Fig. 4

The influence of colonic pH on metabolite production (in mmol per gram of substrate) after 24 h of fermentation. A-F represents total SCFA, acetate, propionate, butyrate, formate, and lactate production, respectively. A t-test was applied to determine the influence of pH on metabolite production with a single substrate or differences in metabolite production between substrates. Benjamin-Hochberg FDR (false discovery rate) correction was adopted for multiple testing. Significant differences between changed colonic pH are labelled with * (p < 0.05), ** (p < 0.01) and *** (p < 0.001), respectively