The gut microbiome as a virtual endocrine organ: Implications for host physiology and behaviour

Abstract Text:

The gut microbiome exerts a marked influence on multiple aspects of host physiology including not just host metabolism and body composition but also brain function and behaviour. This impact relates to its ability to produce or indirectly control a large range of hormonal agents that can play a regulatory role in the activity of local and distal systems and organs. Dysfunction of the hypothalamic–pituitary–adrenal (HPA) axis in particular has been a striking consequence to disrupting the gut microbiota in preclinical studies.  The translational relevance of these findings is apparent in stress-related disorders such as irritable bowel syndrome. Unlike other endocrine organs however, the gut microbiota exhibits compositional plasticity and can be itself be subject to fluctuation as a result of stressors or dietary factors with implications for the associated functionality. This includes stress experienced prenatally, postnatally and during adulthood. Farm animals regularly encounter a variety of such stressors related to handling practises, weaning, housing systems and transport that potentially affect welfare and productivity. While optimising nutrition to promote the gold standard assembly and maturity of the microbiota is one option to counteract the detrimental impact of stress exposure, more targeted interventions may be necessary at various critical points of control across the lifespan. Understanding how best to manipulate the gut microbiota to control host physiological and behavioural responses could have important implications in multiple settings, including the prevention or treatment of stress-related disorders. Expanding this research to farm animals may pave the way for new strategies to enhance animal health and to meet farm production targets.

Keywords:

endocrinology, gut physiology, microbiome,