© 2025. The Trustees of Indiana University
Copyright Complaints
1229 East Seventh Street, Bloomington, Indiana 47405
News, Arts and Culture from WFIU Public Radio and WTIU Public Television
Play Live Radio
Next Up:
0:00
0:00
0:00 0:00
Available On Air Stations
Some web content from Indiana Public Media is unavailable during our transition to a new web publishing platform. We apologize for the inconvenience.

My Bacteria Are Full

We've been hearing a lot about the importance of gut bacteria to our health. Now it turns out that bacteria also have a say in how and when we eat.

Our gut microbes depend on us for a place to live and nutrition to survive. They have a stake in how often and how much we eat. So it makes sense that they should be able to communicate to us when they need a snack.

Researchers found that 20 minutes after a meal, E. coli bacteria in the gut produced different kinds of proteins than they did before the meal. That happens to be the same amount of time it takes for a person to begin feeling full after a meal. Excited that there might be a link there, they did further testing.

They injected doses of the bacterial proteins into both hungry and well fed rats and mice. Analysis showed that the protein produced by the full bacteria stimulated the release of peptide YY, a hormone associated with feeling full. They also found that hungry bacteria did not release the protein.

The bacteria are using the body's chemical signaling system to tell a person they are full.

And though they help us feel full, those bacteria can't help us with impulse controlwhen it comes to that second piece of cake.

Y:        Don, isn't that your second piece of cake?

D:        I'm afraid it is, Yaël. I guess my bacteria haven't had enough to eat yet.

Y:        What are you talking about?

D:        We've been hearing a lot about the importance of gut bacteria. Now it seems that bacteria also have a say in how and when we eat.

Y         :Don't human hormones help control that?

D:        Yes, they do. But think about it. Our gut microbes depend on us for a place to live and nutrition to survive. They have a stake in how often and how much we eat. So it makes sense that they should be able to communicate to us when they need a snack.

Y:        I never thought of it that way.

D:        Researchers found that twenty minutes after a meal, E. coli bacteria in the gut produced different kinds of proteins than they did before the meal. That happens to be the same amount of time it takes for a person to begin feeling full after a meal. Excited that there might be a link there, they did further testing.

Y:        On rats I assume.

D:        Yes. They injected doses of the bacterial proteins into both hungry and well‑fed rats and mice. Analysis showed that the protein produced by the full bacteria stimulated the release of peptide YY. That peptide is a hormone associated with feeling full. They also found that hungry bacteria did not release the protein.

Y:        So, the bacteria are using the body's chemical signaling system to tell a person they are full.

D:        The researchers believe that is what's happening. Now, if they would only help me say no to that second piece of cake.

Stay Connected
Walker Rhea has a B.A. in Comparative Literature from Indiana University. In addition to reading and writing about science, he enjoys performing live comedy in Bloomington, IN and studying dead languages.