Benefits of the Elemental Diet and Low-FODMAP Diet
Medically reviewed by Emily Dashiell, ND
Two common small intestinal bacterial overgrowth (SIBO) diet treatments include the elemental diet, a type of liquid diet, and the low-FODMAP diet, which focuses on limiting certain types of carbohydrates that are not easy to digest.
Stop the multiplication of “bad” gut bacteria
Correct nutritional deficiencies
No diet is proven to treat SIBO in every patient, but your provider might recommend a diet plan that can help keep the condition from coming back. Your SIBO treatment plan may also include antibiotics and specific treatments for any underlying health condition you have (e.g., Crohn's disease or irritable bowel syndrome).
This article discusses the use of the elemental diet and low-FODMAP diet for SIBO. It covers what to eat and avoid on a SIBO diet.
If you have SIBO, talk to your healthcare provider and/or a registered dietitian before changing your diet to make sure that you are meeting your daily nutritional needs.
How the Elemental Diet Works for SIBO
The elemental diet is a liquid diet or a powder mixed with water. It is often used for people who have trouble digesting food because they have compromised digestive systems.
The diet gets its name because the nutrients are introduced into the body as close to their primary (elemental) form as possible.
The elemental diet has been studied as a possible add-on (adjunct) treatment to antibiotics for the following reasons:
The nutrients in the diet are believed to be wholly absorbed in the first part of the small intestine, which reduces the number of food components that are available to bacteria.
The diet reduces the number of overall gut bacteria, which could mean a reduction in bacteria in the small intestine as well.
The diet may increase the amount of bile that gets released from the gallbladder, which could strengthen the small intestine's cleansing wave and reduce bacteria levels.
The diet may affect the immune cells in the lining of the intestines, which could help clear up bacteria.
What to Eat
The elemental diet is given either as a beverage that you drink or through a feeding tube. The amount of liquid you take in slowly increases over the first few days to reduce side effects like diarrhea or abdominal pain.
Each formulation contains nutrients that are in an easy-to-digest form. Typical formulations for the elemental diet include:
Essential and non-essential amino acids
Vitamins (fat and water-soluble)
A small amount of fat
Different commercial variations of the elemental diet can be purchased online. The powdered mixes contain only essential nutritional ingredients, providing 150 to 300 calories or more. Your healthcare provider can tell you how much you need to get adequate nutrition.
No artificial flavors or colors are added to elemental diet mixes (which are only combined with water). The beverage has a bland taste that many people find unpalatable. Some experts suggest adding ice to give the drink texture, which can make it easier to drink.
The length of time you stay on an elemental diet depends on your symptoms and how well you can stick with the program.
One of the biggest challenges of the elemental diet is giving up solid food:
According to one published report, only about 25% of patients are willing to restrict their nutritional intake to liquid feeding long enough to see results from an elemental diet.
Several studies have shown that compliant patients were able to see results in two to three weeks.
People who cannot take on a complete elemental diet might be able to use a partial essential diet that combines liquid feeding with foods that they are able to tolerate, depending on what their healthcare providers recommend and approve. For some people, this approach might be used for long-term maintenance.
The elemental diet must be used only under medical supervision, as it carries risks.
Do not try a homemade elemental diet formulation. Doing so puts you at risk for significant nutritional deficiencies that could negatively affect your health.
The elemental diet is not to be used at the same time as any antibiotic treatment for SIBO.
Related: Overview of the Elemental Diet
How the Low-FODMAP Diet Works
One of the first-line treatment options for SIBO is a low-FODMAP diet. FODMAPs are a group of carbohydrates that include:
Oligosaccharides (comprised of fructans and galactans)
Disaccharides (milk sugar lactose)
With SIBO, two FODMAP types—lactose and fructose— might be poorly absorbed because there is inflammation along the small intestine lining. In addition, other non-absorbed FODMAPs may get fermented by the bacteria in the small intestine, leading to symptoms like gas and bloating.
Following a diet low in FODMAPs can help some people manage their symptoms, but it does not work for everyone. Some research has suggested that the low-FODMAP approach could be beneficial, but more research is needed to know if the treatment is effective enough to be recommended as a standard therapy for SIBO.
What to Eat
Fructans. Non-digestible fructans are found primarily in wheat, many vegetables, and some food additives, including inulin.
Fructose. Fructose is the sugar in many fruits, honey, and high-fructose corn syrup.
Galactans. Also called galactooligosaccharides (GOS), galactans can be found in legumes, including beans, chickpeas, and lentils.
Lactose. Lactose is the sugar in milk and other dairy products.
Polyols. Sugar alcohols with names that typically end in "-ol” are found naturally in some fruits (like blackberries) and vegetables (such as cauliflower and mushrooms) and are often used as artificial sweeteners.
Almost every food group has options that are high in FODMAPs as well as some that are low FODMAP.
Vegetables: eggplant, green beans, cucumber, lettuce tomato, zucchini
Fruits: cantaloupe, grapes, kiwi, strawberries
Dairy: feta, camembert, hard cheeses, almond milk, soy milk
Protein: eggs, firm tofu, tempeh, seafood
Grains: corn flakes, oats, rice cakes, corn pasta, barley-free breads
Sweets: dark chocolate, maple syrup, table sugar
Nuts and seeds: peanuts, macadamia nuts, sunflower seeds
Vegetables: asparagus, cauliflower, peas, mushrooms, onions
Fruits: apples, cherries, dried fruit, peaches, watermelon
Dairy: cow's milk, evaporated milk, ice cream, yogurt
Protein: most legumes, marinated meats, some processed meats
Grains: wheat, rye, and barley-based breads and snacks
Sweets: honey, high-fructose corn syrup, sugar-free treats
Nuts and seeds: cashews, pistachios
The elimination phase of the FODMAP diet can last from two to eight weeks. During this time, you may notice a decrease in your symptoms.
The next phase, the reintroduction process, is very important. The time needed for this phase varies widely, depending on your symptoms.
Here are a few things to keep in mind:
Not every FODMAP type is a problem for every person.
You may want to pick one FODMAP sub-group at a time to test and see how it affects you.
Plan to test each FODMAP group for a week before moving on to the next group.
Most experts recommend keeping a food diary to help you get a better sense of the relationship between the foods that you eat and your symptoms.
The FODMAP diet is not intended for long-term use. Many high-FODMAP foods are an important part of a nutritious, balanced diet. Many also contain prebiotics, which can help keep a healthy balance of bacteria in your gut.
The timing of your meals and snacks is not a factor when following either the elimination or reintroduction phase of the FODMAP diet. You can consume food according to a schedule that works best for you.
However, since re-introducing FODMAP foods may cause symptoms, you may want to pick a time to re-introduce them when you can be at home and take it easy.
SIBO Diet Considerations
Many people with SIBO have other conditions that may need to be managed with specific treatments, including certain diets:
Celiac disease (an autoimmune condition that causes an immune reaction when gluten is eaten)
Chronic pancreatitis (long-term inflammation of the pancreas)
Cirrhosis of the liver (long-term liver damage that leads to scarring)
Crohn's disease (a type of inflammatory bowel disease)
Diabetes (a chronic condition that affects the body's ability to control blood sugar)
People with these chronic health conditions may have SIBO and malnutrition. For example, if you have SIBO, fat-soluble vitamins (A, D, E, and K) may not be adequately absorbed in your intestines. You may also be deficient in iron or vitamin B12. If you can’t replenish your stores with food, you may need to take supplements.
You should work with your healthcare provider and a nutrition expert to manage SIBO and any underlying condition that’s contributing to it. Your treatment needs to be tailored to your symptoms and needs.
What Does Research Say About SIBO Diets?
The research on SIBO diets has been mixed. Some studies have suggested it can be helpful to follow a certain diet if you have SIBO. However, the research has not always been high quality and experts generally say that there is not enough scientific evidence to support a particular diet to treat SIBO.
Here are a few things to consider about the research on SIBO diets:
An older study from 2004 found that a 14-day elemental diet was effective at treating SIBO. However, the study used a small number of patients who also had IBS.
A more recent review from 2020 that included the elemental diet as a possible SIBO treatment concluded there has not been enough evidence to support its use. The researchers also noted that an elemental diet can be hard for people to follow and requires help from a provider, which might limit how many people could realistically try it.
Studies that have looked at using low FODMAP diets for SIBO point out that this diet plan is commonly advised for people with IBS. Researchers have concluded that it is not clear from the studies that have been done whether following a low FODMAP diet helps with SIBO.
Among the studies that noted an improvement, it’s not clear whether people felt better following a low FODMAP diet because the eating plan changed their gut microbiome or because it prevented them from having symptoms related to the gas that is produced by FODMAPs in the GI tract.
Experts do tend to agree that a key part of treating SIBO is to figure out the underlying cause and make sure that it is managed effectively. In some cases, such as for people with chronic diseases that affect their GI system, dietary changes might be part of their treatment.
While there is no one diet that will cure SIBO and work for everyone, making changes to your diet is likely to be part of your SIBO treatment plan. The elemental and low-FODMAP diets are comfy approaches to SIBO. The goal of these diets is to restore a healthy balance of gut bacteria.
If you have SIBO, it’s important to work with your provider on a treatment plan that addresses all your symptoms and needs. You may need antibiotics, nutritional supplements, or specific therapies that help you manage an underlying condition that could be contributing to SIBO.