New research says germs can keep you happy

Gut feeling: The bacteria and germs in a person’s body are called their “microbiome”. © National Geographic

Are the bacteria in your gut somehow affecting your brain? Amazingly, scientists are starting to think the answer to this question is yes. How should we feel about it?

What’s happening

Did you know more than half of the cells in your body are not human? It is true! Your gut is filled with trillions of tiny bacteria.

Most of these germs are harmless. In fact, they keep us healthy. Now, scientists think they might affect our mood too.

Find out more

In one experiment, scientists gave a depressed person’s germs to a rat. It began losing interest in its favourite drink.

Losing interest in things is a symptom of depression.

Scientists suspect that germs could even influence brain diseases like dementia. If true, it could be the clue to a cure.

“We have the edges of the puzzle,” said one scientist. “We are now trying to figure out what is in the picture.”

How should we feel about this news?

Some say…

Yuck! It is scary to think about our germs controlling us without us knowing. I want my body back!

Others think…

It is fascinating! Scientists could end up curing diseases by changing what you eat. How cool is that?

You Decide

  1. Is experimenting on animals wrong? What if it leads to a human cure?


  1. Summarise this article in one sentence.

Some People Say...

“If you do not like bacteria, you are on the wrong planet.”

Stewart Brand

What do you think?

Word Watch

One trillion is one thousand billion.
The tiniest living things on the planet. They are so small that you cannot see them without a microscope. Some bacteria make us ill, but most are harmless.
The feeling of being very sad and not having much energy for long periods of time.
Forgetfulness and memory loss, particularly as someone gets older.


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