Irritable Bowel Syndrome and its Relationship to the Microbiome and SIBO

Irritable bowel syndrome (IBS), also known as spastic colitis, is a common gastrointestinal disorder affecting 10-20% of the developed world. In the U.S. alone, nearly 45 million people are estimated to have IBS, with many remaining undiagnosed. It's more common in women and usually appears before age 45. IBS symptoms include diarrhea, constipation, bloating, cramps, abdominal pain, and gas, without any detectable structural damage in the digestive tract. Diagnosis is made by ruling out other conditions. IBS is categorized into four types: IBS-D (diarrhea dominant), IBS-C (constipation dominant), IBS-M (mixed), and IBS-U (unclassified).

While stress can exacerbate symptoms, IBS is not caused by anxiety but involves dysfunction in the gut-brain axis. Research shows that gut bacteria can influence mental health, contributing to anxiety and depression. Antidepressants are often prescribed to manage IBS symptoms by boosting serotonin levels, which are predominantly produced in the gut and influence digestive functions. However, antidepressants do not address the root cause of IBS.

Recent discoveries indicate that IBS is not psychosomatic; blood tests can now detect specific antibodies (anti-CdtB and anti-vinculin) linked to IBS, particularly post-infectious IBS (following a bacterial infection). Alterations in gut microbiota have been identified as key contributors to IBS, and interventions like antibiotics and probiotics have shown efficacy in improving symptoms. SIBO (small intestinal bacterial overgrowth) is also linked to IBS, particularly in cases with diarrhea.

In conclusion, IBS is a complex condition involving gut-brain interactions, altered gut bacteria, and immune system responses. Effective treatments focus on regulating the gut microbiome.

Marios Dimopoulos, Naturopathic