1. Introduction
Axis, human behavior
These authors contributed equally to this work.Psychobiotics are modulators of the Microbiota-Gut-Brain Axis (MGBA) with promising benefits to mental health. Lifestyle behaviors are established modulators of both mental health and the MGBA. This randomized placebo-controlled clinical trial (NCT04823533) on healthy adults (Communication between extracranial signals and the brain has received increasing attention in recent decades given its impact on cognition and mental processes [Well-being can be defined as the optimal psychological functioning and its experience, where physical and subjective factors are integrated [One of the most studied interventions that modulate microbiome physiology and possibly affect human behavior is psychobiotics administration [In this randomized controlled trial, we aimed to assess the effect of a psychobiotic formulation specifically on well-being, exploring the extent to which these effects might be modulated by lifestyle factors such as diet, physical activity, social connectedness, among others.