You probably know a thing or two about the gut microbiome and how it affects your health. Did you know that the yogurt you had for breakfast or the kombucha you’re sipping on right now contains probiotics that can help balance your gut microbiome? Physiological changes in the gut microbiota may influence obesity, autoimmune disorders, and psychiatric disorders. The most direct ways that the gut microbiome impacts health is by converting nondigestible carbohydrates to short chain fatty acids, action against pathogenic bacteria, and modulation of innate and adaptive immune systems. Now you might be thinking, how is the gut microbiome related to psychiatric disorders if it’s affecting physical body functioning. The answer is that the brain and gut have bidirectional communication that mediate physiological functions. For example, gut peptide secretions are able to enter the bloodstream and stimulate sensory neurons which send afferent projections to the vagus cranial nerve.
A 2018 review done by Gillard Lach and colleagues illustrate the relationship of the gut microbiome and psychiatric disorders. Factors such as diet, age, genetics, antibiotics, upbringing, and even prenatal stress can all have an affect on the gut microbiome. For instance, they note that researchers have found that maternal stress during pregnancy has induced depressive behaviors in offspring, particularly, in adulthood. They found that this prenatal stress induced changes in offspring gut microbiome composition which increased the HPA axis response to stress. In another example, they indicate how researchers have found that deficient gut microbiomes upregulated the NPY gene in the amygdala and hypothalamus. NPY upregulation was associated with higher anxiety-like symptoms in mouse populations.
How do we fix a deficitted gut microbiome? Consuming a healthy diet as well as getting enough exercise positively affects the gut microbiome. It has been shown that changing your diet for a 24 hour duration can positively change the gut microbiome. New clinical studies have shown a new class of treatment for those with psychiatric disorders - psychobiotics. Clinical studies have found that those consuming probiotics such as Lactobacillus spp. had lower plasma cortisol and lower scores of self-reported negative moods.
Our gut microbiome is often overlooked when we’re not feeling mentally or physically well. Luckily, it is something that we can remedy ourselves by practicing a healthy and diverse diet. Short term changes to our diet for a period of a day can already yield benefits to our gut microbiome.
Lach, G., Schellekens, H., Dinan, T. G., & Cryan, J. F. (2018). Anxiety, Depression, and the Microbiome: A Role for Gut Peptides. Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics, 15(1), 36–59. https://doi.org/10.1007/s13311-017-0585-0
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Very interesting read. This made me think about the Clostridioides difficile paper we read for MSBS program; the connection being gut microbiota. In C. diff, one method of treating patients is through fecal transplant. Fecal transplant introduces healthy gut microbiota which helps with treatment of c. diff. This made me think hmm what about fecal transplant for patients who are depressed, can that help treat mental health disorder. There were couple of studies that have shown improvement in mental health disorders after fecal transplant. Kurokawa et al. 2018. conducted a study with n=17 patients with irritable bowel syndrome, and mental health disorder such as anxiety and depression. They did find significant improvement in mental health and irritable bowel syndrome, but due to limited participants they cannot provide certainty for improvement. Need more data to provide causal relationship between fetal transplant and the improvement of mental health. That would be amazing steps towards mental health improvement and treatment.
ReplyDeletereference: Kurokawa S, Kishimoto T, Mizuno S, Masaoka T, Naganuma M, Liang KC, Kitazawa M, Nakashima M, Shindo C, Suda W, Hattori M, Kanai T, Mimura M. The effect of fecal microbiota transplantation on psychiatric symptoms among patients with irritable bowel syndrome, functional diarrhea and functional constipation: An open-label observational study. J Affect Disord. 2018 Aug 1;235:506-512. doi: 10.1016/j.jad.2018.04.038. Epub 2018 Apr 12. PMID: 29684865.
This is really interesting! I have been interested in the gut microbiome since Gen Bio when we read about speculations that our gut microbiota can even influence the cravings we have. One thing that interested me about your post was that you mentioned that “prenatal stress can have an effect on the gut microbiome” and that “researchers have found that maternal stress during pregnancy has induced depressive behaviors in offspring, particularly, in adulthood.” This made me wonder if our microbiomes are able to be rebuilt, or if they are more fixed than we think. In a review article written in 2018 titled “Rebuilding the Gut Microbiota Ecosystem”, it is discussed how the acquisition of a microbiome begins before birth in things like the umbilical cord, the amniotic fluid, and the fetal membranes. The delivery mode (vaginal or Cesarean), and how the child acquires nutrients (breast milk or formula) are factors that strongly impact the gut microbiome composition. After birth, the composition of the human microbiome evolves rapidly and then stabilizes at approximately 3 years of age. The article states that once the biome is established, it essentially stays stable into adult life. While the composition stays relatively stable, the percentages of bacteria in the biome can get out of whack at any time. This is another thing that interested me about your post. I wondered if it is possible to rebuild the microbiome, since the composition of it is so dependent on the first three years of life.
ReplyDeleteThe article discusses many ways of rebuilding the microbiome once it is out of balance. It is said that once good bacteria are no longer able to “control” bad bacteria, the body is in a state of dysbiosis. This causes many illnesses in and out of the intestines, like IBS, obesity, asthma, etc. There are many current treatments, like prescribing prebiotics, probiotics, synbiotics, fecal transplants, and a newer one that involves the introduction of a predatory bacteria to the intestine. WHile all of these can help, I agree with you that the best way to reset the microbiome is by eating a healthy balanced diet and exercising regularly. Thanks for your post! It is good to know that while this is a serious issue, it can be reset with hard work and changing of habits.
Gagliardi A, Totino V, Cacciotti F, et al. Rebuilding the Gut Microbiota Ecosystem. Int J Environ Res Public Health. 2018;15(8):1679. Published 2018 Aug 7. doi:10.3390/ijerph15081679
Thank you for sharing this post! It is very interesting, and I did not think there was an association between the gut microbiome and psychiatric disorders. I took it upon myself to delve further into this and found a systematic review by Chinna Meyyappan, Forth, Wallace, & Milev showed the interactions between the gastrointestinal tract and the brain showed linked to a variety of psychiatric illnesses such as depression, anxiety, substance use, autism spectrum disorder, and eating disorders, and that repopulating the gut microbiome may be useful in the prevention and treatment of psychiatric illnesses (2020). This article supports the information you provided but also discusses multiple other psychiatric illnesses that are associated with the microbiota. In their review, it was discussed that even starting with fecal matter transplants can affect symptoms of psychiatric disorders in both the relief of the symptoms resulting from the transfer of microbiota from healthy donors and transmissions of symptoms through transplantation of microbiota from ill donors (Chinna Meyyappan, Forth, Wallace, & Milev, 2020). Very interesting! Additionally, you mentioned that there were new clinical studies showing that psychobiotics could be a form of treatment to those with psychiatric disorders which would be a great alternative medication to provide patients since the use of some antipsychotic medications is often a trade off of benefiting from the psychotic symptoms but potentially risk experiencing adverse effects. As described in an article by Hamer and Muench, many antipsychotic medications are associated with an increased likelihood of sexual dysfunction, postural hypotension, cardiac arrhythmias, and sudden cardiac death due to the variability of first and second generation antipsychotic classes (2010). Therefore, if we were able to provide patients with psychobiotics in addition to incorporating a healthy and diverse diet they could potentially have the benefits from the psychotic symptoms without these adverse effects allowing patients to have full autonomy in their medical choice and beneficence.
ReplyDeleteReferences:
Chinna Meyyappan, A., Forth, E., Wallace, C. J. K., & Milev, R. (2020). Effect of fecal microbiota
transplant on symptoms of psychiatric disorders: a systematic review. BMC Psychiatry, 20(1).
https://doi.org/10.1186/s12888-020-02654-5
Hamer, A. M., & Muench, J. (2010, March 1). Adverse Effects of Antipsychotic Medications. American
Family Physicians. https://www.aafp.org/afp/2010/0301/p617.html
Hi Ken, I enjoyed reading your post about how our gut microbiome can impact our psychiatry well being. I read a book called “Brain Maker: The Power of Gut Microbes to Heal and Protect Your Brain for Life” by David Perlmutter MD and he essentially makes this point too. Perlmutter also mentioned the bidirectional communication between the brain and gut; he states scientists call the innumerable neurons in the gut “the second brain”. I remember this interesting point Perlmutter stated in the book; research had discovered babies who are born vaginally and go through the birth canal are introduced to the mom’s microbiome that will form the basis of the baby’s gut microbiome (Perlmutter, 2017). Therefore, babies who are born vaginally rather than by cesarean section tend to have a stronger microbiome and are less susceptible to mental disorders. However, there are also many other factors to take into consideration as well such as antibiotic and steroid medication intake frequency, diet, exercise, etc. In the book, there are a series of questions that lets us evaluate our life experiences and how that has shaped what state our gut microbiome may be in. The book also provides dietary recommendations to strengthen our microbiome and help prevent brain disorders and alleviate anxiety and depression. If you would like to delve deeper to learn more about the microbiome and its relationship to the brain, I would recommend this book!
ReplyDeletePerlmutter, D. (2017). Brain Maker: The Power of Gut Microbes to Heal and Protect Your Brain for Life. Yellow Kite.
I will echo my peers as this is indeed a very interesting read! Like Sabitra, I had heard of a way to influence the microbiome through fecal transplants however I did not realize that a change in diet could influence the microbiome!
ReplyDeleteThis led me to wonder how drastic of a change is needed to alter the microbiome and what foods are necessary to create a healthy microbiome? Additionally, does this change last or do dietary changes need to be implemented for a long period of time?
I did some research and here is what I found:
Healthy adult microbiota is principally composed of Firmicutes and Bacteroidetes along with Proteobacteria, Verrucomicrobia, Actinobacteria, Fusobacteria and Cyanobacteria (Eckburg et al., 2005) and is believed to remain stable throughout the majority of the adult life.
How then, can and individual change their microbiome through diet if their microbiome remains stable?
The current answer: prolonged dietary changes.
While the gut microbiome is relatively easily impacted by food, and can be easily varied through day-to-day food intake (Valdes et al., 2018) a recent review has indicated that, in order to create permanent change in the microbiome, an individual must commit to prolonged dietary changes rather than temporary ones (Leeming et al., 2019). The review explains that this is because diet changes have only shown to impact a limited number of gut bacteria (Leeming et al., 2019) and only for a limited time (meaning the microbiome reverts to its “stable” form after some time). Specifically, one study indicated that, even when participants underwent sever diet changes, their microbiomes returned to baseline with 3 days after stopping their diet (David et al., 2014).
A 2021 study echoed the review explaining that habitual dietary changes showed a greater impact on the gut microbiome (Bolte et al., 2021) but did not recommend a set amount of time in which an individual should commit to a diet in order to show a beneficial, long-term impact on the microbiome.
References:
Bolte, L. A., Vich Vila, A., Imhann, F., Collij, V., Gacesa, R., Peters, V., Wijmenga, C., Kurilshikov, A., Campmans-Kuijpers, M., Fu, J., Dijkstra, G., Zhernakova, A., & Weersma, R. K. (2021). Long-term dietary patterns are associated with pro-inflammatory and anti-inflammatory features of the gut microbiome. Gut, 70(7), 1287–1298. https://doi.org/10.1136/gutjnl-2020-322670
David, L. A., Maurice, C. F., Carmody, R. N., Gootenberg, D. B., Button, J. E., Wolfe, B. E., Ling, A. V., Devlin, A. S., Varma, Y., Fischbach, M. A., Biddinger, S. B., Dutton, R. J., & Turnbaugh, P. J. (2014). Diet rapidly and reproducibly alters the human gut microbiome. Nature, 505(7484), 559–563. https://doi.org/10.1038/nature12820
Eckburg, P. B., Bik, E. M., Bernstein, C. N., Purdom, E., Dethlefsen, L., Sargent, M., Gill, S. R., Nelson, K. E., & Relman, D. A. (2005). Diversity of the human intestinal microbial flora. Science (New York, N.Y.), 308(5728), 1635–1638. https://doi.org/10.1126/science.1110591
Leeming, E. R., Johnson, A. J., Spector, T. D., & Le Roy, C. I. (2019). Effect of Diet on the Gut Microbiota: Rethinking Intervention Duration. Nutrients, 11(12), 2862. https://doi.org/10.3390/nu11122862
Valdes, A. M., Walter, J., Segal, E., & Spector, T. D. (2018). Role of the gut microbiota in nutrition and health. BMJ (Clinical research ed.), 361, k2179. https://doi.org/10.1136/bmj.k2179