Irish Journal of Medical Science

, Volume 182, Issue 1, pp 1–6

Bugs on the brain; brain in the gut—seeking explanations for common gastrointestinal symptoms

Review Article

Abstract

Introduction

Gastrointestinal symptoms such as heartburn, indigestion (or dyspepsia), bloating, distension, constipation, abdominal pain, abdominal discomfort and diarrhoea are extremely common worldwide. For some, such symptoms can prove to be chronic and disabling.

Methods

The recent literature on irritable bowel syndrome and, in particular, work emanating form this authors research group, was reviewed.

Results

These functional symptoms commonly occur in aggregations, referred to as functional gastrointestinal disorders (FGIDs). Some of the FGIDs and, most notably irritable bowel syndrome (IBS), have achieved a degree of scientific and clinical credibility as coherent entities. Several lines of evidence ranging from gut motility to the microbiota are under investigation in attempts to explain IBS or its symptomatology.

Conclusion

Though biomarkers for IBS and other FGIDs have proven elusive, considerable progress has been made in understanding possible aetiological factors in IBS; progress which may well lead to better therapeutic strategies.

Keywords

Functional gastrointestinal disorders Irritable bowel syndrome Microbiota Cytokines Gut-brain axis 

References

  1. 1.
    Quigley E, Hunt R (2012) World digestive health day 2012. J Clin Gastroenterol 46:i–iiCrossRefGoogle Scholar
  2. 2.
    Quigley EMM, Abdel-Hamid H, Barbara G et al (2012) A Global Perspective on Irritable Bowel Syndrome. A Consensus Statement of the World Gastroenterology Organization (WGO) Summit Task Force on Irritable Bowel Syndrome. J Clin Gastroenterol 46:356–366PubMedCrossRefGoogle Scholar
  3. 3.
    Quigley EMM (2007) The “Con” case. The Rome process and functional gastrointestinal disorders: the barbarians are at the gate! Neurogastroenterol Motil 19:793–797PubMedCrossRefGoogle Scholar
  4. 4.
    Quigley EMM, Shanahan F (2009) The language of medicine: words as servants and scoundrels. Clin Med 9:131–135PubMedCrossRefGoogle Scholar
  5. 5.
    Walsh K, McWilliams SR, Maher MM et al (2012) The spectrum of functional gastrointestinal disorders in a tertiary referral clinic in Ireland. Ir J Med Sci 181:81–86PubMedCrossRefGoogle Scholar
  6. 6.
    Desmond AN, McWilliams S, Maher MM et al (2012) Radiation exposure from diagnostic imaging among patients with gastrointestinal disorders. Clin Gastroenterol Hepatol 10:259–265PubMedCrossRefGoogle Scholar
  7. 7.
    O’Connor OJ, McSweeney SE, McWilliams S et al (2012) Role of radiologic imaging in irritable bowel syndrome: evidence based review. Radiology 262:485–494PubMedCrossRefGoogle Scholar
  8. 8.
    Khashan AS, Quigley EMM, McNamee R et al (2012) Increased risk of miscarriage and ectopic pregnancy in patients with irritable bowel syndrome. Clin Gastroenterol Hepatol 10:902–909PubMedCrossRefGoogle Scholar
  9. 9.
    Quigley EMM (2004) Functional gastrointestinal disorders; has the genomic era arrived? Gastroenterology 126:1193–1195PubMedCrossRefGoogle Scholar
  10. 10.
    Craig OF, Quigley EMM (2010) Bacteria, genetics and irritable bowel syndrome. Expert Rev Gastroenterol Hepatol 4:271–276PubMedCrossRefGoogle Scholar
  11. 11.
    Quigley EMM (2005) Disturbances of motility and visceral hypersensitivity in irritable bowel syndrome: biological markers or epiphenomenon. Gastroenterol Clin N Am 34:221–233CrossRefGoogle Scholar
  12. 12.
    McKee DP, Quigley EMM (1993) Intestinal motility and the irritable bowel syndrome—is IBS a motility disorder? Part 1. Definition of IBS and colonic motility. Dig Dis Sci 38:1761–1772PubMedCrossRefGoogle Scholar
  13. 13.
    McKee DP, Quigley EMM (1993) Intestinal motility and the irritable bowel syndrome—is IBS a motility disorder? Part 2. Motility of the small bowel, esophagus, stomach and gall bladder. Dig Dis Sci 38:1773–1782PubMedCrossRefGoogle Scholar
  14. 14.
    Quigley EMM (2003) From comic relief to real understanding; how intestinal gas causes symptoms. Gut 52:1659–1661PubMedCrossRefGoogle Scholar
  15. 15.
    McWilliams SR, O’Connor OJ, McGarrigle A-M et al (2012) CT-based estimation of intra-cavitary gas volumes using threshold-based segmentation: in vitro study to determine the optimal threshold range. J Med Imag Radiat Oncol 56:289–294CrossRefGoogle Scholar
  16. 16.
    McWilliams SR, Mc Laughlin PD et al (2012) Computed tomography assessment of intestinal gas volumes in functional gastrointestinal disorders. J Neurogastroenterol Motil 18:419–425CrossRefGoogle Scholar
  17. 17.
    Azpiroz F, Malagelada JR (2005) The pathogenesis of bloating and visible distension in irritable bowel syndrome. Gastroenterol Clin North Am 34:257–269PubMedCrossRefGoogle Scholar
  18. 18.
    Galati JS, McKee DP, Quigley EMM (1995) The response to intraluminal gas in the irritable bowel syndrome: motility versus perception. Dig Dis Sci 40:1381–1387PubMedCrossRefGoogle Scholar
  19. 19.
    Tillisch K, Labus JS (2011) Advances in imaging the brain-gut axis: functional gastrointestinal disorders. Gastroenterology 140:407–411PubMedCrossRefGoogle Scholar
  20. 20.
    Dinan TG, Quigley EMM, Ahmed SMM et al (2006) Hypothalamic-pituitary- gut axis dysregulation in irritable bowel syndrome: plasma cytokines as a potential biomarker? Gastroenterology 130:304–311PubMedCrossRefGoogle Scholar
  21. 21.
    Mayer EA (2011) Gut feelings: the emerging biology of gut-brain communication. Nat Rev Neurosci 12:453–466PubMedCrossRefGoogle Scholar
  22. 22.
    North CS, Hong BA, Alpers DH (2007) Relationship of functional gastrointestinal disorders and psychiatric disorders: implications for treatment. World J Gastroenterol 13:2020–2027PubMedGoogle Scholar
  23. 23.
    Ghoshal UC, Shukla R, Ghoshal U et al (2012) The gut microbiota and irritable bowel syndrome: friend or foe? Int J Inflamm 2012:151085Google Scholar
  24. 24.
    Spiller R, Lam C (2012) An update on post-infectious irritable bowel syndrome: role of genetics, immune activation, serotonin and altered microbiome. J Neurogastroenterol Motil 18:258–268PubMedCrossRefGoogle Scholar
  25. 25.
    Quigley EMM (2007) A 51-year-old with IBS. Test or treat for bacterial overgrowth? Clin Gastroenterol Hepatol 5:114–1143CrossRefGoogle Scholar
  26. 26.
    Pimentel M, Lembo A, Chey WD et al (2011) Rifaximin therapy for patients with irritable bowel syndrome without constipation. N Engl J Med 364:22–32PubMedCrossRefGoogle Scholar
  27. 27.
    O’Mahony L, McCarthy J, Kelly P et al (2005) Lactobacillus and bifidobacterium in irritable bowel syndrome: symptom responses and relationship to cytokine profiles. Gastroenterology 128:541–551PubMedCrossRefGoogle Scholar
  28. 28.
    Konieczna P, Groeger D, Ziegler M et al (2012) Bifidobacterium infantis 35624 administration induces foxp3 + 1 T regulatory cells in human peripheral blood—potential role for myeloid and plasmacytoid dendritic cells. Gut 61:354–366PubMedCrossRefGoogle Scholar
  29. 29.
    Konieczna P, Akdis CA, Quigley EMM et al (2012) Portrait of an immunoregulatory bifidobacterium. Gut Microbes 3:1–6CrossRefGoogle Scholar
  30. 30.
    Jeffery IB, Quigley EM, Ohman L, et al. (2012) The microbiota link to irritable bowel syndrome: an emerging story. Gut Microbes. 3 [Epub ahead of print]Google Scholar
  31. 31.
    Fraher MH, O’Toole PW, Quigley EMM (2012) Techniques used to characterise the intestinal microbiota: a guide for the clinician. Nat Rev Gastroenterol 9:312–322CrossRefGoogle Scholar
  32. 32.
    Codling C, O’Mahony L, Shanahan F et al (2010) A molecular analysis of fecal and mucosal bacterial communities in irritable bowel syndrome. Dig Dis Sci 55:392–397PubMedCrossRefGoogle Scholar
  33. 33.
    Jeffery IB, O’Toole PW, Ohman L et al (2012) An irritable bowel syndrome subtype defined by species-specific alterations in faecal microbiota. Gut 61:997–1006PubMedCrossRefGoogle Scholar
  34. 34.
    Bravo JA, Forsythe P, Chew MV et al (2011) Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve. Proc Natl Acad Sci USA 108:16050–16055PubMedCrossRefGoogle Scholar
  35. 35.
    Chadwick VS, Chen W, Shu D et al (2002) Activation of the mucosal immune system in irritable bowel syndrome. Gastroenterology 122:1778–1783PubMedCrossRefGoogle Scholar
  36. 36.
    Clarke G, Quigley EMM, Cryan JF et al (2009) Irritable bowel syndrome: towards biomarker identification. Trends Mol Med 15:478–489PubMedCrossRefGoogle Scholar
  37. 37.
    Scully P, McKernan DP, Keohane J et al (2010) Plasma cytokine profiles in females with irritable bowel syndrome and extra-intestinal co-morbidity. Am J Gastroenterol 105:2235–2243PubMedCrossRefGoogle Scholar
  38. 38.
    Brint EK, MacSharry J, Fanning A et al (2011) Differential expression of toll-like receptors in patients with irritable bowel syndrome. Am J Gastroenterol 106:329–336PubMedCrossRefGoogle Scholar
  39. 39.
    McKernan DP, Gaszner G, Quigley EM et al (2011) Altered peripheral toll-like receptor responses in irritable bowel syndrome. Aliment Pharmacol Ther 33:1045–1052PubMedCrossRefGoogle Scholar
  40. 40.
    Chang L, Adeyemo M, Karagiannides I et al (2012) Serum and colonic mucosal immune markers in irritable bowel syndrome. Am J Gastroenterol 107:262–272PubMedCrossRefGoogle Scholar
  41. 41.
    Keohane J, O’Mahony C, O’Mahony L et al (2012) IBS and IBD. Irritable bowel syndrome (IBS)-type symptoms in patients with inflammatory bowel disease (IBD): A real association or reflection of occult inflammation? Am J Gastroenterol 105:1789–1794CrossRefGoogle Scholar
  42. 42.
    Quigley EMM, Shanahan F (2010) Irritable bowel syndrome and inflammatory bowel disease: is there an overlap? Pract Gastroenterol 34:32–37Google Scholar
  43. 43.
    Quigley EM, Bernstein CN (2012) Editorial: “irritable bowel symptoms” in inflammatory bowel disease: diagnostic uncertainty meets pathological reality. Am J Gastroenterol 107:1483–1485PubMedCrossRefGoogle Scholar
  44. 44.
    O’Leary C, Wieneke P, Buckley S et al (2002) Coeliac disease and irritable bowel-type symptoms. Am J Gastroenterol 97:1463–1467PubMedCrossRefGoogle Scholar
  45. 45.
    O’Leary C, Quigley EMM (2003) Small bowel bacterial overgrowth, coeliac disease, and IBS: what are the associations? Am J Gastroenterol 98:720–722PubMedCrossRefGoogle Scholar
  46. 46.
    Hayes P, Corish C, O’Mahony E, et al. A dietary survey of patients with irritable bowel syndrome. (submitted)Google Scholar
  47. 47.
    Quigley EMM, Morcos A, Dinan T (2009) Irritable bowel syndrome—role of food in pathogenesis and management. J Dig Dis 10:237–246PubMedCrossRefGoogle Scholar

Copyright information

© Royal Academy of Medicine in Ireland 2012

Authors and Affiliations

  1. 1.Department of Medicine, Alimentary Pharmbiotic CentreUniversity College Cork, Cork University HospitalCorkIreland

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