Supergreens with Spirulina Superkraut is a brilliant sauerkraut. In addition to being naturally fermented and full of friendly bacteria, it contains 5 different vegetables! These include prebiotic vegetables such as kale, broccoli and spring onion. Prebiotic vegetables are fuel for the microbiome in your gut. It also contains the 'superfood' Spirulina, this blue-green algae is full of vitamins and minerals with antioxidant properties.