Consumption of Dietary Premna microphylla Turcz Leaf Alleviates Functional Constipation via Regulating Gut Microbiota and Aquaporins Transport System in Rats

This study, for the first time, explored the preventive effects of a novel pectic polysaccharide from <i>Premna microphylla</i> Turcz leaves (PMTL) on experimental constipation. Diphenoxylate-induced constipation model (CM) rats were fed a standard rodent chow supplemented with or without PMTL (5%, 10%, and 20%) for 6 weeks. Supplementation of PMTL was shown to accelerate intestinal peristalsis, increase fecal water content, improve intestinal morphology, and suppress gut inflammation by facilitating the secretion of excitatory neurotransmitters (MTL, ACH, and SP) and decreasing the secretion of inhibitory neurotransexcitatory neurotransmittersmitters (SS and NO) in the CM rats. PMTL also reduced the expressions of the colonic aquaporins AQP3 and AQP4 in the CM rats to normalize the colonic water transport system. 16S rRNA gene sequencing revealed that PMTL relieved the gut microbiota disorder of the CM rats and promoted the proliferation of several beneficial bacteria, resulting in an increase in fecal short-chain fatty acids. These findings demonstrate that dietary PMTL consumption can ameliorate the development of constipation and PMTL can be considered as a great promising dietary supplement for alleviating constipation.