Implications of psychobiotics and the gut–brain axis in livestock and performance animals: A meta-analysis

Psychobiotics are a type of probiotic that affect cognitive and behavioral functions in the host, have an effect via the gut–brain axis. Proposed mechanisms of psychobiotic effects include modulation via the hypothalamus–pituitary–adrenal axis, direct immune effects, and various neural, hormonal, and metabolic pathways affecting the balance of the gut microbiome. Growing evidence demonstrates that certain psychobiotic strains such as various Lactobacillus, Bifidobacterium, and Streptococcus species confer benefits for treatment or prevention of mental disorders such as depression, anxiety, and different altered mood or emotional states in humans. Many diseases and health problems exist in the production animal, which is often related to stress conditions or events such as weaning, transport, and castration. There is a potential for psychobiotics to reduce the stress experience of these animals, subsequently improving immune function and development, performance parameters, and encouraging desired mental states in livestock and performance animals. Over 100 relevant studies were found in the literature detailing psychobiotic and probiotic usage in humans and animals for neuropsychiatric benefit. Despite some probiotic trials analyzing the effects of psychobiotics on behavior and welfare in mice and human models, no studies to date have been performed to indicate the potential use of psychobiotics in livestock and performance animals for enhanced health and productivity measures. This presentation will evaluate the potential of psychobiotic administration in swine, pre-ruminants, and equids to promote the resolution of stereotypies, stress-induced disordered function, and improved production parameters based on suggested evidence in animal models used to date.

Key Words: psychobiotics, gut health, mental health, gut–brain axis, livestock.

Presented at the 9th Symposium on Gut Health in Production of Food Animals, St. Louis, USA, 2021. For information on the next edition, click here.