It is not uncommon to see patients who have typical symptoms of celiac disease who seem to respond to a gluten-free diet but have negative workup for celiac disease. These patients are said to have nonceliac gluten sensitivity (NCGS), which is characterized by irritable bowel-type symptoms after the ingestion of gluten, improvement after gluten withdrawal from the diet, and negative celiac serologies/biopsies. they can have both intestinal sx (diarrhea, abd discomfort/pain, bloating, flatulence) and extra-abdominal ones (headache, lethargy, poor concentration, ataxia, oral ulceration). Additionally (and previously unknown to me), there are some food items which can also cause these symptoms, called FODMAPs (fermentable, oligo-, di-, monosaccharides and polyols) which are poorly absorbed short-chain carbohydrtates. Presumably, FODMAPs lead to luminal gut distension via osmotic effects and gas production from bacterial fermentation in the gut. A small Australian study was done with a double-blind cross-over methodology of 37 patients with NCGS meeting the criteria for IBS (subjects aged 21-64, 6 men, fulfilling Rome III criteria), continued on their gluten-free diet but also given a 2-week diet of reduced FODMAPs, then randomly placed on diets with high-gluten (16g/d), low-gluten (2 g/d) or control (16 g whey protein isolate/d), with a washout period of 2 weeks, then crossed over to the other diets (see http://dx.doi.org/10.1053/j.gastro.2013.04.051). results:
–several of the patients who stated that they were gluten-responsive did have mild to moderate symptoms on a gluten-free diet, with at least 50% of the patients showing significant improvement on the low FODMAP diet during the run-in period of the study, with decrease in both GI symptoms and fatigue (see their figure 1)
–subsequent addition of the high gluten, low-gluten, or control diet was associated equally with worsening of their symptoms. only 8% had gluten-specific effects. 30% had a significant symptom response to the placebo diet (nocebo effect: patients who have symptoms on placebo meds — i will send around again an interesting article on nocebo effect)
–22 subjects returned 8-17 months later for a 3-day rechallenge trial, already on gluten-free diet, then given FODMAPs reduced diet and additionally elimination of other putative symptom triggers in some patients (salicylates, amines, MSG, and preservatives benzoates, priopionate, sultfites, nitrites, and sorbic acid, as well as added antioxidants and food colors). finding — no gluten-specific differences in response to the addition of gluten vs placebo to the meals. of note, in both of these studies there was a consistent difference by the order of the trial: the first intervention induced more symptoms independent of what the intervention was…
so…. what are these things they call FODMAPs??? there is a good website with a one-page handout for patients (and for us) at http://stanfordhospital.org/digestivehealth/nutrition/DH-Low-FODMAP-Diet-Handout.pdf. basically,
–fructose (honey, fruit, high fructose cornsyrup (HFCS)
–lactose
–fructans (wheat, onion, garlic)
–galactans (beans, lentils, legumes such as soy)
–polyols (sweeteners containing sorbitol, mannitol, xylitol; fruits such as avocado, apricots, cherries, nectarines, peaches, plums)
therefore, you may ask, what can one eat???
–meat, poultry, eggs, fish
–dairy — lactose-free, or small amounts of cream cheese, 1/2 and 1/2, hard cheeses, sherbet
–grains — gluten-free grains, (ie, no wheat)
–fruits — bananas, berries, cantaloupe, grapes, grapefruit, melons, kiwi, lemon, lime
–veges — bamboo shoots, bell peppers, cukes, carrots, celery, corn, eggplant, lettuce, potatoes, squash, tomatoes, zukes
–beverages — none with HFCS, but other fruit/vege juices (1/2 cup at a time), coffee, tea
–seasonings — most spices and herbs. not garlic, honey, onions, molasses, jams, jellies, coconut
bottom line: from my experience, i think it is pretty common for patients to have abdominal bloating, pain, etc. my first approach is to give fiber, make sure bowel movements are regular and soft. but symptoms may well persist. sometimes low gluten diet works in spite of negative workup for celiac dz. and, if so, that’s an easier solution than the above FODMAPs diet. but i will now try using this diet if the patient continues to have symptoms in spite of regular bowel movements and nonresponse to low gluten diet.
geoff