Elaeagnus angustifolia L. fruit alleviates diarrhea via regulating intestinal microbiota and short chain fatty acids

Fruits of Elaeagnus angustifolia L. have been used as Uyghur medicine due to the properties of treating spleen and stomach weakness, indigestion, enteritis, diarrhea, lung heat, and cough. However, the anti-diarrhea mechanism was still not clear. This study explored the mechanism of E. angustifolia fruit alleviated diarrhea from the perspective of gut microbiota. Diarrhea model was established with Folium sennae in mice. Then, the levels of diarrhea rate and diarrhea index of mice were evaluated. Hematoxylin eosin (HE) staining was employed to detect pathological sections of colon tissue. 16S rRNA sequencing analysis was researched to confirm the gut microbiota in mice. Diversity and differential analysis were adopted to analyze the intestinal microflora. Furthermore, Gas chromatography-quadrupole time-of-flight tandem mass spectrometry (GC-Q-TOF-MS) was used to detect the concentrations of short chain fatty acids (SCFAs) in intestine. The high-dose group (3.2 g/kg) of E. angustifolia fruit could significantly reduce the diarrhea rate and diarrhea index of mice caused by Folium sennae (p < 0.01). We also found that E. angustifolia fruit enhanced the diversity of gut microbiota while ameliorating diarrhea. Alpha diversity revealed that the microbial composition of E. angustifolia fruit group tended to be more similar to that of the CON group (no significant difference at p < 0.05). E. angustifolia fruit also induced structural changes of gut microbiota in mice. In addition, the concentrations of SCFAs increased after administration of E. angustifolia fruit. This study demonstrated that E. angustifolia fruit could ameliorate diarrhea by regulating the composition and abundance of intestinal microbiota, together with the levels of SCFAs.