Irritable bowel syndrome (IBS) affects between 11% and 14% of the population characterized by altered gut motility (constipation/diarrhea), visceral hypersensitivity, abnormal brain-gut interaction, autonomic dysfunction, and immune activation (Lin, 2004). Although a diverse range of symptoms exist, 92% of said population exhibit bloating (Lin, 2004).
Researchers have postulated that in order for bloating to occur, gut bacteria traditionally located in the distal intestine, are likely migrating towards the small intestine due to a lack of motility (Lin, 2004). Such bacteria are responsible for fermenting sugars found in food. Such an explanation would help explain bloating in IBS patients from a condition known as small intestinal bacterial overgrowth (SIBO). Furthermore, patients with IBS generally have higher levels of immune activity as measured by activated intraepithelial lymphocytes(a type of white blood cell responsible for destroying antigens) than healthy subjects and may contribute to leaky gut syndrome (Lin, 2004). Having briefly considered some of the characteristics of IBS and SIBO, the following will consider potential interventions for the same.
Kwiatkowski and Langland (2017) noted that SIBO is typically treated with a course of antibiotics (rifaximin) to control/eradicate the condition. However, the researchers also stated that botanical therapies and a low fermentable oligo-, di-, and monosaccharides and polyols (FODMAPs) diets can enhance outcomes when combined with antibiotic therapy (Kwiatkowski & Langland, 2017). For example, thyme, oregano, and salvia behave as a bactericidal substance and help inhibit the continued growth of intestinal microbes while Coptis root, rhizome extract, and Indian Barberry inhibit cell division (Kwiatkowski & Langland, 2017).
Low FODMAP diets are another intervention that can assist in controlling the growth of bacteria; Kwiatkowski and Langland (2017) stated that the efficacy antibiotic therapy for SIBO can be optimized when combined with low FODMAP nutritional interventions. Fermentable carbohydrates promote the growth of intestinal bacteria, thus, restricting their consumption can help reduce the total numbers of gut bacteria, and studies have shown that a low-FODMAP diet can improve symptoms in conditions such as IBS (Kwiatkowski & Langland, 2017). Please see chart below of high and low FODMAP diets
In conclusion, evidence indicates a relationship between IBS and SIBO (bloating). If antibiotic therapy is necessary to control SIBO, introduction of low FODMAP diets may also help expedite time to recovery and a facilitate a more complete return to health. It might also be worthy to note that even if a test for SIBO is not done/inaccessible (in my city), trying a low FODMAP diet is relatively easy and inexpensive. Ultimately, if symptoms lower, then the approach is validated by favorable outcomes.
References
Kwiatkowski, L., Rice, E., Langland, J. (2017). Integrative treatment of chronic abdominal bloating and pain associated with overgrowth of small intestine bacteria: A case report. Alternative Therapies, 23(4), 56-61.
Lin, H. C. (2004). Small intestinal bacterial overgrowth: A framework for understanding irritable bowel syndrome. Journal of the American Medical Association, 292(7), 852-858.
-Michael McIsaac