What most naturally follows?

How to culture microworms
Find a microworm starter culture.
Because these worms don't lay eggs, you will need a few live adult microworms to start your culture. Remember that not all nematode species are a good food source, and some may even make your fish sick.
If your local fish store sells live food, check for microworms there. Try getting in touch with other local hobbyists through aquarist clubs.