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Gluten and intestine

by luciano

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?

by luciano

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.

High glycemic index of gluten-free products

by luciano

“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

Surdough fermentation (I part)

by luciano

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.