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.
