Do not feed anything other worm other than night crawlers(also known as earth worms) as a staple diet. You can feed hornworm(green caterpillars) as an occasional treat but stay away from red words. Nutritionally speaking, night crawlers are your best bet and you don't have to gut load them.
You might also want to try Dubia Roaches when he gets bigger. For now, since he's still a baby, crickets and night crawlers should be easier to digest.