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

I’ve been discussing the human microbiome, the 100 trillion microbes that inhabit our bodies, creatures that happen to be key to our health and wellbeing. This topic has flooded the scientific literature and popular media for quite a few years now. It is easy to see why the world is fascinated with this subject: it opens whole new worlds of understanding about our amazing bodies. It also wakens us to our symbiotic relationship with some of the smallest creatures on this planet, ones we house in our own bodies.

But for Mormons, this topic is especially compelling. In addition to establishing the vital link between the health of our microbiome and our own, the scientific research demonstrates the dramatic impact of the foods we eat on the microbes we house. What is so fascinating is that the diet needed for a healthy microbiome is the same whole food, plant-based diet the Lord revealed to Joseph Smith in 1833, long before the scientific world knew anything about the human microbiome, much less what it eats!

Much of what I’ve written for Meridian has explored the multi-dimensional ways a whole food, plant-based Word of Wisdom diet helps prevent and reverse most of the chronic diseases experienced in Western societies today, such as heart disease, diabetes, strokes, cancer, kidney disease, and osteoporosis.[1] Now, with the added understanding of how the Lord’s counsel also protects our microbiome, we know that the same whole food, plant-based diet can also help prevent (and possibly help reverse) many more of the chronic diseases that have skyrocketed in recent decades, including allergies, food intolerances, gastrointestinal disorders, and the long list of devastating autoimmune diseases (such as Crohn’s disease, type I diabetes, eczema, Grave’s, Hashimoto’s thyroiditis, lupus, MS, psoriasis, rheumatoid arthritis, and ulcerative colitis).[2]

In today’s article, I address an aspect of the human microbiome that should be of great concern to us Mormons who care deeply about our children . . . and their children . . . down to the end of time. This topic relates to our understanding of being stewards of this earth, of our bodies, and of the creatures on this planet. The topic I am addressing today is the relatively new evidence that the modern Western diet is putting our precious, life-sustaining human microbiome on the endangered species list!

The Threat to our Microbiome

Last week, in “The Good and Bad News about Our Microbiome,” I discussed the good news that by changing our diets, we can change our microbiome. This is important because our Western lifestyle is seriously threatening the number, type, and diversity of microbes in our body. Considering that our microbes are a key link 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. Obviously, we can’t afford to stand idly by while it is under threat.

The evidence indicates that those of us living in the Western world have already lost roughly one-third of the diversity of the microbiome our ancestors had. Not only is the diversity down, the number of good bacteria is down, and the number of the bacteria that appears to be relatively harmful has increased . . . dramatically.[2]

For example, in one study, the microbiomes of healthy children in Burkina Faso, West Africa were compared with those of healthy children in Florence, Italy. The youth in Burkina Faso ate a high fiber diet of “mostly millet and sorghum” and consequently had “far more microbial diversity than the Florentines, who ate a variant of the refined, Western diet.” Not only were the Western microbiomes less diverse, these microbiomes were adapted to “protein, fats, and simple sugars,” while the Burkina Faso microbiomes were adapted to degrading the complex carbohydrates (fiber) in the plants they ate.[3]

Many of the types of useful microbes that used to inhabit the bodies of our ancestors no longer inhabit our bodies. In other words, we are losing part of a precious heritage handed down to us from generations of those who have gone before us. What will be the long-term consequence of such a loss? We are becoming aware of the unintended consequences of losing whole populations of creatures and plant life out in the wild, but what about the unintended consequences of losing whole populations inside our bodies? What will the consequences be for our children who will inherit our diminished microbiome? And what about their children?

Already, scientists are so concerned about the possibility of permanently losing some of these microbes that there is a rush to “catalog an ecosystem” that may soon disappear off the planet.[3]

Just think: the symbiotic relationship we have developed with these creatures has existed from the beginning of humankind. We are so dependent on these little bugs that our bodies can no longer perform many of the functions we have delegated to them. These microbes are as important to our body as our liver, pancreas, thyroid, and other organs. In fact, some researchers are calling the microbiome the “forgotten organ.”[4] In other words, it is not optional appendage that we can neglect without consequence.

As our microbiome is threatened, chaos ensues in our body. If this were irreversible, we’d all be in deep trouble! Fortunately, just as diet and lifestyle can put these microbes at risk, so diet and lifestyle can re-establish their health and vitality.[5]

For example, in one study, 20 rural South Africans were put on a high-fat, high-meat diet (including hot dogs, hamburgers, and fries). At the same time, 20 African-Americans on put on a high fiber African diet with lots of corn porridge, beans, and fruit. According to the research—

Changes occurred quickly. Inflammation of the colon, which increases the risk of cancer, decreased in the African-Americans on the African diet; and it increased in the Africans on the American diet. Production of the fermentation by-product butyrate, thought to prevent colon cancer, increased in those eating African fare, and declined in those eating American-style.[3]

So while the South Africans on a fiber-poor, meat- and fat-fed microbiome, experienced threats to their microbiomes, the African Americans on a healthy fiber rich diet actually began to reverse the decades of dysbiosis in their bodies!

This is the good news!

Now, the bad news.

When Temporary Losses May Become Permanent

The obvious bad news is that we see little evidence of widespread change to rescue the imperiled state of our microbiome. In fact, what we see is continuing widespread popularity of Atkins, Paleo, Ketogenic, and other low-carb fads that promote diets that are the exact opposite of what will nurture a healthy microbiome.

But the bad news gets worse. There is increasing evidence that not only are we losing our healthy microbiome, but that in some respects, this may turn out to be a permanent loss.

One piece of evidence comes from research done on mice. The way mouse microbiome responds to the fiber in food is similar to the human microbiome. When fed plenty of fiber, the healthy microbes that feast on fiber flourish in mice and their microbiomes become more diverse. Alternatively, when they are fed a low fiber, Western diet, diversity plummets, along with the good bacteria, while the unhealthy bacteria rise. That makes the results of this next experiment all the most interesting, though also frightening: researchers have discovered that when pregnant mice go on a no-fiber diet, temporary losses can become permanent. Here is a summary of this process that I think is important for us to carefully consider:

When we pass through the birth canal, we are slathered in our mother’s microbes, a kind of starter culture for our own community. In this case, though, pups born to mice on American-type diets—no fiber, lots of sugar—failed to acquire the full endowment of their mothers’ microbes. Entire groups of bacteria were lost during transmission. When . . . these second-generation mice [were put] on a fiber-rich diet, their microbes failed to recover. The mice couldn’t regrow what they’d never inherited. And when these second-generation animals went on a fiberless diet in turn, their offspring inherited even fewer microbes. The microbial die-outs compounded across generations.

. . . what [this] experiment suggests is that by failing to adequately nourish key microbes, the Western diet may also be starving them out of existence.[3]

It is one thing to know that we in the Western world are losing the microbial heritage we received from our ancestors, it is another to realize that we may be giving our children a permanently diminished heritage. If this continues, the children of this generation may never be able to recover the microbiome that protected their ancestors against many of the destructive, life-threatening diseases we are experiencing today. The types of diseases linked to an unhealthy microbiome are, in many cases, devastating diseases that can begin in childhood and cause confusion and chaos throughout a person’s life.

What has caused this tragedy and what can we do about it?

As noted previously, there are many threats to our microbiome, including how we were born, what we were fed as infants, over-sanitization of our bodies and living environments, and widespread use of drugs and chemicals (especially antibiotics). (I plan to address these topics in an upcoming article.) Some of these factors we can’t change now, but others we can do something about. In fact, the Word of Wisdom seems tailor-made to help us do one of the most important things we can ever do to save our microbial heritage: adopting the whole food, plant-based diet the Lord recommends in D&C 89!

Our Low Fiber Diet Can’t Support a Healthy Microbiome

The healthy gut bacteria in our bodies thrive only on dietary fiber, and dietary fiber is only found in whole plant foods. It is completely absent from animal foods and is the first thing that is tossed out when foods are refined. So the typical Western diet, high in animal foods and processed foods, is the very definition of a low fiber diet. While a whole food, plant-based diet, which focuses on “whole” (unrefined/unprocessed) plant foods and excludes animal foods, is the very definition of a high fiber diet.

The two most dramatic changes to our diets in the last 200 years is the transition from whole foods to processed foods and from plant foods to animal foods. Why this change? Basically, we humans love rich foods that are easily digestible. This has led to a dramatic decrease in the amount of fiber we consume through—

  • Breeding of plants to have less fiber
  • Consuming the parts of plants with the least fiber
  • Eating refined plant foods with little or no fiber
  • Consuming more animal foods, which have no fiber

Since 1970, our overall consumption of grain has risen, but the vast majority is refined grains. Likewise, our consumption of fruits and vegetables has risen somewhat, but most of it is processed, and we are still getting far less than the already relatively low target set by the U.S.D.A. What else has risen? Foods that are not healthful to our microbiome and harmful to human health: added sugars, added fats, and animal foods of all kinds (meat, dairy, and eggs).[6]

Our distant ancestors likely consumed between 100–200 grams of fiber a day.[7] That may well be the optimal nourishment for a healthy microbiome, yet compare that with the average American diet of a paltry 16 grams a day.[8] No wonder we have seen skyrocketing rates of disease related to a diminished microbiome!

How many people do you know are concerned enough about their microbiome to make sure they get enough fiber in the foods they eat every day? If the people you know resemble the average person in America, they are paying relatively little attention to the amount of fiber in their diet and yet quite a lot of attention to the amount of protein. Everyone in America, it seems, is concerned about “getting enough protein”! The irony is that nearly everyone (this include vegetarians and vegans) are getting more protein than their bodies can actually use. At the same time, nearly everyone (except vegans) are consuming far less fiber than even the inadequate amounts recommended by the USDA. (For details, see this video on protein and fiber.)

The Word of Wisdom is the Answer!

We Mormons, of all people, should be very invested in this subject!

  • We know our bodies are temples of God, and we are their stewards.
  • We honor and respect our ancestors and the heritage they have left us.
  • We love and treasure our children and wish to leave them a rich heritage and healthy bodies.

The Prophet Joseph Smith received revelation from our Savior to help us care for our bodies, honor our heritage, and to leave our children the treasure of health.

In D&C 89, the Lord tells us He ordained wholesome (think “whole”) plant foods for our “constitution, nature, and use,” with grains ordained as “the staff of life” (D&C 89:10, 14). Meat is ordained to be used “sparingly” and preferable only in times of need (see D&C 89:12–15). This is the very definition of a whole food, plant-based high fiber diet that can help our healthy bacteria to thrive.

Dear readers: this is the good news! Long before the world knew about the community of microbes in our bodies, long before they had the slightest clue how essential those microbes are to our health, and certainly long, long before they knew what diet we needed to consume to help those microbes to flourish, the Lord revealed to the Prophet Joseph Smith the very diet that we now are beginning to understand is the only diet that will save our microbial heritage and give our descendants a fighting chance at enjoying health!

The Lord tells us in the Word of Wisdom that this revelation is “the order and will of God in the temporal salvation of all saints in the last days” (D&C 89:2) and that it was given in “consequence of evils and designs which do and will exist in the hearts of conspiring men in the last days” (D&C 89:4). Those who keep these saying are promised they’ll run and not be weary, find hidden treasures, and “the destroying angel shall pass by them, as the children of Israel, and not slay them” (D&C 89:21).

Let us take the Lord at His word and fully embrace His wisdom that we may receive these promised blessings. Let us save our microbial heritage and teach our children to do the same. Let us safeguard our health and the health of our children that we may accomplish the mighty work we are called to perform in these the last days!

Feeding Your Microbiome a Healthy Word of Wisdom Diet

It is easy to find lists of high fiber foods. Basically, they are the whole (unrefined/processed) fruits, vegetables, grains, and especially legumes. If you’d like to check your current fiber intake, use this “Quick Fiber Check.” (For more details on the fiber in each type of food, check out the handy food calculator “Cronometer.”)

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

Don’t forget that if you have not been consuming a high fiber diet, it can take some time for your body 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] To view the entire series of articles, see “Discovering the Word of Wisdom” for Meridian Magazine. For a short overview of how a whole food, plant-based diet prevents and reverses chronic disease, see the documentary, Fork Over Knives. For an excellent book-length treatment of this topic, see The China Study by T. Colin Campbell.

[2] Justin Sonnenburg and Erica Sonnenburg, The Good Gut: Taking Control of Your Weight, Your Mood, and Your Long-term Health (New York: Penguin, 2015). See also: Robynne Chutkan, The Microbiome Solution: A Radical New Way to Heal Your Body from the Inside Out (New York: Avery, 2015).

[3] Moises Velasquez-Manoff, “How the Western Diet Has Derailed Our Evolution,” Nautilus (November 12, 2015).

[4] Ann M. O’Hara and Fergus Shanahan, “The Gut Flora as a Forgotten Organ,” EMBO Reports, 7(7) (July 2006): 688–693.

[5] LA David et al., “Diet Rapidly and Reproducibly Alters the Human Gut Microbiome,” Nature 505(7484) (January 23, 2014): 559-63.

[6] HF Wells and JC Buzby, “Dietary Assessment of Major Trends in U.S. Food Consumption, 1970-2005,” Economic Information, Bulletin No. 33. Economic Research Service, U.S. Department of Agriculture; Washington DC: March, 2008.

[7] Interview with Jeff Leach, “Human Food Project Reveals Results of Gut Bacteria on A Paleo Diet,” High Intensity Health with Mike Mutzel (September 29, 2015). (See also the Sonnenburgs’ book, The Good Gut.)

[8] M. Katherine Hoy and Joseph D. Goldman, “Fiber Intake of the U.S. Population: What We Eat in America,” NHANES 2009-2010, U.S. Department of Agriculture (September 2014).