The Wheat Series Part 3: Setting Off the Bacterial Alarm Bells – With or Without the Bacteria

The Wheat Series Part 3: Setting Off the Bacterial Alarm Bells – With or Without the Bacteria | The Paleo Diet

Did you miss The Wheat Series Part 1: Wheat and the Immune System? Read it HERE.
Did you miss The Wheat Series Part 2: Opening the Barrier to Poor Gut Health? Read it HERE.

It’s a battle that’s been waging for millions of years. Viruses, bacteria, and a variety of pathogens looking for a nice warm home have evolved more and more sophisticated techniques to evade our immune systems. In response, our immune systems developed an array of specialized cells to launch remarkably targeted attacks at these unwanted invaders.

In the face of this cellular army, pathogens discovered one of their best weapons is a microscopic form of hide-and-seek.

Viruses mimic our bodies so immune cells pass them by.1, 2 Meningitis hangs out in the nervous system where immune cells dare not go, and HIV takes up home in immune cells themselves – after, of course, dismantling a few defenses.

These are all ways of telling the immune system “keep moving, nothing to see here.”

But what would happen if instead of looking for a good hiding place, an invader actually tried to set off the immune system alarm bells? More importantly, why would an invader want to do that?

Well, imagine you’re a plant. When some hungry animal looks at you and says “lunch” you can’t really run away. Nor can you fight back. So what do you do?

You make sure that after the animal has its meal, it is sick enough to think twice about ever touching one of your brethren.

Enter wheat.

In Part One of this series on wheat, I talked about how the normally sluggish digestive immune system can become inappropriately inflamed and lead to disease. Three things can cause this: intestinal permeability (leaky gut); chronic or too high a bacterial load; and dietary antigens.

Wheat has the unique distinction of influencing all three.

The first, intestinal permeability, is promoted by wheat through the release of zonulin.3-5 We covered that in Part Two.

Let’s get to Part Three – chronic or too high a bacterial load.

Of course, you’ve probably already realized that wheat is not bacteria. True. But the same way viruses mimic our bodies, wheat has evolved ways to “mimic” bacteria. All with the purpose of setting off the immune system alarm bells – whether the bacteria is there or not.


Our bodies actually like bacteria.

At least when they stay where they belong – in the gut.6-9 In fact, in Part One, we talked about how much of our digestive immune system evolved to allow us to live with this bacteria.7, 9-11

It’s when the bacteria – especially the less friendly types such as gram negative bacteria – get into our bodies that the immune system takes action. As a result, our immune cells have developed critical tools for the sole purpose of hunting down and identifying bacteria inside the body.

Fortunately, the bad gram negative bacteria has a tell. All over its surface is something called lipopolysaccharide (LPS).12

Antigen presenting cells (APCs) hunt down bacteria using two receptors for LPS called TLR-4 and CD14.12, 13 When LPS binds TLR-4 and CD14, the immune system alarm bells go off.

The diagram below shows the basics of this sophisticated alarm system,14 but the end result is simple. The immune system spins up and inflammation ensues.

The Wheat Series Part 3: Setting Off the Bacterial Alarm Bells – With or Without the Bacteria | The Paleo Diet


That subtitle is actually only partially accurate. A better description might be “wheat – the boy who cried bacterial wolf.”

The problem is our bodies never learn to ignore this particular boy.

Wheat has developed a variety of sophisticated techniques for activating the LPS response. But in some cases, it does it differently from LPS, bypassing key regulatory steps such as CD14 which would otherwise prevent inflammation in places we don’t want it.6, 10

A full description of these mechanisms is beyond the scope of this article and probably your boredom limit. So, the following is only a cursory description, but with lots of journal references that will keep the geekiest of you happy.


Part Two gives an in depth description of how wheat opens up the digestive tract barrier and allows things in our gut to get into our bodies. This includes our intestinal bacteria.15

The Wheat Series Part 3: Setting Off the Bacterial Alarm Bells – With or Without the Bacteria | The Paleo Diet

In other words, wheat actually lets the wolf into the chicken coop and then cries wolf.


Wheat contains its own LPS-like molecule, sometimes called LPSw, that has similar effects but admittedly isn’t as potent as the real thing.16, 17 In one study on mice, LPSw was able to promote a bacterial immune response.17


(No It’s Not a Computer Company)

At the barrier of our gut are a special type of immune cell called dendritic cells. Constantly sampling the contents of our digestive tract, tthey are the on/off switch of the immune system.18 Think of them as Paul Revere riding back to the immune system yelling “the bacteria are coming!”

Wheat contains molecules that very potently activates dendritic cells called α-Amylase/Trypsin Inhibitors (ATIs).19 They act through TLR-4 on the dendrites. And sorry to those of you who love to say you’re “gluten-free” – ATIs, which exist in many grains, are found in a different part than gluten.

ATI’s are responsible for a long known condition called Baker’s Asthma named so because it was common among people who worked with flour.20


TLR-4 and CD14 are not strongly expressed in the gut immune system making it hard to sound the bacterial alarm in the gut.21-23 In an area of the body that’s exposed to bacteria thousands of times each day, an inflammatory response isn’t something we want.21, 22

So it should be concerning to hear that wheat has developed ways of causing the inflammatory response without bothering with TLR-4 or CD14.

The ways wheat does it gets complex. We’ll just touch on them.

First, in several studies, small amounts of gluten were able to flip the dendritic cell’s “on switch” in mice and start an inflammatory response without touching TLR-4.24, 25

Another molecule in wheat (there’s a lot) called wheat germ agglutinin (WGA) can bind and pass right through the gut barrier to interact with immune cells on the other side. WGA then promotes a highly inflammatory response26, 27 including turning dendritic cells on.

Finally, remember all those antigen presenting cells in the gut that avoid sounding the bacterial alarm bells by simply not expressing CD14? Gliadin promotes something called IL-15 which is highly effective at activating APCs that don’t express CD14.28-33

And of a variety of foods tested, gliadin was the only one able to so effectively activate these cells.33


That’s a lot of science and frankly we only just skimmed the surface. So here’s the point – wheat is amazingly effective at activating the bacterial defence mechanisms of our immune cells.

More importantly, this response happens in everyone and not just celiac disease (though there’s evidence it’s more pronounced in celiacs).29

So what happens when our bodies mount a defense against bacteria that isn’t there? The answer to that question is the focus of the final part to this series. But the short answer is it creates a constant state of inflammation as long as we continue to eat wheat.34, 35

Recent research is now associating a state of constant inflammation with the onset of nearly all major chronic diseases36 including heart disease,37 Alzheimer’s disease,38 diabetes,39 cancer,40, 41 and overall morbidity.42

But the question remains does the inflammation that results from wheat inappropriately setting off the bacterial alarms also contribute to these conditions?

That’s a question we’ll hope to delve into in the next two parts. But fortunately, by eating a wheat-free Paleo diet, it’s a question you may never have to worry about.

Read The Wheat Series Part 4: Home Invasion HERE



[1]Alcami, A., Viral mimicry of cytokines, chemokines and their receptors. Nat Rev Immunol, 2003. 3(1): p. 36-50.

[2]Amara, A. and J. Mercer, Viral apoptotic mimicry. Nat Rev Microbiol, 2015.

[3]Lammers, K.M., et al., Gliadin induces an increase in intestinal permeability and zonulin release by binding to the chemokine receptor CXCR3. Gastroenterology, 2008. 135(1): p. 194-204 e3.

[4]Drago, S., et al., Gliadin, zonulin and gut permeability: Effects on celiac and non-celiac intestinal mucosa and intestinal cell lines. Scand J Gastroenterol, 2006. 41(4): p. 408-19.

[5]Visser, J., et al., Tight junctions, intestinal permeability, and autoimmunity: celiac disease and type 1 diabetes paradigms. Ann N Y Acad Sci, 2009. 1165: p. 195-205.

[6]Ohnmacht, C., et al., Intestinal microbiota, evolution of the immune system and the bad reputation of pro-inflammatory immunity. Cell Microbiol, 2011. 13(5): p. 653-9.

[7]McFall-Ngai, M., Adaptive immunity: care for the community. Nature, 2007. 445(7124): p. 153.

[8]Ivanov, II, et al., Induction of intestinal Th17 cells by segmented filamentous bacteria. Cell, 2009. 139(3): p. 485-98.

[9]Cao, A.T., et al., Th17 cells upregulate polymeric Ig receptor and intestinal IgA and contribute to intestinal homeostasis. J Immunol, 2012. 189(9): p. 4666-73.

[10]Smith, P.D., et al., Intestinal macrophages and response to microbial encroachment. Mucosal Immunol, 2011. 4(1): p. 31-42.

[11]Arrieta, M.-C. and B.B. Finlay, The commensal microbiota drives immune homeostasis. Frontiers in Immunology, 2012. 3.

[12]Kawai, T., et al., Lipopolysaccharide stimulates the MyD88-independent pathway and results in activation of IFN-regulatory factor 3 and the expression of a subset of lipopolysaccharide-inducible genes. J Immunol, 2001. 167(10): p. 5887-94.

[13]Perera, P.Y., et al., CD11b/CD18 acts in concert with CD14 and Toll-like receptor (TLR) 4 to elicit full lipopolysaccharide and taxol-inducible gene expression. J Immunol, 2001. 166(1): p. 574-81.

[14]Buer, J. and R. Balling, Mice, microbes and models of infection. Nat Rev Genet, 2003. 4(3): p. 195-205.

[15]Fasano, A., Zonulin and its regulation of intestinal barrier function: the biological door to inflammation, autoimmunity, and cancer. Physiol Rev, 2011. 91(1): p. 151-75.

[16]Yamazaki, K., J.A. Murray, and H. Kita, Innate immunomodulatory effects of cereal grains through induction of IL-10. Journal of Allergy and Clinical Immunology, 2008. 121(1): p. 172-178.

[17]Nishizawa, T., et al., Homeostasis as regulated by activated macrophage. I. Lipopolysaccharide (LPS) from wheat flour: isolation, purification and some biological activities. Chem Pharm Bull (Tokyo), 1992. 40(2): p. 479-83.

[18]Williamson, E., G.M. Westrich, and J.L. Viney, Modulating dendritic cells to optimize mucosal immunization protocols. J Immunol, 1999. 163(7): p. 3668-75.

[19]Junker, Y., et al., Wheat amylase trypsin inhibitors drive intestinal inflammation via activation of toll-like receptor 4. J Exp Med, 2012. 209(13): p. 2395-408.

[20]Sapone, A., et al., Spectrum of gluten-related disorders: consensus on new nomenclature and classification. BMC Med, 2012. 10: p. 13.

[21]Kamada, N., et al., Unique CD14 intestinal macrophages contribute to the pathogenesis of Crohn disease via IL-23/IFN-gamma axis. J Clin Invest, 2008. 118(6): p. 2269-80.

[22]Nagler-Anderson, C., Tolerance and immunity in the intestinal immune system. Critical Reviews in Immunology, 2000. 20(2): p. 103-120.

[23]Smythies, L.E., et al., Human intestinal macrophages display profound inflammatory anergy despite avid phagocytic and bacteriocidal activity. J Clin Invest, 2005. 115(1): p. 66-75.

[24]Palova-Jelinkova, L., et al., Gliadin fragments induce phenotypic and functional maturation of human dendritic cells. J Immunol, 2005. 175(10): p. 7038-45.

[25]Nikulina, M., et al., Wheat gluten causes dendritic cell maturation and chemokine secretion. J Immunol, 2004. 173(3): p. 1925-33.

[26]Dalla Pellegrina, C., et al., Effects of wheat germ agglutinin on human gastrointestinal epithelium: insights from an experimental model of immune/epithelial cell interaction. Toxicol Appl Pharmacol, 2009. 237(2): p. 146-53.

[27]Gabor, F., M. Stangl, and M. Wirth, Lectin-mediated bioadhesion: binding characteristics of plant lectins on the enterocyte-like cell lines Caco-2, HT-29 and HCT-8. J Control Release, 1998. 55(2-3): p. 131-42.

[28]Harris, K.M., A. Fasano, and D.L. Mann, Monocytes differentiated with IL-15 support Th17 and Th1 responses to wheat gliadin: implications for celiac disease. Clin Immunol, 2010. 135(3): p. 430-9.

[29]Bernardo, D., et al., Is gliadin really safe for non-coeliac individuals? Production of interleukin 15 in biopsy culture from non-coeliac individuals challenged with gliadin peptides. Gut, 2007. 56(6): p. 889-890.

[30]Jelinkova, L., et al., Gliadin stimulates human monocytes to production of IL-8 and TNF-alpha through a mechanism involving NF-kappaB. FEBS Lett, 2004. 571(1-3): p. 81-5.

[31]Palova-Jelinkova, L., et al., Pepsin digest of wheat gliadin fraction increases production of IL-1beta via TLR4/MyD88/TRIF/MAPK/NF-kappaB signaling pathway and an NLRP3 inflammasome activation. PLoS One, 2013. 8(4): p. e62426.

[32]Thomas, K.E., et al., Gliadin stimulation of murine macrophage inflammatory gene expression and intestinal permeability are MyD88-dependent: role of the innate immune response in Celiac disease. J Immunol, 2006. 176(4): p. 2512-21.

[33]Tuckova, L., et al., Activation of macrophages by gliadin fragments: isolation and characterization of active peptide. J Leukoc Biol, 2002. 71(4): p. 625-31.

[34]Nilsen, E.M., et al., Gluten activation of peripheral blood T cells induces a Th0-like cytokine pattern in both coeliac patients and controls. Clin Exp Immunol, 1996. 103(2): p. 295-303.

[35]Antvorskov, J.C., et al., Dietary gluten alters the balance of pro-inflammatory and anti-inflammatory cytokines in T cells of BALB/c mice. Immunology, 2013. 138(1): p. 23-33.

[36]Hotamisligil, G.S., Inflammation and metabolic disorders. Nature, 2006. 444(7121): p. 860-867.

[37]Libby, P., P.M. Ridker, and A. Maseri, Inflammation and atherosclerosis. Circulation, 2002. 105(9): p. 1135-1143.

[38]Akiyama, H., et al., Inflammation and Alzheimer’s disease. Neurobiology of Aging, 2000. 21(3): p. 383-421.

[39]Xu, H.Y., et al., Chronic inflammation in fat plays a crucial role in the development of obesity-related insulin resistance. Journal of Clinical Investigation, 2003. 112(12): p. 1821-1830.

[40]Grivennikov, S.I., F.R. Greten, and M. Karin, Immunity, Inflammation, and Cancer. Cell, 2010. 140(6): p. 883-899.

[41]Coussens, L.M. and Z. Werb, Inflammation and cancer. Nature, 2002. 420(6917): p. 860-867.

[42]Krabbe, K.S., M. Pedersen, and H. Bruunsgaard, Inflammatory mediators in the elderly. Exp Gerontol, 2004. 39(5): p. 687-99.

About Trevor Connor, M.S.

Trevor Connor, M.S.Trevor Connor was Dr. Loren Cordain’s last graduate student at Colorado State University. His research with Dr. Cordain focused on the effects of a Paleo style diet on autoimmune conditions. Their pilot study included close to 60 volunteers with diverse conditions ranging from Crohn’s Disease, to Multiple Sclerosis to Hashimoto’s Thyroiditis. The results were very promising, including all eight Crohn’s subjects going into remission on the Paleo Diet.

Trevor started working with Dr. Cordain in 2010, soon after retiring as a Professional Cyclist. At 38, he felt it was time to hang up the bike. Trevor had studied traditional sports nutrition for over a decade and was admittedly very reluctant to accept the Paleo Diet. But after experimenting with the diet himself, Trevor was able to return to the Pro Peloton at 40, getting Top Five’s in several races and establishing himself as the top ranked 40+ rider in the country for several years running.

Trevor now writes the Coaching Section of the international cycling magazine Velo, has his own coaching business, and recently managed the semi-Professional cycling team Team Rio Grande who’s alumni include Teejay Van Gaarderen, a top five finisher at the Tour de France and multiple national champions.

Trevor is currently working on publishing several studies and reviews on the effects of wheat on the digestive immune system. Recently, he moved back to Canada so his wife could pursue her dream of making the 2016 Olympics in pole vaulting (as a Paleo Dieter and ranked top 10 in the country in her mid-30’s.)

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“4” Comments

  1. I can’t thank you enough Dr. Davis. You have cnhegad my life. I have been wheat free for about 8 months with great results. I just wish I could convince family and friends to go wheat-free. I try not to be overbearing with it, but it is frustrating to watch them destroy themselves. I have a close friend who is 6 , 275lbs, and 55 yrs old. He just told me he was recently diagnosed with a heart condition something about a weakening of the arterial wall in the heart. Yikes! I had breakfast with him and he ate a huge bowl of grits and several large white biscuits with gravy. He than ate most of the toast that came with my meal!!! He knows of the dangers of wheat consumption, but apparently this means little. He is no dummy. He has a masters in engineering and a great job. He is a new grandpa with two beautiful grand daughters, which he is constantly showing off pictures of. He has much to live for, but refuses change his diet. Ugh!!!! I also have a brother in-law with a body much like my engineer friend. His health insurer told him he needs to lose 55lbs or his insurance premium will increase significantly. He just went on Weight Watchers. He too knows about wheat. I suggested he lose the wheat and sugar and he will succeed. His response was I love bread and sweets. So, I guess this means he intends to continue the same diet that has made him fat and unhealthy. How do we break through to these people?

    • It’s tough to watch your relatives and friends suffer when you know they can heal by simply making health conscious decisions in their lives. It can be very difficult for people to radically change their diet when they have been accustomed to consuming a Standard Western Diet. All you can do is continue to inform your friends and relatives about the benefits of leading a healthier lifestyle. There are a lot of social, societal, and mental pressures that can influence a person’s diet choices, and ultimately it will come down to the individual to make a health-oriented decision. Positive encouragement and education are essential.

  2. hi,
    Over the past four years, I have had a miriad of health issues.

    I am 71 and live in Australia. My husband is 73, and we have enjoyed 51 years in a wonderful marriage. We have three children and seven grandchildren – with all of whom, we have a very loving and constant relationship.

    Unfortunately, in 2011, my husband had Triple ByPass Surgery together with a valve replacement surgery. Two years later – in late 2012 – he had a Total Knee Replacement and has had a second one just 3 months ago. Sadly, he has recently been diagnosed with Early Onset Parkinson’s Disease and is currently on a CPAP machine for Sleep Aponea.

    In 2011, just after my husband’s heart surgery. I developed Meningitis. I was on Prednisone and then Methotrexate before it finally left me – 3 and a half years later.

    During this same time, I developed Shingles in three nerves. I was left with the debilitating and absolutely heinous and severe Post Herpetic Neuralgia (PHN) pain in the one nerve controlling my right arm, hand and three fingers. I was prescribed Oxycontin and Lyrica (and was also taking the Prednisone mentioned before.) Because of the pain I was suffering, the PHN was later reclassified as Chronic Regional Pain Syndrome (CRPS), ad I was hospitalised for 2 weeks earlier this year, in an attempt to ‘manage’ the pain.

    Also during this time, I had surgery on my Thyroid due to a large 3.5cm tumour (benign), and I am now taking 75 mg of Thyroxine. I also had a tumour on my Adrenal Gland which was not touched.

    I would have had at least 12/14 MRIs, numerous scans and hundreds of blood tests.

    I also had two cataracts both of which required surgery for two new lenses.

    I also had two nasty Retinal bleeds, one necessitating surgery, and just recently I had a small growth removed from my right eye containing ‘cancer cells’.

    Then there were the 5 or 6 Mini Strokes – TIA’s I think?

    I also use a CPAP machine due to having moderate to severe Sleep Aponea.

    I also had a Total Knee Replacement after my MRI showed that my knee was completely mascerated. I did realise that I had a ‘sore’ knee but due to taking the above Oxycontin, the pain was masked until it got so bad that I was wheelchaired for a week before urgent surgery.

    Luckily, neither my husband nor I, have Diabetes.

    I am overweight due to having gained 12 kgs due to the Prednisone and possibly the Lyrica.

    Most times, I do feel well but there are times when I don’t feel well at all.

    Although I believe we eat well, I have thought that maybe our diet is lacking in, or including, something wrong – hence my contact with you guys.

    The Paleo Diet was recently featured on a television show and while my husband does not appear to be interested in it, he does already eat a variety of fruit and veges and he loves red meat. I enjoy mostly fruit but the only vegies I eat, would be pumpkin, potatoes, onions, tomatoes, peas, and stir fry vegies. Our main vegetables in our current diet, would be potato, peas and pumpkin and we have whole grain cereal and bread for the first two meals of the day, plus fat reduced milk.

    Would you kindly advise me further. My husband and I would very much appreciate it.

    We have trialed Medicinal Cannabis with very positive results for both of us, but as it is still illegal here, we have trouble obtaining it on a regular basis.

    Kind regards

  3. Another brilliant amazing article!
    Into the face of who is still going on claiming that the grain issue and the paleo lifestyle is just a fad. Hey folks, how long can you keep on trying to hide the evidence?

  4. Pingback: The Wheat Series Part 3: Setting Off the Bacterial Alarm Bells – With or Without the Bacteria | Health Fitness Daily

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