Are we Ready for a "Microbiome-Guided Behaviour” Approach?

The microbiome is proving to be increasingly important for human brain functioning.A series of recent studies have shown that the microbiome infl uences the centralnervous system in various ways, and consequently acts on the psychological well-being ofthe individual by mediating, among others, the reactions of stress and anxiety. From a specifically neuroethical point of view, according to some scholars, the particular compositionof the microbiome— qua microbial community—can have consequences on the traditionalidea of human individuality. Another neuroethical aspect concerns the reception of thisnew knowledge in relation to clinical applications. In fact, attention to the balance of themicrobiome—which includes eating behavior, the use of psychobiotics and, in the treatmentof certain diseases, the use of fecal microbiota transplantation—may be limited oreven prevented by a biased negative attitude. This attitude derives from a prejudice relatedto everything that has to do with the organic processing of food and, in general, with thehuman stomach and intestine: the latter have traditionally been regarded as low, dirty, contaminatedand opposed to what belongs to the mind and the brain. This biased attitude canlead one to fail to adequately consider the new anthropological conceptions related to themicrobiome, resulting in a state of health, both physical and psychological, inferior to whatone might have by paying the right attention to the knowledge available today. Shiftingfrom the ubiquitous high-low metaphor (which is synonymous with superior-inferior) toan inside-outside metaphor can thus be a neuroethical strategy to achieve a new and unbiasedreception of the discoveries related to the microbiome.