Brain bug

I have a close friend who seems to be the favorite “airport” of all sorts of traveling microorganisms. It’s as if there was a survey among viruses and bacteria and she made it to the list of the top destinations of traveling bugs. They all seem to find her irresistible and if there were ads in the bug world, they are probably promoting, in no quiet terms, that “Being a bug is more fun in Lens’ body.”  

Lens has a really good sense of humor which helps her whenever she is diagnosed with an infection. But I think it will ease her mind to know that each human, by the time they are about three years of age would already be harboring about 100 trillion microbes (mostly bacteria but also includes viruses and fungi) with about 500 species of bacteria in your intestines alone. Most of these will not send you to the ER in record frequency. They actually keep your body from falling apart such as aid in your digestion as well as transform materials into substances that you need but your body cannot produce. They also fight off other microorganisms called “pathogens,” the suspected “terrorists” of your otherwise healthy body.

If microbes played such an essential role in our lives, then expect science to naturally work on identifying them, finding out their specific addresses inside our bodies and most importantly, figure out their jobs in keeping and maintaining our bodily functions. This project is called the Human Microbiome Project. Carl Zimmer wrote an article (June 18, 2012) in the New York Times that revealed insights from the scientists who are doing this mapping. Beyond mere mapping, they are applying the principle of “ecology,” in looking at how these microbes interact with each other and with our bodies.

The work is not easy. Aside from the humongous amount and kind of microbes involved, scientists have also found out that the number and kind of microbes that we become hospitable to, depend on many things including our age and immune system. For my friend Lens, this may mean her immune system may be hospitable to certain “terrorists.”  Why this is so would also depend on many things including genetics. It is especially difficult to study the definitive role of microbes in humans because it is not ethical to deliberately infect a human so we can see what happens. This difficulty becomes even more obvious if you want to study the role of these microbugs in human mental health.  I learned more about this aspect in a related article that appeared in the Scientific American Mind in the same month written by neurobiologist and science-writer Moheb Costandi.

Costandi in his article pointed to the couple of hundred million neurons that reside in the lining of our intestines. Yes, neurons, the ones most people think are just in our brains! This means that they are part of the messaging system which culminates in the brain. This enteric nervous system is called the “second brain” or in common parlance, “gut feel.” It is what makes your insides flutter with “butterfly wings” when you are nervous or anxious. Given their number and the potency they play in our bodily functions, it is extremely difficult to think that the microbes in our intestines would have an absolute “hands-off” policy on our mental state. Costandi cited experiments with mice which manipulated microbe presence in the mice’s bodies and results showed that indeed, it affected their anxiety. If unwanted bugs like the bacteria that gives brain meningitis or the virus that gives brain encephalitis could dim or silence the brain temporarily or fatally, why should we think that other bugs who find a natural home in our bodies cannot affect our minds, positively or otherwise?

Whenever I am more irritable or sensitive than usual and I sense it, I always warn those closest to me by telling them that I have a “bug in my brain.” For better or worse, I know that when I say that, it may not just be a metaphor.

As of this writing, Lens is clear of “terrorists” in her “airport.” She still makes jokes about her condition, more than you would expect from someone who has gotten more than her share of pathogens. Maybe another bug I will call “world peace” is, at least in part, responsible for this attitude. If so, may that bug spread. Everywhere.

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