Design of innovative strategies for oral drug delivery is particularly promising for intestinal disease treatment. However, many obstacles such as poor therapeutic efficacy and low bioavailability and biocompatibility remain to be addressed. Here, we report a versatile formulation based on a helical-shaped cyanobacterium, Spirulina platensis (SP), loaded with curcumin (SP@Curcumin) for the treatment of colon cancer and colitis, two types of intestinal diseases. In radiotherapy for colon cancer, SP@Curcumin could mediate combined chemo- and radiotherapy to inhibit tumor progression while acting as a radioprotector to scavenge reactive oxygen species induced by the high dose of x-ray radiation in healthy tissues. SP@Curcumin could also reduce the production of proinflammatory cytokines and thereby exerted anti-inflammatory effects against colitis. The oral drug delivery system not only leveraged the biological properties of microalgal carriers to improve the bioavailability of loaded drugs but also performed excellent antitumor and anti-inflammation efficacy for intestinal disease treatment.