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This article is part of a series on the Word of Wisdom. To view all the articles in this series, see Discovering the Word of Wisdom.

Last week in Decisions, Not DNA, Determine Destiny, I examined the good news that our wellbeing is not at the mercy of our DNA. Genes have only partial influence on our health, and many environmental factors, including what we eat, can determine how our genes express themselves. Further, the bacteria in our body also have the ability to turn our human genes on and off. This makes it all the more important to eat the type the foods that will nourish a healthy microbiome. As President Monson tells us, “Decisions determine destiny.” In the case of our health, it is the decisions we make about breakfast, lunch, and dinner.

If you’ve missed any of the articles I’ve done so far on the human microbiome, here are the previous titles:

With the power of the microbiome to change our biological destiny in mind, let’s look at one dietary factor that is implicated in death and disease: the consumption of animal foods.

Protein and Fat Centered Diets Promote Disease

Scientific research over the last century has produced a steady stream of research establishing a link between a protein and fat centered diet and chronic disease.[1] Even though plants are the original source of all fat and protein, when we talk about a protein or fat centered diet, these are code words for a diet high in animal foods (meat, eggs, and dairy). The standard American diet is too high in both fat and protein and most of this excess fat and protein comes from animal foods, which are virtually 100% fat and protein. Even the USDA, a governmental agency beholden to the meat and dairy industry, encourages Americans to consume more plant foods and fewer animal foods.[2]

Why are protein and fat centered diets so highly correlated with chronic disease? One clue may be their impact on our microbiome. Considering that our microbiome plays a critical role in everything from our digestion, to our metabolism, to our immune system, to our central nervous system, threats to the health of our microbiome affects every part of our biology and is highly related to many serious forms of chronic disease. Research during the last decade has demonstrated that consuming a diet high in protein and fat-rich animal foods and low in fiber-rich plant foods is a serious threat to the health of our microbiome. Could this be part of the link between diet and disease? The evidence is compelling.

Meat and the Microbiome

As mentioned in an earlier article, the microbes in our body turn out to be their own drug manufacturing plant, producing an impressive number of chemicals that have important consequences for our biology. One well-known study demonstrated that when we consume red meat (i.e. beef, pork and lamb) the gut microbiota uses the L-carnitine in these foods to produce TMA, which in turn is metabolized into the chemical TMAO.[3] TMAO is proatherogenic, meaning it accelerates atherosclerosis, the formation of fatty plaques in the arteries which leads to heart disease, stroke, and other cardiac events.

What’s especially interesting is that omnivorous subjects in the study were shown to “produce significantly more TMAO than vegans/vegetarians following ingestion of L-carnitine through a microbiota-dependent mechanism.” In other words, when individuals who do not consume meat on a regular basis eat a piece of meat, the intestinal bacteria in their bodies produce far lower levels of this chemical than do individuals who regularly consume animal products. The conclusion of the researchers is that “Intestinal microbiota may thus participate in the well-established link between increased red meat consumption and CVD [cardiovascular] risk.”[3] This is just one illustration of the way our diet can impact how microbes in our bodies can translate the consumption of meat into disease.

An earlier study demonstrated that the nutrient choline, which is primarily found in animal foods such as eggs, milk, beef, poultry, and fish, also produces TMAO through the same chemical pathway that relies on our gut microbiota.[4] High choline consumption is also related to an increased risk in cancer.[5]. (For an interesting short video that summarizes this research, see Michael Greger, “Carnitine, Choline, Cancer and Cholesterol: The TMAO Connection.”)

We are also beginning to understand the relationship between animal fat consumption and an unhealthy microbiome. One study done at the University of Chicago showed that saturated fats can promote problematic bacteria in the gut called pathobionts which are pro inflammatory. Further evidence shows that fats can increase gut permeability and also increase the uptake of toxins from the microbiota which spread inflammation throughout the body and may contribute to obesity.[6]

Study after study reveals a connection between diets high in animal foods with a relatively unhealthy microbiome and related chronic diseases. At the same time, diets high in fiber-rich plant foods are associated with healthy microbiomes and the absence of many modern diseases. While the researchers on the microbiome are a diverse lot, the messages they are communicating to the scientific audience, as well as the lay public, are fairly unified:

  1. Our distant ancestors consumed a fiber-rich (i.e. plant-centered) diet, which may explain why they did not experience the modern diseases that are associated today with an unhealthy microbiome.
  2. Native populations living in underdeveloped parts of the world today still tend to consume a fiber-rich diet which nourishes a relatively diverse and healthy microbiome and appears to protect them against many serious Western diseases.
  3. People living in Western societies consume diets that are much higher in fiber-less animal foods and fiber-poor processed foods. As a result, the type, number, and diversity of microbes in their microbiome are severely compromised.
  4. The dramatic change in the gut microbiota of Western peoples is highly correlated with the skyrocketing rates of serious health problems such as allergies, food intolerances, gastrointestinal disorders, and the long list of autoimmune diseases.
  5. By changing our diet (preferably at the youngest age possible), we can change our microbiome and reduce our chances of developing serious chronic disease.[7]

Clearly, as cutting-edge experts are now warning us, “a meat-centered diet impacts the microbiota in a way that is detrimental to health.”[8a] Their recommendation for supporting a diet that is “microbiota-friendly” is to center our diet on fiber-rich plant foods and limit the amount of meat we consume.[8b] Certainly Joseph Smith had no idea of the extent of the wisdom in the truths he was unveiling when he declared the Lord’s will to us:

All wholesome herbs [plants] God hath ordained for the constitution, nature, and use of man . . . [meats] are to be used sparingly; And it is pleasing unto me that they should not be used, only in times of winter, or of cold, or famine. (D&C 89:10, 12–13, emphasis)

A few brief resources on this topic beyond the longer references below:

Microbiome Quick Fixes are Not the Answer

The research on the microbiome has shown that the diet revealed by the Lord in the Word of Wisdom is the ideal diet to nurture a healthy microbiome. But changing one’s diet is not always easy or convenient, and the inexpensive foods the Lord recommends are not going to make the big food companies a lot of money and might very well drive the pharmaceutical companies into bankruptcy.

So, it is not surprising that we hear relatively little about the inexpensive foods God created that can cure the problems caused by microbial imbalances in our bodies. At the same time we hear quite a bit about the expensive, patented products manufacturers are creating to address the same problems.

No doubt some of these expensive products may be useful in specific situations. A good example is probiotics. Probiotics are microbes (e.g. live bacteria and yeasts) in the form of pills that we can gulp down with a glass of water. The right combination for our needs can make a difference in certain situations, but these ingested microbes are like visitors to a city: they can give the economy a little boost, but it is nowhere near the impact the local residents are having. Not only are they relatively few in number compared to the bacteria in our bodies, their lifespan is very short. Their only chance for survival is to be fed the type of foods that will enable them to reproduce. Eating them on top of a poor diet is literally flushing them down the toilet, since that is where they end up soon enough.[9]

The same is true for fiber supplements, which are isolated fiber products that we can add to our diets in the form of pills or powders. The fiber in whole food is packaged the way the Lord designed it: a combination of different fibers, various vitamins, minerals, phytonutrients, water, and potentially thousands of other nutrients that we have not even discovered. No study has proven that the fiber supplements crafted in some expert’s lab come anywhere close to doing for our bodies what the Lord designed wholesome plants to do.

Now, many other products are popping up left and right that are claiming to fix our microbiome with pills and procedures. Expect this to become even bigger business in the years to come.

To be clear: probiotics, fiber supplements, and possibly many other products can play an important role in our health, but the Lord designed our bodies so that we can nurture a healthy microbiome primarily by the way we treat our bodies and the diet we consume. We may want to be highly suspicious of those who suggest quick fixes using pills and procedures that imply we can continue to consume the diet of our choice without consequence.[10]

Let’s give three cheers for the wisdom we’ve been given in D&C 89!

Feeding Your Microbiome a Healthy Word of Wisdom Diet

For help getting started on a healthy Word of Wisdom diet, both for yourself and for your microbiome, see: “Getting Started.”

Don’t forget that if you have not been consuming a high fiber diet, it can take some time for your microbiome to adjust to increased fiber. Here are some tips for adjusting to a higher fiber diet.

Jane Birch is the author of Discovering the Word of Wisdom: Surprising Insights from a Whole Food, Plant-based Perspective and many articles on the Word of Wisdom. She can be contacted on her website, Discovering the Word of Wisdom. Watch the video “Discovering the Word of Wisdom: A Short Film.”



[1] There is a wealth of excellent literature on the relationship between animal food consumption and disease. Two good books to start with are (1) Michael Greger, How Not to Die: Discover the Foods Scientifically Proven to Prevent and Reverse Disease (New York: Flatiron Books, 2015), and (2) T. Colin Campbell and Thomas M. Campbell II, The China Study: The Most Comprehensive Study of Nutrition Ever Conducted and the Startling Implications for Diet, Weight Loss, and Long-term Health (Dallas: Benbella, 2006). For free videos with excellent overviews of this literature, see any of these videos by Dr. Michael Greger: (1) “Uprooting the Leading Causes of Death” (2012); “More Than an Apple a Day: Combating Common Diseases” (2013); “From Table to Able: Combating Disabling Diseases with Food” (2014); and (4) “Food as Medicine: Preventing and Treating the Most Dreaded Diseases with Diet” (2015).

[2] U.S. Department of Health and Human Services and U.S. Department of Agriculture, “2015 – 2020 Dietary Guidelines for Americans,” 8th Edition (December 2015).

[3] RA Koeth, et al, “Intestinal microbiota metabolism of L-carnitine, a nutrient in red meat, promotes atherosclerosis,” Nature Medicine 19(5) (May 2013): 576-85.

[4] Zeneng Wang, et al., “Gut flora metabolism of phosphatidylcholine promotes cardiovascular disease,” Nature 472(7341) (April 7, 2011): 57–63.

[5] EL Richman, et al., “Choline intake and risk of lethal prostate cancer: incidence and survival,” American Journal of Clinical Nutrition 96(4) (October 2012): 855-63.

[6] Justin and Erica Sonnenburg, “Top Foods to Fuel Healthy Gut Bacteria,” High Intensity Health Podcast #81 (April 21, 2015).

[7] There are hundreds of studies that support this basic thesis. See this article for a good popular overview: Moises Velasquez-Manoff, “How the Western Diet Has Derailed Our Evolution,” Nautilus (November 12, 2015). For technical overviews, see: AW Janssen and S Kersten, “The role of the gut microbiota in metabolic health,” FASEB J.29(8) (August 2015):3111–3123; LA David et al., “Diet rapidly and reproducibly alters the human gut microbiome,” Nature 505(7484) (January 23, 2014): 559-63; CA Lozupone, et al., “Diversity, stability and resilience of the human gut microbiota,” Nature 489 (September 2012): 220-230.

[8] Justin Sonnenburg and Erica Sonnenburg, The Good Gut: Taking Control of Your Weight, Your Mood, and Your Long-term Health (New York: Penguin, 2015). [7a] p. 134; [7b] p. 218.

[9] For some advice on the use of probiotics and fiber supplements, see Robynne Chutkan, The Microbiome Solution: A Radical New Way to Heal Your Body from the Inside Out (New York: Avery, 2015).

[10] A few free resources on this topic: (1) Maddie Oatman, “Should You Take a Probiotic?” Mother Jones (April 22, 2013); (2) Maureen Salamon, “Are Fiber Supplements as Good as the Real Thing?” My Health News Daily (July 29, 2011); (3) “Faux Fiber Versus the Real Thing,” Berkeley Wellness, (December 1, 2011).