Central Energy Homeostasis: is it in our gut or in our brain?

Energy homeostasis plays a critical role controlling how much we should eat in order to provide sufficient energy to our bodies. Unfortunately, this system does not always work properly in any bodies in which it signals the body to intake more food even after a person just eat five grilled cheese burgers. Consequently, people with this disorder usually have heavy body weight, or obesity. It is widely believed that the neural system is responsible for regulating energy homeostasis according to Bernard and his teams.

Particularly, according to the article 'Melanocortin-4 receptor-regulated energy homeostasis”, the authors points out that the central melanocortin system accounts for body weights and overall metabolic fitness. Within that neural circuit, MC4R neural population is believed to be the diverging signal although the majority of the population remains unknown. What captured my attention in this article is that the authors also found "there is the contribution of MC4Rs in enteroendocrine L-cells of the intestine which is activated by the release of GLP1 and Peptide YY. Therefore, potentially enhancing centrally mediated MC4R signaling can improve the weight loss and the energy expenditure efficacy".

This finding reminds me the review "Gut-feelings: the emerging biology of gut-brain communication", Mayer and his collaborators claim that gut microbiota can liberate various neurotransmitters, such as peptide YY, GLP1 ghrelin, 5-HT, to elicit satiety and emotional responses. Recently, more and more studies find that microbiota in the gut can influence our behavior. If this is true, it would provide a better clinical avenue to treat energy homeostasis disorder because engineered bacteria are much more targeting than medications.

Link for "Melanocortin-4 receptor-regulated energy homeostasis" :https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5244821/

Link for "Gut-feelings: the emerging biology of gut-brain communication" : https://www.ncbi.nlm.nih.gov/pubmed/21750565

Link for " Body Energy Homeostasis" https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2605663/