Lactulose, but not Macrogol or Bisacodyl, Shows a Prebiotic Effect in a Computer-Controlled In Vitro Model of the Human Large Intestine

Abstract

12], PEG treatment increased the number of Verrucomicrobia and decreased that of Firmicutes. In mice, Macrogol 3350/PEG decreased the microbial density [13] and relative abundance [14], while Lactulose increased it [13]. Bisacodyl increased the gut microbiota metabolites namely SCFA in rats [15]. Furthermore, a slight increase in bifidobacteria was observed after three months of constipation treatment in humans [1].Data on direct comparison of the prebiotic effects of the three laxatives Lactulose, Macrogol and Bisacodyl are sparse. In patients with constipation, the efficacy of Lactulose was similar to that of PEG in relieving constipation in a 4 week treatment [16]. The levels of bifidobacteria, but not lactobacilli, were significantly increased in the patients receiving Lactulose, but not in the patients receiving PEG [16]. In contrary, the total amount of bacteria was rather decreased and the colonic fermentation inhibited by treatment with PEG [16]. To our knowledge, no further studies directly comparing at least two of the three laxatives are available, hindering the comparison of Lactulose, Bisacodyl and Macrogol regarding their prebiotic effect.