You've gotta watch out for additives though. Lots of processed umami sources have extra stuff you might not want. Your best bet is to use natural sources of umami like seaweed and nutritional yeast flakes, packed with flavor and health benefits!
I get why people would say white, but hear me out. Whole grain bread is not only healthier but adds a nice texture contrast with crispy bacon. Plus, it’s better fuel for your body. Just try it with a good quality loaf!