top of page

Exploring the Gut-Oral Health Connection: The Science Behind This Important Relationship

Updated: May 31, 2023

The human body is a complex system where different parts are intricately interconnected. A rising area of interest is the connection between gut health and oral health. Understanding this relationship offers a fascinating glimpse into how our bodies function and gives us tools to enhance our overall health. Let's dive into the scientific research supporting the gut-oral health connection.

The anatomy connecting the oral environment and the gut microbiome
Oral-Gut Microbiome Connection

Understanding the Microbiome

The microbiome refers to all the microorganisms living in our bodies. Both the gut and the mouth have their distinct microbiomes. Recent research has revealed that changes in our gut microbiome can influence oral health, and vice versa[1]. More specifically, when there is an overgrowth of pathogens (ie. bad bacteria, viruses, opportunistic fungi, etc), this microbiome homeostasis can be disrupted and has been linked to various health conditions.

Gut Dysbiosis & Symptoms of Dysfunctional Health

While the symptoms can vary from person to person, some common manifestations of this dysfunctional health include:

  1. Digestive Issues: Gut dysbiosis can lead to a range of digestive symptoms such as bloating, gas, diarrhea, constipation, and even irritable bowel syndrome (IBS). A study published in the World Journal of Gastroenterology found a significant connection between gut microbiota and the development of IBS [2].

  2. Mental Health Conditions: The gut microbiome plays a crucial role in the gut-brain axis, and dysregulation can impact mental health. Research published in Molecular Psychiatry suggests that gut dysbiosis could be associated with mood disorders like depression and anxiety [3].

  3. Obesity and Metabolic Conditions: Gut microbiota dysbiosis may be associated with metabolic disorders, including obesity, type 2 diabetes, and metabolic syndrome, as supported by a review published in Nature Reviews Endocrinology[4].

  4. Autoimmune Diseases: Dysregulation of the gut microbiome has been implicated in autoimmune diseases, such as rheumatoid arthritis, lupus, and multiple sclerosis, as explained in an article in Autoimmunity Reviews[5].

  5. Skin Conditions: Gut dysbiosis can also lead to skin issues, including eczema and acne. An article in the Journal of Dermatological Science found a connection between gut microbiota and acne [6].

Dysregulated Oral Microbiome Associated with Poor Clinical Outcomes

In conjunction with the gut, a dysregulated oral microbiome, or oral dysbiosis, has been associated with numerous systemic health issues and symptoms. Here are a few key studies exploring these connections:

  1. Cardiovascular Diseases: Studies have linked oral pathogens with cardiovascular diseases. A comprehensive review published in Nature Reviews Cardiology outlines evidence linking periodontitis, a condition caused by oral dysbiosis, to an increased risk of cardiovascular disease [7].

  2. Diabetes: Diabetes has been associated with alterations in the oral microbiome. A study published in the Journal of Oral Microbiology indicates that people with diabetes are more prone to periodontitis due to their dysregulated oral microbiome [8].

  3. Rheumatoid Arthritis: There's a demonstrated association between periodontal disease, driven by an imbalanced oral microbiome, and rheumatoid arthritis. A study in Autoimmunity Reviews provides evidence of this connection [9].

  4. Alzheimer's Disease: Oral bacteria, particularly Porphyromonas gingivalis, have been implicated in Alzheimer's disease. Research published in Science Advances supports the idea that this bacterium can contribute to Alzheimer's development[10].

  5. Preterm Birth and Low Birth Weight: A study published in The Journal of Nutrition reveals that pregnant women with periodontal disease, associated with an altered oral microbiome, are at an increased risk of preterm birth and low birth weight[11].

Pathogens disrupt the oral microbiome homeostasis and impact the mouth and rest of the body
Pathogens Can Cause Oral Dysbiosis

Gut Health and Oral Diseases, Oral Health and Gut Diseases

The gut microbiome plays a significant role in our immune system, and its imbalance can lead to local and systemic diseases. A study in the Journal of Oral Microbiology found that gut dysbiosis, an imbalance in the gut microbiome, is associated with periodontal disease, one of the most common oral health issues [12]. This suggests that gut health significantly influences oral health.

Conversely, oral health can also impact gut health. A study in Nature Reviews Gastroenterology & Hepatology demonstrated a connection between oral microbiota and the development of gastrointestinal diseases, such as inflammatory bowel disease and colorectal cancer [13].

The Common Pathway: Inflammation

Both oral and gut health issues share a common pathway: inflammation. Chronic inflammation in the gut can lead to poor oral health, and oral inflammation (such as gingivitis) can contribute to gut inflammation[14]. Thus, managing inflammation through a healthy lifestyle and diet is vital for maintaining both gut and oral health.

Holistic Health: Tending to the Gut-Oral Connection

This gut-oral connection highlights the importance of a holistic (ie. "whole body") approach to health. To maintain good health, it's crucial not just to brush and floss regularly, but also to keep our gut microbiome balanced through a nutrient-dense diet, regular exercise, sufficient sleep, and maintaining a healthy environment. This is why in our office we take a functional approach to your health; we want each of our patients to achieve and maintain optimal health for a lifetime. So that means going beyond the typical lectures about flossing and not eating candy, and we use advanced diagnostics and screening tools to understand your complex system so that we can guide and support you on your journey to peak health.


[1]: Duran-Pinedo, A. E., & Frias-Lopez, J. (2015). Beyond microbial community composition: functional activities of the oral microbiome in health and disease. Microbes and Infection, 17(7), 505-516.

[2] Lee, K. N., Lee, O. Y. (2014). Intestinal microbiota in pathophysiology and management of irritable bowel syndrome. World Journal of Gastroenterology, 20(27), 8886–8897.

[3] Kelly, J. R., Kennedy, P. J., Cryan, J. F., Dinan, T. G., Clarke, G., & Hyland, N. P. (2015). Breaking down the barriers: the gut microbiome, intestinal permeability and stress-related psychiatric disorders. Molecular Psychiatry, 20(10), 731–743.

[4] Kootte, R. S., Vrieze, A., Holleman, F., Dallinga-Thie, G. M., Zoetendal, E. G., de Vos, W. M., Groen, A. K., Hoekstra, J. B., Stroes, E. S., & Nieuwdorp, M. (2012). The therapeutic potential of manipulating gut microbiota in obesity and type 2 diabetes mellitus. Diabetes, Obesity & Metabolism, 14(2), 112–120.

[5] Mu, Q., Kirby, J., Reilly, C. M., & Luo, X. M. (2017). Leaky Gut As a Danger Signal for Autoimmune Diseases. Frontiers in Immunology, 8, 598.

[6] Bowe, W., Patel, N. B., & Logan, A. C. (2014). Acne vulgaris, probiotics and the gut-brain-skin axis: from anecdote to translational medicine. Beneficial Microbes, 5(2), 185–199

[7]: Tonetti, M. S., & Van Dyke, T. E. (2013). Periodontitis and atherosclerotic cardiovascular disease: consensus report of the Joint EFP/AAP Workshop on Periodontitis and Systemic Diseases. Journal of Clinical Periodontology, 40(S14), S24-S29.

[8]: Casanova, L., Hughes, F. J., & Preshaw, P. M. (2014). Diabetes and periodontal disease: a two-way relationship. British Dental Journal, 217(8), 433–437.

[9]: de Smit, M., Westra, J., Vissink, A., Doornbos-van der Meer, B., Brouwer, E., & van Winkelhoff, A. J. (2012). Periodontitis in established rheumatoid arthritis patients: a cross-sectional clinical, microbiological and serological study. Arthritis Research & Therapy, 14(5), R222.

[10]: Dominy, S. S., Lynch, C., Ermini, F., et al (2019). Porphyromonas gingivalis in Alzheimer’s disease brains: Evidence for disease causation and treatment with small-molecule inhibitors. Science Advances, 5(1), eaau3333.

[11]: Mobeen, N., Jehan, I., & Banday, N. (2016). Periodontal Disease and Adverse Birth Outcomes: A Study from Pakistan. The Journal of Nutrition, 146(5), 1145–1152.

[12]: Arimatsu, K., Yamada, H., Miyazawa, H., Minagawa, T., Nakajima, M., Ryder, M. I., ... & Gotoh, K. (2014). Oral pathobiont induces systemic inflammation and metabolic changes associated with alteration of gut microbiota. Scientific Reports, 4(1), 1-8.

[13]: Atarashi, K., Suda, W., Luo, C., et al. (2017). Ectopic colonization of oral bacteria in the intestine drives TH1 cell induction and inflammation. Science, 358(6361), 359-365.

[14]: Genco, R. J., & Sanz, M. (2020). Clinical and public health implications of periodontal and systemic diseases: An overview. Periodontology 2000, 83(1), 7-13.

12 views0 comments


bottom of page