Gluten, FODMAP or gut microbiota: who’s guilty?

Patients with a diagnosis excluding major pathologies (such as colon-rectum cancer, celiac disease, Crohn's disease) may nevertheless suffer from symptoms such as diarrohea, poor digestion, stomach bloating, dyspepsia, as well as from weariness, headache and impaired ability to concentrate.

These patients are referred to as suffering from irritable bowel syndrome (IBS), a condition that does not identify an organic disease, rather a so-called functional syndrome. The doctors say more or less: “You’ve got nothing terrible, learn to live with it”.

On the contrary, diet, together with a good regulation of gut microbiome, can play a crucial role in solving such problems.

Patients with IBS often benefit from a gluten-free diet; for this reason they are labeled with a diagnosis of Non-Celiac Gluten Sensitivity (NCGS).

But gluten is not always the only cause of these problems. Gastrointestinal problems are more often determined by FODMAP. As the acronym states, FODMAP is Fermentable, Oligo-, Di-, Mono-saccharides And Polyols, not digested and poorly absorbed by the small intestine; they pass into the colon and here the resident bacteria make them ferment. The fermentation drags water to the intestine, thus provoking diarrohea and stomach bloating. Among FODMAP we can count fructose, lactose, galactans and polyols, that can be found in many different foods. Fructans, along with gluten, are found in wheat as well as in many fruits and vegetables.

For this reason, gluten sensitivity is a pathology often difficult to discern from low tolerance to FODMAP; non-celiac gluten sensitivity can be considered a pathology with a multi-factorial etiology, where low tolerance to gluten surely plays a role, but where FODMAP and altered microbiome are also important.

Did you know?

• Apples are rich in FODMAP such as fructose and sorbitol; therefore, it is not always true that “an apple a day keeps the doctor away”!
• Diets low in FODMAP should not be followed for more than 6-8 weeks; after this time lapse, foods containing FODMAP should be reintroduced with the help of an expert nutritionist.
• The so-called Mediterranean diet is highly beneficial and strongly compatible with a diet low on FODMAP.

References

1. Gibson PR, Shepherd SJ. Evidence-based dietary management of functional gastrointestinal symptoms: The FODMAP approach. J Gastroenterol Hepatol. 2010 Feb;25(2):252-8.
2. Barrett JS, Gearry RB, Muir JG, Irving PM, Rose R, Rosella O, Haines ML, Shepherd SJ, Gibson PR. Dietary poorly absorbed, short-chain carbohydrates increase delivery of water and fermentable substrates to the proximal colon. Aliment Pharmacol Ther. 2010 Apr;31(8):874-82.
3. Dolan R, Chey WD, Eswaran S. The role of diet in the management of irritable bowel syndrome: a focus on FODMAPs. Expert Rev Gastroenterol Hepatol. 2018 May 18:1-9.
4. Kakodkar S, Mutlu EA. Diet as a Therapeutic Option for Adult Inflammatory Bowel Disease. Gastroenterol Clin North Am. 2017 Dec;46(4):745-767. Eswaran S, Farida JP, Green J, Miller JD, Chey WD. Nutrition in the management of gastrointestinal diseases and disorders: the evidence for the low FODMAP diet. Curr Opin Pharmacol. 2017 Dec;37:151-157.
5. Skodje GI, Sarna VK, Minelle IH, Rolfsen KL, Muir JG, Gibson PR, Veierød MB, Henriksen C, Lundin KEA. Fructan, Rather Than Gluten, Induces Symptoms in Patients With Self-Reported Non-Celiac Gluten Sensitivity. Gastroenterology. 2018 Feb;154(3):529-539.e2.
6. Dieterich W, Schuppan D, Schink M, Schwappacher R, Wirtz S, Agaimy A, Neurath MF, Zopf Y. Influence of low FODMAP and gluten-free diets on disease activity and intestinal microbiota in patients with non-celiac gluten sensitivity. Clin Nutr. 2018 Apr 4. pii: S0261-5614(18)30129-8.