Good Bacteria, Bad Bacteria and Disease

A very interesting article appeared today in The Conversation[i] about research just published in Nature Communications. It is written by the paper’s senior author, Dr. Claire Steves, of King’s College in London.  Using the more-than 2700 medical profiles in the TwinsUK cohort (a group of older British twins who volunteered their medical information for the last 25 years – 96% of whom now have one or more medical conditions), these scientists analyzed the gut bacteria across a range of 38 common diseases and found remarkable consistency in the bacteria that increased and decreased.[ii] That is, “…the microbes weren’t specific to individual disease, but rather to the state of general health.”  Why would this be?  “From a biological perspective, this makes sense.  The environment that each but likes is quite specific; anything that alters it, even slightly, means some sensitive bugs won’t survive.”

Dr. Steves uses the environment of the colon as an example to explain her findings.  It is a very low-oxygen ecosystem, ordinarily, meaning that when someone is healthy, the colon is filled with anaerobic bacteria.  However, when inflammation occurs during disease – even low levels of inflammation – blood vessels open so that white blood cells can get in to clean up invaders.  These immune cells use oxygen “as a weapon” and cause the oxygen level in the colon to rise.  This, however, can kill off many of the commensal microbes, as well.  Worse still, E.coli, which can be highly pathogenic, doesn’t mind the higher oxygen environments.  In fact, the researchers found higher than normal levels of E.coli in all 38 diseases they studied.

I particularly like her suggestions at the end of the article on what practical use we could soon make of this information.  Imagine an over-the-counter poo test  that can be used to monitor general health. A sudden dip in anaerobic gut bugs might be an early warning sign for the onset of the disease.  The test could then also be used to see if treatment is working.  I look forward to that day!

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[i] https://theconversation.com/gut-microbes-are-tiny-sensors-of-your-general-health-99098

[ii] Jackson, MA, et. al. Gut microbiota associations with common dieases and prescription medications in a population-based cohort. Nature Communications. (2018) 9:2655 | DOI: 10.1038/s41467-018-05184-7.