• Who Is In Charge Of Gut Microbes?

    Posted December 29, 2016: by Bill Sardi

    There are a lot of crossed wires in modern medicine these days.  At the speed modern society is moving, futurist Ray Kurzweil says there is an exponential increase in knowledge that means humanity should be able to cure every disease by the year 2030 or even sooner.  [San Diego Union-Tribune]

    With that in mind, one major development now provides a deeper understanding of the origin of disease — gut bacteria.

    Earlier this year when researchers in China gave the red wine molecule resveratrol to laboratory animals and it favorably altered their gut bacteria and indirectly abolished atherosclerosis from their arteries, we should have been able to hear a pin drop in the hallways of the nation’s medical schools.  Who would have ever thunk it?  [MBio 2016]

    An amazing late discovery in the archives of medicine is that “most of the human diseases affecting westernized countries are associated with dysbiosis (unbalanced gut bacteria) and loss of microbial diversity (bacteria) in the gut microbiota.” [Frontiers Microbiology 2016]

    The gut (actually the upper and lower intestines) hosts about 4 pounds of bacteria, which is about 3 trillion cells, more than the rest of the human body.

    We are not only talking about digestive tract disorders like irritable bowel and inflammatory bowel we are talking about food allergy, asthma, obesity, sugar metabolism and all the autoimmune disorders like rheumatoid arthritis.

    An unhealthy balance of gut bacteria helps to explain brain diseases like Alzheimer’s.  [Microbial Ecology Health Disease 2015]  Gut bacteria maybe even explain the mysterious Lou Gehrig’s disease.  [Frontiers Microbiology 2016; Physiological Reports 2015]

    Gut bacteria and eye disease

    In lab animals, consumption of a high-fat diet (60% fat calories) versus a standard diet (16% fat calories) resulted in 50% weight gain and the development of abnormal blood vessels at the back of the eyes which is experienced in humans as wet macular degeneration, a fast-progressive form of blindness.  Americans consume a ~30% fat diet.

    Animals fed a standard diet have been shown to exhibit a ratio of good/bad gut bacteria of 66%/33% and this ratio changed when fed a high-fat diet to 19%/67%.  When these same lab animals are given an antibiotic (neomycin) to sterilize their gut of bacteria, a healthy balance was restored to gut bacteria.  The conclusion drawn from this animal study was that “modifying gut bacteria may… prevent or delay wet macular degeneration.”  [EMBO Molecular Medicine Dec 2016]

    Patients with wet-form macular degeneration are successfully treated with medicine injected by needle directly into the eyes.  Abnormal blood vessels recede and the visual center of the eye (macula) is temporarily spared from damage that could result in legal blindness.  Re-treatment is required with monthly injections to prevent loss of vision.

    Not to dismiss or relegate the success modern medicine has had with these drugs in treating wet-form macular degeneration, the origin of this disease may emanate from the human gut.  What now?

    Ophthalmologists aren’t gut bacteria specialists.  Should these patients be referred to a gastroenterologist?

    That question is partially answered by a recent report published in the journal GUT. [Gut Dec 20, 2016]

    A 74-year old female patient with progressive loss of vision was examined by an ophthalmologist.  Clouding of the normally clear vitreous gel that fills her eyes and massive eye inflammation were observed.  A retina specialist took her to the operating room to surgically remove the inflamed vitreous jelly from her eyes (vitrectomy).

    However, the patient also had watery diarrhea of 6-months duration along with weight loss accompanied by nausea.  A complete gastroenterological assessment that included a colonoscopy had been performed during a prior medical visit with no abnormal findings.

    Over the prior 20 years the patient had been treated with a variety of medications to treat her inflammatory arthritis.  Long-standing inflammation in her gut had eventually resulted in sight-threatening inflammation in her eyes.  The patient was given an antibiotic, which resolved the diarrhea rapidly.

    The question arises: if you are diagnosed with wet-form macular degeneration where abnormal blood vessels invade the visual center of your eyes and you are referred to an ophthalmologist, were you referred to the proper medical specialist?  Injecting medicine directly into the eyes of older adults is a $2 billion business.

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