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The Elemental Diet for SIBO: An Action Plan

Written by Dr. Michael Ruscio, DC on October 16, 2024

Written by Dr. Michael Ruscio, DC on October 16, 2024 — Reviewed by Kellie Blake

How to Use Liquid Nutrition to Get Rid of Intestinal Overgrowths

• What Is an Elemental Diet?|
• The Elemental Diet for SIBO|
• Protocols for Using an Elemental Diet|
• Tips for Success|
• Reintroducing Food|
• Other Treatments for SIBO|

Getting rid of SIBO, or small intestinal bacterial overgrowth, can sometimes be a struggle. If you still have SIBO-type symptoms like bloating, diarrhea, and brain fog after making diet and lifestyle changes, the next step to try could be an elemental diet.

Of course, everybody’s health history is different, and you should work with your healthcare provider to find what is best for you and your SIBO symptoms. However, my experience with my SIBO clients points to a liquid elemental diet as what often finally turns things around when they’ve been suffering from symptoms for a while and other treatments haven’t helped.

That said, there are some tricks and tips for using an elemental diet successfully. Adopting the right techniques can maximize your chances of getting a positive result. 

In this article, I’ll help you understand the science and practicalities of using an elemental diet, so that you can best harness this powerful therapy for SIBO.

What Is an Elemental Diet?

An elemental diet is a liquid meal replacement shake designed to be super easy on your system, as it contains pre-digested nutrients that are easy for your body to absorb. 

Elemental diets are also hypoallergenic, antibacterial, and anti-inflammatory, which is great for allowing your digestive system a break and helping it heal.

Though elemental diets might seem high-tech, the concept behind them is far from new. The earliest versions of liquid nutrition (delivered anally) actually date back to around 3,500 years ago in ancient Egypt and ancient Greece 1 2. 

In the modern era, elemental diets have mainly been used medically in the form of tube feeding for very sick people. The first published clinical studies of the health effects of elemental diets appeared in the 1960s and 1970s 3.

Bringing it right up to date, elemental diets—or specifically semi-elemental diets—are now widely used to benefit a range of common gut conditions, including SIBO. 

To clarify the broad differences between the two types of elemental diet formulas:

A fully elemental formula:

Contains fully broken down macronutrients, i.e. individual amino acids (rather than proteins) and simple sugars like glucose (rather than starches and more complex carbohydrates) 4. The formula tends to be low in fat.

A fully elemental diet is often not very palatable if you’re drinking it (some fully elemental formulations are given through a tube).

A semi-elemental formula:

Contains partially broken down macronutrients, i.e. peptides (a few amino acids joined together) and a combination of simple sugars, glucose polymers like maltodextrin*, and more complex starches 4. A semi-elemental diet contains some fats—primarily medium-chain triglycerides (MCTs), which are easily absorbed. 

Using whey protein hydrolysate as the protein-peptide source makes a semi-elemental diet taste better than a fully elemental diet 4 5. In fact, many people digest, assimilate, and tolerate semi-elemental formulas more easily than fully elemental ones 4. 

*Maltodextrin, derived from plant foods, is a complex carb made up of glucose molecules linked together. Maltodextrin sometimes gets a bad rap because it breaks down so quickly in the small intestine. However, this ease of digestion is desirable in the context of an elemental diet.

The Elemental Diet for SIBO

More up-to-date research is needed to clarify the role of the elemental diet in SIBO. However, one 2004 study at Cedars-Sinai Medical Center showed that a 2-week elemental diet improved breath test results and SIBO-related gastrointestinal symptoms in a group of patients with SIBO and irritable bowel syndrome (IBS).

The study used breath tests to measure SIBO eradication rates. Breath tests that are positive for hydrogen and methane after you swallow a glucose (aka dextrose) or lactulose solution are a medically accepted way to diagnose SIBO. They can do so with reasonable confidence when combined with symptoms like diarrhea or constipation, bloating, brain fog, and abdominal pain. 

In the Cedars-Sinai study:

• 80% of patients had a positive breath test that normalized after two weeks on an elemental diet 6. This is more effective than the typical 51% SIBO eradication rate of antibiotics 7. 
• 65% of the patients in the study also had improvements in their IBS symptoms 6.

The main theory of how it works is that an elemental diet gets rid of SIBO by starving these overgrown bacteria. Elemental formulas might also help eradicate SIBO by: stimulating gallbladder activity that kills small intestinal bacteria; boosting the gut’s immune system; and killing some organisms directly 6.

You may wonder how an elemental formula that provides all the nutrients a human needs for good health could also starve unwanted bacteria in the digestive tract. 

The answer may be that an elemental formulation is designed to be fully absorbed within the first few feet of the small intestine. This means that few or no nutrients reach the lower (distal) part of the small intestine, which is where most bacterial overgrowths occur 8. If bacteria don’t swim in nutrients, they don’t eat.

In short, the nutrients from an elemental diet feed you but not your small intestinal bacteria. 

As well as directly targeting the overgrown bacteria, an elemental diet can work on a more fundamental level to boost underlying gut health, so further microbiome imbalances may be less likely to happen.

For example, there’s evidence that taking a break from solid foods can give an impaired digestive system a chance to rest, heal, and then repair 9 10. You can liken this to a runner who sprains their ankle and needs rest and recuperation to allow the sprain to heal. They wouldn’t continue running on the ankle, as this would increase pain, impair healing, and ultimately mean they’re out of action for longer.

Similarly, an impaired gut can benefit from some downtime that allows more complete healing.

The other thing to note about an elemental diet is that it can reduce systemic inflammation 9 11. Inflammation is associated with an unbalanced microbiome and immune abnormalities, so taking steps to quell inflammation may be helpful.

That said, I advocate starting with simpler treatments for gut conditions first (see the Other Treatments for SIBO section below). But the good news is: At whatever stage you decide to start an elemental diet, it is generally safe to do so—the benefits outweigh the side effects 8.

Protocols for Using an Elemental Diet

Again, there is not a lot of research on the best type of protocol for using an elemental diet. However, I can share with you the three protocols that work best in my clinical experience, and then you can decide what works best for you. 

The three ways my clients use an elemental diet in order of increasing commitment are:

• As a gut-healing meal replacement (maximum of two meals replaced per day for as long as you want or need)
• As a short-term gut reset (full-time use of elemental diet for up to 4 days)
• As a longer-term full-time remedy for tackling bacterial or fungal overgrowths like SIBO (up to 3 weeks full-time use in conjunction with practitioner support)

For longer-term use, which includes tackling SIBO, please note that I strongly recommend having a healthcare practitioner supervise you. You can use the table below to help decide which is the best way to use a semi-elemental formula for your symptoms or circumstances.

Given that our focus in this article is on getting rid of SIBO, let’s assume that you’re most interested in the third and most intensive protocol, above. In that case, what can you and your healthcare provider do to increase your chances of seeing this regimen through successfully?

Tips for Elemental Diet Success

There are many different elemental diet formulations available on the market. So, your first step toward success is to choose one that has a taste and texture you can tolerate all day, every day for 1–3 weeks. Remember that for most people, a semi-elemental diet is the most palatable choice.

I created the tips below for my clients using the Elemental Heal semi-elemental formula, but they will work just as well for any other formulation that suits your own needs and preferences. If you’re allergic to milk proteins or intolerant to whey, look for a whey-free option.

• Make sure to measure and consume enough elemental diet formula to give you sufficient calories for your activities. If you get enough calories, you can even work out at moderate intensity while on the diet.
• If you’re using Elemental Heal, here’s our Dosing Calculator to help you estimate how much you’d need to consume each day and how many bottles to buy. 
• For convenience and to avoid food temptations that may derail you, make all the elemental diet you’ll need for one day in the morning, and refrigerate it for use throughout the day. If you don’t work at home, a fridge at work will do well.
• When blending your elemental diet for immediate use, you can add ice to give it a smoothie-like texture.
• Taking probiotics while you’re on an elemental diet can help you maintain a good bacterial balance while unhealthy overgrowths die away. 

Reintroducing Food After Using an Elemental Diet for SIBO

Exactly how long you spend on an elemental diet will depend on how quickly your SIBO symptoms resolve and the discussions you have with your guiding practitioner.

But, when you’re feeling better and it comes time to start eating solid food again, it’s wise to do so slowly. Reintroducing foods carefully is easier on the immune and digestive systems and will help you identify whether certain foods may be contributing to your symptoms. Ultimately, you want to avoid triggering bacterial overgrowths and SIBO symptoms again.

To help with food reintroduction, I’ve adapted a protocol from a 2021 literature review of eosinophilic esophagitis patients who safely reintroduced foods after a long-term elemental diet 12. 

The premise behind the protocol is that you first introduce the foods that are least likely to trigger a food sensitivity. After several days, you should develop a sense for what you do and don’t tolerate. Then, you add in foods that are slightly more likely to trigger an intolerance or sensitivity, monitoring any symptoms (and removing troublesome foods) as you go. 

When you use this reintroduction approach, you won’t just come to an abrupt stop with your elemental diet. Instead, you’ll continue using it partially to round out your nutritional needs, but you’ll taper off as you slowly add in whole foods. 

Below are two helpful tables to help you through this.

The first table indicates the food groups to reintroduce (from less to more allergenic) and the time frames over which to do this:

The next table gives examples of how tapering off an elemental diet and increasing solid food intake might look in practice. It shows three days of meal ideas for weeks 1–3, during which you’d gradually get back to eating normal whole foods.

In week 4, you’d try the most common allergens, such as fish, dairy, peanuts, or wheat. Remember that one of the main points of doing this reintroduction slowly is so you can better identify any foods that may trigger your symptoms.

Other Treatments for SIBO 

Using an elemental diet for SIBO can be a game-changer, but it can also be quite challenging. That’s why, for many of my clients, I’d recommend other helpful strategies like dietary modifications, probiotics, and antimicrobials first.

A Low-FODMAP Diet

If you’re here, you’ve likely tried many diets already. However, from the research and my clinical experience, a low-FODMAP diet is the most effective choice for SIBO relief. 

A low-FODMAP diet eliminates several types of carbohydrates (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) that can promote too much bacterial growth in the gut. 

Studies have shown that a low-FODMAP diet is an effective way to treat SIBO 13 14. As well as starving bacterial overgrowths, the diet may reduce inflammation, help repair a leaky gut, and improve gut motility, or the rate at which stuff moves through.

I generally recommend a 4–6-week low-FODMAP trial with careful food reintroductions if symptoms improve.

Probiotics

Many people (incorrectly, but understandably) assume you should steer clear of bacteria if you’re trying to rid yourself of a bacterial overgrowth. However, when it comes to the good bacteria in probiotics, nothing could be less true.

In fact, a meta-analysis found that several different combinations of probiotics eradicated SIBO with a success rate of 53% 15, which is about as effective as antibiotics 7. Probiotics can also amp up SIBO eradication when they’re added to a low-FODMAP diet 16.

And, as if that isn’t enough, probiotics are especially helpful for relieving symptoms in people with SIBO 17.

If you’re wondering about which strains to buy, there’s good news: You don’t need to get that granular. Most of the studies showing probiotic benefits used blends of—rather than singular—strains, suggesting that blends are the way to go.

In the clinic, we have found a triple-therapy approach to be the most effective probiotic protocol for most people. Triple therapy is where you combine these three well-researched categories of probiotics:

1. A blend of Lactobacillus and Bifidobacterium species
2. A friendly yeast (Saccharomyces boulardii) 
3. A soil-based probiotic (typically Bacillus species)

The following table gives the dosage and duration that we find most effective for treating SIBO.

I love to recommend a combination of a low-FODMAP diet and triple-therapy probiotics because the results for people with SIBO can be phenomenal.

Antimicrobials

SIBO tends to cause IBS-type symptoms, like bloating, gas, and abdominal discomfort. When I have clients whose IBS-type symptoms are still not under control after trying a low-FODMAP diet and probiotics, we try antimicrobials to get on top of the bacterial overgrowth.

One meta-analysis found that antibiotics alone (mainly rifaximin) eradicated SIBO in 51% of patients 7, which is about the same as probiotics by themselves 15. Because probiotics tend to have far fewer side effects, it’s always worth trying probiotics first. 

But if probiotics alone don’t cut it, combining rifaximin and probiotic supplements can raise the eradication rate to as high as 86% 15. 

Rifaximin is the conventional antibiotic that most medical doctors will use for treating SIBO. When my clients’ health insurance covers a prescription of this antibiotic (which is very expensive), they often want to go this route. 

However, some people either don’t have the insurance coverage or would rather just avoid antibiotics. For them, I recommend herbal antimicrobials that include powerful ingredients like oregano oil, olive leaf extract, or berberine. A study that compared rifaximin and herbal therapy found that herbal antimicrobials got rid of SIBO in 46% of patients, which was better than the 36% eradication rate from rifaximin in that study 18 almost as high as the eradication rates of probiotics (53%) and antibiotics (51%) in other studies 7 15.

The primary distinction between herbal antimicrobials and antibiotics like rifaximin lies in their time frame for effectiveness. While rifaximin typically yields results within 10–14 days, herbal antimicrobials require at least a month to demonstrate benefits 18. 

However, herbal antimicrobials are gentler on the body and do not appear to contribute to bacterial resistance in the same way as conventional antibiotics 19. Combined with an established low-FODMAP diet and probiotics, herbal antimicrobials are often the answer for a determined case of SIBO. 

But when a bigger nudge is necessary, an elemental diet can usually finish what the first three started.

Elemental Diets Can Get Rid of SIBO 

To recap, a highly nutritious liquid elemental diet can be a breakthrough treatment for SIBO. But I always recommend giving other treatments (a low-FODMAP diet, probiotics, and antimicrobials) a try first. These are the fundamentals that can turn around gut health in the longer term, increasing the body’s ability to combat bacterial overgrowths in the future.

At this point, the research we have shows that a more intensive, longer-term elemental diet (full meal replacement for 1–3 weeks) has an excellent chance of treating stubborn SIBO. This intensive approach to an elemental diet requires dedication and careful food reintroduction. But bear in mind, you can always use a partial elemental diet (replacing some but not all meals) alongside healthy eating and probiotics if your symptoms aren’t severe.

If you still can’t quite get on top of suspected SIBO, don’t fret! You can check out my book, Healthy Gut, Healthy You, which dives deeper with the Great-in-8 gut-healing protocol, or you can contact us at the Ruscio Institute for Functional Health to schedule an appointment.

The Ruscio Institute has developed a range of high-quality formulations to help our clients and audience. If you’re interested in learning more about these products, please click here. Note that there are many other options available, and we encourage you to research which products may be right for you. The information on DrRuscio.com is for educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment.