Termites are social insects that thrive on dead plant matter. Their ability to digest lignocellulose and survive on nitrogen-poor food is largely attributable to the activity of the symbiotic gut microbiota, which comprises protists, bacteria, and archaea. My research team has been attempting to entangle this complex, multi-layered symbiotic system, using culture-independent approaches including metagenomics and single-cell genomics. We reconstructed genome sequences of several uncultured prokaryotic species associated with cellulolytic protist cells as endo- or ectosymbionts and predicted their functional roles in the symbiotic system. In my talk, I will introduce this fascinating symbiotic system in the termite gut, including our newest results.