Obesity and Lipotoxicity

Evren Doruk Engin M.D., Ph.D., Evren Doruk Engin, Engin, Evren Doruk

Ayse Basak Engin, Atilla Engin

Obesity and metabolic syndrome is a multisystemic disorder, that is characterized by excess caloric intake and spillover lipotoxicity caused by ectopic lipid accumulation in non-adipose tissues. Low grade chronic inflammation and insulin resistance are the hallmarks of the disorder, which further aggravate the condition. Gut microbiota constitutes an indispensible part of human superorganism's energy harvesting apparatus. The dynamic composition of microbiota changes with age, life style and host metabolic background. The wealth of genetic repertoire provided by these microorganism enables to extend host's substrate processing and harvesting capability. Some of these compounds including short chain fatty acids and indole act as signalling molecules on mammalian cells and modulate their behaviour. Nonetheless, this symbiotic style of interaction is restrained by immune system. The role of chronic low grade inflammation in metabolic syndrome is well established. Treg cells are the key players that sense and reshape the composition of microbiota. In this regard, any disturbance in Treg functionality may aggravate the inflammation and shift the symbiotic balance towards dysbiosis, which is characterized by autoimmunity and insulin resistance. Thus, immune system is responsible for the modulation of host and microbiota metabolisms and Treg cells act as a bridge in between.