Many theories have been developed to explain why animals exhibit certain social behaviours, the impact of the #microbiota, however, has rarely been considered. In a review published in Science Mag this month, scientists have examined several pre-clinical and clinical trials investigating the effect of the microbiota on the social brain. It has been discovered that through a diverse set of pathways the gastrointestinal microbiota is able to send signals to the brain, this is known as the #microbiota-gut-brain axis. The microbiota plays a key role in neurodevelopment from early life into adulthood influencing processes such as #neurotransmission and #neuroinflammation as well as behaviour throughout lifespan. With animals having evolved in a microbial world, these signals may have influenced the animal brain throughout evolution.
The #holobiont hypothesis offers us a new and interesting theory based on substantial evidence. The holobiont concept is a theoretical and experimental framework studying the interactions between hosts and their associated microbial communities in all types of ecosystems. The host and microbial genomes are collectively termed a #hologenome. Any variation in the hologenome caused by changes in the host and/or microbes may affect #phenotypes that could be subject to natural selection.
Social behaviour is defined as only occurring in groups of animals, with many of these behaviours coming with disadvantages, shared risk, conflict and dominance for example. If we can understand the complex relationships between the microbiota and sociability, we may then be able to identify methods for treating social disorders in humans. Social interactions are a vital component for healthy human mental health. Several studies have shown deviations in the gastrointestinal microbiota among individuals with #neuropsychiatric disorders and on analysis of faecal microbiota of children with autistic spectrum disorder (#asd), profound alterations in microbial diversity were found. Emerging evidence suggests that targeting the microbiota through dietary or live #biotherapeutic interventions can improve certain behavioural symptoms associated in some neurodevelopmental disorders. Further understanding of the microbiotas influence on the social brain is vital and could provide us with a new range of understandings for ecology, evolution and human biology.