In TCM each meridian holds an emotion. For the Spleen and Stomach meridians (they are sisters) the emotion is worry and it can also manifest as anxiety and/ or OCD behaviors.
They have done a few animal based studies and now a human one, where they have determined that the flora in the stomach can signal to the brain creating a stress or calming response depending on the flora and bacteria count in the stomach. Probiotics create the good bacteria and a nice environment for the flora so if you have an anxious pup ; ie separation anxiety, overly mouthy, or constantly worried. Adding a Probiotic may be a helpful tool along with Acupressure, Acupuncture, or thunder-shirts. Be sure and ask your veterinarian if it is ok to add Probiotics to your pets diet.
Read the article below for more details…
http://www.huffingtonpost.com/2013/06/17/gut-bacteria-brain-dietary-changes-_n_3455148.html