Psychobiotics: Mechanisms of Action, Evaluation Methods and Effectiveness in Applications with Food Products

Abstract

The gut-brain-microbiota axis consists of a bilateral communication system that enables gut microbes to interact with the brain, and the latter with the gut. Gut bacteria influence behavior, and both depression and anxiety symptoms are directly associated with alterations in the microbiota. Psychobiotics are defined as probiotics that confer mental health benefits to the host when ingested in a particular quantity through interaction with commensal gut bacteria. The action mechanisms by which bacteria exert their psychobiotic potential has not been completely elucidated. However, it has been found that these bacteria provide their benefits mostly through the hypothalamic-pituitary-adrenal (HPA) axis, the immune response and inflammation, and through the production of neurohormones and neurotransmitters. This review aims to explore the different approaches to evaluate the psychobiotic potential of several bacterial strains and fermented products. The reviewed literature suggests that the consumption of psychobiotics could be considered as a viable option to both look after and restore mental health, without undesired secondary effects, and presenting a lower risk of allergies and less dependence compared to psychotropic drugs.

Probiotic Properties, Prebiotic Fermentability, and GABA-Producing Capacity of Microorganisms Isolated from Mexican Milk Kefir Grains: A Clustering Evaluation for Functional Dairy Food Applications

“…The psychobiotic potential of the fermentative microorganisms was assessed by studying their ability to secrete GABA, a neuroactive molecule. According to Del Toro-Barbosa et al (2020) [9], analyzing the production of this neurotransmitter is one of the first in vitro approaches that can be carried out to screen the psychobiotic potential of microorganisms. Tsukatani, Higuchi, and Matsumoto (2004) [19] evaluated the ability of 381 strains of LAB to produce GABA in MRS medium.…”

“…GABA is among the primary neurotransmitters of the mammalian central nervous system, whose role is to control excitatory and inhibitory neurotransmission [8]. Several strains of Bifidobacterium and Lactobacillus have received considerable attention due to their psychobiotic properties, showing mental health benefits [9]. Currently, the food industry is very interested in seeking highly productive GABA strains and optimizing the growth conditions for these bacteria due to the role of this bioactive compound in the treatment of mental disorders as anxiety and depression [10].…”

Bacillus subtilis-Based Probiotic Improves Skeletal Health and Immunity in Broiler Chickens Exposed to Heat Stress

“…The modulation of the gut microbiota by the administration of probiotics, as well as prebiotics and synbiotics, has become a biotherapy strategy for preventing and treating many diseases, from stress-related irritable bowel syndrome to neuropsychiatric disorders [ 25 , 26 , 27 ]. Probiotics (direct-fed microbials) can restore the ecologic stability of gut microbiota by inhibiting pathogens, promoting the growth of beneficial bacteria, and releasing bioactive and immunomodulatory factors to improve the function of the hypothalamic–pituitary–adrenal axis (one of the major stress response systems) and immunity via the microbiota–gut–brain axis and or the microbiota–gut–immune axis [ 28 , 29 ].…”

Current Trends of Enterococci in Dairy Products: A Comprehensive Review of Their Multiple Roles

“…The gut microbiome is now known to play an important role in the so-called gut-brain axis, and to impact their human host's mental health by several mechanisms, including production of neurotransmitters [239]. Enterococcus spp.…”