He doesn't follow many people, but those he does reveal much about the Guy
Guy follows 141 people on Twitter, and you can separate those people generally into four groups.
Bay Area sports teams and personalities
According to his website, Fieri's hometown is Santa Rosa, CA (in Sonoma County), which explains his love of Northern Cali sports teams and personalities: @GoldenStateWarriors, @OaklandRaiders, @CelReece45 (a Raiders player), and @StephenCurry30 (a GOAT, right before Game 7 happened).
Actors and musicians
Some of these people (like Mr. Alright, Alright, Alright) have appeared on one of Guy's many TV shows: @McConaughey, @SethRogen, @ChloeGMoretz, and @RevRunWisdom. He's also a huge fan of Anchorman parody accounts: @Ch4BrickTamland and @ItsWillyFerrell. Sure! And the man clearly listens to country music: @BlakeShelton, @DariusRucker, @TraceAdkins, @TobyKeith. Not a country musician: @Questlove. Are Guy and I both Roots fans? Maybe!