I have expelled these as well using Psyllum Husk capsules.
I read they are eggs from Dog Tapeworm. This is one of the most common forms of tapeworm-- especially if you have pets, or ever got bitten by a flea on your feet when walking in grass, or carpeting. Don't be quick to get rid of your dog-- they can easily be dewormed. I read an article about them from one nutritionist who never owned dogs--but has also seen the same 'seed" in his bowel movements.
These Tapeworms arent as large as the type seen in photos-- so you may never even know you have them.
Nevertheless, these Tapeworms arent healthy to have in the body and if you can rid yourself of them, you will probably notice a big jump in your immune system and health-as well as metabolism.