The Invisible Helpers

The Invisible Helpers

Could we survive without bacteria?

What is the most abundant cell in the human body? Skin cells? Think again. It's bacteria!

Bacteria living in our body outnumber our own cells by 10 to 1. How many bacterial cells do we have in total? The number is anything upwards of an amazing 1000 trillion (one trillion = 1,000,000,000,000).

These bacteria, called normal flora, are found everywhere on your body - skin, hair, eyes, teeth and inside your gut. Your face has 10-100 million bacteria per square centimetre!

Where did these bacteria come from?

As soon as you are born, bacteria from the air, from people and from surfaces that you touch, start to set up house inside your body. Your diet as a baby and the people you come into contact with will establish which bacteria take up residence. By the time you are two years old, you will have developed your own unique collection of normal flora. It's as unique as your fingerprint!

What do these bacteria do?

The bacteria on our skin and outer surfaces prevent harmful bacteria establishing themselves and causing an infection, much like how we prevent weeds taking over the good plants in the garden. Inside our body, the bacteria in our gut produce vitamins - for example some bacteria produce biotin and Vitamin K, essential for our body. Other bacteria in the large intestine and colon help us to digest food better and release stored energy.

What do they get in return?

Protection, free heating and lots of free meals!

Bacteria home sweet home_121117049


Your body is 'home sweet home' for bacteria!

Could we survive without them?

Yes, possibly, but it wouldn't be easy. You would be vulnerable to wide range of infections. Also, scientists estimate that you would probably have to eat three times as much to gain energy for maintaining body functions.

Want to see good bacteria in action?

Try this little experiment, which involves making yoghurt using bacteria. These are very similar to bacteria that are present in our gut.

How can we keep the bacteria happy?

Stress and overuse of antibiotics can disturb the balance of normal flora. A healthy lifestyle, and a well-balanced diet, with a good proportion of fibre will keep the bacteria smiling all day long.

By Zara Mahmoud, @sciencebuz

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