Identifying Small Intestinal Bowel Overgrowth (SIBO) - Preferred Testing and Most Common Symptoms

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sibo testing and symptomsWhile SIBO is quite the buzzword these days, it is not always truly present clinically.

You may have leaky gut, unidentified food allergies or sensitivities, as well as a more general imbalance of gut flora called "dysbiosis" (or all of the above!).

While the treatment approaches can be similar, there are some rather restrictive strategies that may not be necessary if you do not have true SIBO.

Knowing the difference may save you time, energy, and money when developing a protocol for yourself.

The gold standard for SIBO testing is lactulose breath testing. You consume a lactulose (a type of sugar)-containing solution and your breath is sampled at specific time intervals.

If abnormal bacteria are present, they will ferment the sugar early in the gastrointestinal tract, and abnormal levels of methane and/or hydrogen gas will be measured in your breath. Knowing whether you have methane-producing, hydrogen-producing, or mixed-type overgrowth (or no overgrowth), can change the treatment protocol.

Organic Acid and Stool Testing

Other functional testing may include organic acid markers found in the urine that measure metabolites from bacteria and yeast that can also be an indirect measure of overgrowth and dysbiosis.

In my experience, stool testing is too variable at this time to trust. A stool sample could be sent to five different labs and you'd be given five different test results on bacteria and yeast composition.

Stool testing can be helpful for identifying fatty stool, inflammatory markers or otherwise - but is not recommended specifically for "SIBO" testing. A health professional may "suspect" SIBO from stool testing, but that's as far as their confidence can go.

In my experience, the organic acid tests are used for a more general functional picture of intestinal and metabolic health, which may then lead to further investigation into a more specific diagnosis like SIBO.

If you just perform breath testing, the result is that you are either positive or negative for SIBO. While this may be your primary goal for a consultation, if you find that you are negative for SIBO, it can still leave many questions unanswered.

If you look at broader functional markers like those in organic acid testing, you get a lot of information to work with independent of a SIBO diagnosis.

You may not have SIBO, but it doesn't mean that there are not imbalances to address!

So I generally would lead testing with functional urine organic acid testing, and order breath testing after the fact (or ideally do both together). Of course, each case needs to be considered independently and factors like cost are inherently involved.

So why would you seek out SIBO testing in the first place? The first step is to identify the range of SIBO symptoms.

Common SIBO Symptoms:

sibo symptomsGeneral symptoms of SIBO include:

Bloating, gas, burping, abdominal discomfort, constipation and/or diarrhea, heartburn, nausea, headache, tiredness, skin conditions, fatty stools, and symptoms associated with poor absorption of certain nutrients like vitamin D, iron, vitamin K, or Vitamin B12 (ex. energy, bone health, mood).

SIBO can also be involved in low thyroid activity (1), food intolerance (ex. lactose, gluten, etc) (2), gallstones (3), Crohn's disease flareup (4), scleroderma (5), celiac disease (6), pancreatitis (7), diverticulitis (8), diabetes (9), cirrhosis and liver encephalopathy (10), leaky gut and fibromyalgia (11), non-alcoholic fatty liver (12), kidney and bladder inflammation (interstitial cystitis) (13), restless leg syndrome (14), rosacea (15), esophageal inflammation (16), and possibly microscopic colitis (17).

Any condition where dysbiosis may be involved is a trigger for possible SIBO involvement.

Anxiety, Depression, and Mood Disorders:

In my experience, anxiety, depression, and other mood disorders also can be rooted in SIBO (& dysbiosis). The majority of your brain neurotransmitters are actually produced in the gut - and so many intestinal issues can be associated with mood disorders.

Histamine Intolerance

Some bacteria in the gut are histamine-producing. When these bacteria are overgrown, the body cannot handle the excess histamine and symptoms develop. Excess histamine can cause allergic-like symptoms - but also be related to flare-ups with anxiety, inflammation, or difficulty sleeping.

Certain individuals do not metabolize their histamine efficiently due to genetic differences in a few genes (such as DAO, HDC, HNMT or ABP-1) - and are at more risk for short-term and long-term issues with histamine.

Just because you carry one slow copy of a gene does not suddenly make you a candidate - typically those with problems carry two "slow" copies of one or more genes. Moreover, those with slow copies may only experience histamine-related problems when they also have SIBO present.

Stress can cause histamine-like symptoms too.

Those with primary histamine intolerance may actually suffer with something different known as Mast Cell Activation Disorder (MCAD). These individuals need to carry an Epi-pen with them and must be careful about histamine-containing/releasing foods on a daily basis.

MCAD is different than functional issues with histamine intolerance. These are relatively less common variations. Nevertheless, if you're reading this, it may apply to you and help you decide what treatment or testing approaches are best for you .

Usually, I'm only looking at histamine intolerance as a subset of SIBO or dysbiosis, and will dig deeper into histamine as a primary issue only if the client is not responding to a normal SIBO or dysbiosis protocol.

Putting it All Together:

So if you have been suffering with chronic bloating, gas, and intestinal discomfort that doesn't seem to have a rhyme or reason to it - you may benefit from having yourself evaluated for SIBO and related disorders.

Cases of anxiety and depression that do not respond to medication (as much as 30-40% of individuals) may also benefit from evaluation to at least rule out SIBO involvement. The same could be argued for non-responsive skin issues like rosacea, psoriasis, and eczema. Keep in mind that if you've been taking immune-suppressive medication, antibiotic (pharmaceutical and herbal), or probiotic/prebiotics, it may affect test results and make sure you inform your doctor prior to testing and treatment.

In the worst case scenario, having yourself tested may give you some functional information on your gut and metabolism that you can act on today to balance the gut, optimize wellness, & prevent later problems from developing.

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Dr Alex Rinehart

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