Alterations in gut microbiota associated with a cafeteria diet and the physiological consequences in the host.

OBJECTIVE: Gut microbiota have been described as key factors in the pathophysiology of obesity and different components of metabolic syndrome (MetS). The cafeteria diet (CAF)-fed rat is a preclinical model that reproduces most of the alterations found in human MetS by simulating a palatable human unbalanced diet. Our objective was to assess the effects of CAF on gut microbiota and their associations with different components of MetS in Wistar rats. METHODS: Animals were fed a standard diet or CAF for 12 weeks. A partial least square-based methodology was used to reveal associations between gut microbiota, characterized by 16S ribosomal DNA gene sequencing, and biochemical, nutritional and physiological parameters. RESULTS: CAF feeding resulted in obesity, dyslipidemia, insulin resistance and hepatic steatosis. These changes were accompanied by a significant decrease in gut bacterial diversity, decreased Firmicutes and an increase in Actinobacteria and Proteobacteria abundances, which were concomitant with increased endotoxemia. Associations of different genera with the intake of lipids and carbohydrates were opposed from those associated with the intake of fiber. Changes in gut microbiota were also associated with the different physiological effects of CAF, mainly increased adiposity and altered levels of plasma leptin and glycerol, consistent with altered adipose tissue metabolism. Also hepatic lipid accretion was associated with changes in microbiota, highlighting the relevance of gut microbiota homeostasis in the adipose-liver axis. CONCLUSIONS: Overall, our results suggest that CAF feeding has a profound impact on the gut microbiome and, in turn, that these changes may be associated with important features of MetS.

Grape seed procyanidin supplementation to rats fed a high-fat diet during pregnancy and lactation increases the body fat content and modulates the inflammatory response and the adipose tissue metabolism of the male offspring in youth.

OBJECTIVE: Procyanidins are polyphenolic bioactive compounds that exert beneficial effects against obesity and its related diseases. The aim of this study was to evaluate whether supplementation with low doses of a grape seed procyanidin extract (GSPE) to rats during pre- and postnatal periods provides biological effects to their offspring in youth. DESIGN: The metabolic programming effect of GSPE was evaluated in the 30-day-old male offspring of four groups of rats that were fed either a standard diet (STD) or a high-fat diet (HFD) and that were supplemented with either GSPE (25 mg kg(-1) of body weight per day) or vehicle during pregnancy and lactation. RESULTS: Significant increases in the adiposity index and in the weights of all the white adipose tissue depots studied (retroperitoneal, mesenteric, epididymal (EWAT) and inguinal) were observed in the offspring of rats that were fed a HFD and that were treated with GSPE (HFD-GSPE group) compared with the offspring of rats that were fed the same diet but that did not receive the procyanidins (HFD group). The HFD-GSPE animals also exhibited a higher number of cells in the EWAT, a sharp decrease in the circulating levels of monocyte chemoattractant protein-1 (MCP-1) and a moderate decrease in the plasma glycerol levels. The transcriptomic analysis performed in the EWAT showed 238 genes that were differentially expressed between the HFD and the HFD-GSPE animals, most of which were associated with the immune function and the inflammatory response, in addition to genes associated with adipose tissue remodeling and function, lipid and glucose homeostasis and the metabolism of methyl groups. CONCLUSION: The GSPE treatment in rats that were fed an HFD during pregnancy and lactation induced a clear metabolic programming effect in the offspring, increasing adiposity, decreasing the circulating levels of MCP-1 and changing the gene expression in the EWAT toward a better inflammatory profile.

Low doses of grape seed procyanidins reduce adiposity and improve the plasma lipid profile in hamsters.

OBJECTIVE: Procyanidins are polyphenolic compounds with beneficial effects on health in relation to cardiovascular disease and metabolic syndrome. In this study, we evaluated the potential beneficial effects of low doses of a grape seed procyanidin extract (GSPE) on body weight and fat deposition. DESIGN: Four groups of hamsters were fed either a standard diet (STD) or a high-fat diet (HFD) for 30 days and supplemented with either GSPE at 25 mg per kg of body weight per day (STD-GSPE and HFD-GSPE groups) or vehicle (STD and HFD groups) during the last 15 days of the study. RESULTS: A significant decrease in body weight gain was observed in both GSPE-treated animals at the end of the experiment. GSPE treatment significantly reduced the adiposity index and the weight of all the white adipose tissue depots studied (retroperitoneal (RWAT), mesenteric (MWAT), epididymal (EWAT) and inguinal (IWAT)) in both GSPE-treated groups. GSPE administration reversed the increase in plasma phospholipids induced by the HFD feeding. In the RWAT, GSPE treatment increased the mRNA expression of genes related to ß-oxidation and the glycerolipid/free fatty acid (GL/FFA) cycle, mainly in HFD-GSPE animals. In the MWAT, the effects of GSPE at the transcriptional level were not as evident as in the RWAT. Moreover, GSPE treatment induced heparin-releasable lipoprotein lipase activity in the RWAT and MWAT depots. The alterations in the lipid metabolic pathways induced by GSPE were accompanied by lower FFA levels in the plasma and decreased lipid and triglyceride accumulation in the MWAT. CONCLUSION: The use of GSPE at low doses protects against fat accumulation and improves the plasma lipid profile in hamsters. We suggest that GSPE exerts these effects in part through the activation of both ß-oxidation and the GL/FFA cycle, mainly in the RWAT.

Simultaneous genotyping of CYP2D6*3, *4, *5 and *6 polymorphisms in a Spanish population through multiplex long polymerase chain reaction and minisequencing multiplex single base extension analysis.

1. The aim of the present study was to perform a descriptive study of the prevalence of the four major CYP2D6 poor metaboliser (PM) alleles (*3, *4, *5 and *6) in a Spanish population (n = 290) using a method based on a new combination of multiplex long polymerase chain reaction (PCR) and minisequencing through multiplex single base extension (SBE) analysis. 2. The method was validated using different strategies, such as allelic discrimination assay and PCR-restriction fragment length polymorphism (RFLP). 3. The allele frequencies were similar to those described for other Spanish populations, namely 0.9% (95% confidence interval (CI) 0.5-1.3), 16.4% (95% CI 14.9-18.0), 2.7% (95% CI 2.0-3.4) and 0.7% (95% CI 0.3-1.0) for the *3, *4, *5 and *6 alleles, respectively. The results were satisfactory and left little doubt as to the genotypes, which were confirmed either by allelic discrimination assay (*4 and *6) or PCR-RFLP (*3) with 100% concordance. 4. The present study corroborates the low prevalence of the most frequent polymorphism (CYP2D6*4) that leads to null CYP2D6 activity in Spain and the allelic geographical gradient between Caucasian populations in the north and south. The present study reports a technique for the detection of four polymorphisms that account for 98% of the CYP2D6 defect alleles. This multiplex long PCR-SBE technique is a combination of several known methods to genotype CYP2D6 alleles (*3, *4, *5 and*6). Given the importance of CYP2D6 in drug metabolism and the need to genotype a large number of samples, we believe that this method will find broad application.

Effect of naloxone on the loss of consciousness induced by i.v. anaesthetic agents in man.

The effect of a specific opioid antagonist, naloxone, was studied in two comparable groups of patients who received i.v. the dose of an anaesthetic agent required to produce loss of consciousness in 50% of subjects. The first group received naloxone 0.006 mg kg-1 5 min before induction of anaesthesia; the second group received a similar volume of saline solution. Thiopentone, Althesin, diazepam, ketamine and propanidid were studied. The differences in percentage of unconscious patients between the naloxone-treated group and the control group were statistically significant for diazepam, ketamine and propanidid. Naloxone did not modify the induction of anaesthesia with thiopentone or Althesin.

Effects of naloxone on prolactin, luteinizing hormone, and cortisol responses to surgical stress in humans.

To evaluate the possible involvement of endogenous opioid peptides in the responses of PRL, LH, and cortisol to surgical stress, we have studied the effect of naloxone on these hormones in otherwise normal subjects of both sexes undergoing cholecystectomy for gallstones. In 24 subjects (12 males and 12 females), premedication consisted of atropine sulfate (0.007 mg/kg BW); general anesthesia (30 min later) was induced by thiopental (7 mg/kg) and maintained constant by 1% ethrane in a 70%:30% nitrous oxide-oxygen mixture. In 6 males and 6 females, naloxone (0.4 mg) was injected iv before anesthesia induction. After skin incision, a clear PRL release was observed in all subjects; this was more evident in females than in males. PRL release was significantly lower in naloxone-pretreated subjects. LH release was observed only in males and was significantly higher in naloxone-pretreated subjects. Cortisol release occurred in both sexes in a similar way and was not significantly different in naloxone-pretreated subjects. Cortisol release occurred in both sexes in a similar way and was not significantly different in naloxone-pretreated subjects. These results indicate that endogenous opioid peptides are involved in stress-induced PRL and LH release in humans.