Mice that behave like autistic humans saw many of their symptoms disappear when they ate probiotics, the same kind of healthy bacteria found in many yogurts, CalTech biologist Paul Patterson has just told NPR. His research, which will appear in a forthcoming issue of the journal Cell, is part of a growing body of evidence that the connection between the kind of bacteria that live in our gut and our psychological wellbeing is important enough that simply changing what we eat can alter, among other things, our mood and levels of anxiety.
This might seem like a spurious connection, except that scientists think they have some idea how bacteria living in our stomach and intestines are connected to our brain. One connection is through the Vagus nerve, which sends information about our organs to our brain. Some bacteria appear to be releasing neurotransmitters—tiny molecules that directly affect the function of neurons—that can activate the sensory nerves connected to the Vagus.
“These bacteria are, in effect, mind-altering microorganisms,” researcher Mark Lyte of Texas Tech University tells NPR.
Bacteria are also communicating with our bodies through our immune and endocrine systems—i.e., by producing hormones our bodies recognize and respond to. These aren’t just faint signals, either—they’re strong enough that replacing the gut bacteria of an anxious mouse with that of a bold one can make the wallflower less anxious.
Researchers at the Sheppard Pratt psychiatric facility in Baltimore are even conducting trials in which they give patients probiotics in order to see if it improves or stabilizes their mood.
Does this mean companies like Chobani will soon be able to make health claims on their probiotic-infused yogurts, just as cereal companies are allowed to claim their products improve heart health? If the balance of evidence is eventually in their favor, why not?