By Dr. Andrew Cummins
Ankylosing Spondylitis and Spinal Fusion
The medical literature discusses two processes that can contribute to new bone growth in the spine and spinal fusion: entheseal stress and chronic inflammation. The entheses are the areas where tendons and ligaments connect to bone and enthesitis is inflammation of the entheses.
When we feel pain in the tendons and ligaments of our heel, ankle, knee, inside of the upper thigh, hip, buttock, sacroiliac joint, back muscle, spine, rib, chest, low back area, shoulder blade, hand, shoulder, or neck this can be from inflammation of the entheses.
The areas where tendons and ligaments connect to bone can lead to new bone growth mainly from injury and chronic inflammation. This injury can also be referred to as microtrauma or entheseal stress. In my personal and professional experience this microtrauma or stress can be from a physical injury, poor posture, excessive sitting, weak back and gluteal muscles, or a combination of all four. The physical injury does not have to be serious and can be a very minor injury that happened years before the onset of symptoms. The minor injury can even be from constant poor posture while sitting with the back curved and chin forward or with the neck bent and eyes looking down.
When these areas in the body are injured or undergo excessive stress and are damaged, the immune system tries to repair the damage and we have a cycle of chronic inflammation that can lead to new bone growth and possibly fusion. As mentioned in the previous article this new bone growth is weaker and more vulnerable to fracture.
In addition to the injury and stress that can occur at the entheses, where tendons and ligaments connect to bone, chronic inflammation is being produced in the gut with Ankylosing Spondylitis.
This gut inflammation does not stay in the digestive tract however. The inflammation in the gut goes throughout the body and can attack the joints and entheses.
In my experience most individuals have some kind of digestive problem while living with Ankylosing Spondylitis. Even if there is no digestive symptoms, the majority of individuals have subclinical gut inflammation. This means that even if there isn’t any digestive symptoms, there is still inflammation and damage in the gut, especially with the gut lining.
So in addition to having correct posture, walking, and strengthening the back and gluteal muscles, it is essential that our digestive health is in order.
Ankylosing Spondylitis and Chronic Inflammation
To reduce chronic inflammation we have to understand what causes the chronic inflammation. Where does it come from? What is the root underlying cause? What is producing the chronic inflammation? Previously discussed was how microtrauma and stress at the entheses from injury, poor posture, excessive sitting, and weak back and gluteal muscles can lead to a cycle of chronic inflammation. I refer to this as the external part of AS that must be addressed to overcome pain, improve mobility and posture, and possibly prevent or slow spinal fusion. The rest of this article will address what I call the internal part of AS that must be addressed to overcome these symptoms.
The medical literature is full of research describing how the chronic inflammation of the various types of Spondyloarthritis including Ankylosing Spondylitis, and Autoimmune disease starts in the gut. Our microbiome, especially our gut bacteria, control our immune system. This is extremely important because when we are talking about chronic inflammation we are talking about our immune system being out of balance.
If our gut bacteria are out of balance, then our immune system will be out of balance and we will have chronic inflammation. This imbalance comes from too many bad bacteria and too few good bacteria, a condition in the gut known as dysbiosis.
Chronic inflammation is destructive and leads to pain, stiffness, and breakdown of joints. The process of chronic inflammation in addition to other mechanisms such as entheseal stress, can lead to the fusion of joints and vertebrae. So for all of these reasons we want to reduce the chronic inflammation or more appropriately, balance the immune system.
The reason it is so important not to suppress the immune system, but to keep it in balance is because our immune system protects us from infections, including bacterial infections. Especially, as the medical literature points out, an imbalanced microbiome and bacterial infections are at the root of the chronic inflammation and attack on the joints associated with Ankylosing Spondylitis.
To balance the immune system we have to balance our gut microbiome.
Ankylosing Spondylitis and Gut Bacteria
The question is why does the chronic inflammation attack certain areas of the body with Ankylosing Spondylitis?
The research in the medical literature describes a process called Molecular Mimicry.
Bacteria such as Klebsiella and Prevotella, among others, produce proteins in the gut. These proteins produced by the bacteria look similar to proteins on collagen in the body.
This collagen is in ligaments, tendons, joints, and discs of the spine. Areas that are the target of attack with the chronic inflammation in Ankylosing Spondylitis. These ligaments, tendons, and joints are in the spine, hips, sacroiliac joints, below the kneecap, heel of the foot, shoulders, ribs, sternum, and other areas where we feel the pain and stiffness of AS.
Once these bacterial proteins in the gut are exposed to the gut immune system, the cells of the immune system go into the blood stream and travel to sites outside the gut where the ligaments, tendons, and joints are.
The immune system attacks these structures causing damage, inflammation, pain, stiffness, new bone growth, and eventually can lead to fusion because the immune system thinks proteins on the ligaments, tendons, and joints are bad and need to be eliminated.
This causes damage to the joints and entheses, areas where ligaments and tendons attach to bone, and this causes more chronic inflammation.
Wherever there is damage in the body the immune system will try to repair the damage and this leads to chronic inflammation, new bone growth, and eventually fusion can take place.
The immune system thinks these structures are bad because it thinks they are like the proteins produced by the bacteria in the gut. The immune system doesn’t know the difference because the bacterial proteins and the proteins of the collagen in the ligaments, tendons, and joints look the same.
Ankylosing Spondylitis and Diet
So what causes harmful bacteria and other bacteria to grow that can lead to chronic inflammation and the symptoms of Ankylosing Spondylitis?
Diet has one of the biggest impacts on what bacteria grow in our gut. Also, antibiotics can cause an imbalance in our gut bacteria by wiping out the good and the bad. Unfortunately, some of the bad bacteria stay around and start to overgrow, especially when given the right fuel with a diet high in starches and grains such as bread, rice, cereal, pasta, and other processed foods.
Certain bacteria in the gut become a problem when there is overgrowth. The medical literature talks about how starch is a fuel for certain bacteria to grow such as Klebsiella. This is why the medical literature also talks about how a low starch diet has dramatically improved symptoms in individuals living with AS.
This dietary change takes away the fuel for harmful and potentially harmful bacteria to grow.
What about the other studies that do not find a link between Klebsiella and Ankylosing Spondylitis?
The answer is because an overgrowth of Klebsiella isn’t the only reason someone has chronic inflammation, pain, and stiffness associated with Ankylosing Spondylitis. The medical literature also describes an opportunistic bacteria called Prevotella that is associated with Ankylosing Spondylitis. In addition to this, there can be an overgrowth of other bacteria that are considered normal, but they are out of balance with good bacteria such as lactobacillus and bifidobacterium. The problem with gut bacteria can be specific bacteria such as Prevotella and Klebsiella, or can be from an imbalance and overgrowth of other bacteria. The medical literature refers to this imbalance in gut bacteria as dysbiosis.
When I run a functional stool test on individuals with Ankylosing Spondylitis I will sometimes see Klebsiella positive and other times I will see Klebsiella negative and Prevotella positive. Other times both bacteria will be negative. In this case the dysbiosis from the overgrowth of other bacteria can be the culprit. What then could have caused the damage in the gut?
The answer is overgrowth of other bacteria that produce the endotoxin Lipopolysaccharide, LPS. When overgrowth of bacteria and production of LPS is combined with a damaged gut lining or leaky gut, then LPS interacts with the gut immune system causing chronic inflammation. This process is described in more detail below under Ankylosing Spondylitis and the Immune System.
Other times individuals will experience increased inflammation, pain, and stiffness because of compromised digestion from low pancreatic enzymes. Food antigen-antibody complexes can form and this can deposit in joints causing the above symptoms.
For these individuals low/no starches and grains may help, but might not be enough because of low good bacteria, high levels of other bacteria, production of the endotoxin LPS, leaky gut, compromised digestion of food particles from low pancreatic enzymes, and production of antigen-antibody complexes. In most individuals with Ankylosing Spondylitis I see a combination of all these factors on a functional stool analysis. These individuals need a comprehensive and systematic approach to address all of those factors to reduce chronic inflammation and the symptoms of pain, stiffness, reduced mobility, and possibly prevent or slow spinal fusion.
Ankylosing Spondylitis and a Leaky Gut
So why are the bacterial proteins, toxins, and undigested food particles in the gut interacting with the gut immune system that creates the chronic inflammation that attacks the joints? The medical literature describes a process called intestinal permeability, better known as leaky gut.
Another reason for chronic inflammation to start, progress, and continue causing damage in the body is because of damage to the gut lining. The gut lining is a very delicate barrier that is the only thing separating bacteria, undigested food particles, and toxins in the gut from the inside of the body and the gut immune system.
Pathogenic or harmful bacterial products such as LPS, bacterial toxins, undigested food particles, and an imbalance in gut bacteria damage the lining of the gut and can lead to a leaky gut. This allows the bacterial products, undigested food particles, and toxins to interact with the gut immune system. In addition, non-steroidal anti-inflammatory drugs, NSAIDs, damage the gut lining leading to intestinal permeability or leaky gut.
Along with the harmful bacteria, not having enough good bacteria can contribute to a leaky gut. Good bacteria help digest food, keep harmful bacteria under control, neutralize toxins, and keep the gut lining healthy and strong.
Ankylosing Spondylitis and the Immune System
Once this interaction between bacterial proteins, undigested food particles, toxins and the gut immune system takes place the immune system becomes imbalanced and chronic inflammation in the body becomes a major problem.
This is when inflammatory chemicals called cytokines come into play. You might be familiar with inflammatory cytokines such as TNF-alpha and Interleukin 17 because biologic drugs such as Humira (adalimumab) target TNF-alpha and the drug Cosentyx (secukinumab) targets IL-17. The reason the drugs target these inflammatory chemicals is because these inflammatory chemicals are part of what is causing the ongoing damage, inflammation, pain, and stiffness associated with Ankylosing Spondylitis.
Once bacterial proteins, LPS, undigested food particles, and toxins in the gut come into contact with the gut immune system from a leaky gut, cells of the immune system called antigen presenting cells present these products to T cells. The T cells turn into different kinds of T cells that can produce different inflammatory cytokines. Some of the cytokines produced are TNF alpha and IL-17.
Because of molecular mimicry as explained from above, these inflammatory chemicals produced in the gut now travel through the blood stream and attack structures such as the tendons, ligaments, and joints of the spine, hips, and sacroiliac joints because these structures look similar to the bacterial proteins and toxins.
Chronic inflammation can begin in the gut with the overgrowth of potentially harmful bacteria such as Klebsiella, Prevotella, an imbalance of other bacteria, undigested food particles, NSAID use, and a low amount of good bacteria causing damage to the gut lining and disrupting the immune system.
Damage to the gut lining, causing a leaky gut, allows bacterial proteins, toxins, and undigested food particles to interact with the gut immune system.
The gut immune system becomes imbalanced, producing inflammatory chemicals such as TNF alpha and IL-17 and attacks other areas of the body such as tendons, ligaments, and joints of the spine, hips, and sacroiliac joints.
The immune system and chronic inflammation is directed towards the tendons, ligaments, and joints of the spine, hips, and sacroiliac joints because of the process of molecular mimicry.
Once the tendons, ligaments, and joints of the spine, hips, sacroiliac joints and other joints of the body are damaged the immune system and chronic inflammation continues to attack trying to repair the damage to the joints.
The cycle of chronic inflammation causes breakdown, degeneration, pain, possibly new bone growth, fusion, and poor posture.
Having balanced gut bacteria, reducing undigested food particles, a healthy gut lining, and having a balanced gut immune system is absolutely essential to reducing the pain, stiffness, and chronic inflammation of Ankylosing Spondylitis.