Inflammation and the Microbiome

Inflammation occurs as a natural protective response by the body to a harmful pathogen or substance and can be acute or chronic. While it is designed to help the body, there are cases where it can become out of control. Acute inflammation is likely a more familiar response. It occurs immediately in some health-related issues, such as a cut on your hand. The body’s response results in the immune system releasing cells to the site of inflammation to help prevent infection and aid in healing. Some classic signs of inflammation include swelling, redness, pain, heat, and possibly loss of function. 

Chronic inflammation, while not always visible to the human eye, occurs over the course of months to years. Various factors can contribute to this type of inflammation such as failure to eliminate a pathogen, chronic low-level exposure to irritants, autoimmune disorders, and dysregulation within the immune system. Over time, chronic low level inflammation can cause damage to the body’s cells and can lead to an increased risk of developing certain illnesses and cancer (1). Some common diseases in animals that can result from chronic inflammation include allergies, arthritis, and inflammatory bowel disease. 

Not All Inflammation Is Bad

It is important to remember that not all inflammatory responses are bad. While we can’t prevent every possible cause of inflammation, maintaining a healthy lifestyle can go a long way in managing it. Maintaining an optimal weight helps prevent excess strain on the joints and the cardiovascular system, and weight management is most successful through a combination of a healthy diet and exercise. Not only is exercise great for managing weight, one study revealed that a single 20-minute session of moderate exercise stimulated the immune system and reduced inflammation in humans.  Exercise activates the nervous system, triggering a release of hormones that then influence immune cells within the body (2).

Diet can also influence the development of inflammation. Knowing what you are feeding your pet is important. Avoid any foods which may cause allergies or dietary indiscretion. There are a variety of foods and supplements which are known to have anti-inflammatory properties. Supplements, such as Omega 3 fatty acids, can prove to have anti-inflammatory effects within the body. Your veterinarian can help you in determining which supplements may be appropriate for your pet.   

How does the microbiome play a role?

While it is not often thought about on a day-to-day basis, the gut microbiome plays a role in immunomodulation and the development of pro and/or anti-inflammatory effects within the body. While we will not delve into the many intricacies of the microbiome, various immune cells, and their many roles within the immune system, we will summarize a few here.  

The term microbiome includes the genetic and functional profiles of the microorganisms found within the gastrointestinal tract (3). The immunomodulatory effects within the microbiome are quite complex with several cell types and microbes at play. These effects can occur on the local or systemic level.

There are various networks along the intestines that contribute to cross-talk between the host and the microbes. Gut-associated lymphoid tissue (GALT) is found along the gut and is responsible for “the bulk of immune surveillance and defense”(4). In fact, studies involving germ-free animals found that microbes are an important component in the development of GALT(4). 

Along the intestines, there are pattern recognition receptors (PRRs) on and inside intestinal cells. Their purpose is to recognize microbe-associated molecular patterns (MAMPs) in microbes and generate the appropriate responses which can then result in pro-inflammatory or anti-inflammatory responses within the body (4). 

Maintenance of intestinal wall permeability is crucial to the host's health. A disruption to the normal microbial flora can give certain microbial metabolites the ability to permeate through the intestinal wall, gain access to the bloodstream, and cause inflammatory responses within the body(3). Not only does the microbiome contribute to immune surveillance, but it also aids in the metabolism of nutrients which help support overall gut health. Nutrients such as complex carbohydrates are metabolized into substances called short-chain fatty acids (SCFAs). These are involved in intestinal wall integrity, intestinal motility, and the InIS production of anti-inflammatory effects along the gastrointestinal tract (3).  

While these are just a few ways the immune system is affected by the microbiome, it is evident that the microbiome is a key influencer in inflammatory responses within the body. As research continues to expand in this field, our knowledge of the microbiome, its effects on the immune system, and the development of certain diseases will continue to evolve. As we gain more understanding, it is possible we may be able to improve management techniques for certain inflammatory conditions. For now, maintaining a healthy lifestyle is a good place to start.