Watch VoirFilms. In The Gut Movie, we follow the journey of journalist & researcher Kale Brock as, in the quest to discover whether the ‘optimal microbiome’ does indeed exist, he travels from Australia to Namibia to live with The San, an ancient hunter-gatherer people living traditionally from the land. During the excursion Brock monitors his own microbiome and how it changes in conjunction with the new surroundings, and takes microbiome samples of The San to gauge the significant differences in microbiota present across cultures.