An orally administered magnoloside A ameliorates functional dyspepsia by modulating brain-gut peptides and gut microbiota

Functional dyspepsia (FD) is very common worldwide with a high prevalence of 10%–30%, and it becomes a heavy burden to patients because of its hard to be cured. In our previous study, phenylethanoid glycosides were found to exist in Houpo, a traditional Chinese medicine commonly used for the treatment of abdominal distention, pain and dyspepsia. In the present study, the effect of magnoloside A (MA), a main phenylethanoid glycoside in Houpo, on FD was firstly evaluated and its potential mechanism was concluded. MA was orally administered consequently for 3 weeks, and its effect on a FD rat model established through transient neonatal gastric irritation and mature alternate-day fasting was tested. Levels of brain-gut peptides and inflammatory factors in blood or tissues were determined by ELISA methods. Meanwhile, the gut microbiota was analyzed by 16S rRNA gene sequencing and short chain fat acids were determined by GC/MS. MA exhibited anti-FD activities by fastening the delayed gut emptying rate of FD rat and increasing the levels of gastrin, motilin, and calcitonin gene related protein; and decreasing the levels of 5-hydroxytryptamine, nitric oxide synthase, and vasoactive intestinal peptide. On the other hand, MA can modulate the composition of gut microbiota, resulting in the variation of the short chain fat acids. MA ameliorated FD rats by modulating of the secretion of related brain-gut peptides and altering the composition of intestinal microbiota.