Genes involved in obesity: Adipocytes, brain and microflora

Abstract

Obesity and obesity-related disorders such as cardiovascular diseases and metabolic abnormalities including hypertension, hyperinsulinemia, insulin-resistance and type 2 diabetes, are among the most pressing problems in the industrialized world (Friedman, 2003;Kannel et al., 1991 (Reitman et al., 2000), demonstrating that normal adipose tissue development and function is critical for metabolic homeostasis.Obesity results from complex interactions between genes and environmental factors such as diet, food components and/or way of life, and can be viewed as an energy storage disorder in which weight gain results from an energy imbalance (i.e. energy input exceeding output), with most of the excess calories stored as triglycerides in adipose tissue (Smith et al., 2006). Therefore a great deal of attention has focused on the mechanisms controlling food intake and adipose mass, and is of considerable importance for public health and clinical medicine.In this review, we prevalently highlight the complex relationships existing between the white adipose tissue, the central nervous system, the endogenous microbiota, and nutrition. Throughout, we emphasize the most recent findings in the field and consider how it shapes the past knowledge and forecasts the future of research on metabolic disorders, such as obesity.

The Gut Microbiome and the Brain

“…108 Compared with breast milk, infant formula feeding increases fecal concentration of propionate and butyrate. 109 Williams et al examined ileal biopsies of autistic children with gastrointestinal (GI) complaints and found a deficit of genes encoding disaccharidases and hexose transport enzymes, indicating impairment of the primary pathway for carbohydrate digestion and absorption in enterocytes, 110 a finding which suggests that bacterial dysbiosis results from an underlying impairment of digestion and absorption. In a subsequent report, they observed the presence of a unique genus of aerobic gram-negative rods, Sutterella, in ileal biopsies of autistic children with GI complaints but no children with GI complaints who were not autistic.…”

Feeding Our Immune System: Impact on Metabolism

“…This pathology is the result of an imbalance between caloric intake and energy expenditure, resulting in excess energy storage, mostly due to genetic and environmental factors. Among the environmental factors thought to play an important role in obesity, we should count the increased consumption of energy-dense and micronutrient-poor foods, that is, processed food is usually high in starches, added sugars, and added fats [ 136 , 137 ].…”

Ontogeny and nutritional control of adipogenesis in zebrafish (Danio rerio)

“…Vertebrates are capable of storing neutral lipid in several tissues, with adipose tissue serving as the primary depot. The principal cellular component of adipose tissue is the adipocyte, a cell type specialized for storing fat in cytoplasmic neutral lipid droplets and endocrine control of energy balance ( 4,5 ).…”