Is a Carnivore Diet Good for SIBO?

In recent years, there has been an increased interest in diets like the Carnivore diet to overcome health challenges. For many, this seems to be a controversial diet that involves eating primarily or only animal-based products. While some experts have praised the diet for its potential health benefits, others have raised concerns about its safety and effectiveness. In particular, several questions have been raised about the potential of a carnivore diet to improve or worsen Small Intestinal Bacterial Overgrowth (SIBO). Here, I look at the latest research on this topic.

Carnivore diet for SIBO

What is SIBO?

Small Intestinal Bacterial Overgrowth (SIBO) is an increasingly common digestive disorder in which bacteria that typically inhabit the large intestine spread to the small intestine and begin to overgrow. This condition can be caused by a variety of contributing factors, including low stomach acid, gut dysbiosis, structural issues, certain medications, and many other factors.

Common symptoms of SIBO include abdominal pain and bloating, gas, diarrhea and/or constipation, nausea, weight loss/gain, fatigue, and malnutrition. If left untreated, SIBO can lead to further health complications. Treatment options range from antibiotics, herbal medicines, and probiotics to dietary and lifestyle changes. It is crucial to test if you suspect your symptoms may point in the direction of SIBO. The best way is through breath testing when hydrogen, methane (or even hydrogen sulfide if the TrioSmart test is used) gases are measured. (1)

What is a Carnivore diet?

Many dietary approaches encourage consuming plenty of fruits and vegetables. You may even have heard the expression: "eat the rainbow" (of vegetables) or increase your fiber intake.

Well, fibers and prebiotics are indeed crucial to feeding good gut bugs. However, people with IBS (Irritable Bowel Syndrome) and SIBO may find that adding more fibers worsens their gut symptoms, resulting in excess bloating and constipation.

Now, the Carnivore diet takes the opposite approach.

The Carnivore diet is basically a meat-only, zero-carbohydrate diet. It means you can't eat plant-based food like vegetables or fruits (although there are several variations of the Carnivore diet, one of them is what Dr. Paul Saladino represents nowadays, allowing honey, fruits, and raw dairy products.)

Followers of this diet are encouraged to eat animals from nose to tail, including organ meats (liver, kidneys, heart, etc.). The emphasis on organ meat is significant because it contains all vital nutrients such as B vitamins, fat-soluble vitamins (A, D, E, and K), and minerals, including iron, magnesium, copper, zinc, etc. They are often referred to as "natural multivitamins." (2) In Western cultures, people are not accustomed to eating organ meat, and it may even sound distasteful to many. However, eating animals from nose to tail is quite normal in many Eastern cultures.

The Carnivore diet advocates claim that the diet heals many chronic health conditions, from depression, weight problems, and blood sugar regulation issues to fertility. However, it is essential to note that these claims are not backed up by any scientific evidence (yet).

What can you eat on a Carnivore diet?

The Carnivore Diet focuses solely on animal-based food items and typically includes foods such as:

  • Red meat, including beef, lamb, pork, venison, and buffalo, preferably fattier cuts of meat (and possibly grass-fed AND grass-finished meat)
  • Poultry, like chicken and turkey, or organ meats
  • Low-mercury fish like wild salmon, sardines, and herring and seafood like oysters, mussels, crabs, clams, shrimp, lobster, or scallops
  • Other animal products and foods like eggs, tallow, duck fat, bone broth, bone marrow, ghee butter
  • Raw dairy products, butter, cheese (if tolerated or no autoimmune issues present)
  • (Raw honey)
  • Water
  • Quality Salt

It's essential to note that various versions of the Carnivore diet exist. So, one approach may allow raw honey or pork, while the other doesn't. (2)

What can't you eat on a Carnivore diet?

The Carnivore diet restricts all the other food groups, such as:

  • All vegetables and fruits
  • Most dairy products
  • Legumes (beans and lentils)
  • Nuts and seeds like almonds, pistachios, pumpkin seeds, flax seeds, etc.
  • All grains and grain-based products, including rice, wheat, bread, quinoa, pasta, etc.
  • All forms of alcohol, including beer, wine, liquor, etc.
  • All types of sugars
  • Other beverages include tea, coffee, soda, fruit juice, etc.

Can a Carnivore Diet Help Treat SIBO?

Currently, the most common approaches for treating SIBO involve antibiotics, antimicrobials, or the Elemental diet. These approaches have varying success rates. According to studies, around 45% of patients will have recurrent SIBO following the completion of antibiotic therapy. (3) Another study showed that herbal antimicrobial therapy could be just as effective as antibiotics. (4) The Elemental diet seems to be the most effective treatment option, as a 14-day Elemental diet was shown to have around an 80% success rate. (5)

We can also choose from a wide variety of SIBO diets that aim to reduce certain carbohydrates to decrease symptoms like bloating, diarrhea, constipation, abdominal pain, and more. I wrote about the pros and cons of these SIBO diets to understand their mechanisms.

But till today - according to my knowledge - there were no exclusive studies on using any SIBO diet as a treatment option (except the Elemental diet).

In Holistic and Functional medicine, we know that lifestyle changes and addressing the underlying causes are crucial in resolving SIBO and preventing relapse.

So what about the Carnivore diet?

One small observational study (6) found that five participants who followed a zero-carb carnivore diet for at least four weeks tested negative for SIBO at the end of the trial period. Now, it is vital to mention that this study has not been peer-reviewed or validated, and it is a small study to draw long-term conclusions.

But here is what they found:

"Results: five patients who followed the carnivore diet for four weeks or longer tested negative for SIBO, and the one patient who only endured the diet for two weeks had a near complete eradication of her hydrogen elevation. Methane values were generally low both before and after the dietary treatment, but there was a significant decrease in patients 3 and 5.

Conclusions: The carbohydrate, zero fibre, carnivore diet shows great potential for being a readily available, cost-effective, and equally effective alternative treatment for SIBO. According to our observations, it also results in better satisfaction after meals, decreases cravings for sweets, and generates weight loss in patients where it is needed."

This small study observed a positive effect on normalizing the breath test, but we definitely need to wait for more data.

The Carnivore diet pros and cons for SIBO

What are the Benefits of a Carnivore Diet for SIBO?

Since the Carnivore diet is a relatively "new trend," there is not much (official) research on its benefits.

Symptom and (disease) management

Other studies investigated the benefits of low-carb diets on health and showed noticeable improvements in weight loss and metabolic markers. (7) Many people support their statements using research on the ketogenic diet.

One survey by Harvard University showed "adults consuming a carnivore diet experienced few adverse effects and instead reported health benefits and high satisfaction." (8)

Since the diet eliminates all inflammatory and processed foods (seed oils, additives, preservation, and more) and all plant foods that may trigger food sensitivities (oxalates, lectins, salicylates, etc.), it makes sense that many advocates of the carnivore diet report better mood, focus, and more energy, improved insulin sensitivity, better gut health, mental clarity, libido, and weight loss as inflammation reduces.

Regarding SIBO, people generally experience less or no bloating and gassiness because the diet eliminates bacteria's primary food source: carbohydrates (including fiber)! Excess bacteria in the small bowel can become an issue due to their fermentation process leading to bloating, gas, and other symptoms. So yes, it can provide relief in terms of symptoms. But it is also essential to be aware that research shows that our gut microbiome needs fiber to function optimally. Many health issues stem from dysbiosis (an imbalance between beneficial and pathogenic bacteria). To feed your good microbes, they need fiber. (9) There is also more discussion if SIBO is actually also a form of dysbiosis.

Healing a Leaky gut

One of the possible reasons why many autoimmune warriors report improvement in their health could be due to healing the leaky gut with the diet. The Carnivore diet encourages bone broth and animal food sources rich in various amino acids and other nutrients (like glutamine, collagen, and omega-3 fatty acids). These amino acids are the building blocks of the intestinal lining. (10)

Calming down the immune system

It can also help calm down the immune system. Since the gut lining is healing, and most of the possible triggering foods have been removed from the diet, inflammation decreases, not triggering the immune system anymore. Therefore the body has time to focus on repair, and some symptoms like skin, mood, sleep, and gut issues slowly fade away.

What are the Potential Risks of a Carnivore Diet for SIBO?

Promoting food fear & metabolic inflexibility

We can all agree that the Carnivore diet is restrictive by eliminating whole food groups. Therefore the diet can be difficult to sustain long-term due to a lack of variety, especially for those who tend to be a foodie. Additionally, there is a potential risk of under-eating, which can impact metabolism and nutrient levels.

It can also lead to social isolation, as eating out can become a real challenge.

I often hear that people are scared to reintroduce foods to the diet due to presumed symptoms. Others who tried the reintroduction process soon backed up because they realized that previously tolerated foods no longer worked for their bodies. This is happening because of metabolic inflexibility. (Metabolic flexibility is the ability to respond or adapt to changes in metabolic demand.) (11) So, in this case, their gut is incapable of adapting to the "new" foods, possibly due to the dysbiosis from a one-sided diet.

Changes in the gut microbiome

A small study found that in just five days, participants who switched to an animal-based diet experienced significant detrimental changes to the gut microbiome, including a dramatic increase in strains of bacteria in the gut that cause inflammation and have been linked with Crohn's disease and ulcerative colitis.

"The animal-based diet increased the abundance of bile-tolerant microorganisms (Alistipes, Bilophila, and Bacteroides) and decreased the levels of Firmicutes that metabolize dietary plant polysaccharides (Roseburia, Eubacterium rectale, and Ruminococcus bromii)...Finally, increases in the abundance and activity of Bilophila wadsworthia on the animal-based diet support a link between dietary fat, bile acids, and the outgrowth of microorganisms capable of triggering inflammatory bowel disease 6. In concert, these results demonstrate that the gut microbiome can rapidly respond to altered diet, potentially facilitating the diversity of human dietary lifestyles." (12)

Possible nutrient deficiencies

It can lead to nutrient deficiencies if the diet is not designed well. Some folks prefer to consume only lean and muscle meat, which may not provide all the essential nutrients as organ meats. This is why it is crucial to practice nose-to-tail eating (including bone marrow, brains, liver, pancreas, and kidneys). For those who can't accept the thought of eating organ meats, organ meat supplements could be a solution.

Some advocates promote adding quality salt (Celtic or Himalayan salt) to the diet to get enough trace minerals.

Ignoring the root causes and lifestyle changes

Many use this diet as a quick fix. But this band-aid approach may mask the underlying problems, especially when we talk about nervous system dysregulation, stored trauma, hidden infections, (mold) toxicity, and structural issues that can all contribute to SIBO, and the Carnivore diet alone may not resolve.

Sometimes people focus too much on their diet and ignore all other aspects of their health like sleep, stress management, relationships, exercise, environment, and so on. But lifestyle factors are the actual foundational steps of any healing journey. This is why holistic coaching & functional nutrition can be powerful in eliminating mindset blockages, limiting beliefs that may stand in your way, and finding strategies to implement the necessary lifestyle changes to reach your health goals. It can also guide you in finding the underlying causes to prevent SIBO relapse in the future.

It may not be suitable for everyone

People with specific health challenges like chronic kidney diseases, adrenal and thyroid dysfunctions, and eating disorders are not recommended to follow this diet.

Those with histamine intolerance may also need modifications. Fresh animal foods generally contain a lower amount of histamine. Reducing or avoiding aged or processed meats, cheeses, hydrolyzed collagen, bone broth, and shellfish is better as they can trigger histamine-related symptoms. (This might change later, though, if the cause of histamine issues is a Leaky gut, for example).

Is the Carnivore Diet good to follow?

My intake on this question is that the Carnivore diet may be helpful for people with chronic conditions as a therapeutic approach to reduce inflammation and allow time for the body to calm down and heal. It may be a good strategy to be on the Carnivore diet for 3-4 weeks and support the gut healing process, implement the necessary lifestyle changes, and have a plan on how to reintroduce plant-based foods to the diet to feed the beneficial gut microbes. But I wouldn't follow it long-term as a new lifestyle.

References
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  1. Sorathia SJ, Chippa V, Rivas JM. Small Intestinal Bacterial Overgrowth. [Updated 2022 Oct 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK546634/
  2. Saladino, P. (2020). The Carnivore Code: Unlocking the Secrets to Optimal Health by Returning to Our Ancestral Diet (1st ed.). Harvest.

  3. Lauritano, E. C., Gabrielli, M., Scarpellini, E., Lupascu, A., Novi, M., Sottili, S., Vitale, G., Cesario, V., Serricchio, M., Cammarota, G., Gasbarrini, G., & Gasbarrini, A. (2008). Small intestinal bacterial overgrowth recurrence after antibiotic therapy. The American journal of gastroenterology103(8), 2031–2035. https://doi.org/10.1111/j.1572-0241.2008.02030.x

  4. Chedid, V., Dhalla, S., Clarke, J. O., Roland, B. C., Dunbar, K. B., Koh, J., Justino, E., Tomakin, E., & Mullin, G. E. (2014). Herbal therapy is equivalent to rifaximin for the treatment of small intestinal bacterial overgrowth. Global advances in health and medicine, 3(3), 16–24. https://doi.org/10.7453/gahmj.2014.019

  5. Pimentel, M., Constantino, T., Kong, Y., Bajwa, M., Rezaei, A., & Park, S. (2004). A 14-day elemental diet is highly effective in normalizing the lactulose breath test. Digestive diseases and sciences49(1), 73–77. https://doi.org/10.1023/b:ddas.0000011605.43979.e1

  6. Martin, Peter & Johansson, Martina & Ek, Annelie. (2021). A Zero Carbohydrate, Carnivore Diet can Normalize Hydrogen Positive Small Intestinal Bacterial Overgrowth Lactulose Breath Tests: A Case Report. 10.21203/rs.3.rs-148500/v1. https://www.researchgate.net/publication/348629591_A_Zero_Carbohydrate_Carnivore_Diet_can_Normalize_Hydrogen_Positive_Small_Intestinal_Bacterial_Overgrowth_Lactulose_Breath_Tests_A_Case_Report

  7. Harvey, C. J. D. C., Schofield, G. M., Zinn, C., Thornley, S. J., Crofts, C., & Merien, F. L. R. (2019). Low-carbohydrate diets differing in carbohydrate restriction improve cardiometabolic and anthropometric markers in healthy adults: A randomised clinical trial. PeerJ, 7, e6273. https://doi.org/10.7717/peerj.6273

  8. Belinda S Lennerz, Jacob T Mey, Owen H Henn, David S Ludwig, Behavioral Characteristics and Self-Reported Health Status among 2029 Adults Consuming a "Carnivore Diet", Current Developments in Nutrition, Volume 5, Issue 12, December 2021, nzab133, https://doi.org/10.1093/cdn/nzab133

  9. Kassem Makki, Edward C. Deehan, Jens Walter, Fredrik Bäckhed, The Impact of Dietary Fiber on Gut Microbiota in Host Health and Disease, Cell Host & Microbe, Volume 23, Issue 6, 2018, 705-715. https://doi.org/10.1016/j.chom.2018.05.012.

  10. Beaumont, M., & Blachier, F. (2020). Amino Acids in Intestinal Physiology and Health. Advances in experimental medicine and biology, 1265, 1–20. https://doi.org/10.1007/978-3-030-45328-2_1

  11. Goodpaster, B. H., & Sparks, L. M. (2017). Metabolic Flexibility in Health and Disease. Cell metabolism, 25(5), 1027–1036. https://doi.org/10.1016/j.cmet.2017.04.015

  12. David, L. A., Maurice, C. F., Carmody, R. N., Gootenberg, D. B., Button, J. E., Wolfe, B. E., Ling, A. V., Devlin, A. S., Varma, Y., Fischbach, M. A., Biddinger, S. B., Dutton, R. J., & Turnbaugh, P. J. (2014). Diet rapidly and reproducibly alters the human gut microbiome. Nature, 505(7484), 559–563. https://doi.org/10.1038/nature12820