Are river shimp and snails safe to feed to leopard geckos?

I am trying to give my two adult 4 year old female leopard geckos a little variety in their diet. They regularly eat live crickets, and I have fed them the moist canned crickets and mealworms from the pet store, both which they love. There is a river shrimp can and a snail can that do not specify whether leopard geckos can eat them or not, nor have I found the answer online. Are they safe to feed to my leopard geckos? Has anybody fed river shrimp and/or snails to their leopard geckos?