Article

Research Brief: IBS, Low FODMAP Diet & The Gut Microbiome

Published on Thursday, March 03, 2022
by Emily Hamm

Health & Wellness

Did you know your gut microbiome may affect your response to a Low FODMAP diet?

Current research recommends people with Irritable Bowel Syndrome (IBS) trial a Low FODMAP diet to find which foods are possibly causing their symptoms (i.e. diarrhea, bloating, gas, constipation, etc.). In a review article from 2017, it was found that a Low FODMAP diet has proven beneficial to help alleviate IBS symptoms in approximately 50-80% of people diagnosed.

While a Low FODMAP diet can help improve symptoms of IBS, there is still a lot that is unknown about how the Low FODMAP diet works and how it affects your body long-term; specifically how it affects the gut microbiome.

The gut microbiome is the colony of bacteria lining your gastrointestinal tract which impacts your body’s immunity, metabolism, and cognition. The types and amounts of bacteria present are influenced by diet, medication use, supplement use, and disease.

Over the past several years, there has been more research conducted to discover the impact of the gut microbiome on IBS. Researchers want to know more about our gut and how specific bacteria affect our gut health.

In people diagnosed with IBS…

Are there more unhealthy bacteria?
Are there specific bacteria that are beneficial in helping reduce IBS symptoms?
Are there good bacteria that are missing in people diagnosed with IBS?

So many questions which hopefully will lead to more answers that will benefit you and me.

A recent research study conducted by Vervier et al 2021 found that people diagnosed with IBS who have certain kinds of bacteria in their gut are more likely to respond favorably to a Low FODMAP diet. This discovery could lead to more precise nutrition interventions by helping to identify people who will best benefit from the Low FODMAP diet. This new research will also provide more insight into how the Low FODMAP diet works in our bodies.

In the study mentioned above, researchers compared the bacterial gut profiles of people diagnosed with IBS and healthy individuals. They found that in people diagnosed with IBS, some had similar levels of healthy bacteria in their gut compared to healthy individuals while others had more harmful gut bacteria.

The people who had more harmful gut bacteria had a more favorable response to a Low FODMAP diet compared to individuals diagnosed with IBS who had similar levels of healthy bacteria. It was important to note that individuals participating in this study were not taking probiotics and were not taking certain medications that could impact the bacterial profile of their gut.

Examples of unhealthy/harmful bacteria found in higher amounts in some IBS patients:

C. difficile
P. sordellii
C. perfringens
Faecalicatena gnavus

What does this mean? Well if you are diagnosed with IBS it might be worthwhile to find out the bacterial profile in your gut. Your doctor might be able to test this by taking a stool sample. If you have more of unhealthy gut bacteria you might have a higher, more favorable response to a Low FODMAP diet.

Of course, there is more research is needed to identify how high FODMAP foods interact with unhealthy gut bacteria and cause those unpleasant IBS symptoms. However, this recent discovery is a promising start that we are moving in a direction that will help practitioners tailor nutrition interventions to help individuals diagnosed with IBS.