As of recent years, there has been increasing evidence that impairments in an animal's gut microbiota can lead to both physiological and psychological distress. There is little research on the effects in humans, but the evidence that does exist is promising. In animal models, it has been shown that abiosis (lack of internal bacteria) leads to a hyperactive stress response due to an increased release of cortisol. This was able to be reversed, however, when bacteria were introduced to the animals only while still very young. This suggests that there is a critical period in which an animal's microbiome affects the development of neural regulated stress response. It has been shown that in humans, there is a strong correlation between certain diseases (obesity, autism, anxiety, depression, etc.) and dysbiosis, which is the impairment of the internal microbiome. There is also evidence that certain probiotics may increase mood and lower both depression and anxiety symptoms. It is also important to note that many of these studies use anecdotal evidence to back up their claims, so there is still much research that needs to be done to accentuate their validity. If these claims are true, then there is a potential therapeutic opportunity to treat autism, anxiety, and depression before they occur and even after the onset of symptoms. This could also be a better option than current drugs that treat anxiety and depression, such as SSRIs, which can sometimes cause more negative side effects than is worth taking them.
Sources:
Carabotti, M., Scirocco, A., Maselli, M. A., & Severi, C. (2015). The gut-brain axis: interactions between enteric microbiota, central and enteric nervous systems. Annals of gastroenterology, 28(2), 203–209.
Foster, J. A., & McVey Neufeld, K. A. (2013). Gut-brain axis: how the microbiome influences anxiety and depression. Trends in neurosciences, 36(5), 305–312. https://doi.org/10.1016/j.tins.2013.01.005
Mangiola, F., Ianiro, G., Franceschi, F., Fagiuoli, S., Gasbarrini, G., & Gasbarrini, A. (2016). Gut microbiota in autism and mood disorders. World journal of gastroenterology, 22(1), 361–368. https://doi.org/10.3748/wjg.v22.i1.361
The relationship between gut microbiome and mental illness is so interesting! I agree with your last point, that treating an imbalance in gut microbiomes is a better way to treat anxiety and depression. As you mentioned, treatments may include different strains of probiotics that introduce more healthy bacteria into the GI tract.
ReplyDeleteA recent study aimed at helping patients diagnosed with Generalized Anxiety Disorder, by doing a double blind study with probiotics. The probiotic strains included Bifidobacterium bifidum, Bifidobacterium longom, Bifidobacterium lactis and Lactobacillus acidophilus bacteria. The conclusions of the study found that the use of probiotics and SSRIs had positive effects on patients with GAD.
The study worked to combine the effects of SSRIs and probiotics, with further research, I feel like it will be possible to use these probiotic strains alone, to treat GAD. These probiotics are more appealing to patients with anxiety or depression because of the absence of side effects. SSRIs have major side effects that are experienced by thousands. Selective Seretonin Reuptake Inhibitors are associated with Objective Activation Syndrome, which can increase suicidal thoughts, manic episodes, and more (Reid 2015). These side effects decrease the effectiveness of the drugs. If we were able to use probiotics, with minimal side effects, this could be a huge breakthrough in treatment of mental disorders.
Eskandarzadeh, S., Effatpanah, M., Khosravi-Darani, K., Askari, R., Hosseini, A. F., Reisian, M., & Jazayeri, S. (2021). Efficacy of a multispecies probiotic as adjunctive therapy in generalized anxiety disorder: a double blind, randomized, placebo-controlled trial. Nutritional Neuroscience, 24(2), 102–108.
Reid, A. M., McNamara, J. P. H., Murphy, T. K., Guzick, A. G., Storch, E. A., Geffken, G. R., & Bussing, R. (2015). Side-effects of SSRIs disrupt multimodal treatment for pediatric OCD in a randomized-controlled trial. Journal of Psychiatric Research, 71, 140–147. https://doi-org.dml.regis.edu/10.1016/j.jpsychires.2015.10.006