Antibiotic Resistance, Superbugs and Drugs

--- All 200 posts here ---

Antibiotic resistance results, because spontaneous mutations occur so frequently that all bacteria are different.  It is just a matter of exposing enough bacteria to an antibiotic to find one that is insensitive to a particular antibiotic.  More bacteria mean a greater chance of mutations to antibiotic resistance.  The gut contains a lot of bacteria and sewage treatment plants are loaded with gut flora.

Health in Diagrams

Antibiotics are Ubiquitous

All organisms, plants, fungi and animals/humans produce chemicals that kill bacteria, i.e. antibiotics.  I have written many articles about the natural antibiotics of plants, a.k.a. phytoalexins or “antioxidant” polyphenolics, and the human defensins that are peptides with heparin binding domains.  Bacteria also produce viruses, called bacteriophages, that kill other bacteria.  All of these natural antibiotics are small molecules that interact with many different human proteins, and it is these side effects that permit their exploitation as pharmaceuticals.  Thus, statins were selected from fungal antibiotics that inhibited an enzyme needed for human synthesis of cholesterol, metformin was a phytoalexin found to reduce blood sugar and resveratrol is a grape phytoalexin.

Plant Antibiotics are Natural

The flavoring chemicals in herbs and spices have a far more important use in food preparation than titillation of taste buds, since those chemicals kill common food pathogens.  More profoundly, it is important to realize that the selective advantage of phytochemicals/polyphenols/alkaloids/essential oils to the plants that make them, is as natural antibiotics.  Plants kill bacteria, as well as fungi and insects, for a living.

Plant Chemicals Attack all Aspects of Bacteria

Most of the thousand genes that are present in a bacterium code for proteins/enzymes and most antibiotics target those enzymes.  Penicillin binds to an enzyme needed to make bacterial cell walls, streptomycin target protein synthesis, rifampicin blocks RNA synthesis, actinomycin D inhibits DNA synthesis, etc.

Mutation to Antibiotic Resistance is Automatic in Bacteria

Each time a cell replicates, mistakes are made and the new DNA molecule of each chromosome is slightly different than the original.  There are about a thousand genes on the single chromosome of a bacterium and about the same number on each of the 23 human chromosomes.  About a dozen mistakes, mutations, are made each time bacteria replicate.  The mutations that alter the gene target of an antibiotic and produce a bacterial enzyme that is unaffected by the antibiotic, yield an antibiotic resistant bacterium.  The mutant gene now codes for antibiotic resistance and the presence of several resistance genes in the same bacterium produces multiple antibiotic resistant "superbugs."

Mutations are Random, but Antibiotics Select for Resistance

Each cellular replication produces random mutations throughout the bacterial DNA, but of the billion sites along the DNA that can mutate, only a few will produce a modified enzyme that will no longer interact with a particular antibiotic and thus be resistant.  Antibiotic resistance mutants are rare, less than one in a million, but a million bacteria can grow from a single cell in a day and occupy a volume less than a crystal of salt.  Ten hours later, after ten more doublings of the million bacteria, there will be a billion, and there will be a good chance that among those will be a mutant that is resistant to a particular antibiotic.  In the pound of bacteria in the human gut, there are mutants that are resistant to most antibiotics, including the antibiotics that have not yet been developed.  Of course, most of those antibiotic resistant bacteria are just flushed down the toilet.  Treatment with antibiotics kills all of the sensitive bacteria and leaves only the resistant.  Thus, antibiotic treatments select for antibiotic resistant bacteria.

Common Use of Antibiotics Selects for Resistance on Plasmids

Genes are transferred between bacteria by bacteriophages, conjugation (a kind of bacterial sex) and transformation, which is the release of DNA from one bacterium with subsequent uptake by another.  Biofilms, which are communities of many different species of bacteria, stimulate transformation and exploit bacterial DNA as a matrix material to hold the communities together.  The human gut is lined with biofilms and the biofilm bacteria secrete vitamins as the quorum sensing signals that coordinate community activity.  Thus, some vitamins must stimulate transformation, the exchange of DNA among members of the different species of bacteria in the biofilms with evolution of new and novel species.  Rapid change in the gut environment selects for a shift in genes that provide for adaptation to the new environment to small DNA fragments, plasmids, that move most readily between bacteria.  Antibiotic treatment results in antibiotic resistance genes on plasmids.

Use of Multiple Antibiotics Selects for Multiple Antibiotic Resistance Plasmids

Persistent use of an antibiotic will spread resistance to a particular antibiotic through the gut flora, facilitated by antibiotic resistant plasmids.  Replacement of a second antibiotic will result in a new plasmid with both antibiotic resistance genes.  Hospitalization and exposure to a plethora of bacteria with multiple antibiotic resistance plasmids will result in rapid conversion of gut flora to multiple antibiotic resistance upon exposure to any antibiotics.  Hospital staff would be expected to be natural repositories for multiple resistance genes, especially if they are exposed to any antibiotic (or pharmaceutical.)

Most Pharmaceuticals Select for Multiple Antibiotic Resistance Plasmids and Superbugs

The frightening rise of superbugs resistant to all known antibiotics has been attributed to the accelerated use of antibiotics in medicine and agriculture.  Mixing megatons of bacteria in the guts of billions of people with tons of antibiotics, and still more in sewage treatment plants and agriculture, is bound to produce bacteria with every type of multiple antibiotic resistance plasmid imaginable.  But that is not the biggest problem, since fingering the commercial use and misuse of antibiotics ignores biggest exposure of bacteria to antibiotics.  It ignores the fact that most popular pharmaceuticals, NSAIDs, statins, anti-depressants, anti-diabetics, etc., also have substantial antibiotic activity.  Most of these pharmaceuticals started out as phytoalexins and then were found to also have pharmaceutical activity.  Pharmaceuticals are just repurposed natural antibiotics.  When you take an aspirin or Metformin or a statin, you are taking an antibiotic.  When you take a pharmaceutical, you are selecting for multiple antibiotic resistance plasmids in your gut flora and you may be making the next superbug.

Health Diagrams III — Inflammation from Cell to Tissue

---All 200 Posts---

I have explained my perspective in diagrams of the relationship between diet, gut flora and disease:

Health Diagrams I — Gut Flora and Diet

and of the interaction between gut flora, the immune system and autoimmunity:

Health Diagrams II — Curing Autoimmunity and Allergies

Now I am discussing how inflammation, the foundation of most chronic diseases, begins at the cellular level and results in the classic symptoms of tissue inflammation: redness, heat, swelling and pain.

NF-kB is the Transcription Factor that Controls Inflammation Genes

Of the 23,000 human genes, about 1,000 on each of 23 chromosomes, five dozen, e.g. enzymes involved in nitric oxide (vasodilation and erection hormone), synthesis of heparin sulfate and prostaglandin synthesis from omega-6 fatty acids or cytokines (IL-1, IL-6, TNFa), are associated with inflammation.  These inflammatory genes are turned on or expressed in individual cells, when the inflammation transcription factor, NF-kB, is activated by any of numerous external signals, including inflammatory cytokines, bacterial or fungal cell wall materials (LPS or beta-glucan), advanced glycation end products (AGE, e.g. HgA1C, resulting from high blood sugar) or reactive oxygen species (ROS, e.g. super oxide, from insulin resistance).

NF-kB and Inflammation
Superoxid Causes Insulin Resistance

Inflammation is the Foundation of Growth, Birth, Cancer and Pain

We think of inflammation as the sum of physical symptoms, and our purpose in responding to inflammation is typically to limit its impact.  We try to stop swelling by applying cold or hot, and we take aspirin to lower fevers and stop pain.  We fail to realize that inflammation is essential to the growth and development of many different tissues, and that inflammation is a cycle that leads back to normal function.  

Body tissues, such as the lining of the intestines or the uterus, continually produce new cells to replace the old that are sloughed off.  NF-kB must be turned on for these growth and attrition cycles.  Taking aspirin blocks NF-kB in the gut and stops local development of the lining, resulting in weak areas that bleed.  That is why doctors encourage patients to drink a half glass of water before and after swallowing aspirin tablets. 

Another more dramatic example of control of inflammation is conception, gestation and birth.  Conception and gestation require inhibition of inflammation, to permit growth of a foreign organism (a fetus is half sperm genes) in the uterus.  Chronic inflammation limits the ability of the uterus to suppress immune attack and can produce infertility, which is treated by aspirin and heparin, which suppress chronic inflammation.  The return of inflammation at the end of gestation precipitates labor and birth.  Excess Inflammation produces high levels of circulating inflammatory cytokines, which causes postpartum depression.  Depression and chronic inflammation have the same cytokine profiles, i.e. depression is a symptom of chronic inflammation.

Birth and Inflammation

Proliferation, or enhanced cell division, is another aspect of inflammation and is also the foundation for cancer.  That is the reason that some doctors recommend low dose aspirin to reduce colon cancer.  Similarly, since inflammation is the basis for coronary artery disease, doctors sometimes recommend low dose aspirin, although this is controversial.  Doctors also use aspirin as a so called blood thinner, since it blocks inflammatory signaling in platelets and discourages clotting.  Inflammation of nerve cells is experienced by the brain as pain.  

When it is understood that inflammation is an essential feature of many normal, healthy cell and tissue functions, then “inflammation," with its negative connotations, becomes a misnomer.

NSAIDs Inhibit Inflammatory Prostaglandin Production

Aspirin directly inhibits NF-kB activation inside the cell, but it also chemically modifies COX, the enzyme that converts omega-6 polyunsaturated fatty acids (common in polyunsaturated vegetable oils) into inflammatory prostaglandins.  Other NSAIDS (Non-Steroidal Anti-Inflammatory Drugs) just inhibit COX, but Aspirin transfers its acetyl group to make acetyl-COX, which has a new activity that converts omega-6 fatty acids into anti-inflammatory prostaglandins.  The high omega-6 fatty acid content of vegetable/seed oils, such as corn, soy, canola, etc. is why these oils, in contrast to olive oil or butter, are inflammatory.  Omega-3 fish oil is anti-inflammatory, because it is converted to anti-inflammatory prostaglandins.  Plant omega-3 fatty acids are shorter and are not converted to prostaglandins, but inhibit omega-6 conversion.

Aspirin

Nitric Oxide, Vasodilation and Viagra

Swelling is caused by vasodilation, the relaxation of blood vessels, and accumulation of serum in the tissue.  This vasodilation also makes the tissue red and warm from the increased amount of warm blood in the capillaries.  Vasodilation is caused by nitric oxide, NO, that is produced by an enzyme under the control of NF-kB, which takes the nitrogen from arginine (or nitroglycerine).  The NO diffuses easily and binds to receptors that produce an amplified signal, cyclic GMP, that relaxes the muscle cells surrounding blood vessels.  [Viagra is potentially dangerous, because it just exaggerates the amplified signal and obscures the underlying vascular damage, e.g. hypertension, that causes erectile dysfunction by blocking normal vasodilation.]

Nitric Oxide and Erectile Dysfunction

Hot/Cold and Endorphins

The dilemma of whether to use hot or cold therapy to block inflammation is based on a misunderstanding of what the temperature changes are actually doing.  Changing the temperature of the skin alters the structure of sensory proteins in nerves of the skin and triggers signals to the brain that register as hot or cold.  Chemicals, e.g. capsaicin or menthol, can have the same effect without changing skin temperature.  The important response for inflammation control, is return signals from the brain that release neurohormones, e.g. endorphins, from different nerves that reach not only some of the skin that was hot or cold, but also deeper tissue.  The endorphins block inflammation and all of its symptoms.  That is why chemically treated pads are more effective than icing or changing from hot to cold, because "hot" and "cold" signaling chemicals can be applied simultaneously.  None of the treatments is more than skin deep.  Actually chilling or heating tissue below the skin is damaging and causes more inflammation.  Low dose Naltrexone may be effective in some cases of chronic inflammation, by stimulating systemic rebound endorphin production.

Dr. Oz, Pain, Hot/Cold Receptors

Lymphocyte Offloading, Mast Cells, Heparin

Rosacea is a group of diseases that involve inflammation of the face in an exaggerated blush.  Any of the signals that would lead to blushing cause intense vasodilation.  A blush is fleeting, but rosacea is made chronic by another aspect of inflammation, offloading of lymphocytes.  Large numbers of lymphocytes accumulating in response to a local infection would produce pus.  In the case of rosacea, the distributed leucocytes, including neutrophils, respond to the blushing signals by producing inflammatory signals, such as P protein.  The result is cycles of inflammation, autoinflammation.

Mast cells can also be offloaded from blood vessels and provide a link between the immune system and inflammation.  Mast cells display IgE receptors on their surfaces, which bind antigens and trigger release of histamine, heparin and protease.  Histamine is a neurotransmitter that binds to receptors on blood vessels and nerve cells.  In the gut, histamine mediates many digestive processes.  Heparin released along with  histamine, coats the gut and prevents attachment of pathogens by competing for binding to the heparan sulfate proteoglycans (HSPGs) that form the surface of cells that line the gut.  [Heparin is the most common drug used in hospitals and is produced from intestines of cattle and hogs in the meat industry.]  Heparin also binds and inactivates the proteases released from mast cells.  Upon release, the now active proteases attack and activate receptors on nerves and immune cells.

Mast Cells and Heparin

Heparin is Anti-Inflammatory

Heparin is the most negatively charged polysaccharide, mediates most of the receptor/hormone interactions at cell surfaces; facilitates amyloid plaque formation, e.g. in Alzheimer's, atherosclerosis, diabetes, dementia; and controls numerous protease reactions in the complement system and clotting, etc.  There are hundreds of heparin-binding proteins.  Heparin is produced in secretory granules of mast cells by the action of heparanase on heparan sulfate proteoglycans. Heparin is a mixture of small fragments, oligosaccharides of heparan sulfate polysaccharides.  Heparin is anti-inflammatory and is administered to facilitate conception and gestation.  Inflammation also inhibits the genes involved in heparan sulfate proteoglycan production and since HSPGs are a major component of basement membranes of tissues and provide the barrier function of blood vessels in kidneys and brain, inflammation leads to proteinuria and loss of the blood brain barrier.  Since HSPGs have a short half life of six hours and are rapidly recycled, heparin added to the blood is rapidly absorbed by vessels, and heparin taken orally is absorbed by intestinal cells, but does not reach the blood.  HSPGs and heparin are central components of immunity and inflammation.

Heparin and Inflammation

Inflammation Blocks Skin Synthesis of Vitamin D from Cholesterol

Inflammation blocks solar synthesis of vitamin D in the skin and is more important than skin pigmentation, use of sunblock or latitude in producing vitamin D deficiency.  The vitamin D content of food is negligible compared to solar production in the skin.  It is not surprising that rising chronic inflammation is also accompanied by rising vitamin D deficiency.  Vitamin D supplementation is usually ineffective in curing vitamin D deficiency, because the supplements are too low and very high levels of supplemental vitamin D are required to reverse underlying chronic inflammation.  Statins are very effective at blocking cholesterol synthesis and although reducing cholesterol has minimal impact on the target, cardiovascular disease, it dramatically reduces vitamin D causing muscle pain, etc.

Most vitamins are enzyme cofactors synthesized by gut bacteria and used as quorum sensing signals during formation of biofilms.  Vitamin D, in contrast, is a steroid hormone and receptors for vitamin D are inside cells.  The receptor/vitamin D complex is transported into the nucleus where it acts as a transcription factor to control the expression of genes.  Vitamin D controls the expression of defensins in the crypts of the villi of the small intestines.  The antimicrobial activity of defensins is based on the basic amino acids (arginine and lysine) of its heparin binding domains.  Vitamin D also interacts with NF-kB in the nucleus and modulates inflammation.

Inflammation and Vitamin D

Bacteria and LPS

Lipopolysaccharide is a wall component that is indicative of bacteria, just as beta-glucan is indicative of fungi, and both are intense activators of NF-kB and inflammation.  LPS is released from damaged bacteria, e.g. by antibiotic treatment, binds to receptors on the surface of intestines and stimulates inflammation with release of NO, which produces diarrhea.  Food intolerances, which are based on incomplete digestion of food components, because of an incomplete gut flora (immunological responses/food allergies are rare) are probably also the result of LPS release from gut flora and inflammation.

Innate Immunity is also Triggered by LPS

The basic defenses of humans against microorganisms are mediated at the cellular level by triggering molecules common to all microorganisms, e.g. LPS for bacteria.  The responses are equally general: lysozyme to digest bacterial wall peptidylglycan, lactoferrin that binds iron and yields antibacterial peptides.  LPS (and inflammatory cytokines) also stimulates the liver to produce CRP (C Reactive Protein) that binds to choline on bacteria as the first step in phagocytosis and DNAse I that digests NETs (neutrophil extracellular traps) that are the DNA and histones released by triggered neutrophil cells that enmesh bacteria for engulfment by phagocytic cells.  [NETS plug peripheral catheters and can be cleared with probiotics that stimulate DNAse I release from the liver.]  NETs are also present at sites of inflammation and the accompanying nuclear proteins have the basic triplets that stimulate immune presentation and act as autoantigens, i. e. produce anti-nuclear antibodies, in the absence of adequate Tregs.

Diet and Inflammation

The diagram outlines the interactions that produce the tissue symptoms of inflammation.  Many components of modern diet can trigger inflammation:

Sugars and high glycemic starches raise blood sugar and enhance AGE/HgA1C.

Vegetable oils high in omega-6 oils are converted into inflammatory prostaglandins.

Wheat and other grains have high glycemic starch and insoluble fiber that is inflammatory.  Gluten is inflammatory.

Antibiotics damage the gut flora and produce vitamin deficiencies, autoimmunity and allergies.

Food intolerances result from damaged gut flora and produce gut inflammation.

Fish high in omega-3 EPA and DHA are anti-inflammatory.

The Anti-Inflammatory Diet

Health Results from a Balance of:

Diet (meat, fish, eggs, dairy, vegetables), containing macronutrients of protein, starch 30-100 g/d and fat (low omega 6/3 and saturated fat for most calories), and micronutrients

Soluble Fiber, e.g. resistant starch (consult Free the Animal), inulin, pectin, (plant polysaccharides, animal GAGs)

Gut Flora, diverse and adapted to dietary soluble fiber,

Exercise

Resistant Starch, Panacea, but Why?

Mark’s Daily Apple provides an authoritative diet guide (except for the gut flora).

Psoriasis, IL-17, Cathelicidin, TLRs, NFkB, Inflammation and Heparin Therapy

Host DNA Released by Keratinocyte Apoptosis Binds LL-37 and Activates Dendrocytes

Psoriasis is an inflammation of the skin that leads to overproduction of keratinocytes resulting in a thick crust.  Skin inflammation, in this case, is considered a result of autoimmunity, but an autoantigen has not been identified.  It is more likely that psoriasis results from an autoinflammatory condition, in which inflammation produces a complex of self molecules that mimic bacterial DNA and trigger TLR/NFkB inflammation signaling.  And of course, if this is going to be interesting, it has to involve heparin.

Vitamin D Binds to a Transcription Factor Receptor that Controls Antimicrobial Peptides
A significant component of the innate immune system is a group of antimicrobial peptide  (defensins, cathelicidins, e.g. LL-37).  These short polypeptides owe their natural antibiotic activity to numerous basic (positively charged, arginine and lysine) amino acids.  The transcription factor that controls the expression of these peptides is the vitamin D receptor.  Thus, various forms of vitamin D influence the amount of antimicrobial peptides produced in the mouth, skin and crypts of the intestinal villi.  Oral vitamin D3 would be expected to directly improve defensin production in the gut and LL-37 production in the skin.

IL-17 Stimulates Skin Inflammation and LL-37 Production
A specific group of lymphocytes, called T helper 17 cells, produce IL-17.  These Th17 cells accumulate in some sites of inflammation, such as psoriasis and their secretion of IL-17 is associated with ongoing inflammation and may contribute to LL-37 production, as well as apoptosis of keratinocytes in the thickening skin of psoriasis plaques.
http://www.ncbi.nlm.nih.gov/pubmed/19623255?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_SingleItemSupl.Pubmed_Discovery_PMC&linkpos=2&log$=citedinpmcarticles&logdbfrom=pubmed

Th17 Cells Are Produced in the Gut in Response to Segmented Bacteria
One of my readers brought to my attention an article that shows that one of the hundreds of species of gut bacteria, segmented filamentous baceria, stimulates the gut to develop T helper 17 cells that subsequently migrate to sites of inflammation.
http://www.medpagetoday.com/Gastroenterology/InflammatoryBowelDisease/16472
This emphasizes the link between the gut and inflammatory diseases and parallels other examples of gut influence on disease, such as the ability of Helicobacter pylori to affect asthma or parasitic worms to tame Crohn’s disease, allergies and asthma.

Inflammation Lowers Heparan Sulfate Production and Spreads LL-37
One of my students induced inflammation in cells in vitro and showed by quantitative PCR that genes involved in heparan sulfate proteoglycan production are selectively silenced.  This observation explains in part the loss of heparan sulfate in kidneys and intestines that contributes to the leakiness of these organs in response to inflammation and the partial repair of these organs by heparin treatment.  Decrease of heparan sulfate that normally coats cells and binds antimicrobial peptides, such as LL-37, would explain the enhanced movement of LL-37 in psoriatic skin.

LL-37 Binds to Host DNA and Triggers Toll-Like Receptors
DNA is released from keratinocytes in psoriatic skin and this host DNA binds the antimicrobial peptide cathelicidin LL-37.  The LL-37/DNA complex mimics bacterial DNA and triggers the Toll-like receptors (TLR) on the surface of immune cells, dendrocytes, to activate NFkB, the transcription factor controlling inflammation.
http://www.ncbi.nlm.nih.gov/pubmed/19050268?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_SingleItemSupl.Pubmed_Discovery_RA&linkpos=1&log$=relatedarticles&logdbfrom=pubmed

Heparin Treats Psoriasis
It seemed obvious to me that the heparin binding domains (Look at all the basic amino acids in blue in the illustration of LL-37.) of LL-37 were involved in DNA binding and the reason the LL-37 was binding to host DNA, was that heparan sulfate had been depleted as a result of local inflammation.  It also seemed obvious that topical heparin should eliminate psoriasis plaques.  So I did a Google search of psoriasis + topical heparin and got a hit on a 1991 patent application that claims a broad applicability for heparin use in curing symptoms of a wide variety of diseases, including psoriasis.
http://www.patentstorm.us/patents/5037810/description.html
The only topical form of heparin that I know of is Lipactin (available in Canada and Europe?), a treatment for coldsores, which makes sense because herpes viruses use heparan sulfate to infect cells.

Biofilm Transformation, Helicobacter, Klebsiella

Helicobacter pylori causes stomach cancer, but it feeds on hydrogen gas produced by Klebsiella pneumoniae in gut biofilms. DNA released by biofilm bacteria not only transfers antibiotic resistance, but it also provides protection against host antibacterial peptides, such a cathelicidins and defensins.

Exploding Labs

When I was working on host/pathogen interactions and plant disease resistance, I also became familiar with research on the formation of the plant equivalent of cancer, crown galls, and symbiotic bacterial nitrogen fixation. I mention this, because this also exposed me to the free-living bacterial nitrogen fixing system in Klebsiella and to the memorable urban legion of exploding labs. As the story goes, as bacteria convert atmospheric nitrogen gas into ammonia, nitrogen fixation, they use high energy electrons, e.g. from ferrodoxin, and lots of ATP, but they also produce hydrogen gas. In labs where they are researching nitrogen fixation, the excess hydrogen gas would accumulate on the ceiling until... boom! Now those labs are properly vented.

Helicobacter Uses Hydrogen as an Energy Source

Helicobacter pylori is considered the most common bacterial pathogen of humans and is the primary cause of ulcers and stomach cancer. H. pylori lives in the stomach by neutralizing stomach acid with ammonia. Another interesting ability of this bacterium is its ability to use hydrogen dissolved in circulating blood as an energy source. The high energy electrons from molecular hydrogen are transported to its electron transport chain, and the energy is used in membrane transport and ATP production. The circulating hydrogen is produced by gut bacteria.

Klebsiella Is not just a Soil Bacterium, Gut Gases

Klebsiella pneumonia is a lung pathogen and it also forms gut biofilms. Presence in the gut and the ability to produce hydrogen gas has some implications for hydrogen utilizing bacteria like H. pylori. Clearly, the stomach of someone with an abundant source of hydrogen fuel in their blood is a better target for H. pylori colonization. This explains why even at age 50, individuals who were exclusively breastfed have a lower incidence of H. pylori and stomach cancer, since even a single bottle of formula can shift an infant to adult, i.e. Klebsiella gut flora.

Klebsiella Needs Carbs to Produce Hydrogen

K. pneumoniae has been associated with Crohn’s Disease and Ankylosing Spondylitis. It grows in gut biofilms and produces pullulanase, an enzyme that can utilize the branched glucosides left over from the action of amylase on plant starch. So K.p. has an untapped food source and it needs lots of ATP to produce hydrogen gas. The nitrogenase needed for nitrogen fixation and hydrogen production is very sensitive to oxygen, so this means that K.p. needs a partially anaerobic environment and must get its energy from fermentation. Fermentation yields much less ATP than respiration using oxygen, which means that K.p. can only produce hydrogen with lots of glucose from starch.

Low Carb Diet Cures Crohn’s Disease

It turns out that the antigen causing Crohn’s disease is the pullulanse (with collagen mimetics.) As you should expect, it has a basic triplet. Eating a low carb diet reduces the flareups of Crohn’s disease, presumably by starving out the K.p.. It is interesting that nitrogenase is the antigen involved in Ankylosing Spondylitis.

Biofilms Promote Transformation and Antibiotic Resistance

Just as a footnote to the benefit of K.p. as a citizen of a biofilm community, H.p. should also live in those biofilms, since that is the source of the hydrogen it uses. Biofilms also stimulate the exchange of DNA, because the quorum sensing chemical signals trigger the release of DNA. The DNA is a component in the matrix that binds bacteria in the biofilm and can work in conjunction with bacterial acidic polysaccharides and host heparan sulfate. These acidic polymers tend to bind the basic antimicrobial peptides, e.g. defensins and cathecidins produced as a major non-adaptive defense against bacteria. Thus, the release of DNA triggered by quorum sensing, builds matrix, facilitates DNA transformation that is the foundation for the spread of antibiotic resistance in gut biofilms and provides resistance against antimicrobial peptides.

Crohn’s Disease and Cryptidins

The intestines produce enzymes to digest food, antimicrobial peptides to kill pathogens and have lots of surface area to absorb nutrient molecules released from the food macromolecules (protein, polysaccharides, fats). The epithelial cells that line the intestines, enterocytes, must communicate with bacteria in the gut, the gut flora, to maintain bacteria helpful in food digestion, i.e. probiotic bacteria, and trigger an immune response to eliminate pathogens. Probiotic bacteria are tolerated and pathogens are identified and attacked.

Enterocytes are produced by division of stem cells at the bottom of the crypts that are in the valleys between the villi that project into the lumen where the digesting food is. New enterocytes are added at the base of the villi and old enterocytes are sloughed off at the top of the villi. As the new enterocytes move up the villi, they differentiate to produce the dramatic surface of microvilli, the furry brush border that further expands their surface area. The mature enterocytes produce transport proteins on their microvilli to take up sugars, amino acids and fats. The small nutrient molecules pass through the base of the enterocytes and bath the cells below, the lamina propia. The nutrients enter the capillaries of the villi and travel to the liver. Fats are transported through the lymphatic system.

Bacteria that slip through the enterocyte layer encounter macrophages and other types of white blood cells of the lamina propia. Among these cells are the Paneth cells. Fragments of the cell walls of bacteria bind to the NOD proteins of the Paneth cells and trigger the secretion of antimicrobial peptides, the cryptidins. Cryptidins are antimicrobial because of their array of basic amino acids surrounded by hydrophobic amino acids. These short proteins are able to disrupt the membrane function of most bacteria. I think they work on bacteria the same way that amyloid proteins, e.g. amyloid plaque proteins of Alzheimer’s disease, kill human cells. In fact, amyloid fibers bind to heparin and so do antibiotic peptides.

Here is an example of an antibiotic peptide, cryptidin 4,

GLLCYCRKGHCKRGERVRGTCGIRFLYCCPRR

Note the pairs of basic amino acids (blue). These amino acids are necessary for toxicity to bacteria. Heparin binding domains from proteins are produced naturally as proteins are digested to peptides in the stomach by pepsin. Pepsin hydrolyzes proteins next to the basic amino acids and leaves antimicrobial peptides that sterilize incoming food. I have illustrated the cryptidin protein to show how the basic amino acids (blue) are displayed on its surface.

With each meal, the fat content normally stimulates the production of a hormone, cholecystokinin, that binds to a receptor and causes an anti-inflammatory release of cytokines from the vagus nerves that reach the villi. Thus, food normally makes the intestines more tolerant of food antigens.

If the intestines become chronically inflamed, then exposure to normal probiotic bacteria can lead to cycles of inflammation that damage the integrity of the intestines. The intestines lose the ability to discriminate between probiotic and pathogen.

Crohn’s disease is an inflammatory, autoimmune disease of the bowel. The chronic inflammation of the lamina propia eliminate the ability of the Paneth cells to produce cryptidins and bacteria set up residence in the crypts and cause continual inflammation. This disease is typically treated by suppressing inflammation and treating with antibiotics.

Other treatment approaches that have been found effective are omega-3 oils to stimulate production of anti-inflammatory prostaglandins, pre- and probiotics, heparin and helminth eggs, e.g. wireworm.

Crohn’s disease would seem to benefit from the standard recommendation of an anti-inflammatory diet and lifestyle.