The above mentioned article recounts a recent scientific study in which mice that were given high amounts of beneficial probiotics appeared less stressed – and actually produced less stress hormones – when put into abruptly stressful situations, such as being dropped into a pool of water. Moreover, when the connection between the gut and the brain was severed, these mice no longer showed decreased signs of stress.  The author concludes that “There's nothing metaphorical about "gut feelings," for what happens in the gut really does influence what we feel.”