FODMAPs and Transitioning to a Plant-Based Diet

BY DR. EMILY ANNE MCDONALD

Are you experiencing a worsening of digestive function after adding more plant diversity to your diet?

Bloating, cramping, diarrhea, constipation, nausea, and increased flatulence and belching are all indications that you might be having trouble digesting certain carbohydrates found in plant foods. 

Cue FODMAPs. FODMAP is the acronym for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. These are poorly absorbed carbohydrates that pass through the small intestine becoming concentrated further down the gastrointestinal (GI) tract in the large intestine, where they can draw water into the intestine causing diarrhea. Microbes in the large intestine can ferment FODMAPS, producing methane, hydrogen, and carbon dioxide causing the sensation of distension, pain, and bloating. Methane gas can also slow down the motility of the GI tract creating an irregular bowel movements alternating between diarrhea and constipation accompanied by bowel distention. 

The most common FODMAPs are carbohydrates such as:

• Oligosaccharides (Fructans, Galactans): examples include asparagus, artichokes, garlic, onions, legumes, wheat, peas, lentils, and beans

• Disaccharides: mainly lactose (mostly in dairy products), maltose, and sucrose

• Monosaccharides: simple sugars such as fructose and glucose found in fruit, honey, and high-fructose corn syrup

• Polyols: found in stone fruits, many sugar-free sweeteners (erythritol, mannitol, sorbitol, and xylitol), and some vegetables like mushrooms.

What is the FODMAP diet?

The low FODMAP diet was developed by researches at the Monash University in Melbourne Australia as a way to improve irritable bowel syndrome symptoms. The App helps you identify which FODMAPs in particular you might be sensitive to and gives guidance for serving sizes to help mitigate symptoms of Irritable Bowel Syndrome (IBS) without having the eliminate the food altogether. 

While their randomized controlled trials have demonstrated the effectiveness of the low FODMAP dietary approach for the short term, there is also evidence that reinforces the importance of training the body to be able to digest the phytonutrient, fiber-rich foods that contain FODMAPs.

FODMAPs are actually prebiotic: they support the expansion of Bifidobacteriaceae and Lactobacillaceae. These bacteria can metabolize FODMAPs to create short-chain fatty acids (SCFAs) that are being studied for their role in promoting healthy immune function and keeping the population of microbes in favor of health promoting species. 

In order to keep our microbial populations healthy, we need to be eating a rich diversity of plant foods, including FODMAPS, which is why the low FODMAP diet is only a temporary fix. By eliminating or reducing, and then slowing reintroducing high FODMAP foods, we can maximize the health benefits plant foods have to offer. 

For additional tips on eating a low-FODMAP diet, check out The Plant Fed Gut. 

For more information about eating in alignment with your microbiome, check out ZOE, a company that is using real-time data to metagenomic research to drive personalized nutrition programs based on microbiome composition. 

The Takeaway

FODMAPs have been implicated in improved health outcomes such as weight loss, lower blood pressure, lower blood glucose levels, lower levels of inflammatory blood markers, and increased circulating levels of certain antioxidants. This is thought to be due to the SCFAs in addition to the indirect effects of healthier microbiome. We beginning to learning just how important the microbes in our gut are in co-regulating our hormones and immune system.