• Question: How much bacteria is their in a human sell

    Asked by 937gdge22 to Jimi on 16 Mar 2016.
    • Photo: Jimi Wills

      Jimi Wills answered on 16 Mar 2016:


      Normally there shouldn’t be any bacteria in a human cell.


      (1) Some bacteria can invade cells… for example mycoplasma is a type of bacteria that can only live inside cells. They can cause pneumonia.

      (2) Bacteria can live outside cells in the body. There are bacteria on your skin and in your gut, and they are a very important part of your body. You live in harmony together and it’s called symbiosis. The bacteria in your gut help you process your food, and those on your skin help protect your skin against other kinds of bacteria or fungi.

      (3) Inside human cells (and in fact most plant, animal and fungal cells) are things called mitochrondria. These are thought to have evolved from when a cell was invaded by a bacterium, and they started living together in harmony. In a world where oxygen was just starting to be produced and was toxic to the cell, the bacterium offered to suck up all the oxygen, and give other molecules back in return.. and the cell offered shelter to the bacterium. Over millions of years they because completely dependent on each other, and then evolved into the cells we know now. So in a way, we do kinda have bacteria in our cells… but they’re so different now.