Alternative Applications of the Low FODMAP Diet

The three-phased low FODMAP intervention is strict, requiring reduction of all slowly absorbed or indigestible short-chain carbohydrates (ie. FODMAPs: fermentable oligo-, di-, and monosaccharide and polyols) followed by reintroduction of specific FODMAP groups and portions to learn tolerance levels, followed by a personalization phase to develop the most liberal diet possible that also controls symptoms long-term.

The role of FODMAPs in GI symptoms

Increasingly, the gut microbiota are recognized for their role in the pathogenesis of many GI and non-GI conditions. While the mechanisms behind how gut microbiota influence health are complex and remain to be fully elucidated, emerging research suggests significant differences in the gut microbiota composition between healthy individuals versus those with IBS and/or a range of other GI and non-GI conditions. Intestinal dysbiosis may be present in many conditions and can influence intestinal permeability, contribute to inflammatory reactions and initiate immune responses. In those with visceral hypersensitivity due to dysbiosis, gas production from FODMAP fermentation can lead to increased pain sensation compared to healthy controls [1].

While a low FODMAP diet is intensive, successful implementation may have significant benefits for not only IBS but also a range of other patient profiles. These include breastfeeding mothers of infants with colic, athletes experiencing GI distress, patients with Inflammatory Bowel Disease (IBD) in remission and patients with concurrent IBS and Celiac Disease (CeD), endometriosis or Polycystic Ovary Syndrome (PCOS). For these patients a low FODMAP diet may be a tool to reduce GI symptoms and improve quality of life.

Use of a low FODMAP Diet Beyond IBS

Data shows a low FODMAP diet may be a useful short-term diet intervention in breast-fed infants with colic. Mothers in a crossover feeding study who were first allocated to a low FODMAP diet reported improved symptoms of infantile colic, noted by a 32% reduction in crying-fussiness time (P = 0.03). While the mechanism by which the reduction in FODMAPs affects breastmilk and reduces infant colicky behavior remains unclear, results indicate future research into the action by which maternal dietary habits can influence infant behavior are warranted [2]. 

In addition, 35-45% of quiescent IBD patients also meet the criteria for IBS [4]. A low FODMAP diet or a FODMAP gentle approach has clear clinical relevance for IBD patients with IBS-like symptoms, which often include bloating, constipation, abdominal pain, diarrhea and flatulence. Despite medications to manage inflammation, GI symptoms often persist in IBD even during remission and have a significant impact on quality of life [4]. Carbohydrate malabsorption and a pro-inflammatory dysbiotic microbiota profile may be a mechanism by which diet induces GI symptoms. The high osmotic activity and fermentability of malabsorbed FODMAPs may contribute to symptoms and appears to be noticeably pronounced in Crohn’s disease in particular. Though the body of literature is heterogenous, recent research suggests a low FODMAP diet in IBD patients in remission may help improve GI symptoms [5]. These studies have shown improvements in some specific GI symptoms such as pain and bloating as early as two weeks from the start of a low FODMAP diet, though a placebo response may be at play [6, 7].

Finally, roughly 20-23% of patients with CeD meet criteria for IBS [8]. These patients typically present with dysmotility, visceral hypersensitivity and chronic inflammation, especially prior to implementation of a gluten-free diet (GFD). There is significant evidence to suggest that among those with CeD who exhibit good adherence to a GFD and are adequately nourished, a low FODMAP diet may provide value for symptom management [8].

FODMAPs in Endometriosis & PCOS

Recently, there is also interest in the role FODMAPs may play in other inflammatory and endocrine disorders, such as endometriosis & PCOS. Roughly 20% of those with endometriosis also experience IBS-like symptoms, including abdominal bloating, diarrhea, and/or constipation [9]. This can pose a challenge when trying to diagnose these patients. An estimated one in ten women suffers from endometriosis and those with endometriosis are at two to three times greater risk for IBS than the general population. 

To explore the link between endometriosis and IBS, researchers at Monash University conducted a retrospective analysis to investigate how patients with IBS and endometriosis respond to a low FODMAP diet. The study compared the effect of a low FODMAP diet on women with IBS and endometriosis to those with IBS alone and found that a significantly higher proportion of patients with known endometriosis responded to the diet (P = 0.001). Seventy two percent of women reported a >50% improvement in GI symptoms after four weeks of a low FODMAP diet compared with 49% in those with no endometriosis diagnosis [9]. Still, the low FODMAP diet is highly restrictive and should be reserved for those who do not respond to first line-interventions, such as fiber modulation, caffeine and alcohol reduction and addition of omega-3 fatty acids, among others.

FODMAPs may also play a role in PCOS management due to known alterations in the microbiome and increased intestinal permeability that are often present with PCOS. Those with PCOS are at a two-fold greater risk for IBS, potentially due to heightened visceral sensitivity and altered gut motility [10]. While research on the low FODMAP diet in PCOS is lacking, when IBS symptoms occur in the presence of PCOS FODMAP manipulation may provide benefit. However, there are specific concerns when applying low FODMAP in the PCOS population, such as glycemic management and increased risk for disordered eating. Learn more about considerations when using the low FODMAP diet for those with PCOS in our recent webinar with Desiree Nielson, RD: Beyond IBS: Is there a place for low FODMAP in other conditions? 

Looking Forward

These new applications of the low FODMAP diet point to promising ways FODMAP modulation can help a wide array of patients experiencing GI distress. Still, it is important to consider potential implications of a restrictive diet such as the low FODMAP protocol. The restrictive nature of the diet could lead to social, financial and time burden patients, and may lead to nutritional deficiencies, particularly in fiber, calcium, magnesium, vitamin C, folate and riboflavin. Those with active eating disorders, malnutrition, or a poor capacity to follow the diet are not appropriate candidates for a low FODMAP. First-line interventions, such as achieving adequate fiber, protein and micronutrient intake, should always be trialed first for management of GI symptoms.

Those interested in a less restrictive approach and poor candidates for a low FODMAP diet (such as children, those with existing dietary restrictions, such as pregnancy or other therapeutic diet) may benefit most from a FODMAP gentle approach. The FODMAP gentle restricts just high FODMAP foods that are most commonly triggering, such as beans, wheat, garlic, onion, cauliflower, mushroom, lactose-containing dairy and fruits high in excess fructose. As always, patients should work directly with a Registered Dietitian to identify and implement the diet that is best suited to help them. At the Dr. Schär Institute, we have free tools for HCPs and patients to learn about and implement a low FODMAP diet. In addition, ten of our products are certified low FODMAP by Monash University.