Monday, June 11, 2012

the original human social network

the misunderstood hero of our story. it's the brown part. image via wikipedia.

i have felt for some time that the whole 'kill 'em all' anti-bacterial craze is maybe not the best thing ever, and i am not alone--just look at all the probiotic supplements on the market. however, we're still treating just about everything with antibiotics and slathering ourselves in hand sanitizer. we want the bacteria we have designated as good in our bellies and THAT IS ALL, THANK YOU. fueled by the idea that the existence of some good bacteria might mean that there are more good bacteria, researchers have been working hard to identify the types of bacteria we carry around with us, how much this varies from person to person, and what exactly those bacteria are doing that might be helpful, harmful, or neutral to humans.

this month's issue of 'scientific american' has a great cover story this month that summarizes some of the findings from this research. a few facts to set the stage: there are more bacterial cells living in or on us that there are cells that make up our bodies. if you watched bonnie bassler's ted talk that i posted a few months ago, then you might remember her saying that she thinks of us as mostly made of bacteria with a little bit of human thrown in. furthermore, if you pool the genomes of all the different bacterial species that take up residence on humans, there are way, way more bacterial genes in use than human genes.

if you aren't sure of the significance of this, you can think of every gene being responsible for making at least one protein. your body can't do much of anything without an army of proteins, particularly the chemical-reaction-stoking set of proteins known as enzymes. need oxygen? then you need some hemoglobin in your bloodstream. hemoglobin is a protein. want to digest the ice cream you just ate? then you need some lactase in your stomach, the enzyme that breaks down the lactose found in dairy. i think you see where i'm going with this: proteins, like ron burgundy, are kind of a big deal.

microorganisms that might live somewhere in or on your body. image via pharmaceutical microbiology.

so let's recap: we have millions of bacteria living somewhere in or on our bodies, and those bacteria are making millions of different proteins and enzymes, some of which will be secreted outside of their little cell bodies and into our own human bodies. finding out what these proteins are doing in our bodies and how important that is is a major area of current research. are the bacterial proteins helpful? are they harmful? are any of them so helpful that they are, in fact, totally necessary for our bodies to function as they should? we tend to think of bacteria as harmful, causing issues that require a trip to the doctor and a course or two of antibiotics, but what if we need them just as much as they need us?

if you want all the details, you should obviously go buy the current issue of 'scientific american,' but i am going to share a bit about one of the parasitic-turned-commensal species of bacteria, and it's going to get personal. there's this one species of bacteria that has been blamed for intestinal conditions like chronic acid reflux (also known as GERD), stomach ulcers, and even stomach cancer. it's name is H. pylori, and most people have it. not all people who have an H. pylori infection will develop these symptoms, and someone can have GERD without ulcers and ulcers without cancer. like many things biological, it varies from individual to individual. in other words, H. pylori is one bad mother, and, if you have it, you should definitely take antibiotics immediately to get rid of it. or that is what a doctor might tell you, if you go to them complaining that your heartburn medicine has stopped working, like i did this past fall.

making the stomach a safer place? image via Helicobacter pylori symptoms.

well, well, well, lo and behold, new studies show that H. pylori is probably not a parasite at all. in fact, not only is likely not a parasite, but it is quite possibly extremely important to the functioning of a healthy human stomach. it seems that these tiniest of guys play a role in maintaining the optimal pH of the stomach. the contents of your stomach need to be very acidic, but not any more so than a pH of 2. when the pH drops below this, bad things happen. maybe even bad things like GERD. there do seem to be a small percentage of people whose body just doesn't like some of the proteins produced by H. pylori, and these people do have some of the GERD/ulcers kind of issues. but again, we're talking about a small percentage.

H. pylori "infection" is probably so common because it helps your body maintain itself. we need this bacterium to function properly, so it probably isn't a good thing that my screening for the bacterium came back negative. why don't i and others have it? well, as my doctor knows, it's pretty easy to kill H. pylori with a round of antibiotics. while there might not really be enough research completed at this point to make this call, i'm going to suggest that my GERD might actually be caused the absence of H. pylori. it doesn't explain all of my symptoms, but it does suggest a possible reason for the hyper-acidic pit of pain i get in my stomach that lets me know it's time to chug some alka-seltzer. so maybe instead of prescribing a round of antibiotics for those who test positive for H. pylori, we need to "infect" those whose test results come back negative. when you take antibiotics, maybe you also get a prescription for a probiotic to replace the good bacteria you will certainly accidentally destroy along with the bad. and maybe, just in general, we should drop the obsession with cleanliness. we really know so little about the bacterial world, but we do know that we have been coexisting with them well before there were antibiotics. there are some nasty buggers are there for sure, but it seems like the vast majority of them might be friendly. let's give them a chance to help us.

**disclaimer: if you, like me, have a freakish case of GERD, please do not take medicine into your own hands and try to infect yourself with bacteria. let's try to be patient and wait for medicine to catch up with us.