Diet change affects intestinal microbiota restoration and improves vertical sleeve gastrectomy outcome in diet-induced obese rats

Purpose: Obesity, a worldwide health problem, is linked to an abnormal gut microbiota and is currently most efectively treated by bariatric surgery. Our aim was to characterize the microbiota of high-fat fed Sprague-Dawley rats when subjected to bariatric surgery (i.e., vertical sleeve gastrectomy) and posterior refeeding with either a high-fat or control diet. We hypothesized that bariatric surgery followed by the control diet was more efective in reverting the microbiota modifcations caused by the high-fat diet when compared to either of the two factors alone. Methods: Using next-generation sequencing of ribosomal RNA amplicons, we analyzed and compared the composition of the cecal microbiota after vertical sleeve gastrectomy with control groups representing non-operated rats, control fed, high-fat fed, and post-operative diet-switched animals. Rats were fed either a high-fat or control low-fat diet and were separated into three comparison groups after eight weeks comprising no surgery, sham surgery, and vertical sleeve gastrectomy. Half of the rats were then moved from the HFD to the control diet. Using next-generation sequencing of ribosomal RNA amplicons, we analyzed the composition of the cecal microbiota of rats allocated to the vertical sleeve gastrectomy group and compared it to that of the non-surgical, control fed, high-fat fed, and post-operative diet-switched groups. Additionally, we correlated diferent biological parameters with the genera exhibiting the highest variation in abundance between the groups. Results: The high-fat diet was the strongest driver of altered taxonomic composition, relative microbial abundance, and diversity in the cecum. These efects were partially reversed in the diet-switched cohort, especially when combined with sleeve gastrectomy, resulting in increased diversity and shifting relative abundances. Several highly-afected genera were correlated with obesity-related parameters. Conclusions: The dysbiotic state caused by high-fat diet was improved by the change to the lower fat, higher fber control diet. Bariatric surgery contributed signifcantly and additively to the diet in restoring microbiome diversity and complexity. These results highlight the importance of dietary intervention following bariatric surgery for improved restoration of cecal diversity, as neither surgery nor change of diet alone had the same efects as when combined

Rapid perioperative changes in the quantitative properties of plasma lipases and lipoproteins in morbidly obese surgical patients'

Background: The impact of bariatric surgery on abnormalities in blood lipids and lipoprotein metabolism during the perioperative period has been poorly studied. Objective: We studied the impact of bariatric surgery on the composition and quantitative properties of lipoproteins and the activity of lipases in the plasma of perioperative morbidly obese patients. Methods: We examined the plasma lipoproteins and lipolytic activities of 34 morbidly obesepatients one month before surgery (OB), pre-anaesthesia (-S), post-anaesthesia ( S), and one day and one month after open Roux-en-Y gastric bypass (RYGB) surgery. Results: Surgical injury induced acute stress, as evidenced by transitory hyperglycaemia and elevated plasma levels of stress hormones. Lipid profiles revealed a significant reduction during surgery and the day after in the plasma levels of total cholesterol (p < 0.0001), which was mainly due to a decrease in low-density lipoprotein cholesterol (cLDL) and was confirmed with a significant reduction in the plasma levels of LDL (approximately 26% reduction). Significant (p < 0.0001) changes were detected in the plasma levels of high-density lipoprotein cholesterol (cHDL) as well as a significant decrease (approximately 19% reduction) in the plasma levels of HDL. A significant (p < 0.0001) rise was noted in the plasma levels of both Lipoprotein Lipase (LPL) (approximately 2.6-fold increase) and hepatic lipase (HL) (approximately 2.2-fold increase) on the day after surgery, occurring simultaneously with the maximum increase in C-reactive protein (CRP) and a day after the peak values for non-esterified fatty acid (NEFA), adrenocorticotropin hormone (ACTH), cortisol and glucose. Conclusion: The present study reveals unreported quantitative perioperative changes in plasma lipases and lipoproteins and related metabolic determinants that may contribute to the adaptive metabolic response to RYGB-induced stress

Diabetic and dyslipidaemic morbidly obese exhibit more liver alterations compared with healthy morbidly obese

Background & aims: To study the origin of fat excess in the livers of morbidly obese (MO) individuals, we analysed lipids and lipases in both plasma and liver and genes involved in lipid transport, or related with, in that organ. Methods: Thirty-two MO patients were grouped according to the absence (healthy: DM−DL−) or presence of comorbidities (dyslipidemic: DM−DL+; or dyslipidemic with type 2 diabetes: DM+DL+) before and one year after gastric bypass. Results: The livers of healthy, DL and DM patients contained more lipids (9.8, 9.5 and 13.7 times, respectively) than those of control subjects. The genes implicated in liver lipid uptake, including HL, LPL, VLDLr, and FAT/CD36, showed increased expression compared with the controls. The expression of genes involved in lipid-related processes outside of the liver, such as apoB, PPARα and PGC1α, CYP7a1 and HMGCR, was reduced in these patients compared with the controls. PAI1 and TNFα gene expression in the diabetic livers was increased compared with the other obese groups and control group. Increased steatosis and fibrosis were also noted in the MO individuals. Conclusions: Hepatic lipid parameters in MO patients change based on their comorbidities. The gene expression and lipid levels after bariatric surgery were less prominent in the diabetic patients. Lipid receptor overexpression could enable the liver to capture circulating lipids, thus favouring the steatosis typically observed in diabetic and dyslipidaemic MO individuals.This research has received funding from the Fondo de Investigación Sanitaria del Instituto de Salud Carlos III of the Spanish Ministry for Health and Consumer Affairs (PI030024, PI030042, PI070079 and PI11/01159

Bioquímica de primer curso de la licenciatura de Biologia

zip comprimit. Pàgina inicial:158/index.htm[cat] Resum esquemàtic dels principals temes pel desenvolupament d'un curs de Bioquímica. Aquest material inclou problemes resolts així com exercicis d'autoavaluació amb les seves respostes.[spa] Resúmen esquemático de los principales temas para desarrollar en un curso de Bioquímica. El material incluye problemas resueltos, así como ejercicios de autoevaluación con las respuestas

Lipoprotein lipase (LPL) is highly expressed and active in the ovary of European sea bass (Dicentrarchus labrax L.), during gonadal development

The oocytes of many fish species accumulate high amounts of neutral lipids as a caloric reserve for embryonic and larval development. We propose that lipoprotein lipase (LPL, EC 3.1.1.34) plays an important role in supplying the oocytes with fatty acids and we have cloned its cDNA from the ovary of sea bass, and determined the patterns of LPL activity and LPL mRNA expression in the ovary. The cDNA obtained was 3051 bp long with an open reading frame encoding 518 amino acids. The amino acid sequence has a high similarity and shows similar structural features to LPL of other species. Northern blot analysis revealed LPL expression in adipose tissue and gonads only. LPL activity and LPL mRNA expression in the ovary was very high in fish with a gonadosomatic index (GSI) above 5, coinciding with the appearance of a high number of lipid droplets in the ooplasm. The LPL mRNA expression was localised to the follicle cells surrounding the oocyte. Our results suggest that LPL is likely to play an important role in the incorporation of neutral lipids into the oocytes, and that follicle cells, in addition to participating in steroidogenesis, also may be important in building up oocyte lipid reserves. © 2008 Elsevier Inc. All rights reserved.This work was supported by grants from the former Spanish Ministry of Science and Technology (grant AGL2000-1983 to F.P., and Ph.D. FPI bursary FP2000-5907 to A.J.I).Peer Reviewe

Rapid perioperative changes in the quantitative properties of plasma lipases and lipoproteins in morbidly obese surgical patients'

Background: The impact of bariatric surgery on abnormalities in blood lipids and lipoprotein metabolism during the perioperative period has been poorly studied. Objective: We studied the impact of bariatric surgery on the composition and quantitative properties of lipoproteins and the activity of lipases in the plasma of perioperative morbidly obese patients. Methods: We examined the plasma lipoproteins and lipolytic activities of 34 morbidly obesepatients one month before surgery (OB), pre-anaesthesia (-S), post-anaesthesia ( S), and one day and one month after open Roux-en-Y gastric bypass (RYGB) surgery. Results: Surgical injury induced acute stress, as evidenced by transitory hyperglycaemia and elevated plasma levels of stress hormones. Lipid profiles revealed a significant reduction during surgery and the day after in the plasma levels of total cholesterol (p < 0.0001), which was mainly due to a decrease in low-density lipoprotein cholesterol (cLDL) and was confirmed with a significant reduction in the plasma levels of LDL (approximately 26% reduction). Significant (p < 0.0001) changes were detected in the plasma levels of high-density lipoprotein cholesterol (cHDL) as well as a significant decrease (approximately 19% reduction) in the plasma levels of HDL. A significant (p < 0.0001) rise was noted in the plasma levels of both Lipoprotein Lipase (LPL) (approximately 2.6-fold increase) and hepatic lipase (HL) (approximately 2.2-fold increase) on the day after surgery, occurring simultaneously with the maximum increase in C-reactive protein (CRP) and a day after the peak values for non-esterified fatty acid (NEFA), adrenocorticotropin hormone (ACTH), cortisol and glucose. Conclusion: The present study reveals unreported quantitative perioperative changes in plasma lipases and lipoproteins and related metabolic determinants that may contribute to the adaptive metabolic response to RYGB-induced stress