Grains and gastrointestinal symptoms

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Background

• There are myriad blog posts and “expert” opinions on gluten and on its possible detrimental role in non-celiac disorders

• In these opinions the role of fermentable carbohydrates (FODMAPs) and insoluble bran is often dismissed

• On the other, medical doctors and even gastroenterologists have been slow and reluctant to recognise the role of gluten in non-celiac disorders

• What does the evidence say about grains and gastrointestinal symptoms?

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Gluten free diet reduces bowel movements (diarrhoea) in people with sensitive stomach and diarrhoea (IBS-D)

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Vazquez-Roque MI, et al. . Association of HLA-DQ gene with bowel transit, barrier function, and inflammation in irritable bowel syndrome with diarrhea. Am J Physiol Gastrointest Liver Physiol. 2012 Dec 1;303(11):G1262

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Gastrointestinal symptoms can be caused by at least 3 factors of gluten containing grains

• Fermentable carbohydrates , ie. FODMAPs are shown to cause gastrointestinal symptoms in irritable bowel syndrome

• Wheat bran can cause bloating and pain in irritable bowel syndrome (even if helps in constipation)

• Gluten can cause symptoms in a fragment of patients. Non-celiac gluten sensitivity is recognised as own disease entity

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1. Fermentable carbohydrates cause bowel symptoms

The FODMAP story

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FODMAP*

Galactans

Oligosaccharides

Inulin GOS*

RaffinoseFructans

FOS*

Disaccharides

Lactose

Monosaccharides

Fructose Polyols

Isomalt

Maltitol

Lactitol

Xylitol

(Lactulose) Mannitol

*) FOS= Fructo-oligosaccharide*) GOS= Galacto-oligosaccharide

Sorbitol

FODMAP: Fermentable oligosaccharides, disaccharides, monosaccharides and polyols

Jacqueline S. Barrett and Peter R. Gibson Fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) and nonallergic food intolerance: FODMAPs or food chemicals? Ther Adv Gastroenterol(2012) 0(0) 1–8

Fermentable carbohydrates

• Some of them (inulin, fructo-oligosaccharides and galacto-oligosacchariedes) can be classified as soluble fiber

• Those with short chains undergo rapid and extensive fermentation in colon which causes bloating, gas formation, water retention, urge to defecate and diarrhea (or constipation in some cases)– These are called as FODMAPs

• Those with longer chains are less likely to cause extensive symptoms (still can cause minor symptoms)– Resistant starch, beta-glucan, pectin, gums & polydextrose

FODMAPs are proven cause of GI symptoms in randomized trials

• Several randomized trials have been done in humans with sensitive bowel (irritable bowel syndrome)

• The results of these randomized trials are coherent: ” … confirms the fermentative nature of the short-chain carbohydrates and their role in the induction of bloating, distension, abdominal pain and excessive flatus”

Jacqueline S. Barrett and Peter R. Gibson Fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) and nonallergic food intolerance: FODMAPs or food chemicals? Ther Adv Gastroenterol(2012) 0(0) 1–8

Main sources of FODMAPs

Jacqueline S. Barrett and Peter R. GibsonFermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) and nonallergic food intolerance: FODMAPs or food chemicals? Ther Adv Gastroenterol(2012) 0(0) 1–8

In US wheat is a key source of inulin and FOS

• Oligosaccharides inulin and FOS are major causes of GI symptoms in irritable bowel syndrome

• Wheat is a key source of fructans in American and Western diets

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Moshfegh AJ et al. Presence of Inulin and Oligofructose in the Diets of Americans. J. Nutr. 129: 1407S–1411S, 1999

Intake of FOS & inulin

2. Wheat bran may cause GI symptoms in persons with

sensitive bowelInsoluble fiber, such as cellulose in bran can

cause bowel symptoms.

Wheat and rye brans are are also high in FODMAPs

www.pronutritionist.net11

Wheat bran causes symptoms

• In an American randomized trial wheat bran increased abdominal bloating (30 g/d) and did not ease any IBS-related symptom

• In a German randomized trial psyllium (10 g/d) relived bloating ,where as wheat bran (21 g/d) worsened bloating in two weeks’ follow up

• 12 g grams of wheat bran daily was equally effective as placebo in global score of IBS symptoms but increased wind and bloating in a 4 week randomized trial

• Not all randomized trials have shown deleterious effects in sensitive bowel

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Hebden JM et al. Abnormalities of GI transit in bloated irritable bowel syndrome: effect of bran on transit and symptoms. Am J Gastroenterol. 2002 Sep;97(9):2315-20.

Effectiveness of plantago seed husks in comparison with wheat brain on stool frequency and manifestations of irritable colon syndrome with constipation. Med Klin (Munich). 1994 Dec 15;89(12):645-51.

Hotz J, Plein K.Snook J, Shepherd HA. Bran supplementation in the treatment of irritable bowel syndrome. Aliment Pharmacol Ther. 1994 Oct;8(5):511-4.

Wheat and rye brans are also rich sources of inulin and fructo-oligosaccharide (=fructans)

• Wheat, barley and especially rye are rich in fructans but oats is low

• Wheat is also rich in cellulose and and lignin, insoluble fiber components

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Fructans = inulin and fructo-oligosaccharide (FOS)

Frølich W, Aman P, Tetens I. Whole grain foods and health – a Scandinavian perspective. Food Nutr Res. 2013;57

3. Gluten in wheat and other grains may cause symptoms

Work by Biesiekierski Jessica et a. (Melbourne, Australia)

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Gluten caused bowel symptoms in a highly selected population

• A highly selective sample of patients with subjective feeling of gluten intolerance was exposed to blinded gluten challenge

• 60 % of patients reported improvement in symptoms

• Symptoms didn’t improve in 32 % patients

• The test was done on purified gluten (no extra FODMAPs and bran on top of gluten)

www.pronutritionist.net15

Biesiekierski et al. Gluten Causes Gastrointestinal Symptoms in Subjects Without Celiac Disease: A Double-Blind Randomized Placebo-Controlled Trial. Am J Gastroenterol. 2011 Mar;106(3):508-14

Wheat challenge in a highly selected population

• 30 % IBS patients with subjective wheat sensitivity actually show gluten sensitivity in blinded wheat challenge test (12 g/d)

• In those who proved to be wheat intolerant, a dramatic increase in pain, bloating and stool consistency was observed during wheat period

• Bran & FODMAPs may contribute to symptoms as they were not controlled in this trial

www.pronutritionist.net16

Changes in symptom severity over baseline during the double-blind placebo-controlled wheat challenge: 2 weeks on wheat-containing diet and 2 weeks on placebo.

Carroccio A et al. Non-Celiac Wheat Sensitivity Diagnosed by Double-Blind Placebo-Controlled Challenge: Exploring a New Clinical Entity, Am J Gastroenterol. 2012 Jul 24. doi: 10.1038/ajg.2012.236.

Conclusions

• FODMAPs do cause gastro-intestinal symptoms in patients with sensitive stomach (irritable bowel syndrome).

• Wheat bran may cause bloating and pain in some occasions

• Gluten can cause bowel symptoms in a fragment of patients

• Prevalence of wheat and gluten sensitive in general population is not known. Estimations are basing on highly selected populations

• Oats is more or less devoid of FODMAPs, insoluable fiber and gluten, and is therefore better tolerated

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Top 3 readings

• Jacqueline S. Barrett and Peter R. Gibson Fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) and nonallergic food intolerance: FODMAPs or food chemicals? Ther Adv Gastroenterol (2012) 0(0) 1–8, open access

• Grabitske H & Slavin J. Low-Digestible Carbohydrates in Practice. J Am Diet Assoc. 2008;108:1677-1681

• Sapone et al. Proposed new nomenclature and classification of gluten-related disorders. BMC Medicine 2012, 10:13

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Welcome aboard

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http://www.pronutritionistblog.com http://www.pronutritionist.net

Reijo Laatikainen, Authorized Nutritionist, MBA,Dietitian

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