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Bio Complete 3 Review: Effectiveness, Side Effects, Pros and Cons

Written by Sharon Lehman, RDN

Reviewed by Anthony Dugarte, MD 

Last Updated on May 3, 2021

Our Expert Rating:


About This Rating
The average rating of this product is calculated based on the evaluation of the following factors:
  • Support for Claims:1.5
  • Ingredient Safety:3.0
  • Value for the Price:2.0
  • Brand Transparency:4.0

Bio Complete 3 is a dietary supplement that is claimed to improve digestive health, energy, and weight. There is limited evidence to support using its ingredients for digestive health. However, the combination of these ingredients has not been proven to be optimal to support many of the product’s claims.

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Bio Complete 3 Review: Effectiveness, Side Effects, Pros and Cons
Photo by WellnessVerge


  • May support gut health
  • 90-day money-back guarantee
  • Provides fiber, a nutrient many are missing in their diets


  • Lacks a clear and transparent ingredient list
  • Contains only one strain of probiotic
  • Claims to be third-party tested, but lacks a certified seal
  • Expensive

What Is Bio Complete 3?

Gundry MD Bio Complete 3 is a dietary supplement designed to promote optimal digestive health.

It contains a blend of prebiotics, probiotics, and post-biotics that claim to help balance, restore, and nourish the microflora (aka bacteria) found in the digestive tract, support a healthy gut lining, and promote a strong immune system.

The company claims that by supporting gut health, users will experience enhanced weight loss and decreased fatigue, digestive discomfort, and junk food cravings.

The creator of this product, Dr. Steven Gundry, is what I’d consider a “celebrity” physician.

He’s a cardiologist and an author of “The Plant Paradox.”

He has an entire product line centered around his philosophy of “Holobiotics,” which is a self-coined term for his thoughts on the human microbiome—aka the trillions of bacteria that live within and on our bodies.

Dr. Gundry preaches that good health is only possible when these microbes are balanced. That is when the body is full of “good” bacteria while “bad” bacteria is kept to a minimum.

Although Dr. Gundry acknowledges the role of pathogens and an unhealthy diet in the development of gut dysbiosis, or an unbalanced colony of intestinal microbes, he also cautions people against lectins.

Lectins are a type of protein that binds to carbohydrates found in many plant foods.

Dr. Gundry believes lectin-containing foods are harmful to the gut microbiome and can contribute to the development of many digestive disorders, including leaky gut syndrome.

This is one of his trademark nutritional theories and is largely unsupported by scientific evidence.

Bio Complete 3 is one of the many products Dr. Gundry sells designed to restore and improve gut health as the cornerstone to good overall health.

What Is the Gut Microbiome?

Bio Complete 3 is an “all-in-one” supplement that contains prebiotics, probiotics, and postbiotics to promote a healthy gut microbiome.

The gut microbiome refers to the bacteria that naturally reside within the human gut.

These bacteria are responsible for carbohydrate metabolism, the synthesis of some vitamins and amino acids, and antimicrobial activity that protects us from harmful pathogens.

Several lifestyle factors, including stress and an unhealthy diet, can disrupt the diversity of intestinal bacteria and result in digestive issues, obesity, and other diseases.

It’s estimated that 70% of the immune system resides in the small intestine, so a bacterial imbalance can also result in compromised immunity.

Probiotic supplements deliver healthy strains of bacteria to the intestine to increase the number of good bacteria and prevent harmful bacteria from overpopulating the digestive system.

There is sufficient evidence that supplementing with probiotics helps increase the beneficial bacteria in your gut and can relieve symptoms of irritable bowel syndrome and improve the immune system.

Prebiotics are a type of fiber that feeds beneficial gut bacteria. The theory behind prebiotic supplementation is that providing food for good bacteria allows them to grow and weed out harmful strains.

Research supports this theory, as several studies have reported species changes in the microbiome following controlled intake of prebiotics.

Postbiotics refer to compounds that are created by bacterial fermentation. It’s an emerging area of gut microbiome research that is not yet fully defined or understood.

It’s thought that postbiotics play a role in the composition of the gut microbiome and immune system function.

As a registered dietitian, I believe most of what the body needs can be obtained first and foremost from food.

Probiotics can be found in fermented foods like yogurt, pickles, sauerkraut, kefir, and kombucha.

Bananas, apples, and oats are good sources of prebiotics. And, if the thinking is that postbiotics are formed during bacterial fermentation, then fermented foods may also prove to be good sources of these compounds.

That being said, many people report experiencing enhanced digestion when they regularly take a probiotic supplement in addition to eating a healthy diet.

The number one concern I have with Dr. Gundry’s product is the “all-in-one” marketing.

I think this type of language and labeling may lead people to rely on a supplement instead of actual food to obtain the prebiotics and probiotics needed to support digestive health and the microbiome.

The fact that Dr. Gundry considers lectin-containing plants, like tomatoes, potatoes, and beans, harmful to gut health only confounds the issue. It encourages people to eat fewer plant-based foods.

Evaluation of Ingredients

Bio Complete 3 Supplement Facts
Photo by WellnessVerge

The ingredient label on Bio Complete 3 only lists three main ingredients, all of which are proprietary blends registered and trademarked by other companies.

This makes it impossible to know exactly what you’re taking without doing independent research on each of these products. Here’s what I discovered:

Tributyrin (1000 mg, as CoreBiome)

Tributyrin makes up the postbiotic portion of Bio Complete 3. It’s sourced as CoreBiome from a company called Compound Solutions, Inc.

Tributyrin is a triglyceride that supplies the short-chain fatty acid (SCFA) butyrate to the body.

Butyrate and other SCFAs are naturally produced by gut bacteria when they ferment fiber and other food compounds. The SCFAs supply energy to cells lining the digestive tract.

There is no evidence that tributyrin has a positive effect on the human gut microbiome or gut lining since most of the research has been conducted in animal and lab studies.

It seems to reduce oxidative stress in rodents being given high amounts of ethanol.

Since further research in humans is needed, I can't say if this dosage of tributyrin will offer benefits or not.

Sunfiber (200 mg)

Sunfiber is the prebiotic in Bio Complete 3. It’s a soluble fiber product manufactured by a company called Taiyo International.

I couldn’t find any information on what this product contains other than soluble fiber. Yet, it’s listed as certified organic, Non-GMO Project Verified, gluten-free, kosher, and low FODMAP certified, which I find impressive for something that isn’t transparent about how it’s made.

In a randomized controlled trial, participants with irritable bowel syndrome who supplemented with Sunfiber reported less bloating and gas.

However, they were taking 6 grams of Sunfiber per day, and Bio Complete 3 contains only 200 milligrams, or 0.2 grams, per serving, so it may not be enough to generate the same results.

More research in humans is needed to determine the optimal dosage of Sunfiber for the best results.

Bacillus Coagulans (16 mg, as ProDURA)

Bacillus coagulans is the probiotic in Bio Complete 3. It’s sourced as ProDURA, which is made by a company called UAS Labs.

Bacillus coagulans has been found to be effective in the management of diarrhea associated with irritable bowel syndrome.

However, in the study mentioned, participants were supplemented with 2 billion CFUs – colony forming units or the number of bacteria in a probiotic.

Bio Complete 3 only provides the weight of Bacillus coagulans, so there’s no way to know if the number of bacteria per serving is enough to offer the same benefits.

Most other probiotics on the market contain several bacterial strains designed to restore a balanced diversity of bacteria.

I find it strange that this “all-in-one” probiotic blend contains only one strain of bacteria.

Unless you specifically know that your gut will benefit from bacillus coagulans, it seems unlikely that the single strain will do much to rebalance your microbiome.

Verdict on Claimed Benefits

Below is our summary of the available evidence for the claimed benefits of Bio Complete 3 based on the available research:

  • Promotes gut healthModerate Evidence
  • Supports weight lossNo Evidence
  • Enhances energyNo Evidence
  • Decreases food cravingsNo Evidence

Safety, Side Effects, and Dosage

The serving size for Bio Complete 3 is four capsules daily. It’s recommended to take two capsules twice per day before eating.

Remembering to take a supplement twice per day may be challenging for some people.

Bio Complete 3 capsules
Photo by WellnessVerge

There are no significant safety concerns since probiotics and prebiotics are generally considered safe for most healthy people.

However, some people may experience digestive discomfort, like gas and bloating, after starting a probiotic supplement.

Some populations can experience serious side effects, like infection and gastrointestinal problems, from probiotic supplementation.

At-risk populations include critically ill infants, the elderly, and other immunocompromised individuals.

Related: How and When to Take Probiotic Supplements

Cost and Where to Buy

Bio Complete 3 is not sold at retailers and can only be purchased directly from Dr. Gundry’s website.

A single bottle, which contains a 30-day supply of 120 capsules, will cost you $69.95.

Compared to 30-day supplies of other probiotic and gut health supplements in the $20–25 range, the price of this supplement is on the expensive end.

Probiotic blends with added prebiotics and postbiotics typically range from $25–$50 for a 30-day supply.

This product is also available in bulk packages of 3 or 6 bottles, which are somewhat discounted and bring the price of each 30-day supply down to $62.95 and $58.95, respectively.

It’s still a pricey supplement, but ordering in bulk can help you save some money and stock up for several months if this product is right for you.

Keep an eye out for the first-time customer offers on their site, which will save you even more.

You can snag a single bottle of Bio Complete 3 for the discounted price of $49.95 on your first order, and the bulk packages are discounted as well.

You’ll save even more if you join the Subscribe & Save program, where you can lock in a further discounted price.

Shipping is free on orders over $60. The product is backed by a 90-day money-back guarantee.

If you try this supplement and aren’t happy with your results within the first 90-days, the company promises a 100% refund, no questions asked.

Comparison to Alternatives

Moth other digestive health supplements that contain a blend of pre-, post-, and probiotics contain multiple strains of probiotics to help create a diverse, balanced gut microbiome.

Unlike Bio Complete 3, you can find probiotic blends that list exactly what ingredients the prebiotics and postbiotics are sourced from, which provides peace of mind to know exactly what you’re taking.

Dr. Gundry claims he designed Bio Complete 3 so all three main ingredients can work together, but there are no studies that these ingredients do indeed work together better than other blends of pre-, post-, and probiotics.

Although Dr. Gundry’s website claims the product has been tested by an independent third-party facility for safety, the label doesn’t have a corresponding seal to back up this claim.

The Bottom Line

There is plenty of evidence to support claims around gut health benefiting from supplementation with probiotics, prebiotics, and postbiotics.

However, there is no evidence to indicate the “unique” blend of ingredients in Bio Complete 3 is superior to others.

This product may improve digestive health for some people, but it is by no means the top choice available today.

It’s expensive and lacks transparent ingredients, diverse probiotic strains, and certified independent third-party testing.

A Word from Our RD

Not everyone benefits from taking a probiotic due to the different strains found in different supplements.

Everyone’s microbiome is unique and responds differently to different probiotic strains.

Since postbiotics refer to a wide range of compounds, it can be assumed the same can be said about them.

As a registered dietitian, I recommend focusing on food sources of prebiotics and probiotics first.

Prebiotics are found in some plant foods, such as bananas, onions, garlic, and oats.

Probiotics are found in fermented foods, such as yogurt, kefir, and sauerkraut. 

If digestive health doesn’t improve after several weeks, then it may be wise to consider adding a digestive health supplement.

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