Stroke-prone spontaneously hypertensive rat (SHRSP) microbiota increases SBP in WKY rats. A: SBP of 4 microbiota gavage treatment groups over time. Three-way repeated measures ANOVA, P < 0.001 for main effects of strain, gavage, and age. Two-way repeated measures ANOVA, *P = 0.028 for main effect of gavage, #P < 0.05 for WKY g-WKY vs. WKY g-SHRSP. B: mean SBP from 7.5 to 16.5 wk (all time points during microbiota gavage treatments). Two-way repeated measures ANOVA, $P < 0.05 relative to WKY g-WKY. Data are shown as means ± SE, n = 6–7.
Measures of alpha- and beta-diversity vary by strain and microbiota gavage treatments. A: strain and gavage treatment did not affect the microbial community richness (Chao1 index). B: SHRSP microbiota increases the microbial community diversity (Shannon index) of WKY rats. C: principal coordinate analysis of WKY and SHRs gavaged with WKY or SHRSP cecal contents. Unifrac analysis was used to generate distance measurements between each sample. Two clusters were formed corresponding to the gavaged microbiota. Also shown is the 3-dimensional localization of the WKY and SHRSP cecal content used for gavages. Dashed line denotes separation between WKY g-WKY and SHR g-WKY. Data are shown as means ± SE n = 6–7, *P < 0.05 for WKY g-WKY vs. WKY g-SHRSP.
Comparison of phyla between WKY and SHR strains receiving WKY or SHRSP gavage treatments. A: relative abundance of the major phyla of the gut microbiota. B: increased Firmicutes:Bacteroidetes ratio in WKY g-SHRSP, as compared with WKY g-WKY, is due to expansion of Firmicutes as well as contraction of Bacteroidetes. Data are shown as means ± SE n = 6–7, *P < 0.05 for WKY g-WKY vs. WKY g-SHRSP.
Gavage treatments alter the relative abundance of multiple bacterial taxa. Linear discriminate analysis effect size (LEFSe) analysis was used to calculate a linear discriminate analysis (LDA) score for taxa that characterize WKY vs. SHRSP gavage treatment of WKY rats (A), WKY vs. SHRSP gavage treatment of SHR rats (B). Positive LDA scores indicate the enrichment of taxa in g-WKY (green) relative to g-SHRSP (red), and negative LDA scores indicate the depletion of taxa in g-WKY relative to g-SHRSP. Given this relationship, the negative LDA scores can also be interpreted as enrichment in g-SHRSP (red) relative to g-WKY (green). C: taxa found to be significantly different by LEFSe analysis (from A and B) are shown in cladograms to illustrate the phylogenetic relationship between altered taxa. Nodes labeled alpha-numerically in C correspond to the labels in parenthesis in A and B. D: relative abundance of the genus Desulfovibrio in WKY and SHRs gavaged with WKY or SHRSP microbiota. *P < 0.05 relative to WKY g-WKY, n = 6–7.
Shifts in taxon abundance that correlate with SBP. A: the lactate-producing genus Lactobacillus positively correlates with SBP. B–D: the butyrate-producing family Clostrideaceae and acetate-producing genera Holdemania and Coprobacillus negatively correlate with SBP. Data are shown as means ± SE n = 6–7.
Assessment of fecal metabolites by targeted metabolomics. A: short chain fatty acid concentrations. B and C: selected neurotransmitters and amino acids were not significantly different between WKY and SHRs gavaged with WKY or SHRSP microbiota. Data are shown as means ± SE n = 6–7.