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The Paleo Nurse ✚ Presents: Role of Essential Gut Flora Part 2


Role of Essential Gut Flora (continued)

In Part 1 of this series, we discussed the various types of gut flora and began to explore the varied roles of essential gut flora.  In the healthy individual, the essential gut flora forms a bacterial layer that covers the entire digestive track.  This bacterial layer acts as a physical barrier to protect against transitional flora, viruses, parasites, toxins, and undigested food particles.  The gut flora produces acids that lower the pH of the gut wall and make it undesirable for microbes that cause disease.  The essential flora also has the ability to neutralize many toxins and inactivate carcinogens, or substances known to cause cancer.  It also plays a direct role in suppressing the processes by which cancer cells are known to develop and grow.

The essential flora has a direct effect on important immune functions because it is responsible for stimulating the tissues of the lymph system that are located in the gut wall to produce lymphocytes, a type of white blood cell that fights infections.  The lymphocytes then produce immunoglobulins, which are antibodies formed in response to contact with foreign substances (viruses, bacteria, fungi, etc).  The immunoglobulins destroy and inactivate invading substances that enter the body through food and drink.  The essential flora also has a direct impact on the production and function of other many other cells of the immune system.  When the essential flora is damaged, immune function is affected not only in the gut, but throughout the entire body as well.  Essential gut flora plays an important role in the development of regulatory T cells, a critical component of the immune system.  The types, number, and balance of regulatory T cells are directly influenced by the essential gut flora.  The dysfunction of the regulation of different types of regulatory T cells, which may result in an imbalance in certain kinds of T cells, is known to play a key role in the development of autoimmune disease.

A broader explanation of how the gut flora influences immune function is by understanding the balance between the two arms of the adaptive immune response, known as Th1 (cell-mediated) and Th2 (humoral) immunity.  In general, the role of Th1 immunity is to fight infections in the skin, mucous membranes, and cells.  When the essential flora is damaged, the production and function of Th1 cells becomes impaired, allowing more invaders into the body.  The body responds by overcompensating with a Th2 response, which then predisposes the individual to allergic-type reactions, chronic inflammation, and autoimmunity.  Healthy essential gut flora is the key to keeping these arms of the adaptive immune system in balance, thus preventing disease.

Maintaining Healthy Gut Flora

There are many contributing factors to damaged and imbalanced gut flora, including a poor diet high in refined carbohydrates, chronic stress, the use of certain medications, such as antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), and oral contraceptives, cesarean section birth, bottle feeding, and toxic exposure to various chemical substances.  While you may have no control over some of these factors (whether or not you were bottle-fed, for example), there are steps you can take to support your essential gut flora.  A lifestyle that eliminates processed foods and refined carbohydrates, adds an appropriate level of exercise and rest, and seeks to manage stress effectively will go far in maintaining a healthy balance of bacteria in the gut.  The consumption of probiotic-rich foods and drinks, such as sauerkraut and other fermented vegetables, kombucha tea, water kefir, and coconut milk yogurt, can also help to contribute to healthy gut flora.

What steps have you taken to maintain healthy gut flora?


Bouskra D. et al. (2008). Lymphoid tissue genesis induced by commensals through NOD1 regulates intestinal homeostasis. Nature 456(7221), 507–510.

Campbell-McBride, N. (2010).  Gut and psychology syndrome.  Cambridge, United Kingdom: Medinform.

Kosiewicz, M.M., Zirnheld, A.L., & Alard, P. (2011). Gut microbiota, immunity, and disease: A complex relationship. Frontiers in Microbiology, 2(180).

Macpherson, A.J. & Harris, N.L. (2004). Interactions between commensal intestinal bacteria and the immune system. Nature Reviews: Immunology, 4(6), 478 – 485.

Wu, H. & Wu, E. (2012). The role of gut microbiota in immune homeostasis and autoimmunity. Gut Microbes, 3(1), 4 – 13.


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