Cinnamic acid regulates the intestinal microbiome and short-chain fatty acids to treat slow transit constipation

Figure 1 Pharmacological effects of cinnamic acid on slow transit constipation mice. A: Number of fecal remnants in the colon of mice in each group (n = 8); B: Number of fecal remnants in the colon of mice in each group (n = 8); C: 24 h defecations of mice in each group (n = 8); D: Fecal water content of mice in each group (n = 8); E: Intestinal transit rate of mice in each group (n = 8). ^aP < 0.05 and ^bP < 0.01 versus the control group; ^cP < 0.05 and ^dP < 0.01 versus the slow transit constipation model group. NS: Not significant. PRU: Prucalopride; CA-low: Cinnamic acid with low dose; CA-high: Cinnamic acid with high dose.

Figure 2 Hematoxylin-eosin and Alcian blue/periodic acid-Schiff staining of each group of mice. A: HE staining of each group of mice; B: Alcian blue/periodic acid-Schiff staining of each group of mice. PRU: Prucalopride; CA-low: Cinnamic acid with low dose; CA-high: Cinnamic acid with high dose.

Figure 3 Effects of Cinnamic acid on the concentration of 5-HT and vasoactive intestinal peptide. A: Serum concentration of 5-hydroxytryptamine in each group of mice (n = 8); B: Content of vasoactive intestinal peptide in the colon of mice in each group (n = 8). ^bP < 0.01 versus the control group; ^dP < 0.01 versus the slow transit constipation model group. PRU: Prucalopride; CA-low: Cinnamic acid with low dose; CA-high: Cinnamic acid with high dose.

Figure 4 Alpha diversity of intestinal microbiome in each group of mice (n = 8). A: Shannon index evaluation of each group of mice at the OTU level; B: Difference test of Shannon index at the OTU level; C: Shannon index evaluation of each group of mice at the phylum level; D: Difference test of Shannon index at the phylum level; E: Shannon index evaluation of each group mice at the genus level; F: Difference test of Shannon index at the genus level; ^aP < 0.05 and ^bP < 0.01. PRU: Prucalopride; CA-low: CA with low dose; CA-high: CA with high dose.

Figure 5 Beta diversity of intestinal microbiome in each group of mice (n = 8). A: PcoA plot at the operational taxonomic units (OTU) level; B: Venn plot at the OTU level; C: Hierarchical clustering tree at the OTU level; D: Hierarchical clustering tree at the phylum level; E: Hierarchical clustering tree at the genus level; PRU: Prucalopride; CA-low: Cinnamic acid with low dose; CA-high: Cinnamic acid with high dose.

Figure 6 The composition and abundance of the intestinal microbiome in each group of mice (n = 8). A: LefSe analysis of the significantly differential microbiome in each group; B: Differential comparison between multiple groups at the operational taxonomic units level; C: Differential comparison between multiple groups at the genus level; D: Differential comparison between model and CA-low group at the genus level; E: Differential comparison between model and CA-high group at the genus level. ^aP < 0.05, ^bP < 0.01 and ^eP < 0.001. PRU: Prucalopride; CA-low: Cinnamic acid with low dose; CA-high: Cinnamic acid with high dose.

Figure 7 Prediction of phenotypes and biological functions for the significantly differential microbiome in each group. A: Prediction of phenotypes for the significantly differential microbiome in each group; B: Prediction of biological functions for the significantly differential microbiome in each group. ^aP < 0.05. PRU: Prucalopride; CA-low: Cinnamic acid with low dose; CA-high: Cinnamic acid with high dose.

Figure 8 Quantitative analysis of short-chain fatty acids and their correlation with the dominant microbiome (n = 8). A: Short-chain fatty acids (SCFAs) level in each group; B: SCFAs level in model and CA-low group; C: SCFAs level in model and CA-high group; D: Heatmap for the correlation between SCFAs and differential microbiome in each group; E: Heatmap for the correlation between SCFAs and differential microbiome in CA-low group; F: Heatmap for the correlation between SCFAs and differential microbiome in CA-high group. PRU: Prucalopride; CA-low: Cinnamic acid with low dose; CA-high: Cinnamic acid with high dose.