alloprevotella rava alloprevotella rava alloprevotella rava is a gram-negative and anaerobic bacterium from the genus of alloprevotella which has been isolated from the human oral cavity. alloprevotella rava scientific classification domain: bacteria phylum: bacteroidota class: bacteroidia order: bacteroidales family: prevotellaceae genus: alloprevotella species: a. rava binomial name alloprevotella ravadownes et al. 2013 saliva samples of suicidal students are positively correlated with lower alloprevotella rava levels.