SIBO + Autoimmunity

“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 - 

• Acute inflammation = inflammation which begins rapidly and becomes severe quickly. This can be the result of a serious infections such as tonsillitis or acute appendicitis, high-intensity exercise, a physical trauma or even just a scratch or graze. In the case of acute inflammation, it either improves, turns into an abscess, or becomes chronic
• Chronic inflammation = this is usually the result of pathogens that the body cannot break down, including some types of virus, foreign bodies that remain in the system, or overactive immune responses(6).

Chronic Inflammation

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 - 

• Failure to eliminate whatever was causing an acute inflammation
• An autoimmune disorder that attacks normal healthy tissue, mistaking it for a pathogen that causes disease
• Exposure to a low level of a particular irritant, such as an industrial chemical, over a long period

Examples of few diseases and conditions that include chronic inflammation - 

• Asthma
• Chronic peptic ulcer
• Tuberculosis
• Rheumatoid arthritis
• Ulcerative colitis and Crohn's disease

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) - 

• Persistent Stress. One study found that individuals diagnosed with a stress-related disorder were not only more likely to be diagnosed with an autoimmune disease, but were more likely to be diagnosed with multiple AIDs, especially if young in age.
• Environmental pollutants. Because the incidence of autoimmune diseases is rising, researchers suspect environmental factors like infections and exposure to chemicals, pollutants or solvents might also be involved.
• The “Western diet”. Another suspected risk factor for developing an autoimmune disease is the consumption of high-fat, high-sugar, and highly processed foods, thought to be linked to inflammation, which might set off an immune response. However, this hasn’t yet been proven - more research is needed!
• The Hygiene Hypothesis. A 2015 study focused on another theory called the hygiene hypothesis. Because of vaccines and antiseptics, children today aren’t exposed to as many germs as they were in the past. The lack of exposure could make their immune system prone to overreact to harmless substances.
• Bacterial or Viral infections(7), (8). 

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) -

• Fatigue
• Achy muscles
• Swelling and redness
• Low-grade fever
• Trouble concentrating + brain fog
• Numbness and tingling in the hands and feet
• Hair loss
• Skin rashes

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).

• Crohn’s disease can inflame any part of the GI tract, from the mouth to the anus.
• Ulcerative colitis affects only the lining of the large intestine (colon) and rectum.

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)