Mitochondria and the Gut as crucial hubs for the interactions of melatonin with sirtuins, inflammation, butyrate, tryptophan metabolites, and alpha 7 nicotinic receptor across a host of medical conditions.

Abstract

Two important hubs have emerged as cutting edge areas of research across a diverse array of medical conditions, the gut microbiome and mitochondria. This article highlights the role of melatonin in modulating changes in both the gut and mitochondria. The gut microbiome, especially via its production of the small chain fatty acid, butyate, can have a significant impact on immune inflammatory processes. Lower levels of butyrate producing bacteria can increase gut permeability, thereby increasing immune-inflammatory activity. Butyrate may also modulate immune and other cells via the regulation of the content of exosomes from intestinal epithelial cells. Butyrate also induces N-acetylserotonin and melatonin synthesis in the gut, suggesting that some of the effects of butyrate may be mediated via its induction of the melatonergic pathway. The induction of melatonin by butyrate may feed back on the microbiome via melatonin increasing gut bacteria swarming, as well as melatonin optimizing gut barrier and mitochondria functioning. As butyrate readily crosses into the circulation it is likely that the immune- and glia-dampening effects of butyrate also involve the induction of melatonin in these reactive cells. Butyrate also positively modulates mitochondria functioning, suggesting that butyrate, both directly and via melatonin, will have significant impacts on gut, immune, glia and other cells, via mitochondria regulation. Other factors that act to regulate melatonin, including dietary factors and stress, will therefore act to modulate many of butyrate's effects. The regulation of melatonin at these two important hubs has significant treatment and classification implications across a wide array of medical conditions. Overall, gut dysbiosis has a significant impact on central and systemic homeostasis, via decreased butyrate and melatonin driving suboptimal mitochondria functioning. This has implications for the pathoetiology and pathophysiology of a host of medical conditions associated with gut dysbiosis and decreased melatonin production.