Impact of olfactory food ingredients on emotional and digestive state

Modification of the olfactory system can dramatically influence emotion and it is well accepted that mice with olfactory impairments develop pseudo-depressive symptoms (Yuan. M. et al, 2020) and microbiota dysregulation (Shuai-Ming Zhu et al, 2024). On this backdrop, our research is currently focusing on the therapeutic potential of exploiting the olfactory system in mood-related disorders. Different odors can exert anxiolytic and/or antidepressant-like effects in several depression models. To better understand the functional relationships between odors, emotion, microbiota and gut physiology (i.e., visceral sensitivity and motility), mice were chronically exposed to different sensory functional olfactory ingredients in the drinking water through retronasal olfaction. Ingredients were tested in naïve non-stressed animals and in a stress model of depression based on short-term subcutaneous implantation of corticosterone-containing pellets. To study olfactory ingredient impact on emotion, we conducted different behavioural tests (anxiety, depression, nociception). One of the olfactory ingredients reversed CORT-induced depressive-like state. Moreover, it decreased short-term CORT-induced visceral hypersensitivity. Under these experimental conditions, we now study the underlying neurobiological mechanisms with a particular attention on the activity of hypothalamic-pituitary-adrenal axis, excitatory synapse density and neuro-inflammation. At the digestive level, we study microbiota (taxonomy), motricity and permeability. Together these data will give us an insight into how sensory functional olfactory ingredients through retronasal olfaction could be used in human and animal medical applications by modulating the odor- emotion- gut interplay.