It seems quite a few here are fermenting their own yoghurt and kefir. I am currently eating Arla Skyr strained yoghurt or Pakeeza set yoghurt (same company make ‘Lancashire Farm’ and others).
Not sure what you mean by a “live bacteria”. Are you looking for the name of a specific species, a ‘starter’ for making fermented dairy or a freeze dried capsule?
For anxiety foods rich in magnesium, omega-3s and vitamin D are key. These include seeds (pumpkin/ chia/ flax), cocoa or low sugar dark chocolate, and oily fish. All of which are included in the Clever Guts diet.
Magnesium is lost in sweat and loose bowel movements, so what type of IBS you have is relevant as well as your lifestyle.