Bacteria Are Good for You

Hand sanitizers kill 99.9% of bacteria where applied in 30 seconds or less (1).  To a normal brainwashed person, this sounds great that so many bacteria are being killed.  But, what about the 0.1% of bacteria that isn’t killed?

There are 10 times as many bacterial cells in and on our bodies than human cells (2).  Human bodies are composed of about 50 trillion cells, depending on who you ask (3).  Multiply that by 10, and you get about 500 trillion bacteria cells (500,000,000,000) in the human body.

Now back to the 0.1% of bacteria that your 99 cent hand sanitizer did not kill.  0.1% doesn’t sound like a whole lot until you consider the enormous amount of bacteria contained in the human body.  A small patch of skin, area equal to the antibacterial drop that you administered could well contain millions of bacteria.  With a patch of 5 million bacteria, 500 bacteria could still potentially survive.  These 500 bacteria are antibiotic resistant; they could not be killed by your antibacterial product.  The resistant bacteria then multiply, and soon your hand is covered with bacteria resistant to hand sanitizer.

Of course this is an exaggeration.  The mutated bacteria that survived your Walgreens brand antibacterial soap pay a fitness cost in maintaining their antibiotic resistant genes.  Bacterial levels can thus return to normal overtime as wild-type bacteria overwhelm the antibiotic resistant strains.  But, it still highlights one of the upcoming problems in human health: antibiotic resistant bacteria.  Replace hand sanitizer with other antibacterial products and you still select for resistant bacteria, not to mention antibiotics that are being fed to livestock for human consumption--creating antibiotic resistant flora that is transferred to humans through food.  The frightening reality is that scientists are running out of drugs to combat bacteria that simply cannot be killed.

The answer?  The best you can do is to use traditional soap.  Soap causes dirt and other microbes to be washed off your hands with water and down the drain.  For now.


1.  http://www.livestrong.com/article/173900-what-are-the-effects-of-hand-sanitizer-on-bacteria/

2.  http://www.npr.org/templates/story/story.php?storyId=104662183

3.  http://scienceblogs.com/gregladen/2011/11/28/how-many-cells-are-there-in-th/