One of the big medical news stories of the week was the results of 30 years’ worth of research published in JAMA (the Journal of the American Medical Association), examining the connection between stress and the development of autoimmune disease.[i] Over 1 million people in Sweden were tracked for 3 decades, and 100,000 of those were at some point diagnosed with a stress-related disorder. The results are pretty shocking: those diagnosed were 30-40 percent more likely to develop one of 41 different autoimmune illnesses, ranging from rheumatoid arthritis to inflammatory bowel disease to celiac.
While the researchers point out that this does not prove a causal link, i.e. stress causes autoimmunity, they did note that those treated for stress with antidepressants shortly after diagnosis had lower rates of autoimmunity than those who went untreated.[ii]
As you all are well aware, there exists a large and rapidly growing body of research that shows the bi-directional relationship between stress and the human biome. Just last week, in fact, I wrote about on-going research looking at using probiotics to essentially “vaccinate” a person against stress-related disorders, like PTSD. Likewise, the relationship between stress and inflammation – and microbiome perturbations and inflammation – are also well established. This latest research did not include a look at the biomes of those individuals who were diagnosed with the stress-related disorders, and then autoimmune diseases…but I’d put money on there being distinct differences when compared to the microbiomes of the control subjects.
In thinking about all this, I was reminded of a paper I read last year on the relationship of the gut bacteria and stress.[iii]
“The gastrointestinal microbiota has recently emerged as a key facilitator of stress adaption and immune response in the body. At the behavioural level, gastrointestinal content and complexity can impact on anxiety and fear responses…The evidence presented herein suggests that resilience to stress- and immune-related disorders…may be dependent on the diversity and complexity of gastrointestinal microbiota.”
That is…your ability to handle stress, your body’s ability to maintain health (and not develop “immune-related disorders”) appears to be very much dependent on the health of your microbiota.
[i] Song, H, Fang, F, Tomasson, G, et. al. Association of Stress-Related Disorders with Subsequent Autoimmune Disease. JAMA. 2018;319(23):2388-2400.
[iii] Rea, K, Dinan, TG, Cryan, JF. The microbiome: A key regulator of stress and neuroinflammation. Neurobiology of Stress. 2016. 4:22-33.