I come to you today with this issue.
I've just start blender course @blenderguru (I really enjoy it;)).
As you can see (in render) my icing is gone... but sprinkles are there. And when I check it in blender viewport everything is alright. I am just starting learning, so please be nice :)
Rendered image (icing doesn't show up)
Here's how it looks like in Rendered Preview
And here's an image of my particles settings
P.S.: If it can help here's the blender file