Introduction

Small intestinal bacterial overgrowth (SIBO) is defined as the presence of excessive microbiome in the upper GI tract (small intestine). It is the most common of the four types of gut microbiome dysbiosis.

The gut microbiome

The gut microbiome are the trillions of living microbes in our gut (i.e., duodenum, small intestine, and colon). In a healthy digestive system, most of our gut microbiome live in the colon (large intestine/bowel). The small intestine contains very few microbiomes. However, someone experiencing SIBO has lots of multiple types of microbiomes, in their small intestine, primarily Escherichia coli (E coli) and Klebsiella.

SIBO and IBS: the chicken or the egg?

A great deal of attention has been focused on the potential role of SIBO in the onset and maintenance of IBS symptoms. The data on this topic has yielded conflicting results, and the association remains highly controversial. Some doctors strongly believe that SIBO is a cause of IBS and others are not so convinced.

SIBO and IBS share a myriad of symptoms (bloating, distention, abdominal cramps, and diarrhea) and SIBO can be mistaken for IBS and vice versa. To complicate things further, these disorders can occur simultaneously or trigger and maintain each other.

It’s unclear whether SIBO can be a cause of IBS, but people with IBS are more likely than others to test positive for SIBO. In addition, some research has found that IBS symptoms often decrease after antibiotic treatment that focuses on microbiome in the small intestine.

Is SIBO common amongst those living with IBS?

Estimates vary about how many people diagnosed with IBS also have SIBO, but research in the March 2017 issue of Gut and Liver suggested it may be between 19% and 37%.

What causes SIBO?

A well-functioning digestive system normally prevents the overgrowth of microbiome in the small intestine through natural defences such as stomach acid and the muscular contractions that move food through your digestive system, but when these are under-functioning or disrupted, extra microbiome in the colon back up into the small intestine.

The following have been identified as possible causes for this under-functioning and/or disruption to occur.

Low stomach acid. Stomach acid is one way your body kills off microbiome and so without the correct level that can lead to an overgrowth of microbiome.
Slow, small bowel motility. Motility refers to the muscular contractions within the gut that move food and microbiome, through the gastrointestinal tract. The right speed of motility is essential for digestion and absorption of the food you eat as well as the expulsion of waste. When the movement is too slow, microbiome can take hold and multiply in the small intestine.
An immune system dysfunction leading to a weakened immune response which cannot regulate bacterial populations effectively.
Post infectious IBS related to food poisoning.
Anatomic problems in the small intestines, such as obstructions, adhesions, and strictures, including diverticula.
Abdominal surgery complications such as appendectomy, gastrectomy, and cholecystectomy.
Injuries such as traumatic brain injury, sports injury, or car accident.
Medications such as opiates and antibiotics. Acid blockers prescribed to treat symptoms of peptic ulceration or gastro-oesophageal reflux disease (GERD) may lead to colonisation of the small intestine by microbiome.

Diagnosis

SIBO is a medical condition that should be diagnosed by a healthcare professional. However, SIBO is not well understood, and it is also difficult to diagnose.

There is a considerable variation in the number of microbiomes in the small intestine even in people without IBS or SIBO. So it’s difficult to know when a level of microbiome is ‘abnormal.’

Currently, there is no available gold standard test to diagnose SIBO.

SIBO may be diagnosed via:

hydrogen Breath Test. This is the most used test. It measures gas production by microbiome as they breakdown sugars such as glucose and lactulose. Because of a lack of standardization across breath tests, and a high false positive rate, breath testing is not considered overly reliable.
a urine test that measures the byproducts of the microbiome after they are absorbed into your system.
a jejunal aspirate. This involves a doctor accessing part of the small intestine and extracting a small sample of the fluid which is examined under a microscope. This is the most accurate way to diagnose SIBO, but it's very invasive and requires an anesthetic. Because it is an invasive procedure, it is rarely used in clinical practice unless a gastroenterologist thinks it’s necessary.

SIBO symptoms

The symptoms of SIBO are mainly related to the excessive production of gas in the small intestine as fats and carbohydrates are broken down far too early in the digestive process. As the microbiome eat, they produce methane, hydrogen, and hydrogen sulphide gasses. This excessive gas results in bloating, distention, flatulence, abdominal discomfort and changes in stool form (constipation and/or diarrhoea).

SIBO can also cause malabsorption of nutrients.

Treatments for SIBO

Management of SIBO is usually a course of antibiotics. The type of antibiotic prescribed is one that is not absorbed in the stomach and therefore can make its way to the small intestine where it can eliminate any microbiome it finds there. The most common one used is called Rifaximin (aka Xifaxan).

The problem is that even when SIBO is successfully treated with an antibiotic, once the treatment ends, the SIBO tends to reappear. So, people may need to repeat the course of antibiotics.

Alternatives and/or adjuvants to antibiotics include dietary therapy, probiotics and herbal therapy.

And an often overlooked, yet potentially, effective treatment is gut directed hypnotherapy.

Gut Directed Hypnotherapy (GDH) as an adjunct to SIBO treatment

While there is considerable research supporting the effectiveness of GDH in the relief of IBS symptoms, unfortunately, there has been limited research on the effectiveness of GDH for SIBO relief. As a result, GDH, if used, is usually used as a complementary SIBO treatment alongside medication and dietary changes.

Because the symptoms of SIBO and IBS mirror each other to a large degree, it is reasonable to assume that GDH focused on SIBO is going to produce a similar positive effect on the condition as it does on IBS symptoms.

Studies show that GDH can positively affect the brain-gut axis (the constant two-way communication channel between your head brain and your gut brain). We know messages sent along the gut-brain axis can influence and change gut motility - either speed it up or slow it down. And we know slow small bowel transit is a key factor in the creating the conditions for microbiome growth. So a key focus when applying GDH to the treatment of SIBO is to correct the signals between the brain and gut to restore normal gut motility.

Summary

Small intestinal bacterial overgrowth (SIBO) is defined as excessive microbiome in the upper GI tract (small intestine).
Research suggests that SIBO co-exists in up to 37% of people diagnosed with IBS.
What remains unknown is whether SIBO is a cause or a consequence of IBS—or both.
A key causal factor of SIBO is slow small bowel motility, which creates ideal conditions for microbiome growth in the small intestine where it doesn’t belong.
Motility is controlled by the gut-brain axis. The gut brain axis can be influenced by the suggestions given during a GDH programme.
By working with a specialist gut directed hypnotherapist, it is possible to restore normal gut motility and so remove one of the key causes of SIBO – slow transit of food through the small intestine.

What’s next?

If you’re struggling to cope with SIBO, and you’re curious to about how GDH can help you gain relief, reach out. I can help you explore how GDH could help you gain the relief from SIBO that you desire. You can book a 30 minute consultation with me using this link.