Psychobiotic Effects on Anxiety Are Modulated by Lifestyle Behaviors: A Randomized Placebo-Controlled Trial on Healthy Adults.

Ricardo Morales-Torres, Cristóbal Carrasco-Gubernatis, Aitana Grasso-Cladera, Diego Cosmelli, Francisco J Parada, Ismael Palacios-García

Journal: Nutrients 2023;15(7):1706

PMID: 37049546

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Plain Language Summary

The microbiota-gut-brain axis refers to the complex communication system between the human gastrointestinal tract, the micro-organisms which inhabit it, and the peripheral and central nervous systems. In recent years, human trials have linked the microbiome with specific processes that are expected to contribute to well-being. The aim of this study was 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, and others. This study was a four week, double-blind, randomised, placebo-controlled trial. Participants were randomised into one of two groups; placebo or probiotic group. Results showed that there were no significant effects of probiotics on a set of psychological measures of well-being. However, further analysis revealed that healthy lifestyle behaviours were significantly correlated with wellbeing across scales. Authors conclude that their findings demonstrate the need of controlling lifestyle variables as a standard practice in human microbiome research and mental health research in general.

Abstract

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 ( = 135) tested 4 weeks of probiotic supplementation ( R0052 and R0175). We assessed effects on wellbeing, quality of life, emotional regulation, anxiety, mindfulness and interoceptive awareness. We then analyzed if lifestyle behaviors modulated probiotic effectiveness. Results showed no significant effects of probiotic intake in whole sample outcomes. Correlational analyses revealed Healthy Behaviors were significantly correlated with wellbeing across scales. Moreover, the linear mixed-effects model showed that the interaction between high scores in Healthy Behaviors and probiotic intake was the single significant predictor of positive effects on anxiety, emotional regulation, and mindfulness in post-treatment outcomes. These findings highlight the relevance of controlling for lifestyle behaviors in psychobiotic and mental health research.

Address: Center for Cognitive Neuroscience, Duke University, Durham, NC 27710, USA.; Centro de Estudios en Neurociencia Humana y Neuropsicología, Facultad de Psicología, Universidad Diego Portales, Santiago 8320000, Chile.; Programa de Magíster en Neurociencia Social, Facultad de Psicología, Universidad Diego Portales, Santiago 8320000, Chile.; Escuela de Psicología, Facultad de Ciencias Sociales y Centro Interdisciplinario de Neurociencias, Pontificia Universidad Católica de Chile, Santiago 7820436, Chile.

DOI: 10.3390/nu15071706