Dune is more based on the desert dwelling bedouin than Islam.
I recall no islamic references in Dune but tons of Bedouin correlations.
The Fremen are followers of the Zensunni religion. They fight the jihad. Their core fighters are called the Ikhwan or brotherhood, the same word used for the Muslim Brotherhood. Their code of custom is called sharia. Paul Atreides becomes the Mahdi.
But your point is well taken. The problem is that at this point in time it’s difficult to disentangle Arabic from Islamic culture. They’ve pretty much merged.
Here’s an interesting article.
http://baheyeldin.com/literature/arabic-and-islamic-themes-in-frank-herberts-dune.html