New hope for social anxiety disorder

Social anxiety disorder has a connection to the gut microbiota.

KEY POINTS

• Social anxiety disorder makes it hard for sufferers to live a normal life.
• It is multifactorial and often a life-long disability.
• Recently, a microbial connection has been found, providing hope for dietary intervention.

“L’enfer, c’est les autres [Hell is other people].” ―Jean-Paul Sartre

The surprising connection between gut microbes and mood is called the gut-brain axis. It plays a role in depression and anxiety and has recently captured the attention of psychiatrists, who are anxious themselves about the poor efficacy of many mood treatments.

Since the first mouse experiments a decade ago, the gut-brain axis has been found to be involved with anxiety, depression, autism, dementia, and schizophrenia. A new study from John Cryan, Ted Dinan, Mary Butler, and colleagues from University College Cork (UCC) adds social anxiety disorder to that list as well.

Social anxiety disorder is a chronic mental health condition that causes sufferers to be anxious in social situations where they may be exposed to scrutiny and perceived judgement. Everyday social interactions can lead to embarrassment, fear, and excessive self-consciousness.

For someone with social anxiety, it can be exhausting to make it through the day. As Albert Camus noted, “Some people expend tremendous energy merely to be normal.” It affects some 13 percent of Americans, with similar rates in Europe.

If you have social anxiety disorder, you are in good company. Famous sufferers include Franz Kafka, Emily Dickinson, Adele, Jennifer Lopez, and Johnny Depp. This surprising list demonstrates that social anxiety is fully compatible with talent, and even the ability (with a struggle) to take the stage.

Some sufferers self-medicate with drugs or alcohol. Ernest Hemingway, known for his struggles with mood disorders, said, “An intelligent man is sometimes forced to be drunk to spend time with his fools.” However, these cures only exacerbate the problem, and in Hemingway’s case did not prevent his suicide. If you find yourself winding down that path, you would be wise to seek the advice of a mental health provider to help you find a way forward.

It Starts Early

Social anxiety is often a life-long disorder, and for most sufferers, it comes with other unhelpful baggage, including irritable bowel syndrome, depression, and a greater risk of suicide. Talk therapy and antidepressants have had modest success in dealing with this disorder, but sadly, fewer than half of patients respond to treatment. Worse yet, only a fifth of patients achieve remission after three months of treatment.

Clearly, medicine is failing many of those with social anxiety. But if microbes play a role, that’s good news. We can manipulate our gut microbes with dietary changes, and that might provide a valuable lever to lift the anxiety.

The UCC study looked at 31 people with social anxiety and 18 age-matched controls. They discovered two species of bacteria that correlated to anxiety, one positively and one negatively.

Levels of the bacteria Anaeromassilibacillus An250 were higher in the anxiety group. This tracks with a 2022 Harvard study finding that negative emotions were also associated with higher levels of Anaeromassilibacillus An250.

This bacteria, with its tongue-twisting name, represents a new genus, first discovered in a one-year-old Senegalese child with kwashiorkor. It is a member of a family of bacteria that is also associated with autism, depression, and schizophrenia.

In a separate study, Anaeromassilibacillus was found to have higher abundance in untreated depression than in patients on antidepressants, suggesting that the meds may kill it off and improve sociability. Conversely, it’s also possible that a positive response to treatment lowers the abundance. It will take more studies to tease out the direction of causality.

Fortunately, the levels of Anaeromassilibacillus can be reduced with prebiotics, and this has been shown to reduce behavioral irritability in children with autism spectrum disorder.

That’s the dark side of the microbial story—the pathogens. On the positive side, the study noted that levels of the beneficial bacteria Parasutterella excrementihominis were higher in the control group than in the anxiety group. Microbes that are associated with better mood have been termed psychobiotics. The study found other psychobiotic microbes as well, all diminished in patients with social anxiety disorder.

The study adds to the growing body of evidence linking gut microbiota to social brain function. John Steinbeck, another famous anxiety sufferer, said, “A sad soul can kill quicker than a germ.” In fact, today we know that germs and sadness are correlated, and it is probably a two-way street.

Just as important, the study shows that good microbes are associated with less anxiety. John Cryan says, “These preliminary data further confirm that our microbes can be friends with social benefits.”

How Microbes Make a Difference

As well as bacterial strains, the study looked at functional differences. When we eat, our food is shared with our microbiota, which digests fiber and breaks it down into bacterial secretions called metabolites. These go on to participate in further chemical pathways.

In the case of social anxiety, there is an increase in the degradation of aspartate, an amino acid involved in the urea cycle. This in turn affects tryptophan metabolism which is further implicated in stress and psychosis. The authors of the study point out that the gut-brain axis is thus a potential therapeutic target for this early-onset, chronic disorder.

There is still much to be learned about these complex metabolic pathways, but the ability of prebiotics or probiotics to steer the microbiota away from anxiety is very promising. John Cryan is optimistic. He says, “In the future, it will be of interest to test if microbiota-targeted treatments—so-called psychobiotics—will be used in the treatment of symptoms of social anxiety disorder.”

What You Can Do Today

Until more studies are completed, we might take some tips from other studies on general anxiety and depression:

• Eat plenty of fibrous foods, like lentils, onions, artichokes, beans, and berries.
• Try fermented foods, including yogurt, kimchee, kefir, and sauerkraut. They are full of probiotics and prebiotics to reinforce your microbiota.
• Get some exercise, which has been shown to improve your microbiota.
• Try to get sufficient sleep on a regular schedule.

The aim of these steps is to build a diverse microbiota that will keep your gut lining healthy, preventing bacteria and toxins from entering your bloodstream. Once there, these microbes can be pumped to every organ in your body, including your brain. If the gut remains damaged, it can lead to chronic systemic inflammation, which is thought to be responsible for dozens of severe diseases. A strong gut lining can thus maintain the health of your entire body, not just your mind.

These efforts may not completely cure your social anxiety, but they have been shown to reduce generalized anxiety and major depression in several studies. Any improvement at all would be welcome. If you have social anxiety disorder, don’t give up hope. Remember that just when the caterpillar thought the world was ending, she turned into a butterfly—just maybe a social butterfly.

References

Butler, M.I., Bastiaanssen, T.F.S., Long-Smith, C. et al. The gut microbiome in social anxiety disorder: evidence of altered composition and function. Transl Psychiatry 13, 95 (2023).

Ke, Shanlin, Anne-Josee Guimond, Shelley S. Tworoger, Tianyi Huang, Andrew T. Chan, Yang-Yu Liu, and Laura D. Kubzansky. “Gut Feelings: Associations of Emotions and Emotion Regulation with the Gut Microbiome in Women.” bioRxiv, May 26, 2022.

Inoue, Ryo, Yuko Sakaue, Yuki Kawada, Ryuji Tamaki, Zenta Yasukawa, Makoto Ozeki, Satoko Ueba, et al. “Dietary Supplementation with Partially Hydrolyzed Guar Gum Helps Improve Constipation and Gut Dysbiosis Symptoms and Behavioral Irritability in Children with Autism Spectrum Disorder.” Journal of Clinical Biochemistry and Nutrition 64, no. 3 (2019): 217–23.