• New APC and UCC research shows that individuals with social anxiety disorder (SAD) have different microbiota compositions compared to healthy controls. 
  • Transfer of human SAD microbiota to mice increased social fear response in a preclinical model of social anxiety behaviour. 
  • Mice that received the SAD microbiota had alterations in brain oxytocin levels and central and peripheral immunity. 

Christmas is a highly enjoyable social time for many but for those with social anxiety disorder it can be a nightmare. Now new research from SFI Research Centre APC Microbiome Ireland (APC), based at University College Cork (UCC), has discovered that the microbes in the gut may be playing a key role in Social Anxiety Disorder. 

The findings in the study “Social anxiety disorder-associated gut microbiota increases social fear” suggest that gut microbiota can play a role in the heightened social fear response tied to SAD and represent a potential therapeutic target, according to the authors.  

The analysis casually builds on recent findings that SAD patients have distinct microbiomes compared with healthy individuals by showing that transplanting microbiota from six patients with SAD into mice resulted in the mice exhibiting increased sensitivity to fear conditioning during social interactions as well as changes to immune and brain functions. 

According to the Anxiety and Depression Association of America (ADAA) SAD affects 15 million adults or 7.1% of the U.S. population. 

The research, led by APC PI and Vice President for Research and Innovation at UCC Prof John F Cryan says “SAD is an increasing issue for the human population, so it is vital to explore new treatments to address the condition. Discovering a link between the microbiota and the SAD condition is a significant breakthrough that the microbiota represent a potentially a therapeutic target.” 

Researcher Dr Nathaniel Ritz who worked on the study while at APC, suggests that the microbiome could be leveraged to devise therapeutic interventions to combat SAD. Dr Ritz commented “SAD has become a pertinent issue; it causes fear and anxiety in common social situations, which can be very debilitating and negatively impact quality of life. Our study shows that the microbiota in SAD is capable of driving symptoms characteristic of the disorder. This makes for exciting possibilities in the effort to develop therapeutics for patients suffering with SAD.” 

Director of APC Prof Paul Ross says “At APC we are continuing to discover how the microorganisms in our gut can affect a wide variety of human illnesses and conditions including those involved in mental health and wellbeing. Social Anxiety Disorder can be a crippling condition, and this new discovery opens up new therapeutic avenues which take the microbiome into account with the possibility to change its composition to improve health.”  

Read the full article at: https://www.pnas.org/cgi/doi/10.1073/pnas.2308706120