Research Indicates Gut Microbiomes Make Us Social and Friendly

It appears our guts influence more than just our physical and mental health but also our relationships

Hiya!

By now, I hope it’s safe to say we’re well aware of how important our gut microbiome is to our overall health and well-being — even though we’re still discovering and struggling to explain it. The trillions of microorganisms thriving in our gastrointestinal tract are so crucial that experts refer to them as our second brain because, so far, all evidence suggests they influence us far more than we ever dreamed.

For instance, an ever-growing pile of evidence suggests our teeny-tiny gut microorganisms have a staring role in our social behaviors — specifically making us more friendly and social. Two recent animal studies further confirm this idea and suggest reasonable links to suggest the same would be true for us.

Previous Research

Before we dive into the studies, let’s review where we were before them. After all, I said the results of previous studies led experts down this road, to begin with, but they don’t know how gut microbes influence the social brain regions in healthy and diseased states.

For instance, in 2013, researchers analyzed the gut microbes in regular mice and compared them to mice born and raised in germ-free environments, which limited their exposure to microorganisms. Even though each group had equal opportunity to socialize, the germ-free mice showed deficits in social behaviors as adults.

Then there’s this 2017 study suggesting some human neurodevelopmental disorders involving difficulties with social behaviors — like schizophrenia and autism spectrum disorder (ASD) — might be linked to an altered gut microbiome composition.

Yet, no one knows how it happens or which microbe strains might be responsible, but experts think decreased levels of microbiota are associated with changes in neurotransmitters and gene expression within the social regions of our brain.

But that’s not all.

While we’ve barely scratched the surface, researchers are beginning to learn more about the gut-brain axis and how the gut and brain communicate. Like, we know neurons extend branches or appendages (called axons and dendrites) to form connections (called synapses) with other neurons. As these connections grow, linking more and more neurons to each other, the branches form tree-like structures called arbors.

During early development, there’s an excess of these synaptic connections and tons of branches that require pruning in order for our nervous system to produce the appropriate behavior. Remarkably, research using animal models of autism suggests the intricate pruning process within brain regions responsible for our social behaviors depends upon exposure to specific microbes during a particular time period.

We’re a long way from knowing how this might work for us, but researchers are getting closer, and the studies I’m about to share with you are two more rungs on the ladder toward answers.