Effects of Docetaxel Injection and Docetaxel Micelles on the Intestinal Barrier and Intestinal Microbiota.

Increasing evidence has suggested that chemotherapeutics affect the integrity of the intestinal barrier and alter the intestinal microbiota, thus limiting the therapeutic outcomes of cancer chemotherapy. Docetaxel (DTX) is used for breast cancer treatment and has gastrointestinal side effects, but the influence of DTX formulations on the intestinal barrier and intestinal microbiota remains unknown. Therefore, in this work, the influence of DTX injection (free DTX, commercial formulation) and DTX/methoxy poly(ethylene glycol)-block-poly(D,L-lactide) (mPEG-PDLLA) (DTX micelles, nanoformulation) on the integrity of the intestinal barrier and the intestinal microbiota is investigated. It is found that the free DTX causes significantly greater intestinal barrier damage than the DTX micelles. The diversity of the intestinal microbiota, and the relative abundance of Akkermansia muciniphila and Ruminococcus gnavus in the DTX micelle-treated group is significantly higher than that in the free DTX-treated group. Moreover, the tumor growth rate is elevated in antibiotic mixture-pretreated mice, demonstrating that the diversity and composition of the intestinal microbiota may be associated with tumor progression. This work demonstrates that different formulations of chemotherapeutics have different effects on the integrity of the intestinal barrier and the intestinal microbiota.