- DNA bases stack.
- Heparin binding sites of proteins are basic amino acids (Arg, Lys).
- Sugar binding sites in enzymes and lectins are hydrophobic amino acids (Trp, Tyr, Phe).
- Nuclear translocation signals, quartets of basic amino acids, bind to receptors with tryptophans.
- Tryptophans are the most highly conserved amino acids in the same proteins across great evolutionary distances.
- Hydrophobic bonding between tryptophan and a sugar or basic amino acid is ten times greater than hydrogen or ionic bonds.
- Tryptophan/Arginine ladders zip regions of proteins together.
- Polyphenols can disrupt cellular protein interactions by binding to receptors for carbohydrates/heparin, steroid hormones, amyloids, etc.
- Heparin holds dozens of hormones to receptors and changes the shapes of proteins, e.g. clotting and complement.
- Most nucleic acid binding proteins will also bind to the more negatively charged heparin.
- Bacteria use a pair of lysines to mark proteins for export.
- Peptides containing the basic amino acids of heparin binding domains (also produced by the specificity of gastric proteases) are antimicrobial, e.g. defensins, and so are plant polyphenols.
- Many drugs are active because they are domesticated plant polyphenols.
Monday, March 24, 2014
— all 200 Posts —
I started posting to Cooling Inflammation on 21 Aug, 2008 with How Your Diet Makes You Sick or Healthy. My impetus for writing was my growing awareness that diet was the major reason why people were sick, and that health myths were preventing people from being healthy. Inflammation originated by diet-inflicted injury and people attributed their sickness to genetics, environmental toxins and pervasive pathogens.
My Path to the Obvious
My research background started with plant biochemistry, including carbohydrate structural analysis and polyphenol chemistry. At that stage I was interested in understanding how plants protected (phytoalexins) themselves from pathogens, and I expected to use this perspective to explore human innate immunity. From there, I went on to enzymology and protein characterization, biofilm structure, plant genetic engineering and breeding, monoclonal antibody production, mycotoxin detection, stem cell analysis, passive immunity in neonates, computational modeling of collagen and heparin binding, and heparan sulfate proteoglycan inhibition by inflammation. These were temporary foci and the research imperatives, in retrospect, prevented me from seeing the bigger pictures, although they did leave me with a broad skill set.
Perspective: Water and Surface Tension
When I finally decided to slow down, smell the flowers and start having kids, I switched from research to teaching, from university to small liberal arts college. For the first time, I actually thought about what I was teaching and my first revelation was that after teaching biochemistry for twenty years, I didn’t understand water and surface tension. I could provide the platitudes from the Molecular Biology of the Cell, but I couldn’t do it mechanistically with colliding, sticky, energetic water molecules in my mind or at the blackboard. I had to develop functional explanations of hydrogen bonds, entropy and thermal energy, that translated into the structuring of a layer of water molecules responsible for hydrophobic interactions and surface tension. I extended that to include an explanation of the two layers of water holding together cytoplasmic membranes, the tube of structured water that holds together the cylinder of stacked bases in DNA or the shrink wrapping water layer surrounding proteins.
Perspective: Heparin Binding and Amphipathy of Sugars and Basic Amino Acids
As the kids got older, I started to dabble in research again and my expertise in carbohydrate chemistry led me into cartilage (mostly the glycosaminoglycan, GAG, chondroitin sulfate) synthesis and ultimately another GAG, heparan sulfate proteoglycans (HSPGs). I was attracted to the dynamic HSPGs, that recycled with a half-life of six hours and formed layers around chondrocytes that secreted cartilage as they burrowed/ate through living cartilage. I learned that the heparin filled granules of mast cells could be stained with berberine, which similarly stained the heparin in basement membranes of tissues and amyloids of Alzheimer’s, atherosclerosis and diabetes. I was led by protein modeling of collagens to the binding of heparin to proteins and the revelation that basic amino acids (heparin binding domains) and sugars (heparin) are amphipathic, i.e. they have both hydrophobic and hydrophilic regions. This is also true of plant polyphenolics. Thus, polyphenolics, “basic” amino acids, “hydrophobic” amino acids, and sugars will all stack together.
From Heparin Binding to Antigen Presentation
As soon as I realized that basic amino acids were involved in heparin binding, I started to look for the basic amino acids (R for arginine and K for lysine in amino acid sequences) in proteins known to bind heparin. After study of hundreds of structures, it became obvious that heparin binding domains were simply a pair of basic amino acids (RR or KK or RK) with another within a distance of six amino acids. No particular structure was necessary, as I later deduced, since binding to the heparin provided the structure. In fact, in many X-ray crystallographic structures, the heparin binding regions on the surface of the protein are missing, because they are not in a defined shape. I suspected that protein antigens involved in autoimmunity and allergy might be brought into cells for presentation to the immune system by interacting with HSPGs on the surface and so started to check them out for heparin binding domains. I was very skillful at picking out pairs of Ks or Rs within sequences of hundreds of amino acids by that time, so I was shocked to see that the first dozen antigens that I checked, all had a triplet of basic amino acids. I had discovered that autoantigens and allergens utilize a basic triplet analogous to the basic quartet used in nuclear translocation! This also explained why proteins that interact with nucleic acids and are transported into the nucleus with a basic quartet are also prominent autoantigens.
Gut Flora and Immunity
Twenty years ago I read a curious description of leprosy that said that the course of infection could be either innocuous or devastating depending on whether the aggressive or the suppressive part of the immune system dominated. I remained perplexed until I realized that diet and gut flora were the major determinants. I was aware of the importance of diet at the outset of this blog, because it was clear that diet trumped genetics. I was also aware thirty years ago in my studies of passive immunity, that milk contained bifidus factor, now known to be milk oligosaccharides, that controlled the growth of Lactobacilli that in turn controlled the development of the neonate immune system. It was also known that bacteria-free mice had impaired immune systems. It still took me several years for the relationship between diet, gut flora and immunity to make sense. I began searching the literature for connections between gut flora and development of the immune system and soon noted experiments that linked filamentous bacteria with aggressive components and Clostridium spp. with Tregs. A further refinement was linking resistant starch, a soluble fiber, with Clostridium.
My Current Views are Summarized in Three Health Diagrams
Diet, Gut Flora, Inflammation, Antigen Presentation, Tregs and Autoimmunity
Protein from the body and from food don’t normally stimulate the immune system, because there in no inflammation, the proteins lack basic triplets that enhance presentation, and antibody production and aggressive T cells are suppressed by Tregs. Diet can throw the balance toward autoimmunity and allergy, by producing inflammation, e.g. hyperglycemia/AGE or high omega-6 fatty acids/prostaglandins, and starving gut flora needed for Treg production by eating processed food lacking soluble fiber. The combination of inflammation and Treg deficiency causes proteins, either self or potential allergens, which have basic triplets to be presented to the immune system and stimulates attack by the immune system.
The Cure is to Cool Inflammation and Stimulate Tregs with Diet and Bacteria
I have provided an outline with The Anti-Inflammatory Diet to avoid inflammation, to stimulate existing gut flora with soluble fiber and encourage Treg production. Mark Sisson, on Mark’s Daily Apple has provided an excellent dietary guide that also provides starch guidelines. If you already have symptoms of autoimmune disease or allergies, then Richard Nikoley provides gut flora repair advice on Free the Animal, and Dr. B G provides more details on Animal Pharm.
Autoimmunity and allergies are not genetic destiny and they can be cured with diet and bacteria.
Wednesday, March 19, 2014
I have explained my perspective in diagrams of the relationship between diet, gut flora and disease:
and of the interaction between gut flora, the immune system and autoimmunity:
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).
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.
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.
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.]
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.
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.
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.
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.
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.
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,
Mark’s Daily Apple provides an authoritative diet guide (except for the gut flora).
Saturday, March 15, 2014
In this second in a series of posts explaining the concepts that I think are central, but misunderstood, about health, I am focusing on how diet and gut flora impact the immune system and cause autoimmunity and allergies. This cause also suggests a simple cure.
Health in Diagrams I -- Gut Flora and Diet
Health in Diagrams III -- Inflammation from Cell to Tissue
Health in Diagrams III -- Inflammation from Cell to Tissue
Gut Flora to Tregs to Suppression of Autoimmunity
It is important to understand at the outset that autoimmunity and allergies are caused by a damaged immune system, and repairing the damage cures the diseases. Damage to the immune system typically represents a break in the continual development of immune cells in the lining of the intestines. Immune cell development in the gut is dependent on bacteria, the gut flora. Damage to the gut flora, e.g. by antibiotics, processed foods that lack flora feeding fiber or extreme diets, disrupts development of immune cells. Typically, loss of the immune cells that keep the aggressiveness of the immune system in check, regulatory T cells or Tregs, results in autoimmunity. Fix the gut flora and autoimmunity recedes.
Health Requires Suppression of the Aggressive Immune System
For simplicity, I am focusing on the T cells of the immune system that develop in the intestines and either kill other human cells that are dangerous, e.g. virus-infected or cancer cells, or provide protection by regulating the aggression, Tregs. Normal functioning of the immune cells permits elimination of damaged or dangerous human cells, while at the same time avoiding rampages of lethally armed T killers. Examples of untamed T killers in action are degenerative autoimmune diseases, such as arthritis, asthma, prostatitis, celiac, Hashimoto’s thyroiditis, type I diabetes, inflammatory bowel diseases and atherosclerosis.
Milk Births Baby Immune System
It should not be surprising that the focus of immune system development is the gut. We start as babies with explicit links between nourishment and immunological protection. Milk connects the immune systems of mother to baby. Immune cells from the mother are transferred in milk and colonize the respiratory and digestive system of the baby — the mother’s immune system coats and buffers the baby’s exposure to the world. Milk hormones close the baby’s gut and milk bacteria are the first probiotics that exploit the milk prebiotics (bifidus factor, human milk oligosaccharides) to produce a gut flora. [Also note that most commercial probiotics are adapted to grow on cow’s milk and hence these dairy probiotics do not survive in adults.] The lymphatic system of the breast terminates at the nipple and samples antigens/pathogens from the baby’s mouth, resulting in baby-specific secretory antibodies that return in the milk. Milk supports a starter set of gut flora, essentially dairy probiotics, that stimulates development of the baby immune system, but inhibits adult gut flora that would digest the protective components of milk. Formula, on the other hand, is inflammatory to the baby gut, because it supports adult gut flora before the immune system is ready. Inflammation and stimulation of innate immunity is sufficient, if supported with high levels of sanitation, to permit survival of babies fed formula. Milk of any type is incompatible with adult gut flora, so breast milk will attack adult gut flora and adult gut flora will digest and inactivate the otherwise beneficial components of the milk.
Aggressive and Suppressive Cells of Immune System Develop in Intestines
Gut bacteria are required for the development of immune T cells in the lining of the intestines. Mice grown without gut flora do not have functional immune systems. In humans, extensive antibiotic treatment produces defective immune systems that are either overly aggressive, i.e. autoimmune, or susceptible to infection and cancer. They can’t be both. Aggressive T killers are stimulated to develop by filamentous bacteria and Tregs develop in response to members of the Clostridium family. In a healthy body, there is a balance between aggression and suppression; there are functional defenses against infection and cancer, while also avoiding autoimmune disease and allergies.
Suppressive Tregs are Deficient in Autoimmunity
Immune cells result from replicative divisions of stem cells. Antibody producing B cells are produced through a million random rearrangements of antibody genes and those B cells producing antibodies against common self proteins are killed (clonal deletion). Similarly, T cells are produced by rearrangements of receptors and those that would recognize self are eliminated. The T cells then migrate to the intestines where they can develop into killer T cells or Tregs, in response to gut flora. The Tregs act to suppress killer T cells that mistakenly recognize healthy self cells. Thus, the initial elimination of self-attacking T cells or for B cells that produce antibodies that bind to normal cells, is not perfect and the Tregs are needed to avoid the mistakes. Tregs are necessary to avoid the immune attack on healthy cells that is the basis of autoimmunity.
Autoimmunity Starts with Inflammation, but Requires Deficient Tregs
Bacterial or viral infections, or physical damage causing inflammation is the first step in autoimmunity. It is the inflammation that initiates the interactions between proteins, autoantigens, of normal cells and cells of the immune system that bind, internalize, fragment and present the antigen fragments/peptides to activate B or T cells with corresponding receptors. The activated B cells make antibodies specific for the antigen and the T cells will kill cells displaying the antigen. It is interesting that most proteins are not autoantigens and are never involved immune reactions. Only proteins with an unusual triplet of basic amino acids, similar to the quartet of basic amino acids used to transport proteins into the cell nucleus, are candidates to be autoantigens or allergens. In fact, since nuclear proteins already have a quartet, i.e. the nuclear localization signal, they are common autoantigens. The last requirement for autoimmunity is a deficiency in Tregs, because if the Tregs are functioning, they will block attack on healthy cells. Treg deficiency usually results from loss of the type of gut bacteria that stimulate Treg production in the lining of the intestines, i.e. species of Clostridium.
Hospitals are Notorious for Clostridium difficile Infections
Fecal transplants are now recommended as a safe and efficacious treatment for C. diff hospital infections. That makes sense, because hospitals are where antibiotics are routinely used and C. diff can only infect people missing their healthy species of Clostridium. Thus, the hospitals wipe out the gut flora with antibiotics and then recolonize them with their own antibiotic resistant C. diff. More antibiotics can’t fix it, but providing healthy gut flora (transplant) can.
Autoimmune Diseases are Treated/Exacerbated with Antibiotics
Both the aggressive and the suppressive immune cells require gut flora, so after initial antibiotic treatment wipes out bacteria required for suppression and results in autoimmunity, the remaining aggressive half of the immune system can be eliminated by blasting the remaining gut flora with more antibiotics. Of course this will leave a highly compromised, incompetent immune system that will ultimately yield more extreme symptoms. This is the typical medical progression for Crohn’s disease, for example. The alternative is just fixing the gut flora to begin with and curing autoimmunity.
Cure Autoimmunity by Feeding Clostridium Resistant Starch
Autoimmune diseases, by their symptoms, show that sufficient gut flora to stimulate the aggressive half of the immune system is still present. What is missing are the Clostridium species that convert soluble fiber, such as resistant starch, into short chain fatty acids, e.g. butyrate. Patients treated with antibiotics usually walk away from the hospital with a suggestion to eat some yogurt to repopulate their missing gut flora. Unfortunately, dairy probiotics don’t survive in the gut and cannot repair the gut flora and immune system. The result, after the gut fails to repair and the immune system crashes, is autoimmunity. There is a more appropriate possibility to avoid or fix autoimmunity. Some people suffering from autoimmunity (and with remnants of their gut flora intact) have simply fed their gut flora on resistant starch and achieved complete recoveries. Others fail to respond, because their gut flora is too severely damaged and necessary bacterial species are gone. Those individuals need to eat the missing species of bacteria and some probiotics (more common in Asia) contain Clostridium species. Consistent with this use of soluble fiber to feed gut bacteria that produce butyrate and stimulate the suppressive immune system are reports of healing by combining potato starch (RS) and probiotics with Clostridium butyricum (Probiotic-3). Repair of the suppressive immune system by repair of gut flora (including fecal transplants) and feeding gut flora with appropriate soluble fiber, may be a general approach to the cure of most autoimmune diseases and allergies.
Wednesday, March 12, 2014
---All 200 posts here---
This is the first of three posts to summarize my thoughts on diet, inflammation and disease mediated by gut flora. I decided that I needed to make my points as explicit as possible by putting them down in diagrams and making references to my other posts. By the time I finish, I will reach my 200th blog post at Cooling Inflammation.
Everyone Leaves Out Gut Flora
I want to first explain and diagram my current understanding of the relationship between gut flora (the complex community of hundreds of different types of bacteria and fungi in the intestines) and diet. My impression is that many people have health problems based on diet, but when they try to heal their health, they fix their diet and see only limited benefits. Medicine provides only a temporary treatment using dairy probiotics. The problem is that they failed to fix their gut flora, which was also damaged by their unhealthy diet.
Health Requires a Match between Diet and Gut Flora
It is a myth that gut flora will just adjust to diet and a healthy diet leads to a healthy gut flora.
A damaged gut flora lacks necessary species of bacteria. Antibiotics, for example, can permanently delete dozens of particular bacterial species of gut flora that can only be replaced by reintroducing the missing bacteria by eating those bacteria again. The missing bacteria may be needed to digest particular foods and the result is food intolerances, commonly mistaken for food allergies. Antibiotic use frequently leads to autoimmune diseases, that are caused by deficient regulatory T cells of the immune system that develop in the lining of the intestines in response to particular gut bacteria. The natural source of gut bacteria is eating the bacteria clinging to raw or fermented vegetables.
Diagram Showing the Interaction of Food, Gut Flora and the Immune System
Food is just Protein, Fat and Soluble Fiber
The human body produces enzymes to fully digest proteins, fats and one polysaccharide, starch. All other parts of plants and animals are edible (fermented by gut flora) soluble fiber polysaccharides or insoluble, undigestible fiber consisting of cellulose or lignin, which together also make up the undigested organic matter, humus, of soil. Grains are problematical for health, because their starch is readily converted to sugar, i.e. high glycemic, and their fiber is insoluble (not fermented by gut flora) and high in phytate. Phytochemicals, plant polyphenolics, are of questionable value as antioxidants and are of unexplored importance for their antimicrobial impact on gut flora.
Polymers (Protein, Starch) are Hydrolyzed by Enzymes to Oligomers and then Monomers (Amino Acids, Glucose)
The stomach mixes protein digesting enzymes, proteases, and starch digesting amylase, with food protein and starch. Proteases convert the long chains polypeptides, polymers of protein amino acids, into shorter fragments, oligopeptides. The specific nature of the stomach proteases leaves groups of basic amino acids (lysine, arginine), heparin-binding domains, intact. These peptides, similar to the defensins of the microvilli crypts, are anti-microbial and work with residual acidity to reduce bacterial growth in the first part of the small intestines. Pancreatic enzymes then digest the peptides further and the small peptides are ultimately digested by enzymes on the surface of intestinal epithelial cells just prior to absorption. Similarly, starch is degraded to oligosaccharide amylodextrins, which are then hydrolyzed to glucose at the intestinal surface prior to absorption. Amino acids and glucose are not normally available to bacteria in the intestines.
Fats are Dissolved by Bile, Digested by Lipase and Absorbed
Fats are triglycerides, i.e. three fatty acids attached to the three hydroxyl groups of glycerol. Fats are hard to digest, because they form oily droplets. The droplets are dissolved in the intestines with bile, which is an acidic form of cholesterol, that is produced in the liver and stored in the gall bladder. Fat in a meal triggers bile release from the gall bladder into the small intestines. The bile represents a huge reservoir of the cholesterol that is synthesized by the body and dwarfs the cholesterol content of any meal. Statins decrease body production of cholesterol, interfere with bile/fat digestion and lower lipid cholesterol levels. (Unfortunately, lowering lipid cholesterol levels has minimal impact on heart disease and the only impact of statins on cardiovascular disease is through weak anti-inflammatory side effects.) Pancreatic lipase removes two of the fatty acids from each triglyceride. The fatty acids (a.k.a. soap) and monoglyceride are absorbed by the intestinal cells and reformed into triglycerides that make their way to lymphatic lacteals and are dumped into the blood, where they circulate as chylomicrons surrounded in lipoprotein. Lipoprotein lipase binds to heparan sulfate on the surface of blood vessels and gradually removes fatty acids, until the diminished chylomicron is absorbed by the liver and exits as a VLDL. (Note that this is another connection between lipid metabolism and inflammation, since inflammation decreases heparan sulfate on cell surfaces. Heparan sulfate also mediates LDL binding to cells and amyloid stacking.)
Plant Polysaccharides are Soluble Fiber and Food for Gut Flora
All that remains of food after the protein, fat and glycemic starch (glycogen) have been removed in the small intestines are plant cell wall polysaccharides, resistant starch, storage polysaccharides, e.g. inulin, plant beta-glucan, animal glycans, e.g. chondroitin sulfate and heparan sulfate, and insoluble fiber. The insoluble fiber passes on to be a minor contributor to the bulk of stools and the rest of the polysaccharide is potentially fermentable by gut flora into short chain fatty acids (formic, acetic, propionic, butyric acids). Some of the polysaccharides are simple repeating units of one or two sugars in long chains, but others are made of five to ten different sugars in complex branched structures. Simple repeating polysaccharides require just a few different enzymes for their initial synthesis and a few for their digestion. Thus, resistant starch can be digested by a couple of enzymes into glucose that can be used by most gut flora. Arabinogalactan, on the other hand, requires a dozen enzymes for plant synthesis and an equal number of hydrolytic enzymes to produce arabinose and galactose, which require further enzymes for metabolism in a select few of species of gut flora bacteria.
Food Intolerance/“Allergy” Indicates Missing Bacteria
Gut flora in general can produce several hundred different enzymes for digestion of diverse soluble fiber, but most soluble fiber polysaccharides can only be digested by certain bacteria and those bacteria increase, if the complementary fiber is present in the diet. If a fiber is absent from the diet, bacteria that specialize in digesting that polysaccharide will be eliminated. People living on diets limited to just a few types of soluble fiber can only digest those fibers and a shift in diet to other types of soluble fiber will lead to symptoms of dietary upset, such as bloating, gas production and food intolerance. Food intolerances reflect inadequate diversity in gut flora and a mismatch between bacteria and food. Food intolerances can be eliminated by repairing gut flora and the typical repair solution is eating homegrown fermented vegetables that provide the missing species of bacteria.
Immune Cells Develop in Response to Gut Bacteria
Most of the body’s immune cells are in the intestines. Cells of the immune system are constantly dividing in bones and the thymus gland, developing in the lining of the intestines and migrating to other tissues. Filamentous bacteria of the gut flora stimulate the development of aggressive immune cells that kill other cells that are infected with pathogens or viruses or are cancerous. Furrows perpendicular to the flow of food cultivate the growth of Clostridium species that ferment soluble fiber, e.g. resistant starch, and release butyric acid that stimulates the development of regulatory T cells, Tregs. It is the Tregs that control the aggressive immune cells and prevent attack on self (autoimmunity) or innocuous antigens (allergy). It appears that merely eating resistant starch, e.g. potato starch, with probiotics that contain butyric acid producing Clostridium bacteria may provide a cure for many autoimmune diseases.
Gut Biofilms Release Vitamins as Quorum Sensing Signals
The gut flora lines the intestines in numerous biofilm communities, which form from dozens of different species of bacteria that communicate by exchanging molecules called quorum sensing signals. These signals from the biofilms intimately attached to the lining of the intestines are vitamins. Thus, healthy gut flora are the major source of vitamins and other sources, such as fruits and vegetables are only needed, if the gut flora is damaged, e.g. by antibiotics.
Volume of Stools Reflects Gut Flora Fermenting Soluble Fiber
The bulk of bowel movements, stools, is bacteria, the compressed gut flora that accumulated in the colon while fermenting soluble fiber. We always hear that we need to eat fiber for regularity, but since insoluble fiber is only a minor contributor to stool volume and it is associated with anti-nutritive attributes, such as the binding and removal of zinc and iron by phytate, the fiber that counts for regularity is soluble fiber. Regularity results from the fermentation of soluble fiber polysaccharides producing short chain fatty acids, such as butyrate, that are the major source of energy for colon cells. And the growing bacteria in the colon provide most of the bulk of the hydrated stools. Inadequate dietary soluble fiber or damaged gut flora, dysbiosis, leave only dehydrated insoluble fiber and compact stools of constipation. Constipation can result from dehydration or excessive retention, but chronic constipation, even in the presence of adequate dietary soluble fiber, is an indication of damaged gut flora and an increased risk for diseases resulting from deficiencies of Treg production: autoimmune diseases and allergies. Constipation and associated autoimmune diseases can be cured by repairing gut flora and supplying adequate dietary soluble fiber.