Estudios de trasplante de microbiota fecal en síndrome metabólico, obesidad y diabetes, ¿dónde nos encontramos?

Fundamento: El trasplante de microbiota fecal (FMT) consiste en la transferencia de las heces de un donante sano a otro paciente con el objetivo de cambiar o restablecer la composición y función de su microbiota. Su única aplicación clínica actualmente aceptada es el tratamiento de infección recurrente por Clostridium difficile. No obstante, se está estudiando su empleo en enfermedades como la enfermedad inflamatoria intestinal, el autismo y las enfermedades metabólicas. En este último grupo encontramos el síndrome metabólico, la obesidad y la diabetes tipo 2, tres enfermedades relacionadas entre sí y cada vez más prevalentes en nuestro tiempo. Las tres se caracterizan por cursar con una disbiosis de la microbiota intestinal y en este contexto surge la idea del empleo del FMT para su tratamiento. El objetivo de este Trabajo de Fin de Grado es conocer los estudios que se han realizado para evaluar el efecto del FMT con donantes humanos en síndrome metabólico, obesidad y diabetes. Metodología: Se ha llevado a cabo una revisión sistemática utilizando la base de datos PubMed, realizando tres búsquedas por términos MeSH relacionando “fecal microbiota transplantation” con “obesity”, “diabetes” y “metabolic syndrome” y aplicando las metodologías PRISMA y PICO para seleccionar los resultados de interés. Resultados: Se han valorado siete artículos de intervención que evalúan el efecto del FMT con donantes humanos y receptores humanos o animales. Existen pocos resultados concluyentes sobre el efecto del FMT en la microbiota del receptor, debido a que los artículos son heterogéneos y valoran parámetros diferentes. Conclusión: El FMT supone un avance en el conocimiento de la relación entre la microbiota y las enfermedades metabólicas y, conforme obtenemos más información de los estudios de intervención realizados, nos acercamos a la posibilidad de aplicar este procedimiento en el tratamiento de otras enfermedades además de la infección por Clostridium difficile.Background: The fecal microbiota transplantation (FMT) consists in the transfer of gastrointestinal microbiota from a healthy individual to another in order to change or restore the composition and function of the recipient’s microbiota. Nowadays this method is only accepted as a therapeutic option for Clostridium difficile infection. However, there are many studies evaluating its applicability in other diseases such as inflammatory bowel disease, irritable bowel syndrome, autism and metabolic disorders, like obesity, diabetes or metabolic syndrome. In this project we are focusing on these three metabolic diseases, which incidence has increased rapidly worldwide. They are characterized by a dysbiosis of the intestinal microbiota and that is the reason why the idea of fecal microbiota transplantation as a possible therapeutic option arises. The main objective of this project is to analyse the currently available studies that evaluate the effect of fecal microbiota transplantation, from humans to either humans or animals, in the physiopathology of obesity, diabetes and metabolic syndrome. Methodology: A systematic review was carried out using the PubMed database with three independent searches using MeSH terms relating “fecal microbiota transplantation” and “obesity”, “diabetes” and “metabolic syndrome”. PRISMA and PICO methodologies were applied to select the studies of interest. Results: Seven articles from intervention studies that evaluate FMT with human donors and human or animal recipients have been included in this systematic review. To date, there are few conclusive results due to the heterogeneity of the studies. Conclusion: New studies on FMT represent an advance in the knowledge of the relationship between the microbiota and metabolic disorders. As we obtain more information regarding the applicability of this technique and its effect, we approach the possibility of applying it in the treatment of other diseases a part from infection by Clostridium difficile

Do the Effects of Resveratrol on Thermogenic and Oxidative Capacities in IBAT and Skeletal Muscle Depend on Feeding Conditions?

The aim of this study was to compare the effects of mild energy restriction and resveratrol on thermogenic and oxidative capacity in interscapular brown adipose tissue (IBAT) and in skeletal muscle. Rats were fed a high-fat high-sucrose diet for six weeks, and divided into four experimental groups fed a standard diet: a control group, a resveratrol-treated group, an energy-restricted group and an energy-restricted group treated with resveratrol. Weights of IBAT, gastrocnemius muscle and fat depots were measured. Activities of carnitine palmitoyltransferase (CPT) and citrate synthase (CS), protein levels of sirtuin (SIRT1 and 3), uncoupling proteins (UCP1 and 3), glucose transporter (GLUT4), mitochondrial transcription factor (TFAM), nuclear respiratory factor (NRF1), peroxisome proliferator-activated receptor (PPAR) and AMP activated protein kinase (AMPK) and peroxisome proliferator-activated receptor gamma coactivator (PGC1) activation were measured. No changes in IBAT and gastrocnemius weights were found. Energy-restriction, but not resveratrol, decreased the weights of adipose depots. In IBAT, resveratrol enhanced thermogenesis activating the SIRT1/PGC1/PPAR axis. Resveratrol also induced fatty acid oxidation and glucose uptake. These effects were similar when resveratrol was combined with energy restriction. In the case of gastrocnemius muscle, the effects were not as clear as in the case of IBAT. In this tissue, resveratrol increased oxidative capacity. The combination of resveratrol and energy restriction seemingly did not improve the effects induced by the polyphenol alone.This research was funded by MINECO (AGL-2015-65719-R-MINECO/FEDER, UE), University of the Basque Country (ELDUNANOTEK UFI11/32), Instituto de Salud Carlos III (CIBERobn) and Basque Government (IT-572-13). Inaki Milton-Laskibar is a recipient of a doctoral fellowship from the Gobierno Vasco

Involvement of autophagy in the beneficial effects of resveratrol in hepatic steatosis treatment. A comparison with energy restriction

Autophagy eliminates damaged cellular components. In the liver, it has been proposed that it mediates the breakdown of lipid droplets. This study aimed to compare the involvement of autophagy and the oxidative status in the effects of resveratrol and energy restriction as therapeutic tools for managing liver steatosis. In addition, potential additive or synergic effects were studied. Rats were fed a high-fat high-sucrose diet for 6 weeks and then divided into four experimental groups and fed a standard diet: a control group (C), a resveratrol-treated group (RSV, 30 mg kg−1 d−1), an energy restricted group (R, −15%), and an energy restricted group treated with resveratrol (RR). Liver triacylglycerols (TGs) were measured by Folch's method. TBARS, GSH, GSSG, GPx and SOD were assessed using commercial kits. The protein expression of beclin, atg5 and p62, as well as ratios of pSer555 ULK1/total ULK1, pSer757 ULK1/total ULK1 and LC3 II/I were determined by western blotting. Energy restriction increased the protein expression of beclin, atg5 and pSer757 ULK1/total ULK1 and LC3 II/I ratios, and reduced the protein expression of p62, thus indicating that it induced autophagy activation. The effects of resveratrol were similar but less marked than the hypocaloric diet. No differences were observed in oxidative stress determinants except for TBARS, which was decreased by energy restriction. In conclusion, resveratrol can reverse partially dietary-induced hepatic lipid accumulation, although less efficiently than energy restriction. The delipidating effect of energy restriction is mediated in part by the activation of autophagy; however, the involvement of this process in the effects of resveratrol is less clear

Inhibition of serum cholesterol oxidation by dietary vitamin C and selenium intake in high fat fed rats

Cholesterol oxidation products (COPs) have been considered as specific in vivo markers of oxidative stress. In this study, an increased oxidative status was induced in Wistar rats by feeding them a high-fat diet (cafeteria diet). Another group of animals received the same diet supplemented with a combination of two different antioxidants, ascorbic acid (100 mg/kg rat/day) and sodium selenite (200 microg/kg rat/day) and a third group fed on a control diet. Total and individual COPs analysis of the different diets showed no differences among them. At the end of the experimental trial, rats were sacrificed and serum cholesterol, triglycerides and COPs were measured. None of the diets induced changes in rats body weight, total cholesterol and triglycerides levels. Serum total COPs in rats fed on the high-fat diet were 1.01 microg/ml, two times the amount of the control rats (0.47 microg/ml). When dietary antioxidant supplementation was given, serum total COPs concentration (0.44 microg/ml) showed the same levels than those of the rats on control diet. 7beta-hydroxycholesterol, formed non-enzymatically via cholesterol peroxidation in the presence of reactive oxygen species, showed slightly lower values in the antioxidant-supplemented animals compared to the control ones. This study confirms the importance of dietary antioxidants as protective factors against the formation of oxysterols

A dual epigenomic approach for the search of obesity biomarkers: DNA methylation in relation to diet-induced weight loss

Epigenetics could help to explain individual differences in weight loss after an energy-restriction intervention. Here, we identify novel potential epigenetic biomarkers of weight loss, comparing DNA methylation patterns of high and low responders to a hypocaloric diet. Twenty-five overweight or obese men participated in an 8-wk caloric restriction intervention. DNA was isolated from peripheral blood mononuclear cells and treated with bisulfite. The basal and endpoint epigenetic differences between high and low responders were analyzed by methylation microarray, which was also useful in comparing epigenetic changes due to the nutrition intervention. Subsequently, MALDI-TOF mass spectrometry was used to validate several relevant CpGs and the surrounding regions. DNA methylation levels in several CpGs located in the ATP10A and CD44 genes showed statistical baseline differences depending on the weight-loss outcome. At the treatment endpoint, DNA methylation levels of several CpGs on the WT1 promoter were statistically more methylated in the high than in the low responders. Finally, different CpG sites from WT1 and ATP10A were significantly modified as a result of the intervention. In summary, hypocaloric-diet-induced weight loss in humans could alter DNA methylation status of specific genes. Moreover, baseline DNA methylation patterns may be used as epigenetic markers that could help to predict weight loss

Epigenetic Landscape in Blood Leukocytes Following Ketosis and Weight Loss Induced by a Very Low Calorie Ketogenic Diet (VLCKD) in Patients with Obesity

Background: The molecular mechanisms underlying the potential health benefits of a ketogenic diet are unknown and could be mediated by epigenetic mechanisms. Objective: To identify the changes in the obesity-related methylome that are mediated by the induced weight loss or are dependent on ketosis in subjects with obesity underwent a very-low calorie ketogenic diet (VLCKD). Methods: Twenty-one patients with obesity (n ¼ 12 women, 47.9 ± 1.02 yr, 33.0 ± 0.2 kg/m2 ) after 6 months on a VLCKD and 12 normal weight volunteers (n ¼ 6 women, 50.3 ± 6.2 yrs, 22.7 ± 1.5 kg/m2 ) were studied. Data from the Infinium MethylationEPIC BeadChip methylomes of blood leukocytes were obtained at time points of ketotic phases (basal, maximum ketosis, and out of ketosis) during VLCKD (n ¼ 10) and at baseline in volunteers (n ¼ 12). Results were further validated by pyrosequencing in representative cohort of patients on a VLCKD (n ¼ 18) and correlated with gene expression. Results: After weight reduction by VLCKD, differences were found at 988 CpG sites (786 unique genes). The VLCKD altered methylation levels in patients with obesity had high resemblance with those from normal weight volunteers and was concomitant with a downregulation of DNA methyltransferases (DNMT)1, 3a and 3b. Most of the encoded genes were involved in metabolic processes, protein metabolism, and muscle, organ, and skeletal system development. Novel genes representing the top scoring associated events were identified, including ZNF331, FGFRL1 (VLCKD-induced weight loss) and CBFA2T3, C3orf38, JSRP1, and LRFN4 (VLCKD-induced ketosis). Interestingly, ZNF331 and FGFRL1 were validated in an independent cohort and inversely correlated with gene expression. Conclusions: The beneficial effects of VLCKD therapy on obesity involve a methylome more suggestive of normal weight that could be mainly mediated by the VLCKD-induced ketosis rather than weight loss.This work was supported by the PronoKal Group® and grants from the Fondo de Investigacion Sanitaria as well as PI17/01287, PI20/00628 and PI20/00650 research projects and CIBERobn from the Instituto de Salud Carlos III (ISCIII)-Subdireccion General de Evaluacion y Fomento de la Investigación; Fondo Europeo de Desarrollo Regional (FEDER) Ana B Crujeiras is funded by a research contract “Miguel Servet” (CP17/00088) from the ISCIII, co-financed by the European Regional Development Fund (FEDER) and Xunta de Galicia-GAIN (IN607B2020). The funding source had no involvement in the study design or interpretation of the result

Phenolic compounds inhibit 3T3-L1 adipogenesis depending on the stage of differentiation and their binding affinity to PPAR gamma

Phenolic compounds might modulate adiposity. Here, we report our observation that polyphenols and phenolic acids inhibit adipogenesis in 3T3-L1 with different intensity depending on the family and the stage of differentiation. While quercetin and resveratrol inhibited lipid accumulation along the whole process of differentiation, apigenin and myricetin were active during the early and latest stages, but not intermediate, contrary to hesperidin. The activity of phenolic acids was limited to the early stages of the differentiation process, except p-coumaric and ellagic acids. This anti-adipogenic effect was accompanied by down-regulation of Scd1 and Lpl. Molecular docking analysis revealed that the inhibitory activity of these phenolic compounds over the early stages of adipogenesis exhibits a significant correlation (r = 0.7034; p = 0.005) with their binding affinity to the ligand-binding domain of PPAR¿. Results show that polyphenols and phenolic acids would interact with specific residues of the receptor, which could determine their potential anti-adipogenic activity during the early stages of the differentiation. Residues Phe264, His266, Ile281, Cys285 and Met348 are the most frequently involved in these interactions, which might suggest a crucial role for these amino acids modulating the activity of the receptor. These data contribute to elucidate the possible mechanisms of phenolic compounds in the control of adipogenesis

Association between sleep disturbances and liver status in obese subjects with nonalcoholic fatty liver disease: a comparison with healthy controls

The relevance of sleep patterns in the onset or evolution of nonalcoholic fatty liver disease (NAFLD) is still poorly understood. Our aim was to investigate the association between sleep characteristics and hepatic status indicators in obese people with NAFLD compared to normal weight non-NAFLD controls. Ninety-four overweight or obese patients with NAFLD and 40 non-NAFLD normal weight controls assessed by abdominal ultrasonography were enrolled. Hepatic status evaluation considered liver stiffness determined by Acoustic Radiation Force Impulse elastography (ARFI) and transaminases. Additionally, anthropometric measurements, clinical characteristics, and biochemical profiles were determined. Sleep features were evaluated using the Pittsburgh Sleep Quality Index (PSQI). Hepatic status parameters, anthropometric measurements, and clinical and biochemical markers differed significantly in NAFLD subjects compared to controls, as well as sleep efficiency, sleep disturbance score, and sleep quality score. In the NAFLD group, a higher prevalence of short sleep duration (p = 0.005) and poor sleep quality (p = 0.041) were found. Multivariate-adjusted odds ratio (95% confidence interval) for NAFLD considering sleep disturbance was 1.59 (1.11–2.28). Regression models that included either sleep disturbance or sleep quality predicted up to 20.3% and 20.4% of the variability of liver stiffness, respectively, and after adjusting for potential confounders.Current findings suggest that sleep disruption may be contributing to the pathogenesis of NAFLD as well as the alteration of the liver may be affecting sleep patterns. Consequently, sleep characteristics may be added to the list of modifiable behaviors to consider in health promotion strategies and in the prevention and management of NAFLD