Home » Blog » Special Diets » Fodmap Diet For SIBO: Find Out Everything

Fodmap Diet For SIBO: Find Out Everything

Are you trying to follow a fodmap diet for SIBO? You might be wondering what exactly a fodmap is. And what is SIBO anyway?

In this post, you will learn about fodmap foods, how to follow the diet, and how to get your life back to normal afterwards. 

Get the scoop now!

What Is SIBO?

SIBO stands for Small Intestinal Bacterial Overgrowth. This is exactly what it sounds like – too many microbes are growing in your small intestine (1). 

You might be saying “Wait a minute, I thought it was good to have a lot of microbes in my gut.” Well, that is true, but the right place for those microbes is lower down in the large intestine. 

The small intestine is where you absorb most of your nutrients. This is the place for enzymes, not microbes, to break down your foods. 

When you get a lot of microbes growing in your small intestine, they create gas, which causes discomfort, pain and bloating. 

How Do You Know If You Have SIBO?

SIBO is a medical diagnosis, and is made by a doctor. It is based on a breath test. First, you get a baseline sample of your breath by blowing into a collection bag or tube. 

Then, you drink a solution that contains some simple sugars. If you have bacteria in your small intestine, they will break down those sugars. You collect breath samples again at regular time intervals. The results will show whether your breath contains gasses produced by bacteria.

A lot of bacteria in your small intestine results in high levels of gasses like hydrogen or methane on the SIBO test. Your treatment depends on the type of gas that is produced. Often a part of that treatment is following a low fodmap diet for a limited time.

The low fodmap diet is a type of elimination diet that removes the foods that feed those bacteria.

What are Fodmap Foods?

FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols (2). 

Saccharide is just another name for a sugar molecule.

Monosaccharides have one sugar molecule, like fructose. Disaccharides have two sugar molecules linked together, like lactose. Oligosaccharides contain short chains of sugar molecules, usually 2-6 linked together.

A polyol is a sugar with several alcohol molecules (OH) attached. I will talk more about polyols later in this article.

Every carbohydrate molecule is not a fodmap. Fodmaps are more difficult to digest. The gut bacteria can ferment them more easily. This is especially true when those bacteria are living higher up in your gut, in the small intestine.

The Five Types of Fodmap Carbohydrates

One way to group fodmap foods is by the type of sugar they contain. They can fall into one of five categories. 


Fructose is a monosaccharide, meaning it has only one sugar molecule in its structure. Most of your sweet tasting foods are going to fall into this category. It includes things like high fructose corn syrup, honey, agave, corn syrup, watermelon, fruit juices and large amounts of any fruit.


Lactose is a disaccharide, which has two sugar molecules linked together. This form of sugar is found in milk and milk products. Milk, all types of cheese, yogurt, ice cream and anything made with milk can contain lactose.


A fructan is an oligosaccharide, made up of more than two sugar molecules. Fructans are made up of mostly fructose molecules. Many vegetables like beets, broccoli, cabbage, onions, peas, scallions and asparagus fall into this category. Pistachios, cashews, almonds, rye and wheat also contain fructans.


Galactans are oligosaccharides containing a chain of galactose molecules. All kinds of beans, lentil and legumes contain galactans. You can also find cassava, cabbage, beets and artichokes in this category.


Polyols can be mono or disaccharides. They are sometimes called sugar alcohols because of their unique chemical structure. All the sweeteners ending in “ol” are polyols. This includes sorbitol, xylitol, and mannitol, the polyol in mushrooms.. 

There are many other fruits and vegetables that contain polyols. A few of them are sweet potato, pears, plums, prunes, coconut, avocado and almonds.

Following a Low Fodmap Diet

You are getting the idea that there are quite a few foods that contain fodmaps. How can you eliminate that many foods from your diet? 

The Elimination Phase

First of all, the fodmap diet is temporary. If you are sensitive to fodmaps, you should start seeing results from the diet within two weeks. After 4 weeks you should be able to start reintroducing these foods back to your meals.

It is overwhelming to suddenly be put on an eating plan where you are not allowed to eat the foods you are used to having every day. I highly recommend working with someone like a Certified Nutrition Specialist who can help you navigate through this diet. 

I promise that there are resources, apps and meal plans that can make this whole experience easier for you. Working with a guide will set you up for success. You can get through the process in a shorter amount of time, and work on getting back to your new normal, without bloating and gas.

Adding Foods Back

When you have eliminated fodmap foods for several weeks and your symptoms are significantly better, it is time to add foods back. Why would we add back the foods that caused the problem in the first place?

The good news is that most people are not sensitive to the entire list of fodmap foods. You might not be digesting lactose, but beans or mushrooms are no issue for you. Or perhaps you can’t break down the galactan molecules in beans but you are fine with absorbing fructose.

You will reintroduce foods by categories to identify which ones are troublesome for you. So for instance, you might start by adding back foods from the lactose category first. Pick a couple foods from that category, like maybe cottage cheese, yogurt and sour cream. 

You will start with a small amount of these foods and increase the amount over a three day period. Do your symptoms reappear? If they do not, you know lactose is not the problem.

After one category is complete, you will take a three day rest, and then begin again with another category. 

As you can see, the process of adding back foods can take a month or longer, but all the time you are able to expand your selection of foods that you eat.

Finding the Root Cause

You should not have to go through the rest of your life avoiding fodmap foods. Let’s find out how you can get back to a normal and healthy gut.

There is a reason why you were not able to digest and absorb these foods in the first place. You might not have the enzymes necessary to break down this type of carbs. You might also have bacteria living in your small intestine, where they really don’t belong.

Low stomach acid, poor gut motility or a damaged gut lining can be the cause. Let’s take a closer look at these three possible reasons why someone cannot tolerate fodmap foods (3).

Low Stomach Acid

Stomach acid is extremely strong. It is strong enough to burn your skin. Yet it plays a vital role in digestion. 

Stomach acid breaks down the molecules in food, especially the tough to digest fats and proteins. It is also is the first line of defense for your immune system.

Everyday you take in a load of different microbes through your mouth. Stomach acid is able to neutralize most of these threats and keep you from getting sick.

Sometimes you get bacteria living in your stomach and small intestine that is not necessarily bad, it is just in the wrong place. It is supposed to be living further down your digestive tract, in the large intestine.

Stomach acid keeps bacteria levels in the upper part of your digestive tract from growing out of control.

Find out how to check your own stomach acid at home.

Poor Gut Motility

Gut motility means the movement of muscles in the digestive tract. In a healthy digestive tract, the stomach empties an hour or two after eating. Food moves steadily through the small intestine to the colon. It is eliminated within 24 hours.  

If food is hanging out in the stomach and small intestine for too long, it allows bacteria to feed and grow. This bacterial overgrowth interferes with absorption of nutrients and causes bloating and gas. 

Damaged Gut Lining

The cells that line the gut produce many of the enzymes needed to break down sugars, like lactose. Damaged cells will not produce the enzymes. You might find you can’t eat certain foods without gas, bloating and pain.

Gut cells can be damaged by things like chemicals in the diet, medications, conditions like celiac disease or ulcerative colitis, and excessive use of alcohol. You can begin making some of these enzymes again if you heal your gut lining.

Final Thoughts

Some people have trouble digesting and absorbing the types of saccharides in fodmap foods. Bacteria in the digestive tract ferment these foods and cause bloating, gas and abdominal distress.

You might be on a low fodmap diet if you have extreme bloating or SIBO.

This is a temporary diet which should only last about 4 weeks. After this you start adding back foods to figure out which ones are causing your symptoms. 

There is a reason why you are unable to tolerate these foods in the first place. This could be something like low stomach acid, poor gut motility or a damaged gut lining.

As a nutritionist specializing in digestive health, I can help you to organize and navigate through the fodmap diet. I can also help you to figure out the root cause of your condition. If you can fix the root cause, you might be able to eat all of these foods again. 

You don’t have to forgo desserts on your low fodmap diet. I am happy to share Ten Desserts for your Low Fodmap Meals! Just click on the link below to grab your copy.

3 thoughts on “Fodmap Diet For SIBO: Find Out Everything”

  1. Pingback: Low Fodmap Ice Cream [Eat The Real Stuff] - The Whole Story LLC

  2. Pingback: Low FODMAP Restaurants: What You Can Eat

  3. Pingback: Low FODMAP Pasta: What Are Your Choices? -

Leave a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Scroll to Top