Complex sentence: Season 13 was the first season in which men served as guest co-hosts; among them were Joe Scarborough, Bryant Gumbel, Tom Bergeron, and D. L. Hughley.
Split into simpler sentences: Season 13 was the first season in which men served as guest co-hosts. They included Joe Scarborough, Bryant Gumbel, Tom Bergeron, and D. L. Hughley.