All You Need to Know About Using a Predigested Liquid Diet to Restore Health in the Gut and Beyond

• What’s an Elemental Diet?|
• Why Use One?|
• When?|
• How?|
• Quick Tips|
• Reintroducing Food|
• Summary|

An elemental diet is a gut-friendly, hypoallergenic, and complete meal replacement formula that contains predigested nutrients.

Designed to give your digestive tract a rest, an elemental diet can help with a range of health problems. These include issues directly within the gut like gas, bloating, diarrhea, and abdominal pain—as well as more general health concerns, including fatigue, brain fog, and hormonal imbalances.

Elemental diets come in powder form that you add water to. They can be used in different ways—ranging from occasional meal replacements to fully replacing solid food for two weeks or longer.

Before you jump into cutting out solid food, let’s do a deep dive into the evidence for elemental diets so you can have realistic expectations. We’ll also share two steps you should take before going elemental.

What Is the Elemental Diet?

An elemental diet is a liquid meal replacement with easy-to-digest carbohydrates, fats, and proteins, making it gentle on the gut. It also provides all essential vitamins and minerals, ensuring your body gets complete nutrition without the need for solid food.

At the clinic, we only work with elemental diets that are technically “semi-elemental” because they taste a lot better than fully elemental diets.

Semi-elemental diets generally provide [1]:

• Proteins that are partially broken down into peptides (short chains of amino acids)
• Carbs that are partially broken down into a mix of simple sugars and some longer-chain carbs like starches 
• Easily absorbed fats, usually medium-chain triglycerides (MCTs)

By comparison, fully elemental diets are broken down more completely, for example into individual amino acids like l-arginine and l-glutamine and simple sugars like dextrose. Fully elemental diets are also generally low-fat and aren’t very palatable. They are sometimes given via a feeding tube.

Modern semi-elemental diets, especially those with whey protein hydrolysate as the protein source, can taste pretty great. They are also as effective in most situations as the fully broken-down version. 

In fact, many people digest, assimilate, and tolerate semi-elemental formulas more easily than fully elemental ones [1].

Why Use an Elemental Diet?

The elemental diet is potentially helpful in easing: 

• Crohn’s disease (a type of inflammatory bowel disease)
• Eosinophilic esophagitis (a condition in which the esophagus becomes inflamed and does not contract properly)
• Eosinophilic gastroenteritis (similar to eosinophilic esophagitis except that it affects the stomach and intestines)
• SIBO (small intestinal bacterial overgrowth)
• IBS (irritable bowel syndrome)

The table below summarizes how the elemental diet might help each of these health conditions, including how sure we are of potential benefit:

A common feature across the above conditions is dysbiosis — i.e., a gut that is inflamed and a microbiome that is out of balance. In this scenario, an elemental diet may help by:

• Reducing inflammation [6, 7]
• Starving bacterial overgrowths [5]
• Giving the digestive system a chance to rest, heal, and then repair [6, 8]

This last bullet point can be likened to someone with a broken leg who needs a cast and immobilization for proper healing. You wouldn’t walk on a broken leg, as that would increase pain, delay recovery, and ultimately extend the healing time. 

Similarly, an impaired gut can benefit from some downtime to allow for more complete healing.

Elemental Diet—My Perspective as a Clinician

At the clinic, we witness some impressive results when patients use the elemental diet to deal with troubling symptoms arising from poor gut health. 

These symptoms are not necessarily all digestive-related, as you’ll see from the experiences of three of my clients: 

• Randy found that an elemental diet helped improve his chronic fatigue and joint pain, as well as helping with reflux and SIBO. 
• Kacheena discovered that an elemental diet was key to alleviating her debilitating premenstrual syndrome symptoms, which were compounded by IBS. Her condition had been so severe that her healthcare providers had been considering a hysterectomy.
• George uses an elemental diet when needed to successfully control his C. diff symptoms, including stomach pain and diarrhea. 

When Should You Introduce an Elemental Diet?

Despite these great results, an elemental diet is usually not first on the list of therapeutics and treatments that I have my clients try when they’re looking to improve poor gut health.

Before turning to an elemental diet, I generally recommend less restrictive dietary changes and probiotics as the first two steps.

Step 1: Diet for Gut Help 

The Mediterranean diet has been shown to be a good fit for boosting the gut microbiome [9]. It’s anti-inflammatory, whole-food based, and helps keep blood sugar stable.

However, many clients who visit our clinic have significant food sensitivities driving their gastrointestinal issues.

In this case, diets that eliminate potential allergens may improve gut health quicker.

Two diets that we find work well to improve gut health in clients with food sensitivities are:

• The Paleo diet, which contains minimal or no grains and dairy
• A low-FODMAP diet, which restricts a range of carbs that can create excess gas

Other more specialized diets like a low histamine diet or the AIP (autoimmune protocol diet) may also benefit some people. 

I recommend working with a doctor or dietitian to find which elimination diet works best for you—and to help you reintroduce foods once your symptoms have died down.

Step 2: Probiotics to Boost Microbiome Health

Any dietary regimen aimed at improving gut health will usually work better if supplemented with probiotics.

Research shows that probiotics improve leaky gut, reduce inflammation, and correct dysbiosis (imbalances in the gut microbiome) [10]. 

This is the combined, triple-species probiotic approach that we find achieves the best results:

• Lactobacillus/Bifidobacterium species: 1–50 billion CFU daily for 2–3 months
• Bacillus species: 2–6 billion CFU daily for 2–3 months
• Saccharomyces boulardii: 10–15 billion CFU daily for 2–3 months

Step 3: Nothing Working? Think About Introducing an Elemental Diet

I won’t usually suggest an elemental diet unless other treatments have failed to relieve gut symptoms after three months or so.

If diet changes and probiotics haven’t moved the needle enough by then, that’s when I’d usually start suggesting an elemental diet trial to my clients.

That said, there’s no harm in using an elemental diet earlier if you want, as we know that it’s a generally safe treatment [11]. You can also use an elemental diet now and again to soothe a gut symptom flare, or as a convenient way to get nutrition on the run.

How to Use the Elemental Diet

You can be flexible in the way you use a liquid elemental diet. However, in the clinic, we’ve identified three main ways of using elemental diets: 

• To replace all your solid food for 1–4 days as a way of resetting your gut health.
• Intensively for 1–3 weeks as a remedy for potential bacterial/fungal overgrowths (for this, we strongly recommend clinical supervision). 
• On an as-needed basis as a gut-friendly meal replacement (replacing one or two of your daily meals). 

Let’s look a little deeper at these scenarios.

As a Gut Reset

A gut reset of around 48–72 hours is often my client’s first experience of the elemental diet. As we discussed, this will often be after other dietary changes (e.g., the Paleo or low-FODMAP diet) and probiotics have not sufficiently improved gut symptoms.

Using the element diet for a short gut reset is also a good idea if you’ve slipped into unhealthy eating patterns and want to break that pattern. 

Consuming more inflammatory foods than your body can tolerate can cause elusive symptoms like fatigue, poor concentration, and achy joints. In this case, 1–3 days of replacing all your meals with elemental shakes can work wonders. 

After the gut reset is done, you can adopt healthier eating habits again going forward.

As a Remedy for Microbial Gut Overgrowths

Following an elemental diet full-time for 1–3 weeks obviously takes a lot more commitment, but this is what I’ve seen work best for overgrowths like SIBO and Candida.

Why? A liquid elemental meal is fully absorbed within the first few feet of the small intestine. This means nutrients don’t reach the lower part of the small intestine, where most bacterial overgrowths occur [11]. 

If bacteria don’t swim in nutrients, they don’t eat and start to die off. This is not immediate, so you need to persist to fully address bacterial and fungal overgrowths. 

The SIBO study in the table above used a 2-week elemental diet to successfully reduce overgrowths [5]. This fits with the fact that it takes time for unwanted bacteria to be starved off. 

When using an elemental diet for a week or longer, we strongly recommend being monitored by a health professional for any side effects or symptoms of bacterial die-off.

As a Meal Replacement

Elemental shakes are a quick and easy meal replacement. That’s great for busy mornings, for example, or when you’re traveling and have food sensitivities you can’t otherwise easily accommodate.

Replacing just a few meals with a hypoallergenic elemental diet can also be enough to calm your gut through a period when you have symptom flares.

A half elemental diet (up to 50% of daily calories from elemental shakes) has been shown to reduce gut symptoms and IBD flares [8].

Quick Tips 

Here are some practical tips for choosing and using an elemental diet formula day-to-day:

• Drink as much elemental formula as you need for your activity levels and to avoid unwanted weight loss. 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. 
• To stay on track, mix up enough formula for the whole day and keep it in the fridge until you drink it. 
• If you have dairy sensitivities, choose a whey-free elemental formula. Lower carb formulations are also available if that suits your needs better.
• If you prefer, you can sip your shakes all day instead of as meals.
• Cold shakes taste best. Add ice cubes and use a blender to make the shakes nice and frothy. 
• Continue to take any prescription medicines. Dietary supplements are optional.
• You can also drink water, tea, or black coffee. Caffeine is OK for most people, but skip the cream and sugar and be careful if you’re caffeine-sensitive.

Food Reintroduction After Long-Term Elemental Dieting

If you’re doing a full elemental diet for more than a few days (especially the longer-term bacterial overgrowth protocol), it’s best to introduce solid food 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.

To help with food reintroduction, our clinic has adapted a protocol from a 2021 literature review that you might find helpful [12]. It’s detailed in the infographic below.

The premise behind this 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 of 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, and you’ll reap bigger benefits.

For an example of what increasing solid food intake might look like in practice, you could use the example below. 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.

Elemental Diets Have Lots of Potential

To recap, a hypoallergenic liquid elemental diet that meets your nutritional needs can be very helpful for stubborn symptoms that arise from poor gut health. Elemental diets can also make life easier by offering you a safe meal option when you are busy, on the run, or experiencing a symptom flare.

Whether you’re using an elemental diet as a short, targeted three-day reset, a longer-term treatment, or just an occasional meal replacement, I always recommend looking at the basics of gut health first.

A gut-friendly diet (for example a Paleo or low FODMAP diet) and probiotic supplementation are the fundamentals that can turn around gut health in the long term.

If you and your doctor decide that an elemental diet is a good long-term treatment for you, remember that this intensive approach requires dedication and careful food reintroduction. 

For more on helping poor gut health, you can check out my book, Healthy Gut, Healthy You, which dives deeper by using 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.

Dr. Michael Ruscio is a DC, Naturopathic Practitioner, researcher, and clinician. He serves as an Adjunct Professor at the University of Bridgeport and has published numerous papers in scientific journals as well as the book Healthy Gut, Healthy You. He also founded the Ruscio Institute of Functional Health, where he helps patients with a wide range of GI conditions and serves as the Head of Research.