Nondigestible stachyose alleviates cyclophosphamide-induced small intestinal mucosal injury in mice by regulating intestinal exosomal miRNAs, independently of the gut microbiota.

Stachyose has traditionally been considered to exert prebiotic effects primarily through its interaction with gut microbiota. However, this study reveals a novel mechanism by which stachyose alleviates cyclophosphamide (CY)-induced small intestinal mucosa disruption by regulating the intestinal exosomal miRNAs, without relying on the gut microbiota. Specifically, stachyose significantly mitigates CY-caused damage to the intestinal permeability, oxidative stress, and the structure of intestinal villi and crypts in pseudo-germ-free (PGF) mice. The immunofluorescence staining and qPCR analyses show that stachyose treatment restores CY-caused abnormal changes on the levels of tight junction proteins including MUC2, Occludin, Claudin-1, and ZO-1, and pro-inflammatory cytokines including TNF-α, IL-1β, and IL-2. Furthermore, by conducting fecal miRNA transplantation experiment, we further demonstrated that, similar to stachyose, stachyose-shaped intestinal miRNAs protect against CY-induced intestinal mucosal damage in PGF mice. In summary, this study provides new scientific evidence for the direct interaction between nondigestible stachyose and the proximal small intestine. It also opens new avenues for further investigation into the systemic nutritional functions of stachyose, particularly the health benefits of stachyose in the upper gastrointestinal tract.