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Grano Monococco e Microbiota intestinale

by luciano

Lo stato e la salute del microbiota intestinale è al centro di molti studi volti a studiare il ruolo del microbiota nelle malattie e come intervenire a scopo preventivo o curativo.
L’insieme dei microrganismi che popolano il nostro apparato digerente (microbiota) comprende ceppi batterici buoni ma possono essere talvolta presenti anche quelli nocivi. I ceppi indigeni (quelli che caratterizzano il nostro microbiota) ostacolano la colonizzazione dell’intestinoda parte di nuovi microbi, tra cui quelli patogeni. La vitamina K, ad esempio, è sintetizzata da batteri buoni presenti. Batteri indigeni digeriscono e fermentano i favonoidi contenuti nella frutta e nella verdura promuovendo la produzione di sostanze che hanno effetti protettivi sulla salute cardiovascolare. Una funzione essenziale che svolgono i nostri batteri è quella di produrre acidi grassi a catena corta specialmente l’acido butirrico. Questi acidi proteggono l’intestino dalle infiammazioni e dall’insorgenza di tumori.
La ricerca “In Vivo Effects of Einkorn Wheat (Triticum monococcum) Bread on the Intestinal Microbiota, Metabolome, and on the Glycemic and Insulinemic Response in the Pig Model” ha questo tema come focus.
In evidenza:
Abstract: “Einkorn wheat (Triticum monococcum) is characterized by high content of proteins, bioactive compounds, such as polyunsaturated fatty acids, fructans, tocols, carotenoids, alkylresorcinols, and phytosterols, and lower α-, β -amylase and lipoxygenase activities compared to polyploid wheat. These features make einkorn flour a good candidate to provide healthier foods. In the present study, we investigated the effects of einkorn bread (EB) on the intestinal physiology and metabolism of the pig model by characterizing the glycemic and insulinemic response, and the microbiota and metabolome profiles. Sixteen commercial hybrid pigs were enrolled in the study; four pigs were used to characterize postprandial glycemic and insulinemic responses and twelve pigs underwent a 30-day dietary intervention to assess microbiota and metabolome changes after EB or standard wheat bread (WB) consumption. The postprandial insulin rise after an EB meal was characterized by a lower absolute level, and, as also observed for glucose, by a biphasic shape in contrast to that in response to a WB meal. The consumption of EB led to enrichment in short-chain fatty acid producers (e.g., Blautia, Faecalibacterium, and Oscillospira) in the gut microbiota and to higher metabolic diversity with lower content of succinate, probably related to improved absorption and therefore promoting intestinal gluconeogenesis. The observed changes, at both a compositional and metabolic scale, strongly suggest that EB consumption may support a health-promoting configuration of the intestinal ecosystem.”

omissis……”

Einkorn wheat (Triticum monococcum) was one of the first crops domesticated approximately 12,000 years ago in the Near East, alongside emmer wheat (Triticum dicoccum). Typically, einkorn was cultivated on marginal agricultural land, being able to survive in harsh environments and poor soils where other types of wheat could not survive. Spelt wheat (Triticum spelta) represents a hexaploid series of the Triticum genome constitution, which is characterized by great adaptation to a wider range of environments [1]. When compared to polyploid wheats, it has a higher content of proteins and some well recognised bioactive compounds, such as polyunsaturated fatty acids, fructans, tocols, carotenoids, alkylresorcinols, phytosterols, and lower α-, β -amylase and lipoxygenase activities [2]. These compositional traits make einkorn flour a good candidate to provide healthier foods. Specifically, the presence of antioxidant compounds and the protein profile are expected to be related to reduced cardiovascular disease and hypoallergenic effects, respectively. In particular, einkorn was shown to express few T-cell stimulatory gluten peptides, with important implications for celiac disease [3]. In vitro digested einkorn breads evidenced their higher carotenoid level as compared to modern wheats and showed a greater anti-inflammatory effect than the control (wheat bread) in Caco-2 intestinal epithelial cells [4]. Given the crucial role of the gut microbiota in the metabolism of dietary compounds, including the bio-activation of plant polyphenols into health-promoting metabolites and the production of short-chain fatty acids (SCFAs, mainly acetate, propionate, and butyrate) from fiber fermentation, as major orchestrators of the host physiology [5].”

omissis….

“Specifically, for einkorn, one of the most representative ancient grains, in vitro results evidenced a good healthy potential because of its effects on blood concentrations of glucose and insulin with a view to using einkorn-based foods in metabolic diseases [7,8], but none has considered changes in the microbiota structure as well as in the intestinal repertoire of metabolites, potentially influencing multiple metabolic and immunological pathways that are relevant to host health. In an attempt to bridge this gap, here we explored the gut microbiota and metabolome of pigs fed with an einkorn versus wheat-based bread. “

omissis……
Conclusions. “In summary, through the pig model we demonstrated a beneficial impact of EB on several aspects of the host physiology, including insulin release, fecal consistency, and microbiota and metabolome profiles, both in feces and intestinal contents. According to our findings, the consumption of EB could reduce the AUC of the first insulin peak, thus prolonging the sense of satiety. Moreover, it could modulate the intestinal ecosystem, at both the compositional and metabolic scale, towards a configuration specifically enriched in health-promoting bacteria and showing distinct metabolic signatures potentially contributing to maintaining the host homeostasis. The use of the pig model allowed, unlike in clinical human trials, the sampling of the mucosa and the content of the small intestine, thus widening the knowledge on the complexity of the food-microbiota-host interaction along the gastrointestinal tracts. The observed positive effects could be driven by the synergistic interaction of many factors, including, inter alia, the fermentation process, the food matrix, and the flour components, which result in gut-mediated effects. The evaluation of the beneficial effects of a real food is far more complex than using purified compounds, as a direct cause-effect relationship can seldom be ascribed to a single component. It is indeed foods, and not the single components, which create the diet, and exploring their complexity can better reflect their overall role on health. Although further studies and clinical trials are needed, the results that are herein reported represent a first contribution to unravel the anti-inflammatory potential of einkorn-based foods.”

“In Vivo Effects of Einkorn Wheat (Triticum monococcum) Bread on the Intestinal Microbiota, Metabolome, and on the Glycemic and Insulinemic Response in the Pig Model”. Francesca Barone et al. Nutrients 2019, 11, 16; doi:10.3390/nu11010016

Note:
A – Pigs have significant anatomical and physiological similarities with humans, particularly with regard to the intestinal structure, with comparable transit time and analogous digestive and absorptive processes [9,10]. Furthermore, like humans, they are true omnivores, unlike other potential mammalian models, such as dogs, cats, ruminants, rabbits, and rodents, which have evolutionarily developed alternative digestive strategies. Finally, both pigs and humans are colon fermenters and have similar colonic microbiota composition. All of these features make the pig one of the most important models in the field of nutrition [11,12]. Through the pig model, in the present study we investigated the impact of a 30-day nutritional intervention with einkorn or wheat bread on the intestinal ecosystem, by means of next-generation sequencing of the 16S rRNA gene and metabolomics of fecal samples, as well as samples from ileal and colonic compartments. The effects of einkorn vs. wheat bread on animal physiology, blood parameters, postprandial glycemia, and insulin response were also evaluated.

B – The metabolome refers to the complete set of small-molecule chemicals found within a biological sample. The biological sample can be a cell, a cellular organelle, an organ, a tissue, a tissue extract, a biofluid or an entire organism. The small molecule chemicals found in a given metabolome may include both endogenous metabolites that are naturally produced by an organism (such as amino acids, organic acids, nucleic acids, fatty acids, amines, sugars, vitamins, co-factors, pigments, antibiotics, etc.) as well as exogenous chemicals (such as drugs, environmental contaminants, food additives, toxins and other xenobiotics) that are not naturally produced by an organism.
The metabolome refers to the complete set of small-molecule chemicals found within a biological sample. The biological sample can be a cell, a cellular organelle, an organ, a tissue, a tissue extract, a biofluid or an entire organism. The small molecule chemicals found in a given metabolome may include both endogenous metabolites that are naturally produced by an organism (such as amino acids, organic acids, nucleic acids, fatty acids, amines, sugars, vitamins, co-factors, pigments, antibiotics, etc.) as well as exogenous chemicals (such as drugs, environmental contaminants, food additives, toxins and other xenobiotics) that are not naturally produced by an organism.

Grani con minore contenuto di peptidi tossici ed immunogenici

by luciano

In evidenza. Il grano duro Levante, tra quelli analizzati, è quello con un minor contenuto di peptidi immunogenici: “Seppure non “sicuro” per i pazienti celiaci, l’utilizzo di questa varietà, ad esempio nelle formulazioni di baby food, potrebbe ridurre l’esposizione durante il periodo più critico per lo sviluppo della malattia (Ivarsson et al., 2002).”

La ricerca “Composition of peptide mixtures derived from simulated gastrointestinal digestion of prolamins from different wheat varieties. Barbara Prandi et al. 2012. Journal of Cereal Science” analizza 24 varietà di grani (tenero e duro) allo scopo di classificarli in funzione della quantità e tipologia di peptidi tossici ed immunogenici. La ricerca sottolinea che “ Seppure non “sicuro” per i pazienti celiaci, l’uso di questa varietà, ad esempio nelle formulazioni di baby food, potrebbe ridurre l’esposizione durante il periodo più critico per lo sviluppo della malattia (Ivarsson et al., 2002)”.

Riassunto
“Il contenuto di gliadina nel grano è molto variabile, sia qualitativamente che quantitativamente, in funzione della genetica della pianta e delle condizioni di crescita. Le gliadine sono tra i maggiori fattori scatenanti della celiachia: i peptidi derivati dalla digestione gastrointestinale di queste proteine e assorbiti dalla lamina propria provocano le reazioni immunologiche che danneggiano la struttura dei villi nei soggetti affetti. Nel presente lavoro, le miscele peptidiche generate dalla digestione gastrointestinale simulata della frazione prolaminica estratta da diverse varietà di frumento (Triticum turgidum subsp. durum e Triticum aestivum) sono state caratterizzate mediante tecniche LC/MS e LC-MS/MS. I peptidi correlati alla quantità di a-gliadina, così come i peptidi tossici e immunogenici per i pazienti celiaci sono stati identificati e quantificati utilizzando uno standard interno marcato isotopicamente. La quantificazione ha dimostrato forti differenze tra le varietà testate. Alcuni campioni, appartenenti alla stessa varietà e/o area di coltivazione, hanno mostrato un contenuto inferiore di α-gliadina, e una minore quantità di peptidi tossici e immunogenici.”

….omissis. Conclusioni

“In diverse varietà di frumento sono stati identificati e quantificati i principali peptidi prodotti dalla digestione gastrointestinale simulata della frazione prolaminica. Diverse varietà di grano hanno portato a risultati variabili in termini di quantità e tipo di peptidi prodotti. Per quanto riguarda i peptidi patogeni correlati alla malattia celiaca, questi dati sono anche di grande interesse dal punto di vista epidemico, in quanto indicano un’elevata variabilità tra i campioni di grano, e questo potrebbe avere un diverso impatto sullo sviluppo della malattia celiaca. Sebbene tutti i campioni di grano siano risultati capaci di generare peptidi patogeni durante la digestione (quindi nessuna varietà può essere considerata “sicura” per i pazienti celiaci), le miscele di peptidi derivate dalla digestione di T. aestivum contengono peptidi meno tossici rispetto a T. durum e T. turanicum, mentre i peptidi immunogenici erano meno abbondanti nei digeriti di T. durum rispetto a T. aestivum e turanicum. Tra i campioni di T. durum, invece, è stata osservata una variabilità piuttosto elevata: D240 era la varietà con il minor contenuto di peptidi tossici, mentre Levante era quella con un minor contenuto di peptidi immunogenici. Seppure non “sicuro” per i pazienti celiaci, l’utilizzo di questa varietà, ad esempio nelle formulazioni di baby food, potrebbe ridurre l’esposizione durante il periodo più critico per lo sviluppo della malattia (Ivarsson et al., 2002).”

Note:
The innate immune response is activated by some sequence of gluten-derived peptides (PSQQ, QQQP, QPYP and QQPY) (Cornell, 1996; De Ritis et al., 1988), that induce the production of interleukin-15 (Londei et al., 2005).

The adaptive immune response, instead, begins with the recognition of some T-cell epitopes in gluten-derived peptides (Ciccocioppo et al., 2005), which are bound by antigen presenting cells that express the human leukocyte antigens DQ2 or DQ8 (Farrell and Kelly, 2002). Moreover, in the lamina propria, the enzyme tissue transglutaminase catalyzes the deamination of specific glutamine residues in the immunogenic peptides (Van de Wal et al., 1998a), causing a stronger immunological response (Molberg et al., 1998). These complexes are recognized by T-cells that induce the intestinal epithelium damages (Nilsen et al., 1998).

Both toxic and immunogenic peptides can reach the lamina propria taking advantage of mucosal defects allowing their passage between or through the epithelial cells (Matysiak-Budnik et al., 2003).

Immunogenic peptides contain one or more epitopes, whose sequence is recognized by HLA-DQ2 or HLA-DQ8 cells: the epitopes found in several identified peptides were PFPQPQLPY (glia-aI), PQPQLPYPQ (glia-aII) (Arentz-Hansen et al., 2000), PYPQPQLPY (glia-aIII) (Arentz-Hansen et al., 2002) and FPQQPQQPF (glia-gII) (Spaenij-Dekking and Koning, 2005). The first two epitopes were contained in a peptide identified as immunodominant after wheat challenge in celiac people in the study of Tye-Din et al. (2010). Interestingly, the immunodominant HLA DQ8-restricted alphagliadin T cell epitope (QGSFQPSQ), proposed to be one of the major triggers of celiac disease (Van de Wal et al., 1998b) was not found in the digested extract, probably because it contains a cleavage site for pepsin and chymotrypsin, that breaks the peptide bond at the C-terminal of phenylalanine.

Parole chieve: grano duro, grano tenero, peptidi tossici; peptidi immunogenici

Gluten is a complex of reserve proteins found in wheat, barley and rye, composed of gliadins (the alcohol soluble fraction) and glutenins (soluble in dilute acids with denaturing agents) (Osborne, 1907). Gluten-derived peptides are formed in the gastrointestinal tract from the incomplete digestion of gluten proteins. As a matter of fact, gluten is not completely digested from gastric, pancreatic and intestinal proteases due to its high content of proline (Stepniak et al., 2006), since the cyclic structure of this amino acid interferes with the enzyme accessibility to the peptidic bond. Thus, from the gastrointestinal digestion of gluten, proteolitically resistant peptides are formed, some of them implicated in the pathogenesis of celiac disease (Shan et al., 2002).

In different wheat varieties, the main peptides produced by simulated gastrointestinal digestion of the prolamin fraction were identified and quantified. Different wheat varieties led to variable outcomes in terms of amount and type of peptides produced. As far as pathogenic peptides related to celiac disease are concerned, these data are also of high interest from the epidemic point of view, since they indicate a high variability among the wheat samples, and this might have a different impact on celiac disease development. Although all wheat samples were found to generate pathogenic peptides upon digestion (thus no variety can be considered “safe” for celiac patients), peptide mixtures derived from the digestion of

T. aestivum samples were found to contain less toxic peptides than

T. durum and T. turanicum, while immunogenic peptides were less abundant in T. durum digests than in T. aestivum and turanicum. Among T. durum samples, on the other hand, a quite high variability was observed: D240 was the variety with the lower content of toxic peptides, while Levante was the one with a lower content of immunogenic peptides. Albeit not “safe” for celiac patients, the use of this variety, for example in the formulations of baby food, could reduce the exposure during the most critical period for the development of the disease (Ivarsson et al., 2002).

As far as cultivation area/farming practices are concerned, the impact is less evident, but somehow present. Given the variety, which is the most important determinant, some areas of cultivation seem to promote a greater content of a-gliadins, toxic and immunogenic peptides in digests, whereas in digested wheat cultivated in other places, less of these peptides seem to be present. Obviously, a more extensive study (in term of varieties and cultivation areas tested) is needed, besides a comparison between different years of cultivation. Moreover, further studies will be needed in order to better define in vivo the role of the identified peptides and to also define the best farming practices which can further lower wheat pathogenicity.

In diverse varietà di frumento sono stati identificati e quantificati i principali peptidi prodotti dalla digestione gastrointestinale simulata della frazione prolaminica. Diverse varietà di grano hanno portato a risultati variabili in termini di quantità e tipo di peptidi prodotti. Per quanto riguarda i peptidi patogeni correlati alla malattia celiaca, questi dati sono anche di grande interesse dal punto di vista epidemico, in quanto indicano un’elevata variabilità tra i campioni di grano, e questo potrebbe avere un diverso impatto sullo sviluppo della malattia celiaca. Sebbene tutti i campioni di grano siano risultati capaci di generare peptidi patogeni durante la digestione (quindi nessuna varietà può essere considerata “sicura” per i pazienti celiaci), le miscele di peptidi derivate dalla digestione di T. aestivum contengono peptidi meno tossici rispetto a T. durum e T. turanicum, mentre i peptidi immunogenici erano meno abbondanti nei digeriti di T. durum rispetto a T. aestivum e turanicum. Tra i campioni di T. durum, invece, è stata osservata una variabilità piuttosto elevata: D240 era la varietà con il minor contenuto di peptidi tossici, mentre Levante era quella con un minor contenuto di peptidi immunogenici. Seppure non “sicuro” per i pazienti celiaci, l’utilizzo di questa varietà, ad esempio nelle formulazioni di baby food, potrebbe ridurre l’esposizione durante il periodo più critico per lo sviluppo della malattia (Ivarsson et al., 2002).

Per quanto riguarda le aree di coltivazione/pratiche di coltivazione, l’impatto è meno evidente, ma in qualche modo presente. Data la varietà, che è il determinante più importante, alcune zone di coltivazione sembrano favorire un maggior contenuto di a-gliadine, peptidi tossici e immunogenici nei digeriti, mentre nei grani coltivati altrove, questi peptidi sembrano essere meno presenti . Ovviamente, uno studio più ampio (in termini di varietà e zone di coltivazione testato) è necessario, oltre che un confronto tra diversi anni di coltivazione. Inoltre, saranno necessari ulteriori studi per definire meglio in vivo il ruolo dei peptidi identificati e per definire anche le migliori pratiche agricole che possono ridurre ulteriormente la patogenicità del grano.

Glutine e infiammazione intestinale

by luciano

Il glutine induce infiammazione intestinale non solo in soggetti celiaci ma anche in quelli sani.

L’infiammazione intestinale è una condizione dell’apparato gastro-intestinale che colpisce un numero molto ampio e in costante aumento di persone (1). Tale condizione rappresenta per l’individuo non solo uno stato di disagio che incide sulla qualità della vita ma può – se sottovalutata o trascurata – favorire l’insorgere o l’aggravarsi di malattie gravi.
Un ruolo importante ma ancora da esplorare a fondo è svolto dal glutine in quanto pro-infiammatorio.

Lo studio “Il ruolo del glutine nei disturbi gastrointestinali: una revisione. Sabrina Cenni. Disturbi gastrointestinali: una rassegna. Nutrients 2023” fornisce un’utile panoramica della sua efficacia nella prevenzione e nella gestione di questi disturbi.”

“Abstract: Gluten is only partially digested by intestinal enzymes and can generate peptides that can alter intestinal permeability, facilitating bacterial translocation, thus affecting the immune system. Few studies addressed the role of diet with gluten in the development of intestinal inflammation and in other gastrointestinal disorders. The aim of this narrative review was to analyse the role of gluten in several gastrointestinal diseases so as to give a useful overview of its effectiveness in the prevention and management of these disorders.”

“Introduction. Gluten is a protein mass made of a complex network of gliadins and glutenins, which are proteins rich in glutamines and prolines found in most grains, such as barley, wheat, and rye [1 ,2]. Due to its high-water binding capacity and its consequent malleability and elasticity, gluten induces the formation of viscoelastic membranes, thus determining the proper consistency of dough, which allows it to be processed in bread and other foods [ 3– 5]. The high content of glutamines and prolines in gliadins make them difficult to cleave, making them able to escape degradation from gastric, pancreatic, and intestinal proteolytic enzymes [3, 4]. Therefore, gluten is what remains after the removal of starch, water-soluble proteins, and albumins [1]. In Western countries, the gluten dietary intake is approximately 5 to 20 g per day [3 , 4]. In the last decades, the literature reports an increased number of reactions following a widespread exposure to gluten [ 6]. Gluten-related diseases affect up to 10% of the general population and can be classified as three different disorders: IgE-mediated wheat allergy, Celiac disease (CD), and non-celiac gluten sensitivity (NCGS) [2, 6]. However, there is increasing evidence that gluten can trigger an innate and adaptative immune response responsible for intestinal inflammation [7]. Notably, along with other dietary elements, gluten may contribute to the development of inflammatory intestinal disorders, such as inflammatory bowel disease (IBD), as well as functional gastrointestinal disorders (FGIDs) and concur in symptom exacerbation, although its exact role is still under investigation.”

Gluten and intestinal inflammation. “Inflammation is the natural response of the innate immune system to external stimuli, such as microbial pathogens and injuries [8 ]. When the trigger persists and the immune cells are constantly activated, the inflammatory response may become chronic and self-sustainable [8]. The aetiology of inflammation is clear and easily detectable in some health conditions, while in others it can be difficult to identify [ 8]. The pathogenesis of inflammation is multifactorial. Nevertheless, genetic vulnerability, psychological stress, environmental factors, and some dietary patterns have been described as potentially implicated in the development of inflammatory phenotypes [ 8]. There are at least 50 different types of gliadin epitopes that can have an immunomodulatory and cytotoxic role or that can impact the gut permeating activities [ 8 ]; in fact, some of these can stimulate a pro-inflammatory innate immune response and others can activate specific T cells [8].
Gliadins immune cells’ activation is not only observed in celiac patients, as described by Lammers et al. [9, 10]. Indeed, their study concluded that gliadin induced an inflammatory response and, in particular, an important production of pro-inflammatory cytokines (IL-6, IL- 13, and interferon-gamma) both in Celiac patients and in healthy controls, even if proinflammatory cytokine levels were higher in Celiac patients [9, 10]. Similarly, Harris et al. showed that incubated peripheral blood mononuclear cells (PMBC) obtained from healthy HLA-DQ2 positive individuals produced proinflammatory cytokines, such as IL-23, IL-1beta, and TNF-α, when exposed to gliadin peptides [ 8, 11]. These cytokines’ production was significantly higher in Celiac patients compared to healthy controls [8,11]. Accordingly, Cinova et al., in their case-control study, demonstrated that gliadin could stimulate a substantial TNF-α and IL-8 production by monocytes, principally in celiac patients, but also, to a lesser extent, in healthy control individuals [12]. Gliadin also has an important role in modifying intestinal permeability through the reorganization of actin filaments and the modified expression of junctional complex proteins [ 8,13 ]. As demonstrated by Drago et al. and Lammers et al., gliadin’s binding to the chemokine receptor CXCR3 determines a release of zonulin, an active protein, which compromises the integrity of the intestinal barrier through the rearrangements of actin filaments, ultimately leading to an altered intestinal permeability both in Celiac and non-Celiac patients [ 9, 10, 14 ]. In conclusion, Ziegler et al. and Junker et al. reported that amylase trypsin inhibitors, found in gluten-containing cereals, have the capacity to activate toll-like receptors, thus stimulating the release of inflammatory cytokines and inducing a T-cell immune response in both celiac and non-celiac patients [15,16]”.

Einkorn wheat is the exception in relation to gluten-induced intestinal inflammation

A – Einkorn bread evidenced an anti-inflammatory effect. Integrated Evaluation of the Potential Health Benefits of Einkorn-Based Breads A. Gobetti et al. 2017.

B – Protective effects of ID331 Triticum monococcum. Protective effects of ID331 Triticum monococcum gliadin on in vitro models of the intestinal epithelium. Giuseppe Iacomino et al. (PMID: 27374565 DOI: 10.1016/j.foodchem.2016.06.014 )

Note

1 – Worldwide Prevalence and Burden of Functional Gastrointestinal Disorders, Results of Rome Foundation Global Study

BACKGROUND & AIMS: Although functional gastrointestinal disorders (FGIDs), now called disorders of gut-brain interaction, have major economic effects on health care systems and adversely affect quality of life, little is known about their global prevalence and distribution. We investigated the prevalence of and factors associated with 22 FGIDs, in 33 countries on 6 continents. METHODS: Data were collected via the Internet in 24 countries, personal interviews in 7 countries, and both in 2 countries, using the Rome IV diagnostic questionnaire, Rome III irritable bowel syndrome questions, and 80 items to identify variables associated with FGIDs. Data collection methods differed for Internet and household groups, so data analyses were conducted and reported separately. RESULTS: Among the 73,076 adult respondents (49.5% women), diagnostic criteria were met for at least 1 FGID by 40.3% persons who completed the Internet surveys (95% confidence interval [CI], 39.9–40.7) and 20.7% of persons who completed the household surveys (95% CI, 20.2–21.3). FGIDs were more prevalent among women than men, based on responses to the Internet survey (odds ratio, 1.7; 95% CI, 1.6–1.7) and household survey (odds ratio, 1.3; 95% CI, 1.3–1.4). FGIDs were associated with lower quality of life and more frequent doctor visits. Proportions of subjects with irritable bowel syndrome were lower when the Rome IV criteria were used, compared with the Rome III criteria, in the Internet survey (4.1% vs 10.1%) and household survey (1.5% vs 3.5%). CONCLUSIONS: In a large-scale multinational study, we found that more than 40% of persons worldwide have FGIDs, which affect quality of life and health care use. Although the absolute prevalence was higher among Internet respondents, similar trends and relative distributions were found in people who completed Internet vs personal interviews. Worldwide Prevalence and Burden of Functional Gastrointestinal Disorders, Results of Rome Foundation Global Study. Ami D. Sperber et al. Gastroenterology 2021;160:99–114

Pasta acida benefici: riduzione presenza ATI; WGA; Fodmap,s

by luciano

La pasta acida, utilizzata anche per fermentare impasti di farina per la produzione di pane e prodotti secchi da forno, ha numerosi benefici tra cui: la riduzione della presenza ATI e WGA.

La ricerca “Degradation of Wheat Germ Agglutinin during Sourdough Fermentation” Rojas Tovar, Luis E. DOI https://doi.org/10.7939/r3-1474-ec31 evidenzia:
Durante la fermentazione, il pH dell’impasto è sceso a 3,9 ± 0,2, il che ha favorito la degradazione dell’ATI da oligomeri a monomeri; I monomeri ATI sono meno dannosi se consumati. Il WGA viene anche modificato durante la fermentazione del lievito naturale a seconda delle capacità riducenti dei ceppi utilizzati [1].

È stato riportato che il pH è il principale responsabile degli effetti del lievito naturale sulla struttura e sulla bioattività dell’inibitore dell’amilasi-tripsina del grano (ATI). Inoltre, i batteri lattici della pasta madre riducono i legami disolfuro e diminuiscono il potenziale redox dell’impasto. Nello specifico, la glutatione reduttasi del Fructilactobacillus sanfranciscensis riduce il glutatione dimerico ossidato a glutatione, che reagisce ulteriormente per interrompere i legami disolfuro nelle proteine, altera la loro struttura secondaria e promuove la proteolisi delle proteine legate al disolfuro. [2]

Omissis… È stato riportato che i consorzi di lattobacilli e lieviti a lievitazione naturale degradano l’ATI in modo più efficiente rispetto alle colture pure di lattobacilli e quindi possono anche influire sulla degradazione del WGA. [3]

Riferimenti:

[1] “Non Celiac Wheat Sensitivity (NCWS), an intolerance to the ingestion of wheat products, has increased considerably during the past few years. In sensitive individuals, NCWS manifests by intestinal and extra intestinal symptoms in different ways. Two wheat protein fractions have been linked to NCWS, amylase-trypsin inhibitors (ATI) and wheat germ agglutinin (WGA). Physicians recommend that individuals with NCWS adhere to a gluten free diet. However, gluten free diets are often associated with a reduced diversity of products, a higher price and lower sensory and nutritional quality. Thus, it was the objective of this study to explore the possibility of using sourdough fermentation to reduce the bioactivity of these two proteins linked to NCWS in wheat bread. White pastry flour was used to analyze ATI and whole wheat flour for WGA experiments. The analytical techniques used to determine the fate of ATIs and WGA through the fermentation were size exclusion high performance liquid chromatography (SEC-HPLC), and enzyme-linked immunosorbent assay (ELISA). During fermentation, the pH of the dough decreased to 3.9 ± 0.2, which promoted the degradation of ATI from oligomers into monomers; ATI monomers are less harmful when consumed. WGA is also modified during sourdough fermentation depending on the reducing capabilities of the strains used. Initially, commercial whole wheat flour contained 6.6 μg ± 0.7 of WGA per gram. After 24 h fermentation, doughs fermented with Latilactobacillus sakei TMW 1.22 contained 2.7 μg ± 0.4 of WGA per gram of flour, while the doughs fermented with Fructilactobacillus sanfranciscensis DSM20451 and F. sanfranciscensis DSM20451 ΔgshR contained 4.3 μg ± 0.3 and 6.5 ± 1.8 μg, respectively. The WGA-SEC chromatograms show 3 peaks for doughs fermented with F. sanfranciscensis DSM20451 ΔgshR while the chromatograms with the isogenic strain F. sanfranciscensis DSM20451 show a more complex profile with 5 peaks, one of them from a very large molecular size molecule. The concentration of WGA is lower after fermentation with lactobacilli that have high reducing capacity. Clinical studies are required to determine the safety of consumption and the possible reduction in adverse symptoms, but this is a step towards finding new options to incorporate into the diet of NCWS individuals.”

[2] omissis……..Wheat components related to NCWS are fermentable oligo-, di-, and monosaccharides and polyols (FODMAPs), amylase-trypsin inhibitors (ATIs), and wheat germ agglutinins (WGA) [4–7]. NCWS, which is also referred to as gluten sensitivity or gluten intolerance, involves a wide variety of symptoms, including bloating, diarrhea, nausea, and intestinal damage. Extra intestinal symptoms have also been described and may include tiredness, headaches, joint pain and anxiety [5]. Symptoms of NCWS overlap with irritable bowel syndrome (IBS) [6]. Individuals affected by NCWS are normally prescribed a diet which is free of wheat products [8]. Sourdough fermentation does not eliminate gluten proteins that trigger celiac disease but the use of sourdough processes in bread making can be an alternative to gluten free diets to reduce symptoms associated with NCWS. The sourdough process involves longer fermentation times in comparison to straight dough processes, and additionally recruits the metabolic activity of lactic acid bacteria. Sourdough fermentations partially or completely degrade FODMAPs in wheat [9,10] and provide more time and more suitable conditions for wheat aspartic proteases, which are optimally active at low pH, to degrade wheat proteins [11,12]. Wheat flour contains the serine carboxypeptidase D (CPW-II), an exopeptidase with an optimum pH from 4 to 5.5 [13]. The most important proteases in wheat are aspartic proteinases [14] that associate with gluten during mixing and are optimally active at acidic pH [15,16]. Wheat aspartic proteases hydrolyze peptide bonds adjacent to arginine, lysine, phenylalanine, leucine, tyrosine and tryptophan [15,17]. The pH was reported to be primarily responsible for sourdough effects on the structure and bioactivity of the wheat amylase-trypsin inhibitor (ATI) [18]. Moreover, sourdough lactic acid bacteria reduce disulfide bonds and decrease the redox potential of the dough. Specifically, glutathione reductase of Fructilactobacillus sanfranciscensis reduces oxidized, dimeric glutathione to glutathione, which further reacts to disrupt disulfide bonds in proteins, alters their secondary structure and promotes proteolysis of disulfide-bonded proteins [12,19,20].”

[3] This study aimed to determine the fate of WGA and to assess the contribution of thiol-exchange reactions and of proteolysis to WGA modifications during sourdough fermentation. The role of thiol-exchange reactions was assessed by comparing F. sanfrancis- censis DSM20451 with its isogenic glutathione-reductase negative mutant F. sanfranciscensis DSM20451∆gshR [19,20]; the role of proteolytic activity was assessed by protease addition to sourdoughs, and by the use of chemically acidified controls [12]. This study analysed sourdoughs that were fermented with defined strains of lactic acid bacteria. This approach allows an assessment of the contribution of specific metabolic traits—acidification, glu- tathione reductase activity—to the degradation of WGA; however, sourdoughs used in artisanal and industrial practice typically include several species of lactic acid bacteria and additionally include sourdough yeasts or baker’s yeast [37]. Consortia of lactobacilli and sourdough yeasts were reported to degrade ATI more efficiently than pure cultures of lactobacilli [18] and thus may also impact WGA degradation.

Note:
“ WGA is a lectin that is located in the germ of the wheat grain. In the pH-range of 3.5 to 7.4, it forms a dimer with a size of approximately 35 kDa that is relatively heat stable [21–23]. Each monomer is stabilized by 16 intramolecular disulfide bonds [24]. WGA binds N-acetyl glucosamine and its β-(1 → 4)–linked oligomers and has weaker affinity to N- acetyl galactosamine and N-acetyl neuraminic acid [25,26]. WGA’s effects on human health are controversial. Rodent experiments concluded that WGA in doses that substantially exceeded the concentration in wheat decreased growth [27]. In cell culture experiments with Caco2 cells, WGA increased the permeability of the epithelial layer [28] and stimulated synthesis of pro-inflammatory cytokines [29]; WGA also demonstrated toxicity to acute myeloid leukemia cells without significant toxicity to normal cells [30]. The identification of antibodies targeting WGA in human serum indicates its translocation and interaction with the immune system [31]. Owing to the lack of in vivo studies, however, conclusions on the contribution of WGA to NCWS remain speculative [28,32,33].”

Parole chiave: lievito madre; proteolisi; fermentazione; agglutinina di germe di grano; sensibilità al grano; batteri dell’acido lattico

Glutine di alcune varietà di grano: studio comparativo

by luciano

La conoscenza della composizione del glutine del grano tenero, duro e farro è rilevante per la riuscita dei prodotti finali da forno (sopratutto salati) e/o per la produzione di pasta. Le caratteristiche del glutine sono altresì fondamentali se lo scopo è la realizzazione di prodotti idonei per persone geneticamente predisposte alla celiachia, per quelle sensibili al glutine non celiache e, estensivamente, per coloro che soffrono di infiammazioni intestinali. Per tutte queste persone è importante realizzare prodotti che siano il più possibile digeribili e tollerabili. Tra tutti i grani conosciuti il grano monococco è quello che viene considerato il più adatto per tale scopo.
Lo studio “Comparative Study on Gluten Protein Composition of Ancient (Einkorn, Emmer and Spelt) and Modern Wheat Species (Durum and Common Wheat). Sabrina Geisslitz et al. Published: 12 September 2019 in Foods (MDPI)” analizza alcune caratteristiche del glutine di alcuni grani (300) evidenziandone le differenze; analizza, inoltre, l’effetto su di essi dell’uso di fertilizzanti azotati nella coltivazione.

Il motivo dell’interesse nella ricerca di varietà di farro monococco, farro dicocco e farro spelta:
I grani “antichi” monococco (Triticum monococcum L., diploide), farro (T. dicoccum L., tetraploide) e farro (T. aestivum ssp. spelta, esaploide) sono stati coltivati in quantità molto ridotte rispetto al “moderno” specie di frumento frumento tenero (T. aestivum L., esaploide) e frumento duro (T. durum L., tetraploide) nel XX secolo. Le ragioni della scarsa coltivazione dei grani antichi sono le rese in granella inferiori del 30-60%, la presenza di lolla e le scarse proprietà di panificazione rispetto al grano tenero. Tuttavia, i grani antichi sono stati riscoperti negli ultimi 20 anni, poiché un numero crescente di consumatori associa il loro consumo a benefici sensoriali e per la salute dovuti al loro contenuto relativamente più elevato, ad esempio, di acido ferulico, vitamine, alchilresorcinoli e luteina.
Il grano tenero è il più adatto alla panificazione, perché la farina forma un impasto viscoelastico con un’elevata capacità di trattenere i gas quando viene mescolata con l’acqua. Al contrario, le farine di grani antichi producono impasti più morbidi con bassa elasticità e alta estensibilità a causa della scarsa qualità del glutine. Quest’ultima caratteristica si traduce in un glutine meno “forte” [1] e, quindi più digeribile. Inoltre il farro monococco e il farro dicocco non contengono la frazione di glutine (33mer” : Quantitation of the immunodominant 33-mer peptide from α-gliadin in wheat flours by liquid chromatography tandem mass spectrometry. Kathrin Schalk et al. 2017. Scientific Reports.) che è considerata quella che maggiormente attiva la risposta immunitaria nei soggetti celiaci oltre ad essere trale meno digeribili. Quest’ultima caratteristica fà si che questi grani, sopratutto il farro monococco [2] (più propriamente grano monococco) siano candidati principali per diminuire l’esposizione alla celiachia nei soggetti geneticamente predisposti.
In evidenza nello studio:
……omissis. Il contenuto proteico totale è stato ugualmente influenzato dalla localizzazione dell’area di coltivazione e dalle specie di grano, tuttavia, il contenuto di gliadina, glutenina e glutine è stato influenzato più fortemente dalle specie di grano che dalla localizzazione. Farro monococco (più propriamente grano monococco), farro dicocco e farro spelta avevano un contenuto proteico e di glutine più elevato rispetto al grano tenero in tutte e quattro le località scelte per la coltivazione. Tuttavia, il grano tenero aveva un contenuto di glutenina più elevato rispetto a farro monococco, farro dicocco e farro spelta, con conseguente aumento dei rapporti di gliadine rispetto a glutenine dal grano tenero (< 3,8) a farro spelta, farro dicocco e farro monococco (fino a 12,1). Con la consapevolezza che i contenuti di glutenina sono predittori adatti per ottenere un prodotto finale con un buon volume, sono state identificate cultivar che hanno questa caratteristica più accentuata. Infine, farro spelta, farro dicocco e farro monococco hanno una produttività con uso di fertilizzanti azotati (azoto singolo come fattore di input) più elevata rispetto al grano tenero e al grano duro, il che li rende colture promettenti per un’agricoltura più sostenibile.