Serum endotoxin, gut permeability and skeletal muscle metabolic adaptations following a short term high fat diet in humans.
Metabolism
; 103: 154041, 2020 02.
Article
em En
| MEDLINE
| ID: mdl-31785256
ABSTRACT
BACKGROUND:
Our previous work demonstrated that a short-term high fat diet (HFD) increased fasting serum endotoxin, altered postprandial excursions of serum endotoxin, and led to metabolic and transcriptional responses in skeletal muscle in young, healthy male humans.PURPOSE:
The purpose of the present study was to determine if a short-term high fat diet 1) increases intestinal permeability and, in turn, fasting endotoxin concentrations and 2) decreases postprandial skeletal muscle fat oxidation.METHODS:
Thirteen normal weight young adult males (BMI 23.1⯱â¯0.8â¯kg/m2, age 22.2⯱â¯0.4â¯years) were fed a control diet (55% carbohydrate, 30% fat, 9% of which was saturated, 15% protein) for two weeks, followed by 5â¯days of an isocaloric HFD (30% carbohydrate, 55% fat, 25% of which was saturated, 15% protein, isocaloric to the control diet). Intestinal permeability (via four sugar probe test) was assessed in the fasting state. Both before and after the HFD, a high fat meal challenge (HFM, 820â¯kcal, 25% carbohydrate, 63% fat, 26% of which was saturated, and 12% protein) was administered. After an overnight fast, blood samples were collected before and every hour for 4â¯h after the HFM to assess endotoxin, and other serum blood measures. Muscle biopsies were obtained from the vastus lateralis before and 4â¯h after the HFM in order to assess substrate oxidation (glucose, fatty acid and pyruvate) using radiolabeled techniques. Insulin sensitivity was assessed via intravenous glucose tolerance test. Intestinal permeability, blood samples and muscle biopsies were assessed in the same manner before and following the HFD. MAINFINDINGS:
Intestinal permeability was not affected by HFD (pâ¯>â¯0.05), but fasting endotoxin increased two fold following the HFD (pâ¯=â¯0.04). Glucose oxidation and fatty acid oxidation in skeletal muscle homogenates significantly increased after the HFM before the HFD (+97%, and +106% respectively) but declined after the HFM following 5â¯days of the HFD (-24% and +16% respectively). Fatty acid suppressibility of pyruvate oxidation increased significantly after the HFM (+32%) but this physiological effect was abolished following 5â¯days of the HFD (+7%). Insulin sensitivity did not change following the HFD.CONCLUSION:
These findings demonstrate that in healthy young men, consuming an isocaloric HFD for 5â¯days increases fasting endotoxin, independent of changes in gut permeability. These changes in endotoxin are accompanied by a broad effect on skeletal muscle substrate metabolism including increases in postprandial fat oxidation. Importantly, the latter occurs independent of changes in body weight and whole-body insulin sensitivity.Palavras-chave
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Adaptação Fisiológica
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Músculo Esquelético
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Endotoxinas
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Dieta Hiperlipídica
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Mucosa Intestinal
Limite:
Adult
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Humans
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Male
Idioma:
En
Revista:
Metabolism
Ano de publicação:
2020
Tipo de documento:
Article