Broccoli-Derived Exosome-like Nanoparticles Alleviate Loperamide-Induced Constipation, in Correlation with Regulation on Gut Microbiota and Tryptophan Metabolism

Constipation, a common gastrointestinal dysfunction, damages patients' life quality and predisposes them to other serious diseases. Current strategies against constipation often cause drug dependency and side effects. Here, we demonstrated that broccoli-derived exosome-like nanoparticles (BENs), a natural product with high gastrointestinal stability, ameliorated LOP-induced constipation in mice. Specifically, orally administered BENs (17.5 mg/kg/d) effectively shortened defecation time, sped up intestinal propulsion rate, and increased feces amount in constipated mice. BENs also raised excitatory neurotransmitters SP and MTL and reduced inhibitory neurotransmitters VIP and ET-1. Mechanistically, BENs were taken up by gut microbes, restored LOP-disordered gut microbiota, and altered microbial metabolism of SCFAs and tryptophan, as evidenced by the results of fluorescence microscopy, 16S rRNA gene sequencing, and nontargeted metabolomics. Thereinto, BEN-enriched SCFA-producing microorganisms are closely associated with the feces amount and SP and VIP levels and BEN-elevated indole-3-pyruvic acid and 3-indoleacetic acid are highly linked to ET-1, SP, and MTL levels. Conclusively, BENs, mitigating constipation by regulating gut microbiota and microbial tryptophan metabolism, showed high potential to be developed as alternative regimens for constipation.