SIBO, Gluten and IBS: What Is The Connection?

When she came into my office complaining of bloating, Clare (name changed to protect her privacy) was convinced it was from something she was eating. In a way, she was right. Bloating can be caused by many things, some minor, some serious. I considered her case serious, as it was severely impacting her day-to-day life and her overall health. She was deficient in multiple nutrients. By the end of the day, she often appeared seven months pregnant. Because of the discomfort from the severe bloating, she was unable to sleep. In turn, the sleep deprivation was markedly impacting her mental and physical health.

Prior to our visit, Clare had tested negative for celiac disease, but had started a gluten-free diet to help her rheumatoid arthritis and bloating. However, her symptoms were not resolving. Her doctor told her she had IBS, but she wanted to know if there was something she could do to find relief. I suspected Clare was suffering from SIBO.

What is SIBO?

SIBO stands for small intestinal bacterial overgrowth. Normally, the small intestine has few bacteria. Most intestinal bacteria are contained in the large intestine. When there are too many, or they are the wrong type of bacteria in the small intestine, it is called SIBO.

Don’t we need bacteria in our intestine?

We do. Bacteria are important for our immune system, digestion, vitamin production and more. But, when SIBO is present, there are too many bacteria and they are in the wrong place. This can cause malabsorption, inflammation, and some or many of the symptoms below.

What are some of the symptoms of SIBO?

Gas/bloating
Stomach pain
Diarrhea
Weight loss
Fatigue
Nausea
Nutrient deficiencies and their associated symptoms: Vitamin B12, A, D, E, iron, other B vitamins, fat, protein and carbohydrate malabsorption
Carbohydrate intolerance-symptoms such as bloating/pain/gas fatigue after eating
Constipation
Joint pain

What causes SIBO?

To keep bacteria counts at a healthy low level in the small intestine, your body must have normal levels of stomach acid; properly functioning pancreas and gall bladder; normal intestinal motility (ability to move food through the digestive tract); normal mucosa (lining of the digestive tract); and structurally normal valves.

These medical conditions and treatments that affect one of the factors above can predispose someone to SIBO:

Diabetes
Liver or pancreas disease
Celiac Disease/Non-celiac GS
Inflammatory Bowel Disease
Hypothyroidism
IBS
Chronic Constipation
Chemotherapy
Chronic Antibiotic Use
Immune suppressed states i.e. AIDS, Cancer, chronic steroid use
Other chronic diseases
Chronic use of acid-blocking medication

Is SIBO associated with any other illnesses?

In addition to the diseases that predispose someone to SIBO, it is also seen more commonly in people with rosacea, restless leg syndrome, interstitial cystitis, and cirrhosis.

How do you test for it?

It is typically diagnosed using a breath test in which the patient drinks a sugar-containing drink and exhaled gases are measured. If there are too many bacteria, excess gases (hydrogen, methane or both) will be produced. It should be noted that the reliability of this test is less than ideal. Due to the poor reliability of the testing method, some physicians will treat based on symptoms. A direct sample can also be taken from the intestinal fluid to diagnose SIBO, but it is not routinely done.

How is SIBO related to Celiac Disease and Non-Celiac Gluten Sensitivity?

People with celiac disease have a higher incidence of SIBO. A 2003 paper found there was a high incidence of SIBO in celiac patients on a gluten-free diet with ongoing symptoms. Anecdotally, there is a higher incidence of SIBO in non-celiac gluten sensitivity (NCGS) patients, but due to the lack of data surrounding NCGS, the science is that the arena is still to come.

What is the connection to IBS?

Irritable bowel syndrome (IBS) is a common condition. A person with IBS typically has symptoms such as bloating, cramping, abdominal pain, diarrhea and/ or constipation. There is no definitive test or diagnostic marker at this time (although one is under development), so diagnosis is based on symptoms and history. Until we have a better understanding of IBS, there will be a debate on its cause and treatment. Some studies say that up to 50-60% of people with IBS may have SIBO and that by treating the SIBO you will get the resolution of the IBS symptoms.

So, are some cases of IBS actually SIBO? A recent review paper addressed the use of Rifaxamin, an antibiotic used to treat SIBO, as a treatment for IBS patients. Many of the studies showed improvement or resolution of IBS symptoms if the IBS patients were diagnosed with SIBO. Another recent study in children found that 66% of children diagnosed with IBS had SIBO. Treating the SIBO resolved the IBS symptoms. An important update: Rifaximin has now been FDA approved to treat IBS with diarrhea and is bringing great relief to many patients.

How do you treat it?

The underlying cause of the SIBO must be addressed first or treatment will not be effective. For example, if SIBO is due to celiac disease it will never get better without first adhering to a strict gluten-free diet. After treating the underlying cause, the subsequent therapy will depend on a traditional or integrative approach.

Traditional SIBO treatment:
Antibiotics are the mainstay of therapy and are often used in conjunction with motility agents to prevent “build-up” of bacteria by moving things through the intestinal tract. Some physicians will also prescribe a low sugar diet. In severe cases, elemental diets are used. These are liquid diets in which all of the nutrients are broken down and don’t require digestion. The nutrients are absorbed so quickly that the bacteria don’t have time to act on them and produce symptoms. This is done for a short duration to effectively “starve” the bacteria.

Integrative SIBO treatment:
As mentioned above, the underlying cause must first be treated. From there, the following integrative therapies may be used:

Probiotics +/-
Vitamins
Diet/nutritional interventions
Motility agents
Digestive Enzymes
Acupuncture
Elimination Diets
Hypnotherapy
Relaxation Techniques
Stress Reduction
Addressing sleep disorders
Herbal antibiotics
Elemental Diets
Antibiotics

Are there special diets for SIBO?

Many diets are used to treat SIBO. Which diet is used depends on the clinical scenario and the practitioner. Most of the diets have the same goal of reducing sugars that the bacteria would consume. Commonly used diets are Paleo, SCD, GAPS, Candida, Low FODMAP or a general low sugar/carb diet.

Once you treat it, is it gone forever?

Long term outcome varies, but recurrence is common.

How do you best prevent recurrence?

You may be able to prevent or minimize the risk of recurrence by eating a “clean diet” of primarily plant-based whole foods; minimizing processed foods and sugar; reducing stress; exercising; and adopting good sleep habits. Some people will use a less restricted form of one of the above-mentioned diets on a long term basis; each person is different.

Problem solved

So back to my lovely patient, Clare. The cause of her bloating did turn out to be SIBO. Her intuition was correct; what she was eating was bothering her. The sugar in her diet was an issue, due to SIBO and fructose malabsorption. We addressed these issues, identified and treated both, and she is on her way to a new level of energy and health.

If you think you may have symptoms consistent with SIBO, I encourage you to discuss the possibility with your physician. You may be helping yourself and many others by bringing to light an underdiagnosed issue.