Nutritional modulation of the "brain-gut axis"

Abstract

The "brain-gut axis" is a multicomponent conceptual model describing the bidirectional communication pathways connecting cognitive and emotional centres in the brain with neuroendocrine centres, the enteric nervous system and the immune system. This model enables novel explanations for the comorbidity of affective disorders, especially concerning mood and anxiety, in functional gastrointestinal disorders, the visceral hypersensitivity, as well as the effect of various acute and chronic stressors on gastrointestinal function. Furthermore, it offers the possibility to develop new biomarkers of integrated brain-gut function. This review discusses the possibilities to modify brain-gut interaction by nutritional means, offered by the brain-gut axis concept. Dietary interventions directed at serotonergic metabolism and its action in the brain, the hypothalamic-pituitary-adrenal axis, the metabolism of long-chain polyunsaturated fatty acids affecting both brain function and inflammatory cytokine profiles, and gut hormones are elaborated. The central role of the autonomic nervous system is also discussed. It is concluded that the concept of the brain-gut axis indeed enables the development of novel dietary intervention strategies in functional gastrointestinal disorders, but results directly transferable to daily practice are not immediately anticipated.