Is there a bacteria that would eat gluten for cooking?
"How do I make gluten-free bread?" is a question that's answerable simply by searching for "gluten-free bread recipes". The key to those recipes is that they start from a gluten-free flour, and take some steps to ensure that there's enough structure to hold the bread together despite the lack of gluten. There's a bit of variety in gluten-free flours; the good ones are a mix of starches that work better in baking applications than an arbitrary gluten-free flour might.

If in contrast you tried to make gluten-free bread by starting with normal bread and destroying the gluten, you wouldn't have edible bread anymore. You'd have to add other things to create the structure, in which case you might as well just have started with gluten-free flour.