The bacteria inhabiting our guts might be influenced by our social behaviour, according to a study published in the Human Microbiome Journal.

The relationship between the gut bacteria and the brain is called the microbiome-gut-brain axis. In the past, studies have found that people with extreme behavioural conditions, such as autism and depression, have altered gut microbiomes.

Evidence also suggests that the types of bacteria that are predominant in the gut may vary with social behaviour and personality.

People with larger social circles have a larger microbiome diversity compared to more introverted individuals. This might be due to the fact that many species that have found a home in our guts have adapted to transmission through spores. In fact, species of Akkermansia, Lactococcus and Oscillospira are found predominantly in people who are more extroverted.

Akkermansia reduces inflammation in the gut and provides protection from diseases related to metabolism. Oscillospira is also linked to lower incidence of inflammatory diseases. Furthermore, a higher diversity in the gut microbiome means that you are less vulnerable to infections and allergies.

On the other hand, introverts have fewer and less diverse bacteria in their gut. The bacterial genera Desulfovibrio and Sutterella are predominant in introverted individuals. Previous studies have theorised that Desulfovibrio might be involved in the development of autism.

Are you always anxious and stressed out? Do you feel like you're drowning in misery because of everything that's going around you?

People who often experience negative emotions like stress, anxiety, irritability or depression have less diverse gut microbiomes. This is attributed to the fact that neuroticism – a personality trait involving a tendency to feel negative or anxious – is accompanied by unhealthy eating habits and poor sleep which disrupts the gut microbiome population.

Studies show that people with neurotic tendencies have reduced populations of Streptococcus and Corynebacterium. Another study, which looked at rats with stress-induced depression, found a drop in the prevalence of Corynebacterium species.

In contrast, people who experience less stress and anxiety have more diverse microbiomes. A study found that women who consumed fermented products and foods rich in prebiotics, that promote growth and diversity of gut bacteria, experience fewer symptoms of stress and anxiety.

Bacteria associated with dairy intake, Bifidobacterium and Lactobacillus seem to have a positive effect on social behaviour and reduce symptoms of stress and anxiety.

Travelling to far-off destinations and trying out exotic cuisines have positive impacts on the bacteria in your gut.