...really is through his stomach! Who knew??
From ScienceDaily: Gut Bacteria Linked to Behavior: That Anxiety May Be in Your Gut, Not in Your Head
So it looks like researchers have proven that the delicate balance of bacteria that resides in the stomach of each and every person on earth has a lot to do with how that person feels. Through experimenting on lab mice, scientists have shown that it is possible to control how active and adventurous, or passive and quiet, a mouse's behavior is by tampering with levels of orally administered antibiotics.
What this means for people? Apparently, a change in diet or vitamin regimen can have a more powerful and profound effect on treating behavioral disorders than tampering with mood enhancers or other drugs that effect brain chemistry. Through their experimentation on lab mice, researchers were able to show that not only could they change the behavior patterns on mice with simple antibiotic regimens, but that by discontinuing the administration of the drugs they were able to have the mice return to their regular patterns of behavior. This may one day lead to therapy options for emotional and psychological disorders that are far more safe, with fewer side-effects, than many drugs offered today.
So be careful what you throw down that pie-hole. You never know how it might be affecting your mood.