A gut feeling: Microbiome-brain-immune interactions modulate social and affective behaviors

Abstract

The expression of a wide range of social and affective behaviors, including aggression and investigation, as well as anxiety- and depressive-like behaviors, involves interactions among many different physiological systems, including the neuroendocrine and immune systems. Recent work suggests that the gut microbiome may also play a critical role in modulating behavior and likely functions as an important integrator across physiological systems. Microbes within the gut may communicate with the brain via both neural and humoral pathways, providing numerous avenues of research in the area of the gut-brain axis. We are now just beginning to understand the intricate relationships among the brain, microbiome, and immune system and how they work in concert to influence behavior. The effects of different forms of experience (e.g., changes in diet, immune challenge, and psychological stress) on the brain, gut microbiome, and the immune system have often been studied independently. Though because these systems do not work in isolation, it is essential to shift our focus to the connections among them as we move forward in our investigations of the gut-brain axis, the shaping of behavioral phenotypes, and the possible clinical implications of these interactions. This review summarizes the recent progress the field has made in understanding the important role the gut microbiome plays in the modulation of social and affective behaviors, as well as some of the intricate mechanisms by which the microbiome may be communicating with the brain and immune system.

Gut-Brain Axis: Probiotic,Bacillus subtilis, Prevents Aggression via the Modification of the Central Serotonergic System

“…Intestinal microbiota plays an important role in regulation of social behavior, emotional expression, and mental health within the animal kingdom [3, 137,138]. They are essential players in stabilizing homeostasis of the GI tract in response to both acute and chronic stress via the microbiota-gut-brain axis [16,139]. Normally, intestinal microbiota provides protection for animals by competing for attachment sites and nutrients with pathogens as well as production of antimicrobial peptides and neuroactive compounds [140,141].…”

Immunity and ultrasonic vocalization in rodents

“…In addition, immune or behavioral manipulations performed at stages of development that range from the perinatal period, adolescence, and adulthood until senescence, indicate that the impact of behavior–immune interactions is age‐ and sex‐dependent. It is beyond the scope of this article to review the extremely abundant literature dealing with one or the other aspect of this broad subject, and only a few articles from the many available are mentioned here . These reviews also include a large list of references to which the reader interested in a given aspect is referred to.…”

The effect of captivity on the primate gut microbiome varies with host dietary niche

“…Across mammals, the gut microbiome has been implicated in a range of host health outcomes, including GI distress (Cox & Blaser, ; Hooper, Littman, & Macpherson, ; Kassinen et al, ; Rooks et al, ; Suchodolski et al, ; Sylvia & Demas, ; Young & Schmidt, ). It may, therefore, provide insight into NHP risk of GI distress in captive environments.…”