Gut microbiome

The human body is populated by a myriad of microbes; it is an ecosystem. Nothing in the body is microbe-free, and all sorts of microbes are present in our inner microbial community: fungi, bacteria, viruses, protozoa, archaea, etc (Faintuch & Faintuch, 2019; Hallen-Adams & Suhr, 2017; Lurie-Weinberger & Gophna, 2015).

So far, the research has largely focussed on bacteria, estimating that our bodies contain as many bacterial cells as human cells, with 90% of them in our gut (Sender, Fuchs, & Milo, 2016). This part of our microbial community is called the gut flora or gut microbiome, and it plays a fundamental role in human health and disease (Hao & Lee, 2004) The gut with its microbial community is often referred to as ‘our second brain’, but its structure and connections are so complex that some researchers name it ‘the first brain’ (Petra et al., 2015; Quigley, 2017).

Our digestive system with its microbiome is responsible for proper digestion and absorption of food, neutralisation of toxic substances, and production of vitamins, hormones, and neurotransmitters (Cénit et al., 2014; Clarke et al., 2014; Yoshii, Hosomi, Sawane, & Kunisawa, 2019). It is the headquarters of our immune system, ensuring its health, vitality, proper balance, and functions (Belkaid & Hand, 2014; Wu & Wu, 2012). All of these have far-reaching consequences for human health. In short, the gut holds the roots of our health. No matter how far removed from the gut an organ or tissue may be, its health and function are determined, to a large degree, by the state of the gut and its microbial community (Salem, Ramser, Isham, & Ghannoum, 2018).

In any microbial community, if there is balance between various species of microbes, then there is harmony and health. When this balance is damaged by antibiotics, chemicals in food and drink, and other influences, the gut flora becomes imbalanced – this is called gut dysbiosis.

In gut dysbiosis, pathogenic microbes impair food digestion and absorption, leading to multiple nutritional deficiencies. They damage the integrity of the gut wall, making it porous and ‘leaky’ (Fasano, 2011, 2012; Sapone et al., 2006; Sturgeon & Fasano, 2016). Undigested food absorbs through this damaged gut wall, triggering food allergies and intolerances (Camilleri, 2019). Pathogenic microbes in the gut produce toxic substances (Din & Alam, 2020; Kaji et al., 1976; Zioudrou, Streaty, & Klee, 1979), which absorb through the damaged gut wall, causing disease (Borba, Lerner, Matthias, & Shoenfeld, 2020; Din & Alam, 2020; Sanctuary, Kain, Angkustsiri, & German, 2018; Sokolov et al., 2014; Woodford, 2021). In short, in a person with abnormal gut flora the digestive system becomes a major source of toxicity, instead of being a source of nutrition. The immune system reacts to the whole situation, launching systemic inflammation and autoimmunity. Our gut produces and regulates many hormones, neurotransmitters, and other powerful molecules, all of which get out of balance in gut dysbiosis, adding an avalanche of physical and mental symptoms to the whole picture.

Many health practitioners realise that it is impossible to treat such a complex situation without changing the person’s diet. Gut dysbiosis is increasingly being found in cognitive, mental, and autoimmune diseases (Belkaid & Hand, 2014; Capuco et al., 2020; Cénit, Matzaraki, Tigchelaar, & Zhernakova, 2014; Dinan & Cryan, 2017; Foster & McVey Neufeld, 2013; Heintz‐Buschart et al., 2018; Jaglin et al., 2018; Kaplan, Crawford, Field, & Simpson, 2007; Maniscalco & Rinaman, 2018; Perricone & Shoenfeld , 2019; Rogers et al., 2016; Sanctuary et al., 2018; Sokolov et al., 2014; Stevens et al., 2018; Woodford, 2021).

These findings have led to a concept called gut-brain axis (Clapp et al., 2017; Cryan et al., 2019). Research on the gut-brain axis is rapidly growing, and so are the studies looking at dietary interventions to treat these disorders (Lange et al., 2017, Rucklidge & Harrison, 2010; Schnorr & Bachner, 2016; Tillisch et al., 2013).

The GAPS Nutritional Protocol with its central piece – The GAPS Diet – is a global phenomenon, gaining international popularity over two decades. It has been scarcely studied (Babinska et al., 2020; Cekici & Sanlier, 2019; Nazarenkov et al., 2018), and the research has largely focussed on autism (Abele, Tzivian, Meija, & Folkmanis, 2019; Çikili, Deniz, & Çakal, 2019). Yet, this protocol is used by people all over the world to heal from a very long list of mental and physical diseases, including autoimmune, neurological problems, hormonal problems, chronic fatigue syndrome, fibromyalgia, allergies, asthma, eczema, psoriasis and the full list of learning disabilities and psychiatric maladies.

The purpose of the GAPS Nutritional Protocol is to re-balance the gut flora and the rest of the microbiome, heal and seal the ‘leaky’ gut wall, normalise digestion and absorption of food, re-balance the immune and endocrine systems, and provide quality building materials for healing and repair of all the tissues and organs in the human body (Campbell-McBride, 2010, 2020).


The GAPS Nutritional Protocol and the GAPS Diet

GAPS stands for Gut And Psychology Syndrome and Gut And Physiology Syndrome. Its core principles rely on the need for a healthy microbiome for our body to function correctly. The most important part of the protocol is the GAPS Diet (Campbell-McBride, 2020).

The GAPS Diet is based on traditional diets from all over the world and focusses on foods with high-density, easily-digestible nutrition. It eliminates all difficult-to-digest and damaging substances. All foods are cooked at home from fresh natural ingredients. Re-building connective tissues of the patient is a particular focus. Fermented foods are used extensively. Full implementation of the GAPS Diet, over time, eliminates the need for nutritional supplements, as the food provides all the necessary building materials for healing and maintenance of the human body.

The GAPS Diet has several variations (Campbell-McBride, 2020, pp 162-281), but the two main ones are The Full GAPS Diet and The GAPS Introduction Diet. The Full GAPS Diet is followed as a permanent lifestyle, and it is easier to implement. The GAPS Introduction Diet is designed for deeper healing: it is a stage-by-stage introduction of nourishing foods, starting from the easiest-to-digest to more difficult-to-digest foods (see Campbell-McBride, 2020). It can be followed at the beginning of the protocol or at any point when deeper healing is required. The more damaged is the gut of the person, the more it is necessary to go through the GAPS Introduction Diet. This diet is particularly effective in removing abnormal intestinal permeability (leaky gut). Once enough healing in the gut is achieved through The GAPS Introduction Diet, the person moves on to The Full GAPS Diet to continue healing the whole body.

The GAPS Diet removes all toxic and processed substances: processed foods, food additives, antibiotics, toxic metals, butter substitutes and vegetable oils, sugar, grains, starch, soy and industrial meat and dairy. When following the GAPS Diet one should source the cleanest natural foods, to avoid agricultural chemicals. Especially concerning is glyphosate, widely used herbicide which disrupts the gut microbiome, chelates minerals, damages organs and tissues, and impairs liver detoxification (Samsel & Seneff, 2013; Seneff, 2021).

Nutrient-dense animal foods (meat, fish and eggs) and meat/fish stocks are central to the GAPS Diet. The human body is largely made out of connective tissue, the gut wall in particular. Connective tissues of animals and birds, cooked with water, release building materials for the connective tissues of the human being, into the stock (Campbell-McBride, 2020, pp 218-220). Organ meats (liver, hearts, lungs, kidneys, tripe, brain, etc.) are used extensively in cooking, providing a plethora of nutrients, which are missing in muscle meats. Homemade meat stocks, well-cooked connective tissues and organ meats provide proteins, amino acids, cholesterol, minerals, glucosamines, collagens, fat soluble vitamins and all other crucial elements necessary for healing a damaged gut wall and the rest of the body (Campbell-McBride, 2020, pp 248-252).

Animal fats and cholesterol-rich foods (raw butter, homemade ghee, lard, tallow, goose and duck fat), seafood, avocados, cold-pressed olive oil and coconut oil are central to the GAPS Nutritional Protocol.

Low-fat diets have been long promoted as the solution to heart disease (Keys, 1953). The research is mounting to show that this idea is false (Ravnskov, 2002, 2003), and that fat and cholesterol are essential to the proper functioning of our bodies. Every cell of every organ contains a significant amount of cholesterol in its structure (Enig, 2000; Hussain et al., 2019; Nelson, Lehninger, & Cox, 2008; Roberts, Alberts, Johnson, Walter, & Hunt, 2002). This is especially the case in cell membranes, where cholesterol molecules can make up to half of the plasma membrane and even more when the cells are part of protective barriers (Garrow, James, & Ralph, 2003; Nelson et al., 2008). The brain consumes 25% of the body’s cholesterol (Dietschy & Turley, 2001), and cholesterol is involved in cell communication (Enig, 2000; Hussain et al., 2019; Nelson et al., 2008; Purves, Orians, Heller, & Sadava, 2004; Roberts et al., 2002), myelin production and composition (Dietschy & Turley, 2001; Enig, 2000; Hussain et al., 2019; O’Brien & Sampson, 1965), functions and structures of synapses (Dietschy & Turley, 2001; Hussain et al., 2019; Huttenlocher & Dabholkar, 1997), production of steroid hormones (Berg, Tymoczko, Gatto, & Stryer, 2015; Garrow, James, & Ralph, 2003; Seeley et al., 2008) and functions of the immune system (Bhakdi, Tranum-Jensen, Utermann, & Füssle, 1983; Claxton et al., 1998; Iribarren et al., 1997; Muldoon et al., 1997). A low-fat and low-cholesterol diet, together with cholesterol-lowering drugs, can lead to serious health problems and impact brain functioning (Cham, Koslik, & Golomb, 2016; Golomb, Stattin, & Mednick, 2000; Golomb, Kane, & Dimsdale, 2004; Hussain et al., 2019; Tomson-Johanson et al., 2020). Campbell-McBride (2018, 2020) states that animal fats and cholesterol are essential-to-life substances. This is why they are provided in abundance by the GAPS Diet.

Raw organic dairy from natural breads of animals is used in the GAPS Diet. Patients ferment raw milk and cream at home for 24 hours, which makes dairy lactose-free and breaks down casein (Campbell-McBride, 2020). Homemade yogurt, sour cream, kefir, whey and cheese provide probiotic microbes, enzymes and high-quality nutrition. Only raw (unpasteurised) milk and cream from natural breeds of animals are used (Campbell-McBride, 2020) for maximum healing effect. Pasteurisation damages the structure of milk, making it harmful to health and allergenic (Campbell-McBride, 2020, pp 146-150). Raw milk contains a larger amount of psychotropic and mesophilic bacterial populations, healthier than those found in pasteurised milk. In addition, the bacteria contained in pasteurised milk have reached a nonculturable form (Quigley et al., 2013a,b). Consumption of fermented raw milk has yielded positive results on mood and health issues (Baars, Berge, Garssen, & Verster, 2019) and has been suggested as ‘preventive strategies to reduce the incidence of allergic disease’ (van Neerven, Knol, Heck & Savelkoul, 2012, p. 857). Finally, raw milk and homemade fermented dairy products have been found to hold salutogenic effects in immune diseases such as celiac disease (Lerner & Matthias, 2018). For patients with milk allergy, home-fermented dairy products are introduced later in the protocol following specific gradual steps (Campbell-McBride, 2020, pp 179-183).

Apart from fermented dairy, probiotics in the GAPS Diet come from fermented vegetables and fruits, prepared at home. Sauerkraut (fermented cabbage) has been found to contain the recommended range of lactic acid bacteria per gram (between 106 and 108) to be called a probiotic superfood (Orgeron, Corbin, & Scott, 2016). Fermentation of plant matter makes food more digestible, richer in bio-available nutrients and a good source of probiotics and enzymes (Campbell-McBride, 2020, pp 229-245).

Nuts and oily seeds (sunflower, pumpkin and sesame) are used in the GAPS Diet for making bread, cakes and desserts, and they are prepared by soaking, fermenting, and sprouting to remove antinutrients. Antinutrients (enzyme inhibitors, lectins, phytates, oxalates, etc) are substances in natural foods that can damage the human body, impair digestion and cause nutritional deficiencies (Campbell-McBride, 2020, pp 128-129). They are almost exclusively found in plant foods, particularly in their seeds (grains, beans, pulses, legumes, seeds and nuts). Enzymes inhibitors can impair digestion, protein synthesis, functioning of hormones and neurotransmitters and other important functions. Lectins can damage the immune system, the gut wall, the joints and many other organs. Phytic acid binds to vital minerals and makes them unavailable for the body to use. Oxalates and oxalic acid also bind minerals in the body and can cause behavioural abnormalities, painful urination and chronic cystitis. Glucosinolates found in brassica vegetables bind iodine and can contribute to thyroid problems. Polyphenolic compounds, alkaloids, salicylates, saponins, tannins and flavonoids in plants can all cause problems, particularly when the person is unable to digest them (Akande, Doma, Agu, & Adamu, 2010; Freed, 1991, 1999; Pusztai et al., 1993; Sandstead, 1992; Van Damme, Peumans, Pusztai, & Bardocz, 1998). GAPS people have a damaged digestive system and cannot handle many antinutrients. That is why plant foods present the biggest challenge for this group of patients. The GAPS Diet removes the worst offenders such as grains (Cordain, 1999) and, in addition, insists on vegetables and seeds (beans, nuts and other) being prepared carefully before consumption, to make them more digestible (Campbell-McBride, 2020).

Apart from the GAPS Diet, the GAPS Nutritional Protocol involves a few nutritional supplements (mostly used at the beginning of the protocol and discontinued later) and lifestyle changes revolving around the reduction of toxicity from the environment (such as chemical compounds found in cleaning and beauty products). The protocol is described in detail in Dr Campbell-McBride’s books Gut And Psychology Syndrome (2010) and Gut And Physiology Syndrome (2020).



All diseases begin in the gut! This statement, attributed to Hippocrates, is gaining monumental importance in the modern world. Gut dysbiosis is increasingly being observed in a growing list of psychiatric and physical problems, illustrating an intrinsic relationship between the state of the gut and the rest of the body. The GAPS Nutritional Protocol has been specifically designed to heal the human body starting from the root – the digestive system. This protocol has been used by people all over the world to heal from mental and physical illnesses for twenty years. Thousands of glowing testimonies have been published (Campbell-McBride, 2012) but scientific research is lacking. We highly encourage health practitioners and researchers, interested in addressing gut dysbiosis as the cause of mental and physical illnesses, to use the GAPS Nutritional Protocol in their practice and/or empirical studies.



Competing Interests

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Dr Natasha Campbell-McBride is the creator of the GAPS concept and the GAPS Nutritional Protocol.


No financial support has been received for the work reported.

Authors’ Contributions

Sophie Delaunay-Vagliasindi wrote a first version of the manuscript. Natasha Campbell-McBride and Stephanie Seneff supervised and edited. All authors read and approved the final manuscript.


This case was written following the CARE guidelines.

Author’s Information

Sophie Delaunay-Vagliasindi holds a MSc degree in Developmental Psychology from the University of Kent, UK. She is a certified GAPS Coach. She is specialising in the impact of gut flora on development and conducting research for non-profit organisations. Stephanie Seneff is a Senior Research Scientist at MIT in Cambridge, MA. She holds a B.S. degree from MIT in biology, and a Ph.D. in electrical engineering and computer science also from MIT. Her recent research interests are on the role of nutritional deficiencies and toxic chemicals in disease, with a focus on the mineral sulfur and the herbicide glyphosate. Natasha Campbell-McBride is a medical doctor with two postgraduate degrees: MMedSci (neurology), MMedSci (human nutrition). She is the creator of the GAPS concept and the GAPS Nutritional Protocol.



Abele S, Tzivian L, Meija L & Folkmanis V (2019) Low Carbohydrate Diet (SCD/GAPS) for Children with Autistic Spectrum Disorder. International society for nutritional psychiatry research (ISNPR) conference, London, United Kingdom, 20-22 October 2019.

Akande KE, Doma UD, Agu HO & Adamu HM (2010) Major antinutrients found in plant protein sources: their effect on nutrition. Pakistan journal of nutrition9(8), 827-832.

Baars T, Berge C, Garssen J & Verster J (2019) The impact of raw fermented milk products on perceived health and mood among Dutch adults. Nutrition & Food Science.

Babinska K, Celusakova H, Belica I, Szapuova Z, Waczulikova I, Nemcsicsova D & Ostatnikova D (2020) Gastrointestinal symptoms and feeding problems and their associations with dietary interventions, food supplement use, and behavioral characteristics in a sample of children and adolescents with autism spectrum disorders. International Journal of Environmental Research and Public Health17(17), 6372.

Belkaid Y & Hand TW (2014) Role of the microbiota in immunity and inflammation. Cell157(1), 121-141.

Berg JM, Tymoczko JL & Stryer L (2002) Biochemistry, ; W. H. New York: Freeman and Company: New York.

Bhakdi S, Tranum-Jensen J, Utermann G & Füssle R (1983) Binding and partial inactivation of Staphylococcus aureus alpha-toxin by human plasma low density lipoprotein. Journal of Biological Chemistry258(9), 5899-5904.

Borba VV, Lerner A, Matthias T & Shoenfeld Y (2020) Bovine milk proteins as a trigger for autoimmune diseases: Myth or reality?. International Journal8(1), 10-21.

Camilleri M (2019) Leaky gut: mechanisms, measurement and clinical implications in humans. Gut68(8), 1516-1526.

Campbell-McBride N (2010) Gut and Psychology Syndrome: natural treatment for autism, dyspraxia, ADD, dyslexia, ADHD, depression, schizophrenia. Medinform Publishing.

Campbell-McBride N (2012) GAPS Stories: Personal accounts of improvement and recovery through the GAPS Nutritional Protocol. Medinform Publishing.

Campbell-McBride N (2020) Gut and Physiology Syndrome: Natural Treatment for Allergies, Autoimmune Illness, Arthritis, Gut Problems, Fatigue, Hormonal Problems, Neurological Disease and More. Medinform Publishing.

Capuco A, Urits I, Hasoon J, Chun R, Gerald B & Wang J, et al (2020) Current Perspectives on Gut Microbiome Dysbiosis and Depression. Advances In Therapy37(4), 1328-1346. doi: 10.1007/s12325-020-01272-7.

Cekici H & Sanlier N (2019) Current nutritional approaches in managing autism spectrum disorder: A review. Nutritional neuroscience22(3), 145-155.

Cénit MC, Matzaraki V, Tigchelaar EF & Zhernakova A (2014) Rapidly expanding knowledge on the role of the gut microbiome in health and disease. Biochimica et Biophysica Acta (BBA)-Molecular Basis of Disease1842(10), 1981-1992.

Cham S, Koslik HJ & Golomb BA (2016) Mood, personality, and behavior changes during treatment with statins: a case series. Drug safety-case reports3(1), 1.

Çikili Y, Deniz S & Çakal B. Analysis Of The Effect Of GAPS Diet On Individuals With Autism Spectrum Disorder. Journal of Ahmet Kelesoglu Education Faculty1(1), 1-11.

Clapp M, Aurora N, Herrera L, Bhatia M, Wilen E & Wakefield S (2017) Gut Microbiota’s Effect on Mental Health: The Gut-Brain Axis. Clinics And Practice7(4), 131-136.

Clarke G, Stilling RM, Kennedy PJ, Stanton C, Cryan JF & Dinan TG (2014) Minireview: gut microbiota: the neglected endocrine organ. Molecular endocrinology28(8), 1221-1238.

Claxton AJ, Jacobs Jr, DR, Iribarren C, Welles SL, Sidney S & Feingold K (1998) Association between serum total cholesterol and HIV infection in a high-risk cohort of young men. Journal of acquired immune deficiency syndromes and human retrovirology: official publication of the International Retrovirology Association17(1), 51-57.

Cordain L (1999) Cereal grains: humanity’s double-edged sword. World review of nutrition and dietetics84, 19-19.

Cryan JF, O’Riordan KJ, Cowan CS, Sandhu KV, Bastiaanssen TF, Boehme M & Dinan TG (2019) The microbiota-gut-brain axis. Physiological reviews.

Dietschy JM & Turley SD (2001) Cholesterol metabolism in the brain. Current opinion in lipidology12(2), 105–112.

Din ATU & Alam F (2020) Auto-brewery syndrome: a clinical dilemma. Cureus12(10).

Dinan TG & Cryan JF (2017) Brain–gut–microbiota axis—mood, metabolism and behaviour. Nature reviews Gastroenterology & hepatology14(2), 69-70.

Enig M (2000) Know your fats. Silver Spring, MD: Bethesda Press.

Faintuch J & Faintuch S (Eds) (2019) Microbiome and Metabolome in Diagnosis, Therapy, and Other Strategic Applications. Academic Press.

Fasano A (2011) Zonulin and its regulation of intestinal barrier function: the biological door to inflammation, autoimmunity, and cancer. Physiological reviews.

Fasano A (2012) Intestinal permeability and its regulation by zonulin: diagnostic and therapeutic implications. Clinical Gastroenterology and Hepatology10(10), 1096-1100.

Foster J & McVey Neufeld K (2013) Gut–brain axis: how the microbiome influences anxiety and depression. Trends In Neurosciences36(5), 305-312.

Freed DL (1991) Lectins in food: Their importance in health and disease. Journal of Nutritional Medicine2(1), 45-64.

Freed DL (1999) Do dietary lectins cause disease?: The evidence is suggestive—and raises interesting possibilities for treatment.

Garrow JS, James WPT & Ralph A (2003) Human nutrition and dietetics. Churchill Livingstone.

Golomb BA, Stattin H & Mednick S (2000) Low cholesterol and violent crime. Journal of psychiatric research34(4-5), 301-309.

Golomb BA, Kane T & Dimsdale JE (2004) Severe irritability associated with statin cholesterol-lowering drugs. Qjm97(4), 229-235.

Hallen-Adams HE & Suhr MJ (2017) Fungi in the healthy human gastrointestinal tract. Virulence8(3), 352-358.

Hao WL & Lee YK (2004) Microflora of the gastrointestinal tract. Public Health Microbiology, 491-502.

Heintz‐Buschart A, Pandey U, Wicke T, Sixel‐Döring F, Janzen A, Sittig‐Wiegand E & Wilmes P (2018) The nasal and gut microbiome in Parkinson’s disease and idiopathic rapid eye movement sleep behavior disorder. Movement disorders33(1), 88-98.

Hussain G, Wang J, Rasul A, Anwar H, Imran A, Qasim M & Sun T (2019) Role of cholesterol and sphingolipids in brain development and neurological diseases. Lipids in health and disease18(1), 1-12.

Huttenlocher PR & Dabholkar AS (1997) Regional differences in synaptogenesis in human cerebral cortex. Journal of comparative Neurology387(2), 167-178.<167::AID-CNE1>3.0.CO;2-Z.

Iribarren C, Jacobs Jr, DR, Sidney S, Claxton AJ, Gross MD, Sadler M & Blackburn H (1997) Serum total cholesterol and risk of hospitalization, and death from respiratory disease. International journal of epidemiology26(6), 1191-1202.

Jaglin M, Rhimi M, Philippe C, Pons N, Bruneau A, Goustard B & Rabot S (2018) Indole, a signaling molecule produced by the gut microbiota, negatively impacts emotional behaviors in rats. Frontiers in neuroscience12, 216.

Kaji H, Asanuma Y, Ide H, Saito N, Hisamura M, Murao M & Takahashi K (1976) The auto-brewery syndrome–the repeated attacks of alcoholic intoxication due to the overgrowth of Candida (albicans) in the gastrointestinal tract. Materia medica polona8(4), 429-435.

Kaplan BJ, Crawford SG, Field CJ & Simpson JSA (2007) Vitamins, minerals, and mood. Psychological bulletin133(5), 747.

Keys A (1953) Atherosclerosis: a problem in newer public health. Atherosclerosis1, 19.

Lange K, Hauser J, Lange K, Makulska-Gertruda E, Nakamura Y & Reissmann, et al (2017) The Role of Nutritional Supplements in the Treatment of ADHD: What the Evidence Says. Current Psychiatry Reports19(2).

Lerner A & Matthias T (2018) The Salutogenic Effects of Cow’s Milk and Dairy Products in Celiac Disease. Journal Of Clinical & Cellular Immunology09(02).

Lurie-Weinberger MN & Gophna U (2015) Archaea in and on the human body: health implications and future directions. PLoS pathogens11(6), e1004833.

Maniscalco JW & Rinaman L (2018) Vagal interoceptive modulation of motivated behavior. Physiology33(2), 151-167.

Muldoon MF, Marsland A, Flory JD, Rabin BS, Whiteside TL & Manuck B (1997) Immune system differences in men with hypo-or hypercholesterolemia. Clinical immunology and immunopathology84(2), 145-149.

Nazarenkov N, Beeken L, Seeger K, Ananthakrishnan A, Khalili H, Lewis JD & Konijeti GG (2018) Nutritional Adequacy of Popular Defined Diets for Inflammatory Bowel Disease: 736. Official journal of the American College of Gastroenterology ACG113, S415.

Nelson DL, Lehninger AL & Cox MM (2008) Lehninger principles of  biochemistry. Macmillan.

O’Brien JS & Sampson EL (1965) Lipid composition of the normal human brain: gray matter, white matter, and myelin. Journal of lipid research6(4), 537-544.

Orgeron II RP, Corbin A & Scott B (2016) Sauerkraut: A probiotic superfood. Functional Foods in Health and Disease6(8), 536-543.

Perricone C & Shoenfeld Y (Eds) (2019) Mosaic of autoimmunity: the novel factors of autoimmune diseases. Academic Press.

Petra AI, Panagiotidou S, Hatziagelaki E, Stewart JM, Conti P & Theoharides TC (2015) Gut-microbiota-brain axis and its effect on neuropsychiatric disorders with suspected immune dysregulation. Clinical therapeutics37(5), 984-995.

Purves WK, Orians GH, Heller HC & Sadava D (2004) Life, the Science of Biology, 7th. Sunderland, Mass: Sinauer Associates954.

Pusztai A, Ewen SWB, Grant G, Brown DS, Stewart JC, Peumans WJ & Bardocz S (1993) Antinutritive effects of wheat-germ agglutinin and other N-acetylglucosamine-specific lectins. British Journal of Nutrition70(1), 313-321

Quigley L, McCarthy R, O’Sullivan O, Beresford TP, Fitzgerald GF, Ross RP & Cotter PD (2013)a The microbial content of raw and pasteurized cow milk as determined by molecular approaches. Journal of dairy science96(8), 4928-4937.

Quigley L, O’Sullivan O, Stanton C, Beresford TP, Ross RP, Fitzgerald GF & Cotter PD (2013)b The complex microbiota of raw milk. FEMS microbiology reviews37(5), 664-698.

Quigley EM (2017) Microbiota-brain-gut axis and neurodegenerative diseases. Current neurology and neuroscience reports17(12), 1-9.

Ravnskov U (2002) Is atherosclerosis caused by high cholesterol?. Qjm95(6), 397-403

Ravnskov U (2003) Cholesterol Myths. New Trends Publishing, Incorporated.

Roberts K, Alberts B, Johnson A, Walter P & Hunt T (2002) Molecular biology of the cell. New York: Garland Science.

Rogers GB, Keating DJ, Young RL, Wong ML, Licinio J & Wesselingh S (2016) From gut dysbiosis to altered brain function and mental illness: mechanisms and pathways. Molecular psychiatry21(6), 738-748.

Rucklidge J & Harrison R (2010) Successful Treatment of Bipolar Disorder II and ADHD with a Micronutrient Formula: A Case Study. CNS Spectrums, 15(5), 289-295.

Salem I, Ramser A, Isham N & Ghannoum MA (2018) The gut microbiome as a major regulator of the gut-skin axis. Frontiers in microbiology9, 1459.

Samsel A & Seneff S (2013) Glyphosate, pathways to modern diseases II: Celiac sprue and gluten intolerance. Interdisciplinary toxicology6(4), 159.

Sanctuary MR, Kain JN, Angkustsiri K & German JB (2018) Dietary Considerations in Autism Spectrum Disorders: The Potential Role of Protein Digestion and Microbial Putrefaction in the Gut-Brain Axis. Frontiers in nutrition5, 40.

Sandstead HH (1992) Fiber, phytates, and mineral nutrition. Nutrition  reviews50(1), 30–31.

Sapone A, De Magistris L, Pietzak M, Clemente MG, Tripathi A, Cucca F & Fasano A (2006) Zonulin upregulation is associated with increased gut permeability in subjects with type 1 diabetes and their relatives. Diabetes55(5), 1443-1449.

Schnorr SL & Bachner HA (2016) Integrative Therapies in Anxiety Treatment with Special Emphasis on the Gut Microbiome. The Yale journal of biology and medicine89(3), 397–422.

Seeley R, Stephens T & Tate P (2008) Anatomy and physiology. (8th ed.). New York: McGraw- Hill.

Sender R, Fuchs S & Milo R (2016) Revised estimates for the number of human and bacteria cells in the body. PLoS biology14(8), e1002533.

Seneff S (2021) Toxic Legacy: How the Weedkiller Glyphosate Is Destroying Our Health and the Environment. Chelsea Green Publishing.

Sokolov O, Kost N, Andreeva O, Korneeva E, Meshavkin V, Tarakanova Y, Dadayan A, Zolotarev Y, Grachev S, Mikheeva I, Varlamov O & Zozulya A (2014) Autistic children display elevated urine levels of bovine casomorphin-7 immunoreactivity. Peptides56, 68–71.

Stevens BR, Goel R, Seungbum K, Richards EM, Holbert RC, Pepine CJ & Raizada MK (2018) Increased human intestinal barrier permeability plasma biomarkers zonulin and FABP2 correlated with plasma LPS and altered gut microbiome in anxiety or depression. Gut67(8), 1555-1557.

Sturgeon C & Fasano A (2016) Zonulin, a regulator of epithelial and endothelial barrier functions, and its involvement in chronic inflammatory diseases. Tissue barriers4(4), e1251384.

Tillisch K, Labus J, Kilpatrick L, Jiang Z, Stains J, Ebrat B & Mayer EA (2013) Consumption of fermented milk product with probiotic modulates brain activity. Gastroenterology144(7), 1394-1401.

Tomson-Johanson K, Kaart T, Kiivet RA, Veidebaum T & Harro J (2020) Low cholesterol levels in children predict impulsivity in young adulthood. Acta neuropsychiatrica32(4), 196-205.

Van Damme EJ, Peumans WJ, Pusztai A & Bardocz S (1998) Handbook of plant lectins: properties and biomedical applications. John Wiley & Sons.

van Neerven RJ, Knol EF, Heck JM & Savelkoul HF (2012) Which factors in raw cow’s milk contribute to protection against allergies?. Journal of Allergy and Clinical Immunology130(4), 853-858.

Woodford KB (2021) Casomorphins and Gliadorphins Have Diverse Systemic Effects Spanning Gut, Brain and Internal Organs. International journal of environmental research and public health18(15), 7911.

Wu HJ & Wu E (2012) The role of gut microbiota in immune homeostasis and autoimmunity. Gut microbes3(1), 4-14.

Yoshii K, Hosomi K, Sawane K & Kunisawa J (2019) Metabolism of dietary and microbial vitamin B family in the regulation of host immunity. Frontiers in nutrition6, 48.

Zioudrou C, Streaty RA & Klee WA (1979) Opioid peptides derived from food proteins. The exorphins. Journal of Biological Chemistry254(7), 2446-2449.