Fiber Additives Starve Gut Microbes. They Eat Mucus Lining.

SUMMARY:  This is not a 1950s sci-fi movie. This is what is likely happening now in your gut according to an amazing study just now publishing in Cell. If you are eating the Standard American Diet, the normal, helpful bacteria in your gut are not getting natural whole food fiber. Instead they are being fed fiber additives supplemented in processed foods, or isolated fiber supplements you are buying. Surprisingly, both the fiber additives and the supplements FAIL to feed your microbiome, and instead, they CANNIBALIZE the mucus lining for fuel, at least for mice, according to this study. Repeat:  Fiber Additives Starve Gut Microbes. They Eat Mucus Lining.  That compromises the intestinal barrier role in preventing pathogen infection. Bottom line: EAT WHOLE FOOD BASED FIBER to feed your microbiome AND DON’T COUNT ON THE FIBER ADDED IN PROCESSED FOODS OR THE SUPPLEMENTS YOU TAKE FOR THAT FIBER. No wonder so many are sick.

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While this work was in mice, the take-home message from this work for humans amplifies everything that doctors and nutritionists have been telling us for decades: Eat A LOT OF FIBER FROM DIVERSE NATURAL SOURCES, says Martens.Your diet directly influences your microbiota, and from there it may influence the status of your gut’s mucus layer and tendency toward disease. But it’s an open question of whether we can cure our cultural lack of fiber with something more purified and easy to ingest [fiber supplements or that added to processed foods] than a lot of broccoli.”  —Eric Martens, Ph.D., an associate professor of microbiology at the University of Michigan Medical School who led the research along with his former postdoctoral fellow Mahesh Desai, Ph.D., now at the Luxembourg Institute of Health.


[Updated Nov 22, 2016:]  The  importance of eating lots of variety, or diversity, of whole food fiber 

Different fiber types work together to maintain optimal digestive health.  “We can’t expect all fibers to have the same functions, just like we don’t expect all vitamins to have the same functions.  Mixing different types of naturally occurring fibers will ensure that they work together and be as beneficial as possible.” —Dr. Julie Miller Jones, professor emeritus at St. Catherine University, at the 12th symposium at IFT15: Where Science Feeds Innovation,  Consumers should seek a variety of fiber sources to get the maximum health benefits.

This is spot on with the American Gut microbiome findings that while 6 different vegetables each week is good, 30 differing is best. Read that post here.  
[Updated Nov 22, 2016:]  Most Americans eat very little fiber, and the fiber they do eat is not whole food high fiber options

The US average actual fiber consumption is 18 grams per day for men while women ingest about 15 grams.  The recommended daily fiber intake for men is 38 grams of fiber per day, for women the number is 25 grams. The number of Americans who said they are trying to eat more fiber declined from 73% in 2010 to 53% in 2014. The Healthy People 2010 initiative set a goal of 2 fruits and 3 vegetables a day to help adults get the recommended amount of fiber, but just 32% eat that amount of fruit and only 26% eat three vegetables.  Further, those figures are misleading because when consumers choose fruits or vegetables, it’s often low fiber options, such as one piece of lettuce and a thin slice of tomato on a sandwich.  Jones 2015, at the 12th symposium at IFT15: Where Science Feeds Innovation.


The 2016 Cell study details:
  1. The researchers used specially born and raised mice having no gut microbes of their own, that then receive a transplant of 14 bacteria that normally grow in the human gut.
  2. The study looked at the impacts of diet with differing fiber content and those with no fiber, and the researchers looked to see how the microbiota reacted to that fuel.
  3. The researchers then infected some of the mice with certain strains of the bacteria Escherichia coli which causes gut infections in mice that are similar to that which occur in humans. The infections lead to irritation, inflammation, diarrhea, and more.
The study found that in mice, Fiber Additives Starve Gut Microbes — They Eat the Gut Mucus Lining.
All diets except for the natural whole food diet comprised of 15% fiber from minimally processed grains and plants, starved the gut microbiota.  
When fed those diets of fiber additives, the microbiota was starved and the helpful bacteria began to munch on the natural layer of mucus that lines the gut, eroding it to the point where dangerous invading bacteria could infect the colon wall.

 

A diet having about 15 percent fiber from minimally processed grains and plants:

allowed the mucus layer to stay thick, and the infection didn’t take full hold.

What Happened in the No fiber Diet:

When the researchers substituted a diet with no fiber in it, even for a few days, some of the microbes in their guts began to munch on the mucus. They observed that the more dangerous E. coli-like bacteria called Citrobacter rodentium flourished more in the guts of mice fed a fiber-free diet. Many of those mice began to show signs of illness and lost weight.  

[Updated Nov 19, 2016]  In reply to your comments, you are correct, I have mentioned another lab, the Sonnenburg Lab, and their analysis that elimination of microbiota-accessible carbohydrates (MACs) from the diet results in thinner mucus, increased proximity of microbes to the epithelium, and heightened expression of inflammatory markers.  MACS is a great new term because it means “the main component of dietary fiber that serve as the primary metabolic input for the gut microbiota” aka fuel for the microbiome.  The Sonnenburg published findings are,  Quantitative Imaging of Gut Microbiota Spatial Organization, Oct. 2015.  

What does that look like?

What Happened in a Diet that was Rich in Prebiotic Fiber in a purified form of soluble fiber that is similar to what some processed foods and supplements currently contain:

That diet resulted in the SAME erosion of the mucus layer as observed in the lack of fiber.

The bacteria that flourished are those that preferred the fuel provided — no surprise there…

For the low-fiber and no-fiber conditions, the four bacteria strains that flourished the most were the only ones that make enzymes that are capable of breaking down the long molecules called glycoproteins that make up the mucus layer.

The researchers could see which fiber-digesting enzymes the bacteria were making. They detected more than 1,600 different enzymes capable of degrading carbohydrates – similar to the complexity in the normal human gut. The researchers found that the mix of enzymes being made changed depending on what the mice were being fed, with even occasional fiber deprivation leading to more production of mucus-degrading enzymes.

The mucus layer images tell the story

Images of the mucus layer, and the “goblet” cells of the colon wall that produce the mucus constantly, showed that for a diet having reduced fiber the layer was thinner, and in the presence of the infection, the mucus layer was thin and patchy with inflammation spanning a wide area. Mice having a fiber-rich diet before being infected also had some inflammation, but it was across a much smaller area.  That means they were better protected from the infection.

Mucus production

While mucus is constantly being produced and degraded in a normal gut, the change in bacteria activity under the lowest-fiber conditions meant that the pace of eating was faster than the pace of production – almost like an overzealous harvesting of trees outpacing the planting of new ones.

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“While this work was in mice, the take-home message from this work for humans amplifies everything that doctors and nutritionists have been telling us for decades: Eat A LOT OF FIBER FROM DIVERSE NATURAL SOURCES, says Martens. “Your diet directly influences your microbiota, and from there it may influence the status of your gut’s mucus layer and tendency toward disease. But it’s an open question of whether we can cure our cultural lack of fiber with something more purified and easy to ingest [fiber supplements or that added to processed foods] than a lot of broccoli.”

Here’s what a Whole Foods Diet looks like 
Study and related links

A Dietary Fiber-Deprived Gut Microbiota Degrades the Colonic Mucus Barrier and Enhances Pathogen Susceptibility, Nov 17, 2016, Volume 167, Issue 5, p1339–1353.e21, DOI: http://dx.doi.org/10.1016/j.cell.2016.10.043

University of Michigan Health System, High-Fiber Diet Keeps Gut Microbes From Eating The Colon’s Lining, Protects Against Infection, Animal Study Shows

High-fiber diet keeps gut microbes from eating the colon’s lining, protects against infection, animal study shows,

Eating fiber keeps gut microbes from eating you, 

[Updated Nov 19, 2016]   Quantitative Imaging of Gut Microbiota Spatial Organization, Oct. 2015  — Sonnenburg published findings, elimination of microbiota-accessible carbohydrates (MACs) from the diet results in thinner mucus, increased proximity of microbes to the epithelium, and heightened expression of inflammatory markers.

Bottom line:   EAT LOTS OF DIFFERENT WHOLE FOOD BASED FIBER to feed your microbiome, AND DON’T COUNT ON THE FIBER ADDED IN PROCESSED FOODS OR THE SUPPLEMENTS YOU TAKE FOR THAT FIBER.

Best in Health thru Awareness,

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Last updated: February 15, 2017 at 15:41 pm to add these two sections to stress diversity of fiber is important:

  1. Updated Nov 22, 2016:  It’s not just about eating more fiber, its important to eat variety, or diversity, of fiber.  
  2. Updated Nov 22, 2016:  Most Americans eat little fiber, and most don’t even know to eat more

Prior update Nov 19, 2016 added Sonnenburg links (elimination of microbiota-accessible carbohydrates (MACs) from the diet results in thinner mucus, increased proximity of microbes to the epithelium, and heightened expression of inflammatory markers.)

 

6 thoughts on “Fiber Additives Starve Gut Microbes. They Eat Mucus Lining.”

  1. Baking with coconut flour is not easy as it takes MANY eggs. Maybe where a 1/4 cup of regular flour is needed substituting with coconut flour is reasonable. I do wish here were more recipes for the use of coconut flour.

    1. Hi! You are absolutely right that it is not easy cooking with coconut flour! And failures are expensive because of the ingredient cost. I actually only use coconut flour and/or almond flour in baking. It has taken me a long time, with a lot of failures, to find coconut flour recipes that are excellent. The few that I have found to be excellent, approved by family and friends, are on my Pinterest Coconut Four Board. The “Dessert board” has family and friend approved recipes that use either all almond flour, or a blend of almond flour with coconut flour. I hope you check them out. Please let me know if you have found coconut flour recipes that seem to work! I’m always interested in adding to those boards!

  2. I especially like Paul Whiteley Pearls on this article, Dietary fibre deficiency and gut barrier integrity http://questioning-answers.blogspot.com/2016/12/dietary-fibre-deficiency-and-gut-barrier-integrity.html?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+QuestioningAnswers+%28Questioning+Answers%29 :

    Fibre (UK spelling) comes in various different forms typically categorised as soluble and insoluble depending on their relationship with water. Using a “gnotobiotic mouse model” – where mice were “colonized with a synthetic human gut microbiota composed of fully sequenced commensal bacteria” – Desai et al reported on the effects of different diets with different fibre content. Their results make for important reading as a fibre-deprived gut was associated with the rise of some rather potent bacteria that seemed to enjoy dining out on the “colonic mucus barrier, which serves as a primary defense against enteric pathogens.” Yes, mice gut barriers – or some of their components at least – were being eaten by the very bacteria they contain. Enjoy your lunch.

    I’m not dwelling too much on the Desai findings, bearing in mind their focus on mice not humans, but I do want to raise a couple of potentially relevant points. First is the focus on the intestinal barrier and how that so-called ‘leaky gut’ seems to show a connection to dietary fibre intake. Yet more research bringing this woo-like term in from the scientific cold (see here). Next is the idea that if the Desai results are transferable from mouse to humans, they could be relevant to quite a lot of people who perhaps don’t enjoy as much dietary fibre as they should. Further, there may be particular groups of people who might be particularly prone to a poor diet [3] (see here too) where the already discussed term ‘leaky gut’ is also relevant (see here); also bringing in the idea of a role for those trillions of wee beasties (the gut microbiota) that call us home.

    I’ll be watching for how this research area pans out…

  3. Coconut Flour. This is a fiber not used much in the US that healing diets use.

    The benefits of Coconut Flour is explained in the article, A Low Carbohydrate, Guten-free Four, A Review Article, http://interscience.org.uk/v4-i1/1%20ijahm.pdf If it doesn’t load, just google the title.

    Overseas, they’ve looked at adding coconut flour to wheat flour based foods: Breads with coconut flour addition up to 10% ranked ‘good’ and 20% ranked ‘satisfactory’, whereas 30% substitution [ranked] negatively affected appearance, texture and overall acceptability of the product, ranked ‘poor’ in sensory evaluation. See the study at: Use of coconut flour as a source of protein and dietary fibre in wheat bread, https://www.researchgate.net/publication/235199278_Use_of_coconut_flour_as_a_source_of_protein_and_dietary_fibre_in_wheat_bread

    This UK 201 article, Coconut Flour – A Low Carbohydrate, Gluten-free Four, A Review Article, http://interscience.org.uk/v4-i1/1%20ijahm.pdf, explains:

    Coconut flour has been found in several studies to have a glycemic lowering effect, because coconut meat has a simple carbohydrate content coupled with a high fiber, it yields a flour that is less disruptive to blood sugar levels.

    Coconut flour is extremely high in fiber with almost double the amount found in wheat bran. This flour can be used much like wheat flour to make a multitude of delicious breads, pies, cookies, cakes, snacks and desserts. It contains more calorie free fiber than other wheat alternatives. Coconut flour also provides a good source of protein. While coconut flour does not contain gluten (the type of protein found in many grains) it does not lack protein. It contains more protein than enriched flour, cornmeal and also as much as wheat flour.

    Coconut is a natural low-carb, high-fiber food ideally suited for low carbohydrate diets. One cup of shredded fresh coconut (80 grams) contains 3 grams of digestible carbohydrate and 9 grams of fiber. The remaining 68 grams consists primarily of water, fat, and protein. Although a piece of fresh coconut may taste sweet, its digestible carbohydrate content is lower, and its fiber content is higher than most fruits and vegetables. By promptly absorbing and promoting the timely expulsion of irritating agents, carcinogens and even parasites, natural fiber is essential for the systematic cleansing and detoxification of the body.

    The Food and Nutrition Research Institute of Department of Science and Technology also said that coconut flour has a total dietary fiber (TDF) content that is even greater than the popular dietary fiber sources like oat brand and flaxseed (Mauro, 2013)

  4. This UK 201 article, Coconut Flour – A Low Carbohydrate, Gluten-free Four, A Review Article, http://interscience.org.uk/v4-i1/1%20ijahm.pdf, explains:

    There are two types of carbohydrate in foods: digestible and non-digestible. The type of carbohydrate that is of concern to most people is digestible carbohydrate (starch and sugar). These are the carbs that the body converts into fat and packs into our fat cells.

    Consumption of excess carbohydrates, contribute to an assortment of health problems such as insulin resistance, obesity, and diabetes.

    Non-digestible carbohydrate, on the other hand, is composed of fiber and passes through the digestive tract without being broken down or absorbed and is passed out of the body. Instead of contributing to health problems like starch and sugar, fiber promotes good health.

    Refined flours are concentrated in simple carbohydrates which are rapidly metabolized and cause destructive blood sugar fluctuations in the body.

Now I'd like to hear your thoughts... comments are always welcome!