What do apples, onions, hummus, and ice cream have in common? They’re all rich in FODMAPs: a set of short-chain carbohydrates that may trigger the symptoms of IBS or irritable bowel syndrome.
Those pesky symptoms include bloating, gas, cramping, and altered elimination like constipation and/or diarrhea.
FODMAPs is the acronym for a set of fermentable sugars and prebiotic fibers present in a range carbohydrate food. FODMAP stands for “Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols”.
Oligosaccharides include galacto-oligosaccharides and fructans, present in foods such as the gluten containing grains (wheat, barley, and rye), onions, garlic, legumes and select nuts.
Disaccharides include lactose, found in cow’s milk, soft cheeses, and yogurt and sucrose
Monosaccharides include fructose, glucose, and galactose, present in apples, pears, high fructose corn syrup, and honey.
Polyols are the alcohol-based sugars, such as sorbitol, mannitol, xylitol, erythritol; but are also present in some fruits and vegetables, as well as the synthetic sweetener, sucralose.
HOW THE GUT MICROBIOTA COMES INTO PLAY
The gut microbiota ferments these sugars and ‘fibers into gasses (e.g., hydrogen, methane) and short chain fatty acids (e.g., butyric acid), the primary fuel for the epithelial lining of the intestinal tract.
If you have IBS, then an excessive intake of these fermentable carbohydrates can increase small intestinal water volume and gas production, stretching the nerves lining the intestinal wall, leading to visceral hypersensitivity and the cramping pain and watery stools. Nutrient malabsorption and intestinal hyperpermeability often follow.
While fruits, vegetables and beans are loaded with fiber, vitamins, minerals, and phytonutrients, it is their unique carbohydrate profile that may aggravate indigestion and promote bacterial overgrowth.
This is especially true if colonic bacteria have migrated through the ileocecal value to proliferate in the small intestine, creating the condition known as Small Intestinal Bacterial Overgrowth (SIBO). As such, a low FODMAP diet has been used as part of a successful protocol to treat IBS and SIBO.
THE LOW FODMAP DIET – A PROGRESSIVE 3-PHASE PLAN
The low FODMAP diet is a 3-phase diet consisting of a 2–6-week elimination phase to observe for symptom improvement, followed a 6–8-week reintroduction phase to identify contributing foods. A long-term “personalization phase” follows, during which the goal is to maintain symptom improvement on a minimally restrictive diet.
The low FODMAP diet was developed by dietitian, Sue Shepherd, Peter Gibson and their colleagues, at Monash University in Melbourne, Australia to help with the symptoms of IBS.
This research group conducted a controlled, cross-over study of 30 patients with IBS and demonstrated a diet low in FODMAPs effectively reduced functional gastrointestinal symptoms.
“Subjects with IBS had lower overall gastrointestinal symptom scores (22.8; 95% confidence interval, 16.7-28.8 mm) while on a diet low in FODMAPs, compared with the Australian diet (44.9; 95% confidence interval, 36.6-53.1 mm; P < .001) and the subjects' habitual diet. Bloating, pain, and passage of wind also were reduced while IBS patients were on the low-FODMAP diet.”
Additionally, in a review article in the journal, Gut, in 2017, researchers Staudacher and Whelan propose “Dietary restriction of short-chain fermentable carbohydrates (the low fermentable oligosaccharide, disaccharide, monosaccharide, and polyol (FODMAP) diet) is now increasingly used in the clinical setting. Initial research evaluating the efficacy of the low FODMAP diet was limited by retrospective study design and lack of comparator groups, but more recently well-designed clinical trials have been published. There are currently at least 10 randomized controlled trials or randomized comparative trials showing the low FODMAP diet leads to clinical response in 50%–80% of patients with IBS, in particular with improvements in bloating, flatulence, diarrhea and global symptoms”.
To help study participants stay committed to a FODMAPs diet, Monash University developed educational materials and the Monash app that rates the fermentability of hundreds of foods using a “fermentability scale” based on lab testing and clinical tolerability of IBS patients.
The Monash app rates each food with a qualitative “traffic light” color system: green foods have low levels of oligosaccharides, fructose, polyols, and lactose, while red light foods are high in one or more of them. It also offers a quantitative assessment of two different portion sizes, guiding the user to determine a dose they might find tolerable.
DISCOVERING WHICH FOODS TRIGGER YOUR SYMPTOMS
When a person with IBS suffers from gas, bloating, cramping or abnormal bowel movements, their task is to discover which of these foods might trigger their symptoms.
Given the uniqueness of our genomes, the gut microbiome, and the environments in which we live, a food that is fine for one person might be problematic for another.
People find they can tolerate certain FODMAPS but can handle little to none of the others without discomfort.
4 RECOMMENDATIONS FOR A SUCCESSFUL OUTCOME
If you are concerned that you have IBS and/or SIBO, seek out a practitioner who has experience working with the low FODMAP diet to successfully resolve your symptoms.
While a low FODMAP diet does not work for everyone, it is now being considered a first line therapy that should be investigated.I would also suggest that you start taking FODMATE™ an innovative enzyme formula designed for short-term use that can help support digestive health, including relief from occasional cramping, bloating, gas, abdominal pain, diarrhea, and constipation that may result from the consumption of high FODMAP foods.
Benefits of FODMATE™:
Digestive enzyme blend helps break down potentially troublesome FODMAPs
Helps overcome occasional digestive issues without the need for a complicated, restrictive diet
Enhances efficacy of low FODMAP diet when greater restrictions are necessary
Promotes continued consumption of nutrient-dense, antioxidant-rich, plant-based foods
Improves restrictive diet compliance while reducing confusion, frustration, and other challenges to quality of life
3. Complicating matters for most people with IBS, is the fact that there are several versions of the FODMAP diet, with some foods on some lists and not on others. This can be confusing and challenging and will require your complete commitment to the process of a food elimination diet and the personalization phase of the FODMAP diet.
4. I also tell my patients to look to cookbooks and other trusted resources as an invaluable support to assist them with adhering to a low FODMAP diet. Here are my top three picks:
The Complete Low FODMAP Cookbook authored by Dr. Sue Sheperd (one of the original Monash University researchers) offers 150 simple, flavorful, and gut friendly recipes to ease the symptoms of IBS and other digestive disorders. Monash University’s website features dozens of low FODMAP recipes at https://www.monashfodmap.com/recipe/
Another take on a low FODMAP diet is provided by Norm Robillard in The Fast Tract Digestion - IBS.
Dr. Alison Siebecker’s site, SIBO Info, offers a multitude of resources for the low FODMAP diet in the treatment of SIBO at https://www.siboinfo.com/dietrecipe-websites.html
NEED FOR CAUTION AND FUTURE RESEARCH
Fiber and phytonutrient-rich foods are among the most nutritious, so completely eliminating them completely is not advisable and in fact, may be detrimental. Evidence is emerging that long-term elimination of these fermentable carbohydrates is accompanied by changes in the gut microbiota and its metabolic output.
In another Australian study, researchers studied 27 patients with IBS using two diets with different FODMAP content, and then crossed over to the other diet after a 21-day washout period.
“The low FODMAP diet was associated with lower absolute abundance of total bacteria, butyrate-producing bacteria, prebiotic bacteria, and A. muciniphila and R. gnavus. Marked lower relative abundances of Clostridium cluster XIVa and A. muciniphila, and a significantly higher abundance of R. torques were also observed.
Finally, bacterial taxonomic diversity of a large cluster of primarily butyrate-producers was greater on the low FODMAP diet. Comparison with faecal microbiota on habitual diet indicated that the low FODMAP intake was associated with reduced absolute abundance of bacteria, but the higher FODMAP intake associated with the typical Australian diet showed evidence of specific stimulation of the growth of bacterial groups with putative health benefits.
The functional significance and health implications of such changes might lead to caution about reducing FODMAP intake in the longer term. Liberalising FODMAP restriction to the level of adequate symptom control should be exercised. The low FODMAP diet should not be recommended for asymptomatic populations.”
Other researchers have investigated the effect of a 4-week low FODMAP diet on stool microbiota in IBS. “Using fluorescence in situ hybridization, the first demonstrated a 50% reduction in FOMAP intake led to a marked 6-fold reduction in relative abundance of Bifidobacteria compared with controls who maintained their habitual diet.” Staudacher, Whelan Gut. 2017:66(8): 1517-1527
Substantial evidence demonstrates clinical efficacy of the low FODMAP diet in IBS, but additional research is needed to fully understand its impact on the GI microbiota and its function.
Future research will focus on identifying the effect of individual FODMAPs on the abundance of various microbial populations, their metabolic outputs, and the long-term consequences of this diet in IBS and other gastrointestinal conditions.
While you are working to manage your IBS, don’t forget that your body needs these fibers, nutrients, and phytonutrients to thrive. These fermentable carbohydrates keep our bodies healthy.
A low FODMAP diet is intended to be progressive, beginning with elimination, reintroduction, and determination of the tolerable quantities of fermentable carbohydrates. Reintroduction of these foods should be attempted to restore diversity of a healthy microbial flora and SCFA production and reduce the need for long-term food restriction in the management of IBS.
References:
1 Halmos, et al. Gastroenterology 2014 Jan;146(1):67-75.e5. doi: 10.1053/j.gastro.2013.09.046.
2 Staudacher, Whelan Gut. 2017;66(8):1517-1527.
3 Halmos, et al Gut. 2015:64(1):93-100