I hadn't thought of it from that angle ~ the "organic greens" powder I've been using to boost green color has spirulina in it, along with other greens like spinach, moringa, even broccoli, among other greensI know it’s quite common, but what I think of as the weirdest ingredient I’ve used so far is spirulina which is “cyanobacteria” and I wouldn’t have thought bacteria could be an ingredient in soap!