Infection Connection: We Are Living in a Bacterial World

And I am a bacterial girl. (Go ahead...sing it! You know you want to!)

This week, I finished the book Good Germs, Bad Germs: Health and Survival in a Bacterial World by Jessica Snyder Sachs. Whether you’re on the job or just have a passing interest, this is a truly fascinating book.

Sachs writes about our long, strange trip with bacteria and other microorganisms. Some might think that it’s a simple matter to realize that bacteria are bad, and the proliferation of antibacterial soaps and hand sanitizers makes it obvious that such a message has caught on. It’s much more complicated than that. Sachs mentions what Nobel prize-winning molecular biologist Joshua Lederberg calls the “microbiome.” Lederberg says, “It would broaden our horizons if we started thinking of a human as more than a single organism. It is a superorganism that includes much more than our human cells.”

Essentially, each of us is a walking, talking ecosystem, carting around millions of bacteria that most often protect us, but sometimes harm us. From the moment we are born, we begin developing our occupying microflora, including Staph epidermidis and coryneform bacteria on our skin, Strep salivarius on our teeth, E coli in our gut, and Lactobacillus in our vagina (if you happen to have one, that is). These organisms create protective biofilms that aid in digestion, keep harmful bacteria from getting a toehold, secrete acids that keep the “bad” bacteria at bay, and even send out chemical signals that help regulate our immune system. I find it an incredibly elegant and fascinating system, and I both adore and fear it.

I adore it because it’s obvious that we have co-evolved over millions of years; our microflora coexist peacefully with us in a mutually beneficial relationship. I fear it because it seems to be such a delicate balance, and changing one small part of it can trigger an unpleasant infection, or even a life-threatening one. (Any woman who has taken antibiotics for an infection knows how easily that balance can be upset; it’s a common occurrence to have the antibiotics wipe out our usual genital flora like Lactobacillus and have yeast set up camp. Usually not life-threatening, but definitely not pleasant.)

I find the connection between our microbiome and our immune system especially fascinating. (If I hadn’t concentrated on Microbiology, I would have gone into Immunology. I find both very interesting, and they are closely connected.) You’ve probably read about the recent explosion in asthma and food allergies in kids; many researchers are looking into whether or not kids’ immune systems are not being challenged the way they used to. I don’t think anyone (not any rational, thinking person, anyway) would dispute that vaccines for life-threatening infectious diseases are a must; but our world has definitely become a little more sanitized these days, and it is not necessarily for our protection.

It might seem to be a paradox, but an unchallenged immune system can go into hyperdrive all too easily. When we’ve been exposed to minimal allergens, the presence of an unexpected one can wreak havoc as the immune system summons the troops and engages in a campaign of shock and awe against all invaders. A veritable monsoon of cytokines, interleukins, and other immune-boosting or immune-suppressing chemicals are loosed upon unsuspecting cells; if the immune system mistakenly attacks our own healthy cells or tissues, auto-immune disorders like rheumatoid arthritis, scleroderma, and Sjögren’s syndrome can result.

My relationship with microorganisms has always been a love/hate one. I loved my job, and I loved the “detective work” aspect of it, but I hated the devastation and mortality I saw. I am fascinated by their mechanisms of resistance (one of them is called an efflux pump, in which the bacteria take in an antibiotic within its cell walls and immediately pump it right back out...I picture a sailor frantically bailing out a leaky boat), but worry about how that resistance is resulting in literally untreatable infections. Sachs quotes Rockefeller University researcher Vincent Fischetti concerning bacterial antibiotic resistance: “Don’t ever underestimate bacteria.” I recognize the relationship for what it is, but each of you also has a love-hate relationship with your own microflora, whether you realize it or not.

When it comes to the “war on bacteria,” it seems that we would benefit the most from an uneasy détente. When it comes to preventing what can be devastating infectious diseases like measles, bacterial meningitis, diphtheria, and so many others, vaccines are good things. But it is pointless—and perhaps even dangerous—to believe that a sterile world is beneficial or even possible. The vast majority of bacteria that we encounter in our daily lives is not going to go after us (except for those who are immunocompromised...that is a very dangerous state to be in), as long as we keep ourselves fairly healthy, with our microbiome in general balance. Maybe it’s wise to not mobilize weapons of mass destruction against the critters we encounter every day; a little soap and water is usually going to be enough to keep our own private ecosystem in balance.

Good luck, and hey...let’s be careful out there.

♪ ♫ Bugs may come and bugs may go, and that’s all right, you see. Experience has made me rich, and now they’re after me...’cause we are living in a bacterial world....♪ ♫