Hard to see specs on your pic, but I did also have had them. They started to show while I was on a raw diet, and even more when I was on no carb+ pumpkin seed+garlic cleanse. 2 stool test identified nothing to my disappointment.
I suspect that they may be eggs, but I am not sure. After a while, I self-diagnosed with ropeworm according to the evidence.. But none of the descriptions of ropeworm would mention the black specs. While I was on Miracle-Mineral-Supplement protocol I saw them getting smaller and smaller in size. I know I still have the rope, but the amount of black specs is greatly diminished. Stool normalized and some days I see nothing at all. But some days I see them still but super tiny.