I always thought it was funny that the entirety of civilization is addicted to and powered by worm shit in the story....and they don't even know it.
Of course, our civilization is addicted to and powered by rotten vegetable matter, so it's really not such a huge leap and is, in fact, a huge improvement.
Shit is better than putrescence, IMO. Apparently Herbert agreed.

Then it gets even MOAR fucked up in the sequels

I sort of prefer *related=http://videosift.com/video/Dune-Thug-Notes but still enjoyed it.

Dune - Thug Notes has been added as a related post - related requested by RFlagg.

tl;dr

Some shit happens
Sting cameo
Some more shit happens
Sting cameo
Worms
Poison
Messiah
Some nuclear shit happens
Sting cameo
Regime Change

Roll credits

As a matter of pedantry.....Paul knew full well before the Jihad started, that it would spread to the stars.

This was the least fucked up possible future he saw and even though he knew it involved the death of his love Chani, he chose that future over the "golden path".

*Massive spoilers from later books below*
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His second son Leto (yes another one) eventually fulfilled this and basically calls his father a big pussy for avoiding it in the 1st place.

The Golden path being ascent to godhood and becoming the greatest tyrant the human race would ever know. (Worm-man super hybrid)

(The end result being that the human race would finally be free of the fatalism Paul and Leto II were trapped by, by the time his reign ended millennia later.)