scholarly journals Effect of a High-Fat Diet on the Small-Intestinal Environment and Mucosal Integrity in the Gut-Liver Axis

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3168
Author(s):  
Takashi Nakanishi ◽  
Hirokazu Fukui ◽  
Xuan Wang ◽  
Shin Nishiumi ◽  
Haruka Yokota ◽  
...  

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.

2020 ◽  
Author(s):  
Mingming Song ◽  
Shiyao Zhang ◽  
Zixuan Tao ◽  
Yujie Shi ◽  
Yonghong Xiong ◽  
...  

Abstract The changes of small intestinal homeostasis have been recognized to contribute essentially to the obese development. However, the core small intestinal regulator which mediates overnutrient impacts on the homeostasis of the small intestines remains elusive. Here, we identify the MMP-12 as such a responsive factor in mouse small intestines. Taking advantages of the nano delivery system, we demonstrate that small intestine-specific MMP-12 knockdown alleviates high-fat diet feeding-induced metabolic disorders and improves intestinal homeostasis in mice, including a significant decrease in lipid transportation, bile acid reabsorption, and inflammation. In parallel, the small intestinal integrity is recovered and the gut microbiota composition is reversed towards that under normal diet feeding. Mechanistically, MMP-12, differing from its traditional elastolytic function, acts as a transcriptional factor to activate Fabp4 transcription through epigenetic modification. In translational medicine, clinical applications of our nanosystem and therapeutic interventions targeting MMP-12 will benefit patients with obesity and associated diseases.


Parasitology ◽  
2012 ◽  
Vol 139 (6) ◽  
pp. 716-725 ◽  
Author(s):  
ALBA CRISTINA MIRANDA DE BARROS ALENCAR ◽  
RENATA HEISLER NEVES ◽  
ALBANITA VIANA DE OLIVEIRA ◽  
JOSÉ ROBERTO MACHADO-SILVA

SUMMARYThe consumption of a high-fat diet modifies both the morphology of the small intestine and experimentally tested effects of schistosomiasis mansoni. However, whether a schistosomiasis infection associated with a high-fat diet causes injury to the small intestine has never been investigated. Mice were fed either a high-fat or a standard-fat diet for 6 months and were then infected withSchistosoma mansonicercariae. Physical characteristics of the intestinal tissue (mucosal thickness, small intestinal villi length and height, and abundance of goblet cells and enterocytes on the villous surface) and the distribution of granulomas along the intestinal segments and their developmental stage were measured at the time of sacrifice (9 or 17 weeks post-infection). The group fed a high-fat diet exhibited different granuloma stages, whereas the control group possessed only exudative granulomas. The chronically infected mice fed a high-fat diet exhibited higher granuloma and egg numbers than the acutely infected group. Exudative, exudative/exudative-productive and exudative-productive granulomas were present irrespective of diet. Computer-aided morphometric analysis confirmed that villus length, villus width, muscular height and submucosal height of the duodenal and jejunal segments were affected by diet and infection. In conclusion, a high-fat diet and infection had a significant impact on the small intestine morphology and morphometry among the animals tested.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Naoki Sugimura ◽  
Koji Otani ◽  
Toshio Watanabe ◽  
Geicho Nakatsu ◽  
Sunao Shimada ◽  
...  

AbstractNon-steroidal anti-inflammatory drugs (NSAIDs) cause damage in the small intestine in a bacteria-dependent manner. As high-fat diet (HFD) is a potent inducer of gut dysbiosis, we investigated the effects of HFD on bacterial flora in the small intestine and NSAID-induced enteropathy. 16S rRNA gene analysis revealed that the population of Bifidobacterium spp. significantly decreased by fold change of individual operational taxonomic units in the small intestine of mice fed HFD for 8 weeks. HFD increased intestinal permeability, as indicated by fluorescein isothiocyanate-dextran absorption and serum lipopolysaccharide levels, accompanied by a decrease in the protein expressions of ZO-1 and occludin and elevated mRNA expression of interleukin (IL)-17A in the small intestine. HFD-fed mice exhibited increased susceptibility to indomethacin-induced damage in the small intestine; this phenotype was observed in normal diet-fed mice that received small intestinal microbiota from HFD-fed mice. Administration of neutralizing antibodies against IL-17A to HFD-fed mice reduced intestinal permeability and prevented exacerbation of indomethacin-induced damage. Thus, HFD-induced microbial dysbiosis in small intestine caused microinflammation through the induction of IL-17A and increase in intestinal permeability, resulting in the aggravation of NSAID-induced small intestinal damage.


2007 ◽  
Vol 282 (46) ◽  
pp. 33346-33357 ◽  
Author(s):  
Su-Hyoun Chon ◽  
Yin Xiu Zhou ◽  
Joseph L. Dixon ◽  
Judith Storch

Intestinal monoacylglycerol (MG) metabolism is well known to involve its anabolic reesterification to triacylglycerol (TG). We recently provided evidence for enterocyte MG hydrolysis and demonstrated expression of the monoacylglycerol lipase (MGL) gene in human intestinal Caco-2 cells and rodent small intestinal mucosa. Despite the large quantities of MG derived from dietary TG, the regulation of MG metabolism in the intestine has not been previously explored. In the present studies, we examined the mRNA expression, protein expression, and activities of the two known MG-metabolizing enzymes, MGL and MGAT2, in C57BL/6 mouse small intestine, as well as liver and adipose tissues, during development and under nutritional modifications. Results demonstrate that MG metabolism undergoes tissue-specific changes during development. Marked induction of small intestinal MGAT2 protein expression and activity were found during suckling. Moreover, while substantial levels of MGL protein and activity were detected in adult intestine, its regulation during ontogeny was complex, suggesting post-transcriptional regulation of expression. In addition, during the suckling period MG hydrolytic activity is likely to derive from carboxyl ester lipase rather than MGL. In contrast to intestinal MGL, liver MGL mRNA, protein and activity all increased 5–10-fold during development, suggesting that transcriptional regulation is the primary mechanism for hepatic MGL expression. Three weeks of high fat feeding (40% kcal) significantly induced MGL expression and activity in small intestine relative to low fat feeding (10% kcal), but little change was observed upon starvation, suggesting a role for MGL in dietary lipid assimilation following a high fat intake.


1984 ◽  
Vol 246 (6) ◽  
pp. G683-G686
Author(s):  
K. Westbury ◽  
P. Hahn

Fructose-biphosphatase (EC 3.1.3.11) activity was determined in the proximal and distal parts of the small intestinal mucosa of rats 1-30 days of age. Activity was found to increase to a maximum on about the 10th postnatal day and then to decrease. It was always higher in the proximal than in the distal portion of the gut. The enzyme showed a wide range of pH optimum around 7.0 and was inhibited by AMP. In 10-day-old rats activity determined 24 or 48 h after a single injection of cortisone or triiodothyronine was significantly decreased. This effect was no longer found for cortisone in 14-day-old animals. Weaning 18-day-old rats to a high-fat diet for 5 or 7 days delayed but did not prevent the usual decrease in activity seen at weaning.


1985 ◽  
Vol 104 (2) ◽  
pp. 435-443 ◽  
Author(s):  
A. N. Janes ◽  
T. E. C. Weekes ◽  
D. G. Armstrong

SummaryTwo groups of six sheep were fed either dried-grass or ground maize-based diets for at least 4 weeks before slaughter. Samples of the small intestinal mucosa and spancreatic tissue were assayed for a-amylase, glucoamylase, maltase and oligo-l,6-glucosidase.The pancreatic tissue contained high activities of α-amylase and much lower activities of glucoamylase, maltase and oligo-1,6-glucosidase. There was no effect of diet on the specific activities of any of these enzymes in the pancreatic tissue.The activity of α-amylase adsorbed on to the mucosa of the small intestine was greatest in the proximal region of the small intestine, the activity generally declining with increasing distance away from the pylorus. There was no diet effect on the absorbed α-amylase activity.Similar patterns of distribution along the small intestine were observed for maltase, glucoamylase and oligo-1,6-glucosidase with the highest activities in t he jejunum. There was no overall effect of diet on glucoamylase or maltase specific activities and glucoamylase total activity, although the total activities of maltase and oligo-1,6-glucosidase were significantly greater for the sheep fed the ground maize-based diet (P < 0·05).It is suggested that ruminant animals may be capable of digesting large amounts of starch in the small intestine through an adaptation in the activity of the host carbohydrases.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Yanliu Lu ◽  
Yimei Du ◽  
Lin Qin ◽  
Di Wu ◽  
Wei Wang ◽  
...  

Gypenosides extracted from Gynostemma pentaphyllum (Thunb.) Makino have significant role in reducing serum lipid level and treating fatty liver diseases, however, without clear mechanism. As gypenosides share the similar core structures with bile acids (the endogenous ligands of nuclear receptor FXR), we hypothesize that gypenosides may improve hypercholesterolemia via FXR-mediated bile acids signaling. The present study was designed to validate the role of gypenosides in reducing levels of serum total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C), as well as in regulating bile acids homeostasis and related gene expression levels. The C57BL/6 male mice were divided into four groups. Mice in groups ND and HFD were fed with normal diet and high fat diet for 38 weeks, respectively. In groups HFD+GP and HFD+ST, mice were fed with high fat diet for 38 weeks and treated with gypenosides and simvastatin (positive control) from weeks 16 to 38, respectively. Serum TC and LDL-C levels were assayed by commercially available kits. Expression levels of genes were tested by the quantitative real-time PCR. The LC-MS/MS was applied to quantify major bile acids in mice livers. Our results showed that gypenosides significantly decreased serum TC and LDL-C levels. The gene expression level of Shp was downregulated while the levels of Cyp7a1, Cyp8b1, Fxr, Lrh1, Jnk1/2, and Erk1/2 were upregulated by gypenosides. Indicated by LC-MS/MS technology, gypenosides increased the hepatic levels of several free bile acids and most taurine-conjugated bile acids while decreasing glycine-conjugated bile acids levels. In addition, gypenosides decreased the CA/CDCA ratio. Gypenosides may improve the abnormal lipid profile of HFD-fed mice via two pathways: (1) enhancing the bile acids biosynthesis from cholesterol; (2) decreasing the CA/CDCA ratio which is positively related to cholesterol absorption.


2001 ◽  
Vol 280 (1) ◽  
pp. C126-C134 ◽  
Author(s):  
Tonghui Ma ◽  
Sujatha Jayaraman ◽  
Kasper S. Wang ◽  
Yuanlin Song ◽  
Baoxue Yang ◽  
...  

Immunocytochemistry showed expression of aquaporin-1 (AQP1) water channels at sites involved in dietary fat processing, including intrahepatic cholangiocytes, gallbladder, pancreatic microvascular endothelium, and intestinal lacteals. To determine whether AQP1 has a role in dietary fat digestion and/or absorption, mice were placed on a diet that contained 50% fat. Whereas wild-type mice (3–3.5 wk of age, 10–12 g) gained 49 ± 5% (SE, n = 50) body weight in 8 days, and heterozygous mice gained 46 ± 4%, AQP1 null mice gained only 4 ± 3%; weights became similar after return to a 6% fat diet after 6 days. The null mice on a high-fat diet acquired an oily appearance, developed steatorrhea with increased stool triglyceride content, and manifested serum hypotriglyceridemia. Supplementation of the high-fat diet with pancreatic enzymes partially corrected the decreased weight gain in null mice. Absorption of [14C]oleic acid from small intestine was not affected by AQP1 deletion, as determined by blood radioactivity after duodenal infusion. Lipase activity in feces and small intestine was remarkably greater in AQP1 null than wild-type mice on low- and high-fat diets. Fluid collections done in older mice (that are less sensitive to a high-fat diet) by ductal cannulation showed threefold increased pancreatic fluid flow in response to secretin/cholecystokinin, but volumes, pH, and amylase activities were affected little by AQP1 deletion, nor were bile flow rates and bile salt concentrations. Together, these results establish a dietary fat misprocessing defect in AQP1 null mice.


2015 ◽  
Vol 139 (6) ◽  
pp. 791-795 ◽  
Author(s):  
Stephen Lagana ◽  
Susan Hsiao ◽  
Fei Bao ◽  
Antonia Sepulveda ◽  
Roger Moreira ◽  
...  

Context HepPar-1 and Arginase-1 are urea cycle enzymes used to distinguish hepatocellular carcinoma from other carcinomas. HepPar-1, but not Arginase-1, is known to be immunoreactive with normal human small intestine. Objectives To better define and compare the immunohistochemical staining patterns of HepPar-1 and Arginase-1 in adenocarcinomas arising in the small intestine, including the ampullary region. Design Staining for HepPar-1 and Arginase-1 was performed on 20 nonampullary small intestinal adenocarcinomas and 32 adenocarcinomas from the ampullary region. Ampullary adenocarcinomas were divided into intestinal morphology (15), pancreatobiliary morphology (14), and unclassifiable (3). Nonneoplastic small intestinal mucosa and colorectal adenocarcinomas were used as control groups. Results HepPar-1 stained 12 of 20 nonampullary small intestinal adenocarcinomas, with a median of 63% of cells staining in positive cases. It also stained 11 of 15 ampullary carcinomas with intestinal morphology, with a median of 75% of cells staining in positive cases. Two of 14 ampullary carcinomas with pancreatobiliary morphology were positive for HepPar-1. Arginase-1 showed positivity in 2 ampullary region carcinomas and diffuse positivity in 1 duodenal adenocarcinoma. Two of 22 colorectal carcinomas stained for HepPar-1 with none positive for Arginase-1. Conclusions HepPar-1, but not Arginase-1, usually shows positivity in small intestinal adenocarcinomas and ampullary adenocarcinomas with intestinal morphology, but only rarely shows positivity in ampullary adenocarcinomas with pancreatobiliary morphology. HepPar-1 positivity in metastatic adenocarcinoma with intestinal morphology is suggestive of an upper gastrointestinal primary site.


2011 ◽  
Vol 300 (1) ◽  
pp. E188-E194 ◽  
Author(s):  
Juan C. Marini ◽  
Bettina Keller ◽  
Inka Cajo Didelija ◽  
Leticia Castillo ◽  
Brendan Lee

The synthesis of citrulline from arginine in the small intestine depends on the provision of ornithine. To test the hypothesis that arginase II plays a central role in the supply of ornithine for citrulline synthesis, the contribution of dietary arginine, glutamine, and proline was determined by utilizing multitracer stable isotope protocols in arginase II knockout (AII−/−) and wild-type (WT) mice. The lack of arginase II resulted in a lower citrulline rate of appearance (121 vs. 137 μmol·kg−1·h−1) due to a reduced availability of ornithine; ornithine supplementation was able to restore the rate of citrulline production in AII−/− to levels comparable with WT mice. There were significant differences in the utilization of dietary citrulline precursors. The contribution of dietary arginine to the synthesis of citrulline was reduced from 45 to 10 μmol·kg−1·h−1 due to the lack of arginase II. No enteral utilization of arginine was observed in AII−/− mice (WT = 25 μmol·kg−1·h−1), and the contribution of dietary arginine through plasma ornithine was reduced in the transgenic mice (20 vs. 13 μmol·kg−1·h−1). Dietary glutamine and proline utilization were greater in AII−/− than in WT mice (20 vs. 13 and 1.4 vs. 3.7 μmol·kg−1·h−1, respectively). Most of the contribution of glutamine and proline was enteral rather than through plasma ornithine. The arginase isoform present in the small intestinal mucosa has the role of providing ornithine for citrulline synthesis. The lack of arginase II results in a greater contribution of plasma ornithine and dietary glutamine and proline to the synthesis of citrulline.


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