L-Arabinose attenuates loperamide-induced constipation through the regulation of gut microbiota in mice.

L-Arabinose is a plant-specific pentaose with various functional properties. Here, the effects of L-arabinose on long-term constipation were investigated. According to the results, L-arabinose significantly attenuated loperamide-induced constipation by enhancing the gastrointestinal motility and relieving intestinal injuries. In addition, L-arabinose reduced neutrophil proportion and inflammatory cytokine concentrations in constipated mice, exhibiting immunomodulatory activity. Furthermore, the 16S rRNA analysis showed that L-arabinose ameliorated the gut microbiota dysbiosis induced by loperamide, and Lactobacillus was the most significant dominant strain at the genus level in the L-arabinose group. More importantly, the effect of L-arabinose was diminished by gut microbiota depletion, further confirming the necessity of gut microbiota in L-arabinose-initiated constipation treatment. Mechanistically, L-arabinose increased the abundance of Lactobacillus, ameliorating the gut microbiota dysbiosis, which further attenuated the constipation by enhancing the gastrointestinal motility and relieving intestinal injuries. In summary, L-arabinose can ameliorate loperamide-induced constipation in mice through the regulation of gut microbiota.