Cool beans B. Miso is an excellent choice as it will help populate your internal flora. Just in case you didn't know that it is very important NEVER to boil miso and you will be destroying the active bacteria and other goodness. If you add sea vegetables like Wakame or any other veggies you first cook all the veggies without the miso in. Then when the veggies are done you turn the heat off and add you miso and let it sit for a few minutes.
Something that adds great flavor to miso soup is that in the same pot that you will be making the soup I sauté some onions in toasted sesame seed oil the add you water and that ever other veggies. My fave veggie to add are wakame shitake mushroom and daikon. Shoot just thinking about it has made my mouth water so I'm headed for the kitchen to make some. If you have never tried toasted sesame seed oil you will be in for a treat. The aroma from it is fab.