share several genes allowing both to survive inhospitable habitats allowing them to flourish from temperatures between 39-158 degrees Fahrenheit.

Dr. M (1801 Posts)

Craig McClain is the Executive Director of the Lousiana University Marine Consortium. He has conducted deep-sea research for 20 years and published over 50 papers in the area. He has participated in and led dozens of oceanographic expeditions taken him to the Antarctic and the most remote regions of the Pacific and Atlantic. Craig’s research focuses on how energy drives the biology of marine invertebrates from individuals to ecosystems, specifically, seeking to uncover how organisms are adapted to different levels of carbon availability, i.e. food, and how this determines the kinds and number of species in different parts of the oceans. Additionally, Craig is obsessed with the size of things. Sometimes this translated into actually scientific research. Craig’s research has been featured on National Public Radio, Discovery Channel, Fox News, National Geographic and ABC News. In addition to his scientific research, Craig also advocates the need for scientists to connect with the public and is the founder and chief editor of the acclaimed Deep-Sea News (, a popular ocean-themed blog that has won numerous awards. His writing has been featured in Cosmos, Science Illustrated, American Scientist, Wired, Mental Floss, and the Open Lab: The Best Science Writing on the Web.

2 Replies to “Sea Monsters Lurk in Your Gut”

  1. Craig, did you seriously think I could let a broad and stereotypically libelous statement like “vicious, nasty bacteria” go by without comment? Scandelous! I could not find the paper you describe to find out what bacteria the Japanese group was looking at. However, the bacteria lining your (and everyone else’s) digestive track are your friends. They help you out by synthesizing vitamins and by breaking down some polysaccharides we have no enzymes to digest ourselves. For that matter, since there are an order of magnitude more bacteria in your colon than you have cells in your body, you’d be well served remembering who is in the minority in this situation…

  2. It’s online-before-in-print, and it’s open access, and the abstract (with links) is at

    Deep-sea vent [epsilon]-proteobacterial genomes provide insights into emergence of pathogens.
    S. Nakagawa and others.
    Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0700687104

    Hooray! for most of my gut bacteria. (Thanks, guys!)

    But the authors found that some deep-sea proteobacteria are closely related to Helicobacter and Campylobacter, which are, to me and my digestive tract, decidedly vicious and nasty (although I don’t know about their viscosity). The deep-sea bugs’ genomes indicate they have a lot of metabolic tricks (such as multiple respiration pathways or metal-detox capabilities, and even virulence determinants) that are very close to those that the Helicos and Campys are using to be so nasty to us — colonizing and evading host defenses and such.

    Pretty cool.

    And I think Craig was assuming we all know that we’d be dead without our bacterial friends in our guts.

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