Wheat Intolerance Syndrome?

Even though we’ve lived in our house for many years, some of our neighbors refer to our house as the ‘Walden’ house; the Waldens lived here for a long time before we did. Probably when we move, our neighbors will call our present home the “Hochman” house, regardless of who resides there.

I think nomenclature in medicine has a similar reluctance to adopt new terms.  A recent medical progress report (Guandalini S, Polanco I. J Pediatr 2015; 166: 805-10) suggests dropping the term “Nonceliac gluten sensitivity” (NCGS) in favor of “Wheat Intolerance Syndrome.”

It’s probably a good idea and their arguments are sound. Two key points:

  • “There is no proof that gluten is causing NCGS.”
  • It is likely that the majority of patients considered NCGS have not even eliminated celiac disease before instituting a gluten-free diet.

With regard to the first point, the authors note that recent studies have suggested that a “FODMAP” (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) diet is likely the culprit in many cases of so-called NCGS.  They review a pivotal double-blind study (see related blog post: An Unexpected Twist for “Gluten Sensitivity” | gutsandgrowth) there was no role for gluten “at least in these patients with IBS-like NCGS.”  In addition, other studies have demonstrated a strong role for a placebo/nocebo effect of dietary elimination.  “It is quite conceivable that a portion of patients with NCGS, and arguably a substantial one, fall in this category.”

With regard to the second point, it is not a good idea to initiate a gluten-free diet before excluding the diagnosis of celiac disease (hence the prior term: “nonceliac” gluten sensitivity).  A related comment from the authors is that a “Grade 1 [Marsh] intestinal lesion has traditionally been considered of a very low specificity for celiac disease.”  More testing in this circumstance can help determine if celiac disease is the reason, including checking the levels of ϒδ T-cell receptors in intraepithelial lymphocytes (very specific for celiac disease) and/or detection of IgA anti-tissue transglutaminase antibody deposits in intestinal mucosa.

Other pointers:

  • Genetic testing for HLA-DQ2 and/or HLA-DQ8 genotypes (which are nearly 100% in celiac disease) are present in about 40% of NCGS which does not differ from the general population
  • “Estimating the prevalence of NCGS is impossible.”  Estimates have ranged from 0.6% of the U.S. population to as high as 50% according to some websites.

Bottomline: While “Wheat Intolerance Syndrome” works fine for me, I think the term nonceliac gluten sensitivity is going to be around for a while.  Hopefully, more families and care providers will exclude celiac disease before contemplating this label and consider other foods as potential contributors to the symptomatology.

Related Reference: “Coeliac Disease and Noncoeliac Gluten Sensitivity” Meijer CR, Shamir R, Mearin ML. JPGN 2015; 60: 429-32.  This reference covers much of the same territory.  The Table 1 in this article nicely summarizes the relevant literature/studies from 2008-2014.

Related blog posts:

 

What to make of FODMAPs

Consumption of FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) may trigger irritable bowel syndrome (IBS) symptoms.  Some research indicates that a diet low on FODMAPs may be beneficial (J Hum Nutr Diet 2011; 24: 487-95).  This study tried to assess whether a low FODMAPs diet which had been reported from a single center in Australia would be effective for IBS.

In this study, consecutive patients with IBS were divided into two groups.  39 received standard dietary advice based on UK National Institute for Health and Clinical Excellence (NICE) guidelines.  43 patients were placed on a low FODMAP dietary advice.  Patients were selected into each group consecutively (not randomized). This study reported a 76% satisfactory symptom response in the FODMAP group vs a 54% response in the control group (p=0.038).  Overall, 86% of FODMAP group had improved composite score compared with 49% of standard treatment group. Specific improvements were noted in bloating, abdominal pain, and flatulence.  The average age of the study population was 38 and 71% were females.  60% had diarrhea-predominant IBS.

NICE guidelines for IBS:

  • Healthy eating principles: regular eating, taking time to eat
  • Limit high fat foods and fizzy drinks
  • Limit insoluble fiber for diarrhea and gradually increase for constipation
  • Limit sugar-free sweets and foods with sorbitol
  • Limit fruit to 3 portions/day
  • Avoiding ‘resistant’ starch may be useful (eg. sweetcorn, green bananas, part-baked and reheated bread)
  • Addition of oats and linseeds may be helpful

Low FODMAP diet

  • Reduce high fructan foods (eg wheat and onion)
  • Reduction in high galactooligosaccharide foods (eg chickpeas, lentils)
  • Reduce high polyol foods and polyol-sweetened sources.  Replace with suitable fruits and vegetables
  • In patients with lactose malabsorption, reduce high lactose foods (eg milk, yoghurt) to smaller volumes or substitute lactose-free products
  • In those with fructose malabsorption, decrease excess fructose

Of course, reading the author’s description of a low FODMAP diet is confusing.  Translation:

Include more bananas, blueberries, lettuce, potatoes, gluten-free breads or cereals, rice, oats, hard cheeses, lactose-free milk, sugar, molasses, and artificial sweeteners that do not end in “ol.”

Avoid/eliminate apples, pears, canned fruits in natural juices, high-fructose corn syrup, cows’ milk (due to lactose), soft cheese, broccoli, cabbage, pasta, bread, baked goods from wheat/rye, mushrooms, and sweeteners like sorbitol or others that end in “ol.”

Since this diet has attracted more widespread attention, basic familiarity is important for all physicians who treat IBS.  A useful resource to explain this diet is the Wall Street Journal:

http://online.wsj.com/article/SB10001424052970204554204577023880581820726.html

This link has a good table illustrating the recommended dietary choices.

Whether FODMAPs will be superior to other dietary advice for IBS is still uncertain.  Though, given the limited number of effective treatments for IBS, this small study is a promising development.

Additional references:

  • -Clin Gastro & Hep 2009; 7: 706. n=17. 13 responded to very low carb diet (<20g/day)
  • -Clin Gastro & Hep 2008; 6: 765. Dietary triggers for IBS include fructose/fructans: honey, high fructose corn syrup, wheat, fruits.
  • -IBD 2006; 13: 91. Dietary guidelines for IBS.
  • -Clin Gastro Hepatol 2005; 10: 992-996. Obesity increases IBS symptoms; diet with low fat, high fruit/fiber have fewer symptoms
  • -Gut 2004; 53: 1459-1464. Food elimination based on IgG antibodies. Patients did better on diet with implicated foods than with control diet (diet was blinded/randomized).
  • -Am J Gastro 2011; 106: 508-514. randomized, double-blind trial showing efficacy of GFD for non-celiacs.  60% vs 32& placebo response.
  • -Nutr Clin Pract. 2011;26:294-299.  GFD for non-celiacs.
  • -Gastroenterology 2011; 141: 1941./Am J Gastro 2011; 106: 915.  Exercise improves IBS symptoms.