Probiotics are in foods and in supplements, such as Probios powder. They can help reestore the beneficial gut bacteria. DE can be hard on lungs to breathe in to humans and chickens. It will not deworm a chicken. It also will do nothing for diarrhea. If you have a local vet who will do a test on some fresh droppings, you could see if there are worms or coccidia or other parasites. Runny poops can be caused by a number of issues, including drinking a lot of water.