The gut microbiota represents a huge community of microorganisms that play essential roles in immune modulation and homeostasis maintenance. Microbiota transplantation is an important approach to prevent and treat disease as it can inhibit pathogen colonization and positively modulate bacterial composition. However, the development of oral bacterial therapeutics has been restricted by low bioavailability and limited retention in the gastrointestinal tract. Here, we report a simple yet highly efficient method to coat gut microbes via biointerfacial supramolecular self-assembly. Coating can be performed within 15 min by simply vortexing with biocompatible lipids. Bacteria coated with an extra self-assembled lipid membrane exhibit significantly improved survival against environmental assaults and almost unchanged viability and bioactivity. We demonstrate their enhanced efficacies in oral delivery and treatment using two murine models of colitis. We suggest that biointerfacial supramolecular self-assembly may provide a unique platform to generate advanced bacterial therapeutics for the treatment of various diseases.