Sauerkraut and Social Anxiety

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“It made me worse, not better,” Morris announced immediately, without any of the timidity that someone with his degree of social anxiety usually displays.

Morris was alluding to his aborted attempt to use fermented foods to treat his debilitating social anxiety, as per my suggestion. Two weeks earlier, we reviewed the latest data on the gut-brain axis. I expected this data would appeal to someone with Morris’ scientific background, and, indeed, it did. To be completely honest, I stressed the role played by individual susceptibility to social anxiety.

After reminding Morris that this natural approach was not as evidence based as I would like and explaining why we needed more controlled studies to be fully confident, I mentioned sauerkraut or kimchi as easy options. I cited articles from mainstream medical literature—an imperative for a researcher like Morris—and pointed to the progressive uptick in credible scientific data, both on this specific topic and on lifestyle medicine in general.^1-6

To be sure, attention to gut health and its presumptive impact on psychiatric symptoms, especially in vulnerable populations, was steadily increasing.⁷ For someone like Morris, whose paralyzing social anxiety dictated his career choices and derailed his social life, this seemed like an avenue worth pursuing. Morris reported that he had read about research on the microbiome, and its relationship to many medical conditions, noting that data seemed to leapfrog by the day.

Despite his infirmities, Morris was not doing poorly career wise. Morris had accrued academic accolades that would make any practicing physician envious. Yet he intentionally chose a field that required next to no social contact because he dreaded speaking with people. With the assistance of a prescription for propranolol (a beta-blocker) he no longer had problems presenting his research at conferences. But the addition of propranolol only went so far for Morris; speaking to individuals on a more casual basis was far more daunting.

Despite his apparent success, Morris deeply regretted that his social anxiety dictated his career choice and limited his options overall. He had studied medicine because his parents pressured him to pursue a reliable profession, and he was too timid to object. “Your brother does well as a gastroenterologist (GI), so why shouldn’t you?” his father reasoned, according to Morris. Morris had considered specialties like radiology, anesthesiology, or pathology, which do not include direct patient care, but he still suspected that the collegial interaction needed to succeed in those specialties lay outside of his comfort zone.

In fact, his medical school clerkships were so painful that he left his competitive MD-PhD program and transferred to a PhD only tract. Unlike persons with schizoid personalities, or those on the autism spectrum, who also shun human interactions, Morris bemoaned his limitations and wished he could be different, and more like his affable and socially adept brother.

Instead, Morris labored in a laboratory, day in and day out, making impressive advances in his research, but almost never venturing into the hospital halls where he might—heaven forbid—encounter another human. The pay for bench research was far less than his brother earned via clinical care, but Morris was willing to make a monetary sacrifice to avoid an even worse evil: social interaction.

At his first appointment, he explained how difficult it was to muster the courage to make any appointment at all¾but the loneliness was gnawing at him. When his brother started a family, he felt even more alone. His mother understood his trepidations, for she also suffered from social anxiety which was obscured by her outgoing partner. She had offered to pay for a matchmaking service to help Morris bypass the dating scene, but even that prospect petrified him.

We attempted treatment with serotonin reuptake inhibitors, which is standard for social anxiety, but the sexual adverse effects made him more fearful. He explained that he was already scared enough to go on a date; worrying about impaired bedroom performance in the future would only add more pressure.

Having heard him out and having disclosed the caveats, we decided that fermented foods were worth a try. Surprised to hear that this experiment increased his distress, I asked for details about the fermented food that he chose. I needed to understand what made him worse. That is when he said that he used kombucha, not sauerkraut, yogurt, or kimchi.

“I googled ‘fermented food’ to find the best, and instantaneously, I was bombarded with ads for assorted brands of kombucha. So I tried kombucha first.” He continued, “With tag lines about probiotics and antioxidants and ‘gut health’ everywhere, it seemed like the right choice. I’m lactose-intolerant, so that took yogurt and kefir off the table.” Pausing a moment, he went on to say that “sauerkraut sounded like something that my grandmother made. And I dislike spicy food” [which is included in kimchi, the Korean equivalent to sauerkraut] “and so that ruled out kimchi. Kombucha sounded so much more current.”

“Kombucha? Isn’t that expensive?” I responded, trying to buy time as I googled kombucha, trying to unearth details about the caffeine content of the popular tea product.

“Yes, it certainly was expensive,” he responded. “That’s why I tried it only twice.”

No wonder this fermented food made Morris so anxious. Even though tea has less caffeine than coffee, any caffeine at all can induce anxiety. There was a short, easy to understand answer as to why Morris felt worse.

Morris was relieved to learn why this promising approach failed. To ease the tension, I told him about the low cost of sauerkraut and how he could get a month’s worth of sauerkraut for the price of a single kombucha. “And it’s even cheaper if you ferment your own from sliced cabbage and kosher salt—a process that is amazingly easy compared to what you synthesize every day in your lab.” He smiled and said that he would give it a shot. “My mother will appreciate knowing that her mother’s recipes might be relevant to modern medicine. Maybe my GI brother even tells his patients about this technique for gut health.”

In this short appointment, Morris learned about approaches to social anxiety and about making sauerkraut, and I learned an important lesson for the future. In addition to adding the customary caveats about controlled studies and fermented foods, I will be sure to remind patients to avoid caffeinated fermented foods like kombucha if they want to avoid added anxiety.

Dr Packer is an assistant clinical professor of psychiatry and behavioral sciences at Icahn School of Medicine at Mount Sinai in New York, New York.

References

1. Hilimire MR, DeVylder JE, Forestell CA. Fermented foods, neuroticism, and social anxiety: an interaction model. Psychiatry Res. 2015;228(2):203-8.

2. Balasubramanian R, Schneider E, Gunnigle E, et al. Fermented foods: harnessing their potential to modulate the microbiota-gut-brain axis for mental health. Neurosci Biobehav Rev. 2024;158:105562.

3. Aslam H, Green J, Jacka FN, et al. Fermented foods, the gut and mental health: a mechanistic overview with implications for depression and anxiety. Nutr Neurosci. 2020;23(9):659-671.

4. Schneider E, Balasubramanian R, Ferri A, et al. Fiber & fermented Foods: differential Effects on the microbiota-gut-brain axis. Proc Nutr Soc. 2024;1-16.

5. Ribera C, Sánchez-Ortí JV, Clarke G, et al. Probiotic, prebiotic, synbiotic and fermented food supplementation in psychiatric disorders: a systematic review of clinical trials. Neurosci Biobehav Rev. 2024;158:105561.

6. Merlo G, Sugden SG. The power of lifestyle psychiatry: a new approach to mental health. Am J Lifestyle Medicine. 2025.

7. Merlo G, Bachtel G, Sugden, SG. Gut microbiota, nutrition, and mental health. Front Nutr. 2024;11:1337889.