A peculiar characteristic of this cereal is the high food tolerability. In the last few years numerous experimental evidences of the reduced toxicity of the monococcus wheat prolamins have been obtained. In particular, the prolamins of this cereal are not able to induce lesions in the intestinal mucosa of celiac patients (Auricchio et al., 1982; De Vincenzi et al., 1995; 1996) and to agglutinate K562 (S) cells, a in vitro tests strongly correlated with the “toxicity” of the prolaminic peptides. Furthermore, T. monococcum accessions of immuno-dominant sequences able to stimulate T lymphocytes have been identified (Molberg et al., 2005; Spaenij-Dekking et al., 2005; Zanini et al., 2013). Recently, Gianfrani et al. (2012) reported the results of a study on two monococcus wheat genotypes, Monlis and ID331, compared with the variety of tender wheat Sagittarius. However, while the proliferates of Sagittarius and Monlis, a variety of monococcus wheat free of ω-gliadins, are able to promote the proliferation of enterocytes in the crypts of the mucous membranes of celiac patients and to induce the synthesis of interliquine 15 (IL- 15) in intestinal villi enterocytes, ID321 prolamins, a monococcus wheat line containing only one ω-gliadin, show no effect. The results suggest that Monlis is able to activate innate immunity and promote the synthesis of interleukin 15 (IL-15), a key molecule in the induction of adaptive immunity, while ID331 does not seem capable of eliciting this type of immune response. All this is in agreement with the observation that the prolamins of the Monlis variety and other monococcus wheat genotypes without ω-gliadin behave like the prolamins of soft wheat in their ability to agglutinate K562 (S) cells and alter the intestinal epithelium. These rare toxic genotypes of monococcus wheat (<2%) differ from the others due to the peculiarity of not producing ω-gliadins, in which sequences able to counteract the toxicity of the other prolamins seem to be present. Although monococcus wheat proteins show reduced cytoxicity towards intestinal cells, the presence of immune-dominant epitopes precludes their use in the celiac diet.On the other hand, considering that the incidence and severity of celiac disease depends on the quantity and the harmfulness of the prolamins and that some monococcus wheat genotypes have a high bread making quality coupled with absence of cytotoxicity and reduced immunogenicity, it is expected that use of monococcus flours in the diet of the general population, in which there is a high percentage of individuals genetically predisposed to celiac disease but not yet celiac, can help to contain the spread of this form of food intolerance. This suggests that the monococcus wheat, recently reported in cultivation in Italy by researchers of the Council for Research and Experimentation in Agriculture (CRA) of Rome and San Angelo Lodigiano, will play an important role in the prevention of celiac disease, both directly in the form of bread and pasta both indirectly as a model species for the study of the role of innate immunity in the onset of celiac disease. FROM: The new frontiers of food technologies and the celiac disease Norberto Pogna, Laura Gazza (2013). Volume 212, 1 December 2016, Pages 537-542 Further confirmations were highlighted by the research: Protective effects of ID331 Triticum monococcum gliadin on in vitro models of the intestinal epithelium. Giuseppe Jacomino et al. 2016. Highlights: • ID331 gliadins do not enhance permeability and do not induce zonulin release. • ID331 gliadins do not trigger cytotoxicity or cytoskeleton reorganization. • ID331 gastrointestinal digestion releases ω (105-123) bioactive peptide. • ω (105-123) exerts a protective action against the toxicity induced by T. aestivum. Abstract A growing interest in developing new strategies due to coeliac disease. In the current study, we investigate the biological effects of ID331 Triticum monococcum gliadin-derived peptides in human Caco-2 intestinal epithelial cells. Triticum aestivum gliadin derived peptides were used as a positive control. The effects on epithelial permeability, zonulin release, viability, and cytoskeleton reorganization were investigated. Our findings confirmed that ID331 gliadin did not enhance permeability and did not induce zonulin release, cytotoxicity or cytoskeleton reorganization of Caco-2 cell monolayers. We also demonstrated that ID331 ω-gliadin and its derived peptide ω (105-123) exerted to protective action, mitigating the injury of Triticum aestivum gliadin on cell viability and cytoskeleton reorganization. These results may represent a new opportunity for the future development of innovative strategies to reduce gluten toxicity in the diet of patients with gluten intolerance.
Digestion of Gluten Peptides in the Large Intestine
It has been shown that removing gluten from the diet affects the composition of the bacterial community in the large bowel, where the undigested food in the small intestine and could be hydrolyzed by microbial metabolism, generating beneficial compounds for the host.
“Alimentary protein digestion followed by amino acid and peptide absorption in the small intestinal epithelium is considered an efficient process. Nevertheless, unabsorbed dietary proteins enter the human large intestine as a complex mixture of protein and peptides.53,63 The incomplete assimilation of some dietary proteins in the small intestine has been previously demonstrated, even with proteins that are known to be easily digested (e.g., egg protein).64,65 The high proline content of wheat gluten and related proteins renders these proteins resistant to complete digestion in the small intestine. As a result, many high molecular weight gluten oligopeptides arrive in the lower gastrointestinal tract.66 While gluten peptides pass through the large intestine, proteolytic bacteria could participate in the hydrolysis of these peptides. A recent study from our group has shown that some of the gluten ingested in the diet is not completely digested while passing through the gastrointestinal tract, and is consequently eliminated in feces.
Moreover, it has been shown that the amount of gluten peptides present in feces is proportional to the amount of gluten consumed in the diet. Therefore, several gluten peptides are resistant to both human and bacterial proteases in the gastrointestinal tract.66,67
The large intestine is the natural habitat for a large and dynamic bacterial community. Although the small intestine contains a significant density of living bacteria, the density in the large intestine is much higher. The large intestine has as many as 1011–1012 cells per gram of luminal content that belong to thousands of bacterial taxa. Furthermore, the large intestinal microbiota is extremely complex and performs specific tasks that are beneficial to the host.68–71 Among the important functions that the intestinal microbiota performs for the host are several metabolic functions.72 In contrast to the rapid passage of dietetic components through the small intestine, the transit of the luminal material through the large intestine is considerably slower. The longer transit time in the large intestine has been associated with important bacterial metabolic activity.53 Therefore, undigested food in the upper gut could be hydrolyzed by microbial metabolism in the large intestine, generating beneficial compounds for the host.
The resistance of gluten peptides to pancreatic and brush border enzymes allows large amounts of high molecular weight peptides to enter the lower gastrointestinal tract. Therefore, gluten peptides are available for microbial metabolism in the large intestine and could be important to the composition of the intestinal microbiota. It has been shown that removing gluten from the diet affects the composition of the bacterial community in the large bowel.78,79 De Palma et al.78 observed that healthy subjects who followed a gluten-free diet for 1 month had reduced fecal populations of Lactobacillus and Bifidobacterium, but the population of Enterobacteriae such as E. coli appeared to increase. Similar results were obtained in studies with CD patients. Treated CD patients also showed a reduction in the diversity of Lactobacillus and Bifidobacterium species.80,81Gluten Metabolism in Humans. Alberto Caminero, … Javier Casqueiro, in Wheat and Rice in Disease Prevention and Health, 2014”
An opportunity to be seized: digestible and tolerable gluten. Why?
Gluten (it is a protein compound that is formed when glutenin and gliadin, present in flour, are strongly mixed with water) is responsible for celiac disease in genetically predisposed subjects. Not all gluten is at the origin of this pathology: the research has, in fact, isolated some sequences of amino acids (they are the “bricks” that constitute gluten) that are responsible for the adverse reaction of the innate and adaptive human immune system. These sequences are present (even several times) in the molecular chains (peptides) that constitute gluten, and, above all in gliadins. There are many studies that aim to create grains or flours without these sequences, mixtures where the action of particular bacteria present in the acid paste destroy the toxic fractions. Particular enzymes (proteases produced by Aspergillus) have been identified that can activate a complete enzymatic digestion of gliadin, reducing or eliminating the reactive response of gluten-sensitive T cells. (Toft-Hansen H et al Clin Immunol. 2014 Aug; 153 (2): 323-31. Doi: 10.1016 / j.clim.2014.05.009. Epub 2014 Jun 3).
Gluten is indigestible as such, only if divided into constituent amino acids it can be digested and, after being passed into the blood, be assimilated. The action of “chopping up the gluten is carried out by the enzyme pepsin (it is the most important of the digestive enzymes and, activated by hydrochloric acid, attacks proteins and breaks them down into fragments called polypeptides which will then be broken down into individual amino acids by trypsin ), present in the stomach and the enzyme trypsin produced by the pancreas present in the intestine. These two enzymes are not always able to “break up” the gluten and the residues are eliminated by “normal” people. These residues, on the other hand, if they contain toxic sequences activate the response of the immune system that fights them as “enemies”. The more gluten is strong (ie the stronger the bonds of the molecules that make up gluten) the more difficult and the action of enzymes will be longer. You can be born celiac but you can also become genetically predisposed. At greater risk, of course, are the relatives and relatives of celiacs. Scientific research has shown that the use in the diet of foods produced with grains as light as possible and tolerable (with the least possible amount of “toxic epitopes”) reduces the possibility of becoming celiac and is indicated for non-celiac gluten sensitive people. An example regarding the monococcus wheat we find in the study:
“…..Conclusions: Our study shows that Tm (Grano Monococco) is toxic for CD patients as judged on histological and serological criteria, but it was well tolerated by the majority of patients, suggesting that Tm is not a safe cereal for celiacs, but that it may be of value for patients with gluten sensitivity or for prevention of CD.Copyright of European Journal of Nutrition is the property of Springer Science & Business Media B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder’s express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.”
For some time now, scientific research has highlighted another gluten-related disease: non-celiac gluten sensitivity (NCGS). Today it is possible to diagnose it only through a long and complex series of analyzes which, for this reason, cannot be widely applied. The research (well summarized in the attached research) is still on the high seas, in fact, in the realization of biomarkers suitable to diagnose this pathology in a certain and simple way. Finally it should be noted that although there are very many studies, researches and tests on patients, these have proved too partial to be able to define “with certainty” how the NCGS is activated. Gliadins, however, play an important role as anti-gliadin antigen has been found in patients diagnosed with this disease. Finally, the research showed that a light and tolerable gluten is less invasive for those with irritable bowel disease.
“In formulating Gluten Free products, therefore, the first problem to be solved is the absence of the protein network on which to build the product. This deficiency affects the structure of the product both in terms of volume and organoleptic level. The formulations are based mainly on mixtures of starches and substances that act as “glue” and often have a strong nutritional imbalance, ie a strong fiber deficiency and a high glycemic index. The Glycemic Index clarifies how quickly the ingested carbohydrate is demolished, absorbed and released into the bloodstream as an energy source for the cells. Foods with low Glycemic Index release energy in a prolonged way, constantly and allow to avoid the feeling of hunger a few hours after a meal. Foods with high Glycemic Index release energy in the form of glucose very quickly with the result that the feeling of hunger is not slow to be felt and the excess glucose is transformed into fat storage. In the report “Glycemic Index and Gluten Free Products” by Dr. Alessandra Bosetti, clinical dietician at the Sacco hospital, the need to reconsider the characteristics of the dieto-therapeutic products to improve their glycemic index and nutritional adequacy emerge . In the various baked products there is also a series of organoleptic defects summarized here:
• Biscuits: lack of bite consistency, too hard structure or excess of sand, lack of taste persistence;
• Baked cakes: no volume, they dry quickly, gumminess, lack of taste, unbalanced nutritional profile;
• Bread, pizza: it lacks volume, it lacks elasticity in the crumb, poorly homogeneous crumb, gumminess, unbalanced nutritional profile.
In the different formulations corn flours, rice, quinoa, buckwheat are used, to which are added amides with structuring or emulsifying function and hydrocolloids. The latter have the important function of absorbing and retaining the water of the mixture and during cooking to create a gelatinized starch containment mesh. The main hydrocolloids used include guar gum, xanthan, carrageenan and hydroxymethylcellulose. To make the best use of these products, it is advisable to use hot water or long resting times that allow optimal hydration of the fibers. Still little has been studied on kneading machines: the spiral kneader the fork or the diving arms are the least suitable when there is no gluten to be formed or oriented. Normally planetary mixers are used to have the best hydration of the different components; moreover, if they allow an optimal oxidation of the dough, the mesh formed by rubbers and starches shows a better resistance and functionality. ” From: https://www.sigmasrl.com/it/blog/im purchased-del-gluten-free
The study highlights the action of sourdough both in hydrolyzing (breaking) the proteins rich in proline (gliadin) involved in activating the human immune system both in the hydrolyser gluten (favoring digestibility) and ,above all, the high glutenins molecular weight.
Sourdough and its potential for degradation of gluten
Sourdough is produced using a culture of lactobacillus, frequently in combination with yeast. Sourdough is the oldest method for leavening bread and is still used for some applications. For example, in making bread from rye, perhaps because the dough made from rye flour needs a low pH to be appropriate for baking (Arendt et al., 2007). In comparison with yeast-treated doughs for wheat- or rye-based breads, sourdough produces a distinctively tangy or sour taste, mainly as a result of lactic acid produced by the lactobacilli. Moreover, during sourdough fermentation, proteolysis provides compounds that are precursors for the aroma volatiles and amino acids which are converted by microbes to compounds which are precursors of flavours (Gänzle et al., 2008). Traditionally sourdough is added as an ingredient to unmodified flour of wheat or rye for breadmaking. However, some authors (Rizzello et al., 2007) have proposed sourdough as the major ingredient and the only source of proteins for making gluten-free bread.
An important study that highlights the interesting characteristics of ancient varieties of wheat in relation, above all, to some widespread gastrointestinal diseases (“This manuscript reviews the nutritional value and health benefits of ancient wheats varieties, providing a summary of all in vitro, ex vivo, animal and human studies that have thus far been published.”)
Ancient wheat species “Although there is no precise definition, it is generally accepted that ancient wheat has remained unchanged over the last hundred years. In contrast, modern species have been extensively modified and subject to cross-breeding in what is commonly referred to as the “Green Revolution”. This term was developed to refer to a set of research and technological transfer initiatives that occurred between the 1930s and the late 1960s. The Green Revolution was initiated by Strampelli, who was among the first, in Europe and in the World, to systematically apply Mendel’s laws to traits such as rust resistance, early flowering and maturity and short straw. As a consequence, Italian wheat production doubled, an achievement that during the fascist regime was referred to as the “Wheat Battle” (1925–1940) . After the Second Word War, some of Strampelli’s wheat varieties were used as parents in breeding programmes in many countries in a phase of the Green Revolution, defined as Norman Borlaug’s Green Revolution. This phase was instrumental in the development of the high-yielding varieties . Thereafter, during the 1960s, research was concentrated on improving the storage protein quality, thereby increasing the technological properties. Agronomists bred cultivars of maize, wheat, and rice that were generally referred to as “high-yielding varieties” based on a higher capacity for nitrogen-absorption than other varieties. High levels of nitrogen in the soils causes the lodging of wheat before harvest. Therefore, semi-dwarfing genes were bred to improve to reduce both lodging and the maturation cycle. The principle results of this revolution were the development of modern varieties characterized by higher yield, a reduced susceptibility to diseases and insects, an increased tolerance to environ- mental stresses, a homogeneous maturation (to optimize harvest) and a higher gluten content (to improve bread and pasta quality). Whilst these intensive breeding programs helped to increase production and techno- logical quality, a concomitant decrease in genetic variability as well as a gradual impoverishment of the nutritional and nutraceutical properties of the wheat occurred, mainly determined by the complete replacement of ancient local breeds with modern varieties.”
Some passages of the study help to focus the most significant evidences that, although referring to a limited number of researches, open interesting perspectives for a greater use of ancient grains in order to reduce the disorders deriving from the ingestion of gluten:
About monococcum wheat: “Compared with soft wheat, einkorn showed a lower content of both total and resistant starch (mean value: 655 vs 685 g/kg dry matter (DM) and 25.6 vs 30–88 g/kg DM respectively) . However, the amount of amylose molecules, that are digested more slowly, was higher than the amount of amylopectin molecules, thereby lowering both glucose and insulin levels in the blood after meals  and maintaining satiety for longer periods . By evaluating the average protein content, einkorn protein values were 59% higher than those of modern wheat , but the bread-manufacturing quality of storage proteins were poor, making it better suited to the preparation of cookies or pasta . The comparative analysis of lipids and fatty acid composition in einkorn and soft wheat germ revealed a higher content of lipids (+50%) in einkorn, with a greater proportion of monounsat- urated fatty acids (+53%), and lower polyunsaturated (−8%) and saturated fatty acids (−21%) . With respect to phytochemicals, einkorn showed the highest concentration of phytosterols and tocols (1054 and 57 μg/g DM respectively), but this difference was mostly marked in the HEALTHGRAIN dataset . In addition, einkorn, khorasan wheat and emmer wheat cultivars showed the highest content of total carotenoids (2.26, 6.65 and 8.23 μg/g DM respectively) and lutein (7.28, 4.9 and 2.7 μg/g DM), the major carotenoid with respect to all the other species [18,19]. Of interest, several lines of einkorn showed lutein values from three to eight-fold higher than soft wheat and two-fold greater than those for durum wheat. Some authors suggested that the higher carotenoid content in einkorn-made products could be a result of lower processing losses, linked to lower lipoxygenase activity . “
Although there is insufficient evidence to suggest that ancient wheat varieties prevent gluten-related disorders, several studies have shown that a diet based on less-immunoreactive wheat products, with fewer amounts and types of reactive prolamins and fructans, may help in the improvement of gastrointestinal and/or systemic symptoms of some auto-immune or chronic diseases (eg, irritable bowel syndrome, etc.) . These less-immunoreactive varieties, like einkorn, may be good targets for slowing the development of disease in populations genetically predis- posed to celiac disease and other wheat sensitivities .
On the other hand, a subsequent paper investigating how in vitro gastro-intestinal digestion affects the immune toxic properties of gliadin from einkorn (compared to modern wheat), demonstrated that gliadin proteins of einkorn are sufficiently different from those of modern wheat, thereby determin- ing a lower immune toxicity following in vitro simulation of human digestion .
Although concrete functional benefits are difficult to ascertain from random individual human trials, since they are subject to differences and/or limitations in experimental design, participant number and participant characteristics in the case of parallel arm studies, results unanimously suggest that the consump- tion of products made with ancient wheat varieties ameliorate not only pro-inflammatory/anti-oxidant parameters (where investigated) but also glycaemic and lipid status. Ancient wheat species and human health: Biochemical and clinical implications. Stefano Benedettelli et altri. September 2017. (Available online at www.sciencedirect.com)
Lodging is the bending over of the stems near ground level of grain crops, which makes them very difficult to harvest, and can dramatically reduce yield.
Ancient wheat species and human health
– the structure of the gliadin and the toxicity of some fraction –
Gluten which is a protein compound formed by the prolamine, known as gliadin in wheat and responsible for the main phenomena of adverse reactions, and glutenin present mainly in the endosperm of cereal caryopsis such as wheat, spelled, rye and barley. Gluten is formed when water, flour and yeast are mixed: gliadin and glutenin combine to form a mixture characterized by viscosity, elasticity and cohesion. Therefore the quantity and integrity of the proteins that make up the gluten present in a flour are an important index to evaluate the quality and aptitude for baking.
Gliadin and glutenin, therefore, have been the subject of numerous research both in relation to the properties concerning the rheological characteristics of the doughs and to the adverse reactions that activate the immune system. Studies have been carried out on celiac disease that have discovered who and how this pathology is caused: they are some peptides (a set of amino acids) present, especially in the gliadin that contain sequences that are toxic, ie they activate the adverse reaction in genetically predisposed subjects of the immune system. The gliadin, in turn, is composed of several sub-units and these contain the “toxic” fractions in different quantities and qualities. Not only has William Hekkins’ research highlighted how the shape and location of gliadin molecules also influence not only chemical and physical properties but also toxicity.
“The gliadin proteins are heterogenous in different regions of the molecule and consequently differ in phisical and chemical properties. About 35% of the gliadin molecule is the alfa helix form, whereas 35% are beta turns(5). The latter are concentrated in the N terminal and C terminal more apolar parts of the gliadin. The remaining part has a random structure. These form have conseguences for the immunogenecity of the different regions in the molecule. Especially beta-turns are immunogenic.” The Toxicity of wheat prolamins William TH. J. M. Hekkens Annales Nestlé 1995 n. 51.
The study also analyzed the mechanism underlying the toxicity by detecting how “the passage of undigested gliadin fragments (fragments longer than 8 amino acids) or a lower tolerance to gliadin causes the immune system to react”. It is not enough, therefore, to know how much gliadin is present in a grain, but it is necessary to have the complete screening of its sub-units (quality, quantity, and, according to the study mentioned also form and position). The study on the “structure of gliadin” could partly explain why some ancient grains (for example, the monococcus), despite having a quantity of gliadin (and in particular alpha gliadin) not inferior to modern grains, have almost zero toxic levels.
The Toxicity of wheat prolamins
Over the years, numerous evidences have emerged that the ingestion of certain short-chain carbohydrates, including lactose, fructose and sorbitol, fructans and galacol oligosaccharides, induces the typical symptoms of irritable bowel syndrome.One method of decreasing the amount of FODMAPs and possibly the bioactivity of ATIs in bread (and thus theoretically improving its tolerability), is the utilization of prolonged fermentation processes in breadmaking. Sourdough fermentation activates some proteolytic and fructosidase enzymes in dough, and can thus decrease the amount of proteins and fructans in the end products [14,15,16,17]. The FODMAP content of sourdough bread can be reduced by up to 90% by utilizing a specific sourdough system, as demonstrated in our previous study . Taken together, sourdough baking could theoretically result in wheat products with improved gastrointestinal tolerability. (Pilot Study: Comparison of Sourdough Wheat Bread and Yeast-Fermented Wheat Bread in Individuals with Wheat Sensitivity and Irritable Bowel Syndrome Reijo Laatikainen et altri. Published: 4 November 2017.) Note: The references in the text refer to the bibliography of the aforementioned study.
Yeast, on the other hand, produces inulinase and invertase enzymes which work together to effectively hydrolyze fructans (Nilsson and others 1987). Fermentation with S. cerevisiae for 1.7 h reduced fructan content of whole wheat and white flour by 33% and 48%, respectively (Knez and others 2014). (A Grounded Guide to Gluten: How Modern Genotypes and Processing Impact Wheat Sensitivity – Chapter Fermentation and microbial enzymes – Lisa Kissing Kucek, Lynn D. Veenstra, Plaimein Amnuaycheewa, and Mark E. Sorrells. Comprehensive Reviews in Food Science and Food Safety Vol. 14, 2015)