Intestinal permeability after Mediterranean diet and low-fat diet in non-alcoholic fatty liver disease

Abstract

BACKGROUNDIn non-alcoholic fatty liver disease (NAFLD), a high-fat or high-fructose diet increases intestinal permeability and promotes derangement of the gut-liver axis. We hypothesize that, diet could be able to modulate intestinal permeability in patients with NAFLD.AIMTo detect diet-induced modification of intestinal permeability in patients with NAFLD undergoing a Mediterranean diet or a low-fat diet.METHODSThe current study was a dietary intervention for non-diabetic, patients with biopsy-verified NAFLD and increased transaminases. A crossover design was employed: participants underwent 16 weeks of Mediterranean diet, 16 wk of free wash-out, and 16 weeks of low-fat diet. Both diets were hypocaloric and no consumption of supplements was allowed. All patients were followed bimonthly by a dietitian. Evaluations of clinical and metabolic parameters were completed at baseline and at the end of each dietary period. Intestinal permeability was assessed by chromium-51 ethylene diamine tetraacetate excretion testing (51Cr-EDTA).RESULTSTwenty Caucasian patients, 90% male, median age 43 years, body mass index (BMI) 30.9, with biopsy-verified NAFLD were enrolled. At the end of 16 weeks of a Mediterranean diet, a significant reduction in mean body weight (-5.3 ± 4.1 kg, P = 0.003), mean waist circumference (-7.9 ± 4.9 cm, P = 0.001), and mean transaminase levels [alanine aminotransferase (ALT) -28.3 ± 11.9 IU/L, P = 0.0001; aspartate aminotransferase (AST) -6.4 ± 56.3 IU/L, P = 0.01] were observed. These benefits were maintained after 16 wk of wash-out and also after 16 wk of low-fat diet, without further improvements. Fourteen of the 20 patients had intestinal permeability alteration at baseline (mean percentage retention of 51Cr-EDTA = 5.4%), but no significant changes in intestinal permeability were observed at the end of the 16 wk of the Mediterranean diet or 16 wk of the low-fat diet.CONCLUSIONMediterranean diet is an effective strategy for treating overweight, visceral obesity and serum transaminase in patients with NAFLD. If the Mediterranean diet can improve intestinal permeability in patients with NAFLD, it deserves further investigation.

Increased Colonic Permeability and Lifestyles as Contributing Factors to Obesity and Liver Steatosis

“…These observations require larger and prospective studies to discern the role of Mediterranean Diet on the prevention and management of metabolic and associated diseases [90,91]. Furthermore, the questionnaire we used in our study was aimed to assess the timing but not the load (i.e., intensity and volume) of exercise performance in our subjects.…”

The Effect of the Mediterranean Diet on Metabolic Health: A Systematic Review and Meta-Analysis of Controlled Trials in Adults

“…Findings and heterogeneity levels largely remained unchanged, but were attenuated for waist circumference (−0.94 cm; 95% CI, −2.08-0.19; I 2 = 100%; 24 studies), HDL-cholesterol (0.93 mg/dL; −0.06-1.92; I 2 = 98%; 31 studies), and alanine transaminase (−2.39 UI/L; −5.77-0.99; I 2 = 96%; 7 studies), whereas reduction of glycosylated hemoglobin (HbA1c) was larger in the MD, compared to a control condition (−0.29%; −0.40-−0.18; I 2 = 4%; 5 studies). In addition, results were largely similar when cross-over trials [29,35,65,77,88,97,108,109] were excluded, although this attenuated the between-group difference in insulin concentrations (−0.77 µU/mL; 95%CI, −1.71-0.17; I 2 = 97%; 15 studies) and hepatic fat mass (−2.04%; −5.95-1.88; I 2 = 86%; 2 studies). Results remained unchanged when studies with ≥1000 participants [31,51,62,93,103] were excluded from the analyses.…”

“…Sensitivity analysis, by excluding the non-randomised controlled trials [35,80,[85][86][87]101,102], was conducted for 18 MetSyn components and risk factors (Supplementary Materials Table S13). Findings and heterogeneity levels largely remained unchanged, but were attenuated for waist circumference (−0.94 cm; 95% CI, −2.08-0.19; I 2 = 100%; 24 studies), HDL-cholesterol (0.93 mg/dL; −0.06-1.92; I 2 = 98%; 31 studies), and alanine transaminase (−2.39 UI/L; −5.77-0.99; I 2 = 96%; 7 studies), whereas reduction of glycosylated hemoglobin (HbA1c) was larger in the MD, compared to a control condition (−0.29%; −0.40-−0.18; I 2 = 4%; 5 studies).…”

Liver Cirrhosis and Sarcopenia from the Viewpoint of Dysbiosis

“…Cumulative evidence has highlighted the relevance of increase in intestinal permeability (i.e., leaky gut syndrome) and consequent bacterial translocation in the development of CLDs. Particularly, in recent hypotheses regarding patients with non-alcoholic fatty liver disease (NAFLD), intestinal permeability impairment, dietary habits, and gut dysbiosis are considered to be the main pathogenic triggers [ 85 , 86 , 87 ]. Leaky gut is associated with chronic inflammation [ 87 ].…”

“…In advanced liver diseases, intestinal permeability can be enhanced by portal hypertension, which consequently leads to increased bacterial translocation that further damages liver function. Furthermore, these pathogenic mechanisms are implicated in most LC-related complications, such as SBP, hepatorenal syndrome, severe ascites, HE, sarcopenia, and HCC [ 85 , 86 , 87 ]. In LC rats, intestinal bacteria such as Gram-negative bacilli in mesenteric lymph nodes were more likely to be detected compared with control, and the same strain of bacteria was detected in ascites [ 88 , 89 ].…”