Deciphering the quorum-sensing lexicon of the gut microbiota

The enduring coexistence between the gut microbiota and the host has led to a symbiotic relationship that benefits both parties. In this complex, multispecies environment, bacteria can communicate through chemical molecules to sense and respond to the chemical, physical, and ecological properties of the surrounding environment. One of the best-studied cell-to-cell communication mechanisms is quorum sensing. Chemical signaling through quorum sensing is involved in regulating the bacterial group behaviors, often required for host colonization. However, most microbial-host interactions regulated by quorum sensing are studied in pathogens. Here, we will focus on the latest reports on the emerging studies of quorum sensing in the gut microbiota symbionts and on group behaviors adopted by these bacteria to colonize the mammalian gut. Moreover, we address the challenges and approaches to uncover molecule-mediated communication mechanisms, which will allow us to unravel the processes that drive the establishment of gut microbiota.