Microalgal biomass-assisted delivery of probiotics for modulation of gut homeostasis and alleviation of intestinal inflammation

The clinical application of orally delivered probiotics as live therapeutics in the treatment of colitis is hampered by suboptimal bacterial bioactivity and inadequate gut retention. Here, we present a novel symbiotic approach that combines Spirulina microalgae and probiotics (SP@BC) to enhance the therapeutic efficacy of bacteriotherapy. The SP@BC is established by attaching chitosan-coated probiotic strains (BCCS) on Spirulina platensis (SP) via electrostatic self-assembly. Following oral administration, the natural antioxidative bioenzymes present in SP can persistently protect probiotics from oxidative damage in inflamed intestines. Furthermore, the helical-shaped SP can be easily trapped by the intestinal villi, resulting in a significantly enhanced gut retention of the SP@BC system. In a mouse model of colitis, orally administrated SP@BC distinctly improves intestinal permeability, reduces gut inflammation, and restores intestinal microbial homeostasis. The microalgae-assisted delivery of probiotics is highly effective, safe, and easily manufacturable, showcasing promising potential for the clinical translation of probiotic therapies.