Cooked sourdough bread does not contain probiotics. But is it good for the gut? YES. And these benefits come from the very fact that probiotics were present in the first place.
Sourdough bread is far better for your digestion when compared to other breads that have been fermented with commercial yeast. But if you want to narrow it down even further, varieties of sourdough bread like ancient grains will be even easier to digest due to their grain structure.