Can study of the ADRB3 gene help improve weight loss programs in obese individuals? / ¿Puede el estudio del gen ADRB3 ayudar a mejorar los programas de pérdida de peso en individuos obesos?

INTRODUCTION: Obesity is a chronic disease of multifactorial origin characterized by excess weight and excess fat accumulation, and whose etiology includes intrinsic (genetic, physiological, and metabolic) and extrinsic (social and cultural) factors. Fat accumulation is caused by a prolonged imbalance in the energy balance influenced, among other factors, by adaptive thermogenesis, which is triggered by cold environmental conditions, or by hypercaloric intake. Thermogenesis is regulated by the sympathetic nervous system and occurs in the muscle and brown adipose tissue. There are adrenergic receptors in brown adipose tissue, including the beta-3 adrenergic receptor (ADRB3), the main receptor for the regulation of thermogenesis. The presence in heterozygosis of an SNP-type polymorphism in the ADRB3 gene (Trp64Arg; rs4994) is associated with a lower lipolytic activity, a predisposition to obesity, and resistance to weight loss. The objective of this study was to analyze through a systematic review the weight loss program most appropriate for carriers. METHODS: A retrospective study of published papers on rs4994 polymorphism in the SNP and PubMed databases was conducted. RESULTS: Most published studies suggest the presence of obesity and resistance to weight loss in carriers, and report significant improvements in anthropometric parameters when patients receive fat-rich hypocaloric diets. CONCLUSIONS: Based on these conclusions, specific nutritional and physical exercise guidelines are proposed for individuals carrying the Trp64Arg allele.

Microbiota Features Associated With a High-Fat/Low-Fiber Diet in Healthy Adults.

A high intake of dietary saturated fatty acids (SFAs) is related to an increased risk of obesity, inflammation and cancer-related diseases, and this risk is attenuated only when SFAs are replaced by unsaturated fats and unrefined carbohydrates. The gut microbiota has recently emerged as a new environmental factor in the pathophysiology of these disorders, and is also one of the factors most influenced by diet. We sought to determine whether the gut microbiota of healthy individuals whose intake of SFAs exceeds World Health Organization (WHO) recommendations exhibits features similar to those reported in people with obesity, inflammation, cancer or metabolic disease. Healthy non-obese subjects were divided into two groups based on their SFAs intake. Body composition and gut microbiota composition were analyzed, and associations between bacterial taxa, diet and body fat composition were determined globally and separately by sex. Metagenome functional pathways were predicted by PICRUSt analysis. Subjects whose SFAs intake exceeded WHO recommendations also had a dietary pattern of low fiber intake. This high saturated fat/low fiber diet was associated with a greater sequence abundance of the Anaerotruncus genus, a butyrate producer associated with obesity. Analysis of data of high SFAs intake by sex showed that females presented with a greater abundance of Campylobacter, Blautia, Flavonifractor and Erysipelatoclostridium, whereas males showed higher levels of Anaerotruncus, Eisenbergiella, a genus from the order Clostridiales (FamilyXIIIUCG_001) and two genera from the Lachnospiraceae family. PICRUSt analysis confirmed these data, showing a correlation with a decrease in the abundance of sequences encoding for transporters of some metals such as iron, which is needed to maintain a healthy metabolism. Thus, the microbiota of healthy people on a high SFAs diet contain bacterial taxa (Anaerotruncus, Lachnospiraceae Flavonifractor, Campylobacter, Erysipelotrichacea and Eisenbergiella) that could be related to the development of some diseases, especially obesity and other pro-inflammatory diseases in women. In summary, the present study identifies bacterial taxa that could be considered as early predictors for the onset of different diseases in healthy subjects. Also, sex differences in gut microbiota suggest that women and men differentially benefit from following a specific diet.

[Lifestyle modulation of gut microbiota]. / Modulación a través del estilo de vida de la microbiota intestinal.

INTRODUCTION: In recent years, the advance in gut microbiota knowledge has shown that is key in the development and health status of humans. There are many factors that influence the gut microbiota and its balance, being our lifestyle one of the key factors. There is an association between feeding and practicing physical exercise. People who have an active life have a healthier diet, richer in fiber, vegetables and fruits, while sedentary lifestyle is associated with diets with higher fat content and lower fiber. Our feeding behavior and the practice of physical exercise, determine the microbial diversity, as well as the presence of beneficial bacteria for our health. The influence of these factors is determined by the physiological state of the individual (illness/health, obese/lean, young/old), thus more research is needed to determine how changes occur in the microbiota depending on the individual in order to be able to move towards customized nutrition and exercise recommendations according to the needs of each individual.

INTRODUCCIÓN: En los últimos años, el avance en el conocimiento de la microbiota intestinal nos ha demostrado que es clave en el desarrollo y en el estado de salud del ser humano. Son numerosos los factores que influyen sobre la microbiota intestinal y su equilibrio, y nuestro estilo de vida es uno de los factores claves. Existe una asociación entre la alimentación y la práctica de ejercicio físico. Las personas que tienen una vida activa tienen, además, una alimentación más saludable, más rica en fibra, verduras y frutas, mientras que el sedentarismo se asociada al consumo de dietas con mayor contenido de grasa y poca fibra. Nuestro estilo de vida, entendido como alimentación y realización de ejercicio físico, determina la diversidad microbiana, así como la presencia de bacterias beneficiosas para nuestra salud. La influencia de estos factores está determinada por el estado del individuo (enfermedad/salud, obeso/delgado, joven/anciano), por lo que es necesaria más investigación para determinar cómo se producen los cambios en la microbiota en función del individuo, con el fin de poder avanzar hacia una nutrición y unas recomendaciones de ejercicio personalizadas acordes a las necesidades de cada persona.

Anorexia and bulimia nervosa: virtual diffusion of the disease as a lifestyle / Anorexia y bulimia nerviosas: difusión virtual de la enfermedad como estilo de vida.

Introduction: Adolescence is a vulnerable period for the onset of eating disorders (ED) such as anorexia and bulimia nervosas. Body dissatisfaction, a precipitating factor for ED, leads adolescents to seek information on the Internet about diets. In this context, pro-Ana (proanorexia) and pro-Mia (probulimia) are on-line pages that promulgate highly harmful contents for health related to weight loss and ED. Objectives: The aim of this study was to analyze quantity, quality and social diffusion strategies used by pro-Ana and pro-Mia webpages. Methods: A web search was done in the Google Chrome browser, using the keywords "anorexia", "bulimia", "eating disorders", "Ana and Mia", "pro-Ana and pro-Mia", "anorexic nation", "obesity", "healthy lifestyles" and "healthy nutrition". The top 20 results for each search were selected and analyzed according to positioning rates (PageRank, PR). The quality of these resources was analyzed by a previously published questionnaire. Finally, a study of the diffusion in social networks like Facebook and Twitter was performed for pro-Ana and pro-Mia pages using SharedCount. Results: Searches for pro-Ana and pro-Mia reported more than a million entries. The pages were poorly positioned. Blog contents were the most shared between all the analyzed pages. Conclusions: pro-Ana and pro-Mia are resources with a clear intention to establish a contact with people with an eating disorder or who are at risk for developing one, in order to strengthen the communication through the blogosphere.

Introducción: la adolescencia es un periodo vulnerable para padecer trastornos de la conducta alimentaria (TCA) como la anorexia y la bulimia nerviosas. La insatisfacción corporal, uno de los factores precipitantes de los TCA, conduce a las adolescentes a la búsqueda de información sobre dietas en internet. En este contexto, las páginas pro-Ana (proanorexia) y pro-Mía (probulimia) difunden contenidos altamente perjudiciales para la salud relacionados con la pérdida de peso y los TCA.Objetivos: en el presente trabajo se analizan la cantidad, el posicionamiento, la calidad y la difusión de las páginas pro-Ana y pro-Mía. Métodos: se realizó una búsqueda de páginas web en el navegador Google Chrome con las palabras clave "anorexia", "bulimia", "trastornos de la conducta alimentaria (TCA)", "Ana y Mía", "pro-Ana y pro-Mía", "anorexic nation", "obesidad", "estilos de vida saludables" y "nutrición saludable". Se seleccionaron los 20 primeros resultados de cada búsqueda según los índices de posicionamiento de PageRank y se analizó la calidad de dichos recursos mediante un cuestionario. Para el estudio de la difusión de páginas pro-Ana y pro-Mía en redes sociales como Facebook y Twitter se utilizó el programa SharedCount. Resultados: pro-Ana y pro-Mía dieron más de un millón de entradas, siendo páginas mal posicionadas, de tipo blog en su mayoría, con mayor difusión en Facebook y Twitter comparadas con otras de mejor calidad. Conclusiones: pro-Ana y pro-Mía son recursos con una clara intencionalidad de contactar con personas que padecen un TCA o están en riesgo, con el fin de reforzar la comunicación entre ellas a través de la blogosfera.

Dynamic effects of cofactors and DNA on the oligomeric state of human mitochondrial DNA helicase.

We examined the effects of cofactors and DNA on the stability, oligomeric state and conformation of the human mitochondrial DNA helicase. We demonstrate that low salt conditions result in protein aggregation that may cause dissociation of oligomeric structure. The low salt sensitivity of the mitochondrial DNA helicase is mitigated by the presence of magnesium, nucleotide, and increased temperature. Electron microscopic and glutaraldehyde cross-linking analyses provide the first evidence of a heptameric oligomer and its interconversion from a hexameric form. Limited proteolysis by trypsin shows that binding of nucleoside triphosphate produces a conformational change that is distinct from the conformation observed in the presence of nucleoside diphosphate. We find that single-stranded DNA binding occurs in the absence of cofactors and renders the mitochondrial DNA helicase more susceptible to proteolytic digestion. Our studies indicate that the human mitochondrial DNA helicase shares basic properties with the SF4 replicative helicases, but also identify common features with helicases outside the superfamily, including dynamic conformations similar to other AAA(+) ATPases.