SIBO is not a “primary disease”. It is a consequence of gut dysfunction, the root cause of which is suspected to be autoimmune. We attempt to unravel SIBO’s complex relationship with autoimmunity and leaky gut syndrome and also delve into how chronic inflammation - which doesn’t sound so bad! - is linked and the role it plays in chronic disease.
“Changes of lifestyle in industrialized countries have led to a decrease of the infectious burden and are associated with the rise of allergic and autoimmune diseases, according to the ‘hygiene hypothesis’.”(1)
Interestingly, autoimmune disorders occur almost exclusively in developed countries. People in poorer nations without the modern amenities of running clean water, flushing toilets, washing machines, and sterile backyards don’t get these diseases. They form a huge health burden, costing millions to healthcare systems and shortens lifespans considerably(2).
Autoimmune diseases (AIDs) are on the rise and currently 80 types of autoimmune conditions have now been recognised(3)! The immune system would normally send an army of fighter cells only when a foreign threat has been detected, but in the case of autoimmunity (AI), the PD-1 mechanism, comprising of B and T lymphocytes whose function is to check immune cell activity and prevent them from attacking healthy cells, becomes ineffective(4). Immune cells can no longer tell the difference between foregein invading cells and your own cells and mistakenly attack healthy cells within the body, known as immunopathology. Once the immune system mistakes a part of your body, like your joints or skin, as foreign, it releases proteins called antibodies that attack indiscriminately and the immune system is put on high alert - one reason fatigue is a uniting symptom of AI. Some only attack one organ such as Type 1 Diabetes where AID damages the pancreas, but others such as systemic lupus erythematosus (SLE), can affect the whole body(5).
“Inflammation appears connected to almost every known chronic disease — from heart disease to cancer, diabetes to obesity, autism to dementia, and even depression.”(2)
“Autoimmune conditions are connected by one central biochemical process: A runaway immune response also known as systemic inflammation that results in your body attacking its own tissues.”(2)
Inflammation is a defence mechanism triggered when the immune system recognises damaged cells, irritants, and pathogens, and begins the healing process. When something negatively affects a part of our body, the body’s biological response is to remove the harmful stimuli. So inflammation is normally a good thing - it’s a sign that the body is trying to heal itself. Indeed, it’s a vital part of the immune response - infections, wounds, and any damage to tissue would not be able to heal without an inflammatory response. But in those with autoimmune conditions, inflammation spirals out of control and causes serious damage, and can trigger chronic diseases including AID(2).
There are 2 different types of inflammation which can occur in the body -
So when acute inflammation turns into chronic (long-term) inflammation, it turns from a positive response into a very damaging one. Although damaged tissue cannot heal without inflammation, when chronic, it can eventually cause several diseases and health conditions.
The most common causes of chronic inflammation are -
Examples of few diseases and conditions that include chronic inflammation -
Inflammation + Misbehaving Nerves
Inflammation often causes pain because the swelling pushes against sensitive nerve endings within tissues, sending pain signals to the brain. However, not all chronic inflammation causes pain. Chronic inflammation can also occur at the microscopic level, making it undetectable via image testing. “Other biochemical processes also occur during inflammation, affecting how nerves behave...”(6). This is particularly important to SIBO + IBS sufferers, as both are now suspected to be triggered by nerve damage of the enteric nervous system (ENS) or “the gut brain”, leading to autoimmunity and gut dysfunction, which in turn causes SIBO, further inflammation and gut damage(7). When it lasts for months or years, tissue death and thickening and scarring of connective tissue occurs.
Thus, it is critical to healing that chronic inflammation is reduced as much as possible and managed.
As usual, not enough research has been carried out to determine the true cause(s) of autoimmune disease but it is suspected that multiple factors could be at play(2) -
The Mystery of AI
In some cases, a condition can be labeled “autoimmune” based on conventional wisdom or expert consensus rather than hard science. The term “autoimmune” can loosely apply to any condition of unknown cause in which inflammation is present or the immune system appears to be overactive. But an infection can cause similar symptoms and outcomes. It could be that some of these conditions now considered to be autoimmune will turn out to be chronic infections by organisms we’ve not yet identified(9).
Many autoimmune diseases have similar symptoms and the first common symptoms - fatigue, muscle aches and a low fever - are vague and inconclusive. This makes diagnosis a challenge. Add to this the classic sign of all autoimmune disease - inflammation - which can evade detection, especially if it's on a microscopic level. Each AID has its own unique symptoms(5) but here are a few they often have in common (you’ll notice many overlaps with SIBO which is no coincidence) -
Irritable Bowel Disease (IBD)
Inflammatory bowel disease (IBD) is a term used to describe autoimmune conditions that cause inflammation in the lining of the intestinal wall. Each type of IBD affects a different part of the GI tract(5). It is classed as a “structural disease” as underlying physical damage causes the symptoms and chronic inflammation or ulcers which can be detected with an X-ray, endoscopy, surgery, or biopsy(10).
IBS + SIBO + AI
Groundbreaking research indicates that IBS-D (Irritable Bowel Syndrome associated with diarrhea) and IBS-M (mixed - associated with both diarrhea and constipation); “...are triggered by food poisoning, resulting in the production of antibodies that damage the enteric nervous system and trigger IBS.”(7)
As these two dysfunctional gut conditions - IBS and SIBO - are intricately linked, this revolutionary new finding means that both IBS and SIBO may have to be renamed and reclassified as an autoimmune disease of the gut(7)! So they may soon officially fall under “IBD” classification. Of course, more research is needed - we say this a lot! But it makes sense - the immune attack on the nervous and muscular systems of the GI tract (ENS) could be the cause of the dysfunction and mobility disorders of the gut. It is this gut dysfunction which allows pathogenic bacteria to colonise, resulting in IBS and SIBO.
Stress, Gut Dysfunction + AI
So we know that small intestinal microbial dysbiosis is merely a symptom of a dysfunctional gut disorder(11) and that stress disorders have been linked to gut dysfunction(7). As stated above, it is also believed that chronic or persistent stress is a major cause of autoimmune disease(9). Considering that AIDs and gut dysfunctional conditions share this major cause in common as well as similar symptoms, it is not surprising that they are intricately related.
“A new study has raised the possibility that stress may cause autoimmune disease, such as lupus or rheumatoid arthritis, because it found a higher incidence of autoimmune diseases among people who were previously diagnosed with stress-related disorders.”(9)
Leaky Gut Syndrome/Intestinal Hyperpermeability
SIBO causes considerable damage to the small bowel mucosa and structures (see Gut Dysbiosis/SIBO In Depth), which can lead to leaky gut syndrome or intestinal hyperpermeability - when the intestinal barrier’s increased permeability, allows large protein molecules (such as food molecules) to escape into the bloodstream.
Leaky Gut is a chronic condition that is common but often undiagnosed or misdiagnosed. As the condition of the gut degrades, the health impacts can be dramatic(12). This condition of the gut is known to have a number of potential complications including immune reactions that cause food allergies or sensitivities, acute and chronic inflammation, and autoimmune diseases(13).
How is Leaky Gut Damaging?
Once your gut barrier is “leaky” and toxins, viruses, bacteria and food particles flood your bloodstream, the immune system marks them as dangerous invaders and initiates the immune response, causing inflammation in an attempt to get rid of them. As the gut barrier disintegrates and more particles escape into your bloodstream, your immune system responds with wave after wave of inflammation. Eventually it becomes over stressed and begins firing less accurately. This in turn leads to autoimmunity as your own tissues end up in the crossfire. What’s more, many of the particles that are now flooding your bloodstream look a lot like your body’s own tissues (self-antigens). Your immune system will then create antibodies against these substances which mistakenly attack your tissues in the process, in a phenomenon called molecular mimicry.
Histamines (noun) - an organic nitrogenous compound involved in local immune responses, as well as regulating physiological function in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus. Histamine is involved in the inflammatory response and has a central role as a mediator of itching(27).
Histamines are chemicals created by our immune system for one important job - to get rid of an irritant (allergens) or potential threats. They are an integral part of the body’s defence system, starting a chain reaction and an inflammatory response that nudges those allergens out of your body or off your skin. That’s why people experiencing allergic reactions are often given “antihistamines” to control the release of histamines that produce these symptoms. They can make you sneeze, tear up, or itch. It is also a component of your stomach acid that aids in digestion by breaking down foods in your gut. So it’s pretty important.
How SIBO Causes Histamine Intolerance
“Food sensitivities such as histamine intolerance almost always indicate there is something going on in your gut.”(28)
As we discussed above, SIBO causes intestinal hyperpermeability or leaky gut, leading to an increase in food sensitivities and intolerance reactions. When the damaged gut lining allows food particles to enter your bloodstream, your immune system responds to these “invaders” by triggering the inflammatory symptoms you experience as histamine intolerance - flushing, hives, headaches, itching etc. Leaky gut causes the immune system to become overactive resulting in immune dysfunction (autoimmunity) where immune cells can no longer distinguish between potential threats, food molecules and our own cells and attacks indiscriminately (see above for more info). But SIBO and other autoimmune conditions have a crazy complex relationship with histamine which we’ve tried to summarise below.
The SIBO/Autoimmune - Histamine Relationship
Symptoms of Histamine Intolerance
SIBO is both caused by, and causes gut dysmotility, which inhibits your ability to properly digest foods and allows food and bacteria to sit in your digestive system longer. This worsens inflammation, leaky gut and food intolerances as well as histamine intolerance further. Following The SIBO Diet + The Healing Protocol will help reduce these symptoms, calm inflammation and break the vicious cycles to restore balance and wellness to the body.