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

By Sharon Lehman, RDN

Medically Reviewed by Anthony Dugarte, MD

Last Updated on November 8, 2021

Dietitian 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 some 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.

Written by
Sharon Lehman, RDN
Registered Dietitian Nutritionist
Sharon Lehman, RDN is a Registered Dietitian Nutritionist and writer with over 10 years of experience in the health and wellness industry. She earned her Bachelor of Science degree in Dietetics and completed her dietetic internship at the University of Delaware and a Master of Education degree from Wilmington University with a concentration in elementary and secondary school-based counseling.
Medically Reviewed by
Anthony Dugarte, MD
Medical Reviewer
Anthony Dugarte, M.D., C.S.C.S. is a health and wellness writer and medical content reviewer. In addition to dedicating the last 7 years to medical research, Dr. Dugarte also has more than a decade of experience in strength and conditioning, nutrition, and rehabilitative exercise, as well as authoring and reviewing health and wellness-related content.

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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


  • 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 postbiotics that are claimed 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,” a self-coined term for his thoughts on the human microbiome—aka the trillions of bacteria that live within and on our bodies. (1)

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 are 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. (2)

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.

Many supplements claim to benefit leaky gut, which is a buzzword in the health world these days.

Leaky gut syndrome isn’t currently recognized as a medical diagnosis, but some of the symptoms it’s characterized by are legitimate health concerns. (3)

Leaky gut refers to increased permeability of the intestinal lining. This means some substances, like undigested food and toxins, “leak” from the intestine out to the bloodstream.

These misplaced substances are believed to be one cause of inflammation and chronic health issues, like autoimmune diseases, arthritis, acne, and allergies. (4)

Leaky gut is also characterized by digestive symptoms, like bloating, gas, stomach pain, and diarrhea.

This is opposed to the lining of healthy intestines, which create more of a tight barrier to filter what gets absorbed and what passes through the intestines.

It isn’t understood what causes increased intestinal permeability. However, some lifestyle factors, including a diet high in sugar and unhealthy fats, high levels of stress, and alcohol use, are thought to play a role. (5)

Changes to intestinal permeability are seen in some digestive disorders, like celiac disease and irritable bowel syndrome.

However, more research is needed to understand and confirm a link between intestinal permeability and chronic disease in body systems outside the digestive tract. (6)

It’s common to hear about probiotics and collagen supplementation for leaky gut, but there isn’t enough sufficient evidence to identify which interventions, if any, can repair the intestinal lining.

What Is 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. (7)

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. (8, 9)

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. (10)

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. (11)

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.

We know the gut microbiome plays an essential role in healthy digestion and immune system function.

Dr. Gundry capitalizes on this knowledge by selling products, including Bio Complete 3, designed to restore and improve gut health as the cornerstone to good overall health.

However, it is vital to note that people should obtain prebiotics and probiotics needed to support digestive health and the microbiome from food instead of relying on a supplement.

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.

Tributyrin (as CoreBiome), 1,000 mg

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 research has been conducted in animal and lab studies. (12)

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.


Tributyrin is a type of triglyceride similar to fatty acids naturally produced by the bacteria in your gut. It has mainly been studied in animal and lab studies, so more human research is needed to conclude if supplementation offers any health benefits.

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 supplemented with Sunfiber reported less bloating and gas. (13)

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.


Sunfiber is a prebiotic fiber that has been linked to improvements in bloating and gas in patients with irritable bowel syndrome. However, the amount of Sunfiber used in research greatly exceeds the amount in Bio Complete 3, so any such benefit may not be comparable.

Bacillus coagulans (as ProDURA), 16 mg

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

One type of B. coagulans, called B. coagulans MTCC5856, has been found to be effective in the management of diarrhea associated with irritable bowel syndrome. (14, 15)

However, in the study mentioned, participants were supplemented with 2 billion CFUs (the number of bacteria in a probiotic).

Bio Complete 3 only provides the weight of B. coagulans in milligrams. Typically, the number of probiotics is listed as CFUs on the Supplement Facts label.

Since the original publication of this review, Gundry MD contacted us, claiming that one serving of Bio Complete 3 contains the same amount of probiotics (2 billion CFUs) as the study mentioned earlier.

This information is not provided to consumers on the Gundry MD website, product listing, or Supplement Facts label, so you’ll have to decide how comfortable you are accepting this claim without evidence to support it.

I would love to see the company offer more transparency or research regarding the probiotics in  Bio Complete 3.

Probiotics are identified by their genus (family). Each genus contains several species and strains. This is important to know because each probiotic strain has its own function. Benefits are strain-specific and can not be applied to all strains within the same genus. (16)

In this case, Bacillus is the genus, and Coagulans is the species. The above-mentioned study uses a specific strain of B. coagulansB. coagulans MTCC5856. However, the specifics regarding the strain used in Bio Complete 3 are not provided by the company.

Without knowing which probiotic strains a product contains, it’s hard to directly compare it to the existing research regarding health benefits.

Most probiotic supplements contain several types of probiotic bacteria to restore a balanced diversity of bacteria. It’s common for the probiotic strains in supplements to differ slightly from those that have been studied.

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


Some strains of Bacillus coagulans are linked to improvements in symptoms of irritable bowel disease. Unfortunately, Gundry MD does not disclose the specific strain of B. coagulans used in Bio Complete 3 so it’s hard to make a direct comparison to the existing research regarding health benefits.

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

I found no evidence linking any of the ingredients in Bio Complete 3 to weight loss, enhanced energy, or decreased food cravings.

There is some evidence that Sunfiber and some strains of B. coagulans, the probiotic in this product, are linked to improvements in digestive symptoms related to irritable bowel syndrome.

However, I can’t say there is strong evidence to support the claim that this product promotes gut health. Gundry MD contains significantly less Sunfiber per serving than dosages used in research, and they don’t specify which strain of B. coagulans this product contains.

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

Some people may experience digestive discomfort, like gas and bloating, after starting a probiotic supplement. (17)

Some populations can experience serious side effects, like infection and gastrointestinal problems, from probiotic supplementation. (18)

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

Although Dr. Gundry’s website claims the product has been tested by an independent third-party facility for safety, Bio Complete 3’s label doesn’t have a corresponding seal to back up this claim.

You should always speak with a healthcare professional before starting any supplement.

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. In addition, 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.

How Bio Complete 3 Compares to Alternatives

Moth 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 alternative probiotic blends that list exactly what ingredients the prebiotics and postbiotics are sourced from, which provides peace of mind to know what you’re taking.

Before taking a probiotic, you should speak with a healthcare professional and research any digestive symptoms or health issues you have to see which probiotics genus, species, and strains may be beneficial.

There is a wealth of information available regarding which types of probiotics are the best fit for digestive disorders, women’s health issues, weight loss, mental health, and immunity.

For a comparison, Seed Daily Synbiotic contains 24 types of probiotic strains, plus prebiotics, to support digestion, skin, immunity, heart health, and the synthesis of micronutrients in the gut. Each strain included in the formula is backed by research.

The dosage for Seed Daily Synbiotic is two capsules per day and costs $49.99 for a one-month supply, which is more reasonable on both counts than Bio Complete 3.

Dr. Gundry claims he designed Bio Complete 3 so all three main ingredients can work together. However, there are no studies that these ingredients work together better than other blends of prebiotics, probiotics, and postbiotics.

Related: Best Probiotics of 2022, According to Dietitians

The Bottom Line

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

Bio Complete 3 claims to support weight loss, energy, and enhance digestive health despite only containing one type of probiotic.

There is no evidence to indicate the “unique” blend of ingredients in Bio Complete 3 is superior to other probiotic-containing supplements, nor that it will support weight loss, enhance energy, or reduce food cravings.

Bio Complete 3 is expensive and lacks diverse probiotic strains and certified independent third-party testing.

Some people may report improved digestive health after trying Bio Complete 3, but it is by no means the top digestive health supplement available today.

If you’re considering a probiotic, I recommend choosing one that contains multiple types of probiotics and contains well-studied strains of bacteria.

You should speak with your healthcare professional before starting any dietary supplement.

Next Steps

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

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

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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At WellnessVerge, we only use primary references for our articles, including peer reviewed medical journals or well-respected academic institutions.

  1. Current understanding of the human microbiome:
  2. Current understanding of dysbiosis in disease in human and animal models:
  3. The Leaky Gut: Mechanisms, Measurement and Clinical Implications in Humans:
  4. Leaky Gut As a Danger Signal for Autoimmune Diseases:
  5. Risk factors associated with intestinal permeability in an adult population: A systematic review:
  6. The intestinal epithelial barrier: A therapeutic target?:
  7. Part 1: The Human Gut Microbiome in Health and Disease:
  8. The efficacy and safety of probiotics in patients with irritable bowel syndrome: Evidence based on 35 randomized controlled trials:
  9. Beneficial Effects of Probiotic Consumption on the Immune System:
  10. Insight into the prebiotic concept: lessons from an exploratory, double blind intervention study with inulin-type fructans in obese women:
  11. Postbiotics and Their Potential Applications in Early Life Nutrition and Beyond:
  12. Tributyrin Supplementation Protects Immune Responses and Vasculature and Reduces Oxidative Stress in the Proximal Colon of Mice Exposed to Chronic-Binge Ethanol Feeding:
  13. Randomized clinical study: Partially hydrolyzed guar gum (PHGG) versus placebo in the treatment of patients with irritable bowel syndrome:
  14. Bacillus coagulans MTCC 5856 supplementation in the management of diarrhea predominant Irritable Bowel Syndrome: a double blind randomized placebo controlled pilot clinical study:
  15. Bacillus coagulans MTCC 5856 for the management of major depression with irritable bowel syndrome: a randomised, double-blind, placebo controlled, multi-centre, pilot clinical study:
  16. A gastrointestinal anti-infectious biotherapeutic agent: the heat-treated Lactobacillus LB:
  17. Probiotics:
  18. A systematic review of the safety of probiotics: