Visitor Count


counter for blogger

Sunday, November 4, 2012

Symbiotic bacteria

When I started doing some research about the bacteria that live in us and on us, I was blown away by the sheer numbers, varieties and power of the microorganisms [living single-celled entities that can only be seen with a microscope] that our bodies harbour. Those who study these bacteria tend to actually begin to wonder about who is in charge, the microbes or us. Their cells outnumber ours by a factor of 10 to 1 – it’s just because they’re smaller than our cells that they only weigh about 4 or 5 pounds altogether. The most amazing revelation is that their DNA produces 3,000,000 genes to our measly 23,000 – that’s over 100 times more genes, the pieces of DNA that code for the molecules that tell our bodies what to do to become us. If you watch the first few minutes by clicking on the video, you’ll really understand what is being discovered! It’s a veritable scientific revolution!

Looking at things from my new perspective after a week of this kind of research …. I understand that our planet formed about 4½ billion years ago, and the first living single celled microorganisms, mostly bacteria, appeared about ½ a billion years later. Then these simplest forms of life spent the next long 3 billion years evolving and learning and communicating until they got nature to help them by coming up with the idea of creating multi-celled creatures that they could inhabit. The bodies of these relatively big creatures acted as a nice warm safe home and and fed them and, in exchange, they did chores like digesting the food their host ate and creating an immune system to keep them healthy. 
The system worked so incredibly well that in the next billion years of evolution lots and lots of multi-celled creatures evolved and they got smarter until we human types came along a couple of hundred thousand years ago with enough brains and scientific know-how to finally, in just the last couple of years, start to figure this all out.  Pretty shocking perspective - but those are the facts.
Looking back at the evolutionary processes again, plants preceded animals because they could absorb the energy of the sun and use it to convert carbon dioxide into solid carbon compounds that allowed them to grow into things like grass or trees or carrots. Then came animals that harboured bacteria in their special stomach that would break down the long chain cellulose fibers that gave plants their structure.  They were herbivores and and they mostly ate grass and leaves. Then evolution marched forward and created carnivores and omnivores like us that could get their energy by eating the herbivores like cows and sheep  and goats. Apparently until humans learned to control fire and cook roots and leaves of plants, they could get almost no nutrition from vegetable matter. Scientists think our hunter gatherer ancestors eating meat and cooked vegetables had it made, they got lots of energy from both and so they could outsmart other creatures and evolved by getting even smarter and bigger brains that made them able to create our modern world.In all this, the bacterial flora we host were fine because up until the 1930’s [in my lifetime] when refrigerators and freezers came along, people managed to keep food from going bad by fermenting it. Fermenting breaks down food and produces lots of good bacteria like those in our intestinal system. The bacteria that digest our food could thrive on the arrangement and so did we and we multiplied.
But then we began to eat strange things like ‘cheesies’ and sugar coated cereals and chocolate bars and lots of convenient junk food that our myriads of bacteria didn't thrive on and so our immune system didn't work well either. Then when some bad bacteria or harmful viruses made us really sick we were given antibiotics that killed off lots of the good bacteria we needed to stay healthy.
The consequences of eating mostly processed food and what to do about it, comes in the next post – if you are still with me after this very broad brush treatment of our evolution and complex symbiotic living systems..    Rie

1 comment: