Endotoxin increase after fat overload is related to postprandial hypertriglyceridemia in morbidly obese patients.

The low-grade inflammation observed in obesity has been associated with a high-fat diet, though this relation is not fully understood. Bacterial endotoxin, produced by gut microbiota, may be the linking factor. However, this has not been confirmed in obese patients. To study the relationship between a high-fat diet and bacterial endotoxin, we analyzed postprandial endotoxemia in morbidly obese patients after a fat overload. The endotoxin levels were determined in serum and the chylomicron fraction at baseline and 3 h after a fat overload in 40 morbidly obese patients and their levels related with the degree of insulin resistance and postprandial hypertriglyceridemia. The morbidly obese patients with the highest postprandial hypertriglyceridemia showed a significant increase in lipopolysaccharide (LPS) levels in serum and the chylomicron fraction after the fat overload. Postprandial chylomicron LPS levels correlated positively with the difference between postprandial triglycerides and baseline triglycerides. There were no significant correlations between C-reactive protein (CRP) and LPS levels. The main variables contributing to serum LPS levels after fat overload were baseline and postprandial triglyceride levels but not glucose or insulin resistance. Additionally, superoxide dismutase activity decreased significantly after the fat overload. Postprandial LPS increase after a fat overload is related to postprandial hypertriglyceridemia but not to degree of insulin resistance in morbidly obese patients

Endotoxin increase after fat overload is related to postprandial hypertriglyceridemia in morbidly obese patients.

The low-grade inflammation observed in obesity has been associated with a high-fat diet, though this relation is not fully understood. Bacterial endotoxin, produced by gut microbiota, may be the linking factor. However, this has not been confirmed in obese patients. To study the relationship between a high-fat diet and bacterial endotoxin, we analyzed postprandial endotoxemia in morbidly obese patients after a fat overload. The endotoxin levels were determined in serum and the chylomicron fraction at baseline and 3 h after a fat overload in 40 morbidly obese patients and their levels related with the degree of insulin resistance and postprandial hypertriglyceridemia. The morbidly obese patients with the highest postprandial hypertriglyceridemia showed a significant increase in lipopolysaccharide (LPS) levels in serum and the chylomicron fraction after the fat overload. Postprandial chylomicron LPS levels correlated positively with the difference between postprandial triglycerides and baseline triglycerides. There were no significant correlations between C-reactive protein (CRP) and LPS levels. The main variables contributing to serum LPS levels after fat overload were baseline and postprandial triglyceride levels but not glucose or insulin resistance. Additionally, superoxide dismutase activity decreased significantly after the fat overload. Postprandial LPS increase after a fat overload is related to postprandial hypertriglyceridemia but not to degree of insulin resistance in morbidly obese patients

Effect of virgin olive oil and thyme phenolic compounds on blood lipid profile: implications of human gut microbiota.

PURPOSE: To investigate the effect of virgin olive oil phenolic compounds (PC) alone or in combination with thyme PC on blood lipid profile from hypercholesterolemic humans, and whether the changes generated are related with changes in gut microbiota populations and activities. METHODS: A randomized, controlled, double-blind, crossover human trial (n = 12) was carried out. Participants ingested 25 mL/day for 3 weeks, preceded by 2-week washout periods, three raw virgin olive oils differing in the concentration and origin of PC: (1) a virgin olive oil (OO) naturally containing 80 mg PC/kg, (VOO), (2) a PC-enriched virgin olive oil containing 500 mg PC/kg, from OO (FVOO), and (3) a PC-enriched virgin olive oil containing a mixture of 500 mg PC/kg from OO and thyme, 1:1 (FVOOT). Blood lipid values and faecal quantitative changes in microbial populations, short chain fatty acids, cholesterol microbial metabolites, bile acids, and phenolic metabolites were analysed. RESULTS: FVOOT decreased seric ox-LDL concentrations compared with pre-FVOOT, and increased numbers of bifidobacteria and the levels of the phenolic metabolite protocatechuic acid compared to VOO (P < 0.05). FVOO did not lead to changes in blood lipid profile nor quantitative changes in the microbial populations analysed, but increased the coprostanone compared to FVOOT (P < 0.05), and the levels of the faecal hydroxytyrosol and dihydroxyphenylacetic acids, compared with pre-intervention values and to VOO, respectively (P < 0.05). CONCLUSION: The ingestion of a PC-enriched virgin olive oil, containing a mixture of olive oil and thyme PC for 3 weeks, decreases blood ox-LDL in hypercholesterolemic humans. This cardio-protective effect could be mediated by the increases in populations of bifidobacteria together with increases in PC microbial metabolites with antioxidant activities.This work was supported by Instituto de Salud Carlos III FEDER (RD12-0042, CB06/03/0028, CD10/00224, CP06/00100, CB06/02/0029, CA11/00215), Ministry of Economy and Competitiveness (AGL2012-40144-C03-01, AGL2012-40144-C03-02, AGL2012-40144-C03-03, FPI:BES- 2010-040766), Agency for Management of University and Research Grants (2009 SGR 1195, 2014 SGR 240). We thank M Angels Calvo for the growth of pure cultures, Malén Massot for helping us in the elaboration of the FISH-FC protocol, Óscar Fornas and Cristina Llop for their technical assistance and Borges Mediterranean Group.http://dx.doi.org/10.1007/s00394-015-1063-