What is small intestinal bacterial overgrowth (SIBO)?

 

Our gastrointestinal tract is home to a huge population of micro-organisms called our gut microbiome, which has a significant role in maintaining your overall health.  Its disruption is associated with the development of many gut diseases^1-2 including small intestinal bacterial overgrowth (SIBO).  Specialised SIBO supplements are often the answer to disrupted gut microbiomes.

In a healthy gut, the number of microbes increases as you move down the intestinal tract, with low levels in the small bowel and high levels down in the large bowel. If the delicate environment is disrupted, bacteria can overgrow in the small intestine causing small intestinal bacterial overgrowth (SIBO)^3-4. Low stomach acid and intestinal motility issues are common causes of SIBO, as stomach acid and intestine contraction (peristalsis) patterns help keep bacteria levels low in the small bowel³.

 

SIBO is often thought to be irritable bowel syndrome (IBS) as many symptoms are similar including bloating, abdominal pain, constipation and diarrhoea. SIBO is sometimes accompanied by vitamin deficiencies, most commonly seen with vitamin B12, but folate levels can also increase³.  SIBO supplements with specific specialist herbs are a good option to try if you think you have persistent IBS that is not responding to IBS treatment and could actually be SIBO.

 

Various bacteria types can grow in the small intestine and different species may produce different gases as they feed on the food passing through. Gases produced by bacteria in regards to SIBO are hydrogen, hydrogen sulphide and methane. These gases can be measured via a breath exhalation test, such as the one offered by the Functional Gut Clinic.

 

When seeking a diagnosis, those suffering constipation and wind symptoms should have their methane gas exhalation measured, whereas those with severe diarrhoea predominant symptoms should have hydrogen exhalation measured⁴. If you have persistent daily eggy smelling flatulence accompanying your diarrhoea it may be better to have a hydrogen sulphide breath test instead.

 

If you suspect you may have SIBO you can self-refer to The Functional Gut Clinic. Treatment normally involves rifaximin antibiotics, but some prefer antimicrobial herbal treatment instead.  They will recommend what is best for you, which may include SIBO supplements.

 

 

References

1. Jandhyala, S.M., Talukdar, R., Subramanyam, C., Vuyyuru, H., Sasikala, M. and Reddy, D.N. (2015). Role of the normal gut microbiota. World Journal of Gastroenterology, 21(29): 8787-8803
2. Kim, S.M., Guevarra, R.B., Kim, Y.T., Kwon, J., Kim, H., Cho, J.H., Kim, H.B. and Lee, J.H. (2019). Role of Probiotics in Human Gut Microbiome-Associated Diseases. Journal of Microbiology and Biotechnology, 29(9): 1335-1340
3. Bures, J., Cyranu, J., Kohoutova, D., Forstl, M., Rejchrt, S., Kvetina, J., Vorisek, V. and Kopacova, M. (2010). Small intestinal bacterial overgrowth. World Journal of Gastroenterology, 16(24): 2978-2990
4. Rao, S.S.C. and Bhagatwala, J. (2019). Small Intestinal Bacterial Overgrowth: Clinical Features and Therapeutic Management. Clinical and Translational Gastroenterology, 10(10): e00078
5. Rezaie A, Buresi M, Lembo A, Lin H, McCallum R, Rao S, Schmulson M, Valdovinos M, Zakko S. (2017) Pimentel M. Hydrogen and Methane-Based Breath Testing in Gastrointestinal Disorders: The North American Consensus. Am J Gastroenterol. ;112(5):775-784.