Lactobacillus plantarum bacteriocin is associated with intestinal and systemic improvements in diet-induced obese mice and maintains epithelial barrier integrity in vitro

Gut Microbes. 2019;10(3):382-397. doi: 10.1080/19490976.2018.1534513. Epub 2018 Nov 8.

Abstract

We investigated the Lactobacillus plantarum bacteriocin plantaricin EF (PlnEF) system for its contributions to L. plantarum mediated benefits in a mouse model of diet-induced obesity. C57BL/6J mice on a high-fat diet (HFD) were administered a rifampicin resistant mutant of L. plantarum NCMIB8826 (NICMB8826-R) or an isogenic ΔplnEFI mutant strain, LM0419, every 48 h for nine weeks. Mice fed wild-type L. plantarum, but not LM0419, reduced their consumption of the HFD starting three weeks into the study and exhibited an overall 10% reduction in weight gain. The responses were independent of glucose homeostasis, as both NCMIB8826-R and LM0419 fed mice had improved oral glucose tolerance compared to sham controls. Although bacteriocins have antibacterial properties, the ileal, cecal, and fecal microbiota and cecocolic metabolomes were unchanged between mice fed either wild-type L. plantarum or the ΔplnEFI mutant. Instead, only mice fed NCMIB8826-R showed an increased production of ZO-1 in ileal tissues. To verify a potential role for the plantaricin EF system in supporting intestinal epithelial function, synthesized PlnEF peptides were applied to Caco-2 cell monolayers challenged with TNF-α and IFN-γ. The combination of PlnE and PlnF were required to prevent sustained cytokine-induced losses to Caco-2 cell para- and transcellular permeability and elevated IL-8 levels. In conclusion, this study shows that probiotic L. plantarum ameliorates the effects of obesogenic diets through a mechanism that involves the plantaricin EF system and likely includes L. plantarum - induced fortification of the intestinal epithelium.

Keywords: Probiotics; bacteriocins; high-fat; intestinal barrier integrity; lactobacillus; metabolome; microbiome; obesity; weight gain.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Bacteriocins / genetics
  • Bacteriocins / metabolism*
  • Bacteriocins / pharmacology
  • Caco-2 Cells
  • Diet, High-Fat / adverse effects*
  • Humans
  • Intestinal Mucosa / drug effects
  • Intestinal Mucosa / metabolism*
  • Lactobacillus plantarum / chemistry*
  • Lactobacillus plantarum / genetics
  • Male
  • Mice, Inbred C57BL
  • Mutation
  • Obesity / pathology*
  • Obesity / therapy
  • Probiotics / administration & dosage
  • Probiotics / chemistry*
  • Tight Junctions / drug effects
  • Tight Junctions / metabolism
  • Zonula Occludens-1 Protein / metabolism

Substances

  • Bacteriocins
  • Tjp1 protein, mouse
  • Zonula Occludens-1 Protein
  • plantaricin EF

Grants and funding

The authors would like to acknowledge the financial support of the American Diabetes Association (grant # 1-13-GSK-29). DDH is supported by the National Science Foundation (NSF) Graduate Research Fellowship (grant # 1148897).