Effect of a High-Fat Diet on the Small-Intestinal Environment and Mucosal Integrity in the Gut-Liver Axis.
Takashi NakanishiHirokazu FukuiXuan WangShin NishiumiHaruka YokotaYutaka MakizakiYoshiki TanakaHiroshi OhnoToshihiko TomitaTadayuki OshimaHiroto MiwaPublished in: Cells (2021)
Although high-fat diet (HFD)-related dysbiosis is involved in the development of steatohepatitis, its pathophysiology especially in the small intestine remains unclear. We comprehensively investigated not only the liver pathology but also the microbiome profile, mucosal integrity and luminal environment in the small intestine of mice with HFD-induced obesity. C57BL/6J mice were fed either a normal diet or an HFD, and their small-intestinal contents were subjected to microbial 16S rDNA analysis. Intestinal mucosal permeability was evaluated by FITC-dextran assay. The levels of bile acids in the small-intestinal contents were measured by liquid chromatography/mass spectrometry. The expression of tight junction molecules, antimicrobial peptides, lipopolysaccharide and macrophage marker F4/80 in the small intestine and/or liver was examined by real-time RT-PCR and immunohistochemistry. The abundance of Lactobacillus was markedly increased and that of Clostridium was drastically decreased in the small intestine of mice fed the HFD. The level of conjugated taurocholic acid was significantly increased and those of deconjugated cholic acid/secondary bile acids were conversely decreased in the small-intestinal contents. The expression of occludin, antimicrobial Reg IIIβ/γ and IL-22 was significantly decreased in the small intestine of HFD-fed mice, and the intestinal permeability was significantly accelerated. Infiltration of lipopolysaccharide was significantly increased in not only the small-intestinal mucosa but also the liver of HFD-fed mice, and fat drops were apparently accumulated in the liver. Pathophysiological alteration of the luminal environment in the small intestine resulting from a HFD is closely associated with minimal inflammation involving the gut-liver axis through disturbance of small-intestinal mucosal integrity.
Keyphrases
- high fat diet
- insulin resistance
- high fat diet induced
- adipose tissue
- mass spectrometry
- liquid chromatography
- metabolic syndrome
- poor prognosis
- skeletal muscle
- type diabetes
- endothelial cells
- staphylococcus aureus
- high resolution
- wild type
- toll like receptor
- immune response
- single molecule
- diabetic rats
- high glucose
- photodynamic therapy
- single cell
- antibiotic resistance genes