Recent findings within the microbiota–gut–brain–endocrine metabolic interactome

Mark Obrenovich,1–4 Thriveen Sankar Chittoor Mana,5 Herleen Rai,2 Dorjee Shola,4,6 Christopher Sass,2,3 Benjamin McCloskey,4 Bruce S Levison7 1Pathology and Laboratory Medicine Service, 2Research Service, Cleveland Veterans Affairs Medical Center, 3Department of Chemistry, Cleveland State University, 4Gilgamesh Foundation, 5Division of Infectious Diseases and HIV Medicine, Case Western Reserve University, Cleveland, OH, 6Gene Targeting Resource Center, The Rockefeller University, New York, NY, 7Department of Pediatrics, University of Toledo, Toledo, OH, USA Purpose of review: We have established that many metabolic biomes exist within the complex mammalian gut. Substantial metabolism occurs within these biomes and is called co-metabolism of the host and resident microorganisms. This gut–brain–endocrine metabolic interaction emphasizes how bacteria can affect the brain and the hormonal axes in the process of co-metabolism. This review highlights new findings in this regard. Recent findings: In this review, we explore how the gut microbiota affect the development and regulation of the hypothalamic–pituitary–adrenal axis and neurochemistry from mental health and behavioral health to memory, depression, mood, anxiety, obesity, and the development of the blood–brain barrier. Summary: This review describes the implications of the findings for clinical practice or research. Interaction of small molecules within these biomes is now described collectively as a “metabolic interactome”. Metabolites of the gut–brain–endocrine axis and our overall gut health constantly shape the host phenotype in ways previously unimagined, and this niche represents potential targets for treatment and drug design, since the interaction or biochemical interplay results in net metabolite production and/or end products to exercise either positive or negative effects on human health. Keywords: neurotransmitters, gut brain axis, metabolomics, microbiota, microbiome, HPA