Even Eyes Contain Bacteria!

Mouse eyes were studied in the article being discussed, but the results are probably applicable to many mammal eyes.

Writing about coral in the Journal Science, paleontologist Dr. George D. Stanley noted:

Symbiosis is the most relevant and enduring biological theme in the history of our planet.

If you aren’t familiar with the term, “symbiosis” refers to organisms of different species living together. There are three general forms:

(1) Parasitic symbiosis, in which one organism benefits and the other is harmed

(2) Commensal symbiosis, in which one organism might benefit but neither is harmed

(3) Mutualistic symbiosis, in which all organisms in the relationship benefit

I have written extensively on mutualistic symbiosis (see here, here, here, here, here, here, here, here, here, and here, for example). Not only does it fascinate me, but it was also the major scientific issue that led me away from atheism. When one sees the amazing mutualistic relationships that exist all over nature, it becomes clear that these organisms were designed to work together.

Bacteria tend to develop a lot of mutualistic relationships. Indeed, you would not be nearly as healthy as you are if it weren’t for the many mutualistic bacteria that live in and on your body. And while it is widely-known that you can find mutualistic bacteria in many parts of a mammal’s body, it was thought that you would never find them living in the eye for any extended period of time. That’s because mammal eyes contain an enzyme called lysosyme, which kills bacteria. However, new research indicates that at least one species of bacterium, Corynebacterium mastitidis, makes its home in at least some mammal eyes.

The researchers were studying mice and found that some had the bacterium in their eyes, while others did not. Now, of course, it could be that the bacterium had found its way to the eyes and had not been killed yet, so the researchers added the bacterium to the eyes of some of the mice that didn’t originally have it. Even after several weeks, the bacterium was alive and well on the eyes. To make sure this wasn’t a result of bad immunity, they added other species of bacteria to the eyes, and all those were killed by the mice’s immune systems.

Interestingly enough, when mice without the bacterium in their eyes were put in the same cages as mice that had it in their eyes, the bacterium was not transferred. However, when the mice that had the bacterium in their eyes had pups, the pups all had it. This led the researchers to conclude that the bacterium doesn’t “infect” the eyes (at least not easily), but it is passed down from one generation to the next.

But what is the bacterium doing there? To find out, the researchers treated some of the mice that had the bacterium with an antibiotic that kills it. They then infected those mice as well as mice that still had the bacterium in their eyes with a fungus that infects eyes. They found that the mice without the bacterium got the infection, but the mice that still had the bacterium in their eyes did not. Thus, the bacterium is protecting the eyes of the mice from at least some forms of infection.

Amazingly, the bacterium seems to do this by triggering an immune response from the mice. While this immune response destroys other organisms (like other bacteria and the fungus used in the experiment), it doesn’t kill the bacterium! The researchers don’t know how it survives, but they confirmed that it does. Here is what the authors state:

Our findings indicate that true commensalism with benefit to the host can exist at the ocular surface and uncover the importance of the local gamma-delta-T cell response in this process. We suggest that tuning of the local immune response by commensals may be necessary to maintain immune homeostasis in the ocular mucosa and may play a broad role in diseases of the ocular surface.

The “gamma-delta-T cell response” is the immune response that kills infecting organisms but not the bacterium that triggers it.

Now notice that the authors are careful to call the relationship between this bacterium and the mice “commensalism” and not “mutualism.” There are probably three reasons for this. First, while the mouse clearly benefits in at least some situations, it is not certain that the bacterium does. However, I would say that since the bacterium has a place to live (and presumably food to eat), it is probably benefiting. Second, this bacterium is found on the skin of many mammals and is thought to neither harm nor benefit the mammals. Thus, it is commonly called a commensal bacterium. Finally, the researchers can’t rule out the possibility that the bacterium becomes harmful in specific situations.

Since I don’t have to be as careful on my blog as the researchers do in the scientific literature, I will go ahead and suggest that this is another wonderful example of the abundant mutualistic symbioses that exist throughout God’s creation. As I stated in a previous post, there is at least some evidence that nature was designed to operate this way, and the negative relationships we see among organisms now are a result of the curse under which all creation groans. (Romans 8:20-22)

12 thoughts on “Even Eyes Contain Bacteria!”

  1. Darwin and his believers seem obsessed with the concept of competition between organisms. Even to the point of extending that concept to humans, and historically endorsing racism in the process. There’s a movie that has come out on that topic recently (which I have not watched yet): “Human Zoos: America’s Forgotten History of Scientific Racism”

    The high degree of beneficial mutualism seen in nature completely contradicts the “life is a struggle for supremacy” philosophy of the Darwinistic racists/white supremists.

      1. I read your “did Darwin promote racism” blog. I appreciate that you’re not trying to demonize Darwin even though you disagree with him. Nevertheless, I’m not buying your thesis that “evil people are going to be evil” regardless of what doctrine they believe in. The truth matters; false beliefs have bad consequences.

        In particular, I strongly disagree with any implication that the Bible and Darwin’s “The Descent of Man” are equally racist and can equally be used to promote racism. Racist “creationists” twisted the Bible way out of shape, and ignored large portions of it. Racist Darwinists, on the other hand, were just following the logical implications of their (wrong) scientific beliefs. Continuing to follow those same logical conclusions, most evolutionists today are pro-abortion, while pretty much all “creationists” are pro-life.

        It is a mistake of our time to conflate slavery and racism. Abraham Lincoln was both a committed Christian, anti-Slavery, and quite racist by our standards. During Biblical times, the Romans enslaved fellow Romans, the Greeks enslaved fellow Greeks, etc. It wasn’t a matter of race or even social class – a general could be down on his luck, have too many debts he can’t pay, and be sold into slavery. The Bible had rules for servitude, which included releasing everyone from bondage after seven years. The ancient Hebrews didn’t follow those rules closely, for which God chastened them sorely. I guess because of those rules of servitude one could say that the Bible “endorses” slavery, though I would argue that, like divorce, it was only suffered “because of the hardness of your hearts” and “from the beginning it was not so.” (Matthew 19:8) But there is nothing in the Bible to endorse racism. Quite the opposite, see for example Acts 10:15.

        1. I never even came close to implying that the Bible and Darwin’s “Descent of Man” are equally racist. However, what I did say (and what cannot be denied) was that creationists in Darwin’s time were just as racists as the Darwinists. Indeed, Darwin himself was significantly more charitable towards what he called “other races” than many preachers were in his day. Evil people will do evil things. Those who want to be racist might use evolution to put a scientific veneer on what they want to believe. Nevertheless, the theory itself is not racist.

          I don’t know of any studies that find Darwinists more likely to be pro-abortion than pro-life. Once again, that seems to depend more on preconceived notions. Pretty much every theistic evolutionist I know would identify as a Darwinist and yet is pro-life, and pretty much every atheist I know (Darwinist or otherwise) is pro-abortion.

        2. I did watch the Human Zoos movie and I totally recommend it. It was produced by Discovery Institute and you can find it free on YouTube.

          According to the film, Catholics seemed to have the best track record when it came to combating evolutionary racism during those dark days. The same cant be said for much of upper crust protestantism at the time. Thank God all of Christianity is on the same page now.

  2. Question: Jay, you stated that “pretty much every atheist I know (Darwinist or otherwise) is pro-abortion.”

    What kinds of atheists are covered in this “otherwise” category?

    And what percentage of atheists are in the “otherwise” category? (just a rough estimate off the top of your head)

    But anyway, eye bacteria, pretty neat!

    I had actually wondered before I read the full post “Well, why wouldn’t you find bacteria in the eye?” (and then of course found out, oh, because of lysosyme)

    Other bacteria develop resistance and immunity to antibiotics, so it would make sense that the eye could have bacteria that are resistant or immune to the eye’s natural ‘antibiotic’

    1. The options for non-Darwinian atheists are abundant. Some favor the idea of design, but it’s not God who designed. It’s some super race of aliens, interdimensional beings, etc. Some go so far as to say that we are actually a simulation being run by an advanced life form. Some, like Dr. Lynn Margulis (the originator of the endosymbiosis theory for how prokaryotes became eukaryotes) favor a naturalistic view of origins in which the driving mechanism is symbiosis, not natural selection. Others, like Dr. Jerry Alan Fodor and Dr. Massimo Piattelli-Palmarini, favor a naturalistic view in which natural selection is a minor (or non-existent) player. Still others, like Dr. Thomas Nagel, simply admit that Darwinism (along with its variants) doesn’t work, and biologists need to come up with a theory that does. Most of my close atheist friends fall into the Fodor/Piattelli-Palmarini camp and the Nagel camp.

      Percentage is hard to judge. A majority of my close atheist friends are non-Darwinists, but I am sure my close atheist friends aren’t a representative sample of atheists. I would say that non-Darwinist atheists are probably a tiny percentage of all atheists, because most people (atheist or otherwise) are poorly-educated when it comes to science and are unwilling to do the work necessary to question the High Priests of Science. As a result, they simply parrot what the High Priests proclaim, all the time thinking they are intellectual superior to those who are actually exercising critical thinking.

      1. hmm, that makes me wonder, do your non-darwinian atheist friends regularly encounter darwinian atheists, and how do those exchanges go down?

  3. Next Question: If I had some kind of infection, instead of taking a round of antibiotics, could I drink tears?

    And theoretically, how much tears would I need to drink in order for the lysosyme in the tears to effectively battle the infection?

    1. Your stomach acid would destroy the lysosyme. Also, there is an issue of concentration. Even if you could protect it from your stomach acid, the concentration is high enough to protect the surface of your eyes from bacteria, but you would need to increase the concentration to make it effective over a larger volume.

      1. Well, I wonder if it would be possible to do that with lysosyme in a capsule form (would it be protected from the stomach acid and can enough lysosyme be fitted into a capsule to have a high enough concentration)?

        I imagine the difficulty would be in developing a capsule that didn’t dissolve completely until it got to the intestines (or at least almost there). Most supplement capsules are made of Bovine Gelatin which, to my knowledge, dissolves completely in the stomach.

        1. There are special coatings that break down only in the presence of intestinal enzymes, so you can protect medicine from stomach acid. However, lysosyme is a broad-spectrum cell destroyer. I would think it could be bad for lots of cells in your body.

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