Konjac glucomannan with probiotics acts as a combination laxative to relieve constipation in mice by increasing short-chain fatty acid metabolism and 5-hydroxytryptamine hormone release

Nutrition. 2021 Apr:84:111112. doi: 10.1016/j.nut.2020.111112. Epub 2020 Dec 13.

Abstract

Objectives: Various probiotics and natural products can help to relieve constipation. This study aimed to explore the constipation-relieving effects and potential mechanism of a combination laxative of konjac glucomannan and probiotics.

Methods: This study evaluated the gastrointestinal-tract viability of probiotics in vitro. A constipation model was constructed in BALB/c mice, and the efficacies of the combinations verified in terms of their bowel movement-promoting effects, including the first black-stool defecation time and gastrointestinal transit rates of mice. Colonization by the probiotics was determined by quantitative real-time polymerase chain reaction. Hematoxylin-eosin staining, gas chromatography, enzyme-linked immunosorbent assay, quantitative real-time polymerase chain reaction, and Western blot were also used for analysis.

Results: Lactobacillus paracasei X11 (X11) and L. casei YRL577 (YRL577) had outstanding gastrointestinal-tract viability. Konjac glucomannan (KGM) + X11, Prunus persica + X11, and Prunus persica + YRL577 significantly relieved constipation. In addition, KGM promoted the colonization of X11. Meanwhile, KGM + X11 effectively promoted the metabolism of short-chain fatty acids in mice better than other combinations, and the 5-hydroxytryptamine (5-HT) content in the KGM + X11 group was the highest among all the groups. Therefore, KGM + X11 was selected for further research. The combination laxative promoted the secretion of 5-HT, up-regulated mRNA and protein levels of 5-HT receptor 4 and serotonin transporter via the 5-HT pathway, and effectively relieved constipation.

Conclusions: The combination laxative konjac glucomannan-probiotic (KGM + X11) promoted defecation in constipated mice, possibly by increasing short-chain fatty acid metabolism and 5-HT hormone release.

Keywords: 5-hydroxytryptamine; Combination laxative; Constipation; Natural product; Probiotics; Short-chain fatty acid metabolism.

MeSH terms

  • Animals
  • Constipation / drug therapy
  • Fatty Acids, Volatile
  • Hormones / therapeutic use
  • Laxatives / therapeutic use
  • Mannans
  • Mice
  • Mice, Inbred BALB C
  • Probiotics*
  • Serotonin

Substances

  • Fatty Acids, Volatile
  • Hormones
  • Laxatives
  • Mannans
  • Serotonin
  • (1-6)-alpha-glucomannan