Exploitation of Leuconostoc mesenteroides strains to improve shelf life, rheological, sensory and functional features of prickly pear (Opuntia ficus-indica L.) fruit puree.

Strains of Leuconostoc mesenteroides were identified from raw prickly pear (Opuntia ficus-indica L.). Five autochthonous strains were selected based on the kinetics of growth and acidification on prickly pear fruit juice, and the capacity to synthesize exo-polysaccharides. All selected Leuc. mesenteroides strains showed an in vitro mucilage-degrading capability. A protocol for processing and storage of fermented prickly pear fruit puree (FP) was set up. Unstarted FP and chemically acidified FP were used as the controls. Starters grew and remained viable at elevated cell numbers during 21 days of storage at 4 °C. Contaminating Enterobacteriaceae and yeasts were found only in the controls. Viscosity and serum separation distinguished started FP compared to the controls. Colour parameters, browning index, sensory attributes, antimicrobial activity, vitamin C and betalains levels were positively affected by lactic acid fermentation. Increase of free radical scavenging activity in ethyl acetate soluble extract suggested an effect of selected strains on phenolic profiles. Started FP markedly inhibited the inflammatory status of Caco-2/TC7 cells, and also contributed to maintaining the integrity of tight junctions. Started FP scavenged the reactive oxygen species generated by H2O2 on Caco-2 cells. All selected strain variously affected the immunomodulatory activity towards anti- and pro-inflammatory cytokines.

Two wheat decapeptides prevent gliadin-dependent maturation of human dendritic cells.

Celiac disease (CD) is a small intestinal enteropathy, triggered in susceptible individuals by the ingestion of dietary gluten. Dendritic cells (DC) are instrumental in the generation and regulation of immune responses and oversee intestinal immune homeostasis promoting and maintaining oral tolerance to food antigens. The aim of this study was to monitor the effect of peptic-tryptic digest of gliadin (PT-gliadin) on the maturation of human monocyte-derived DC and the impact of pDAV and pRPQ decapeptides in the modulation of PT-gliadin-induced phenotypic and functional DC maturation. Immature DC (iDC) were challenged in vitro with PT-gliadin. In some experiments iDC were pre-treated with pDAV or pRPQ and after 2h PT-gliadin was added to the cultures. We found that PT-gliadin up-regulates the expression of the maturation markers HLA-DR, CD83, CD80 and CD86. The functional consequence of PT-gliadin treatment of iDC is a significant increase in IL-12, TNF-alpha production as well as in their T cell stimulatory capacity. On the contrary, the digest of zein had no effect on DC maturation. Interestingly, we found that pre-treatment of iDC with pDAV or pRPQ decapeptides significantly prevents the functional maturation of DC induced by PT-gliadin. On the other hand, pDAV and pRPQ did not revert the PT-gliadin-induced phenotypic maturation of DC. Here we report, for the first time, that naturally occurring peptides are able to prevent the gliadin-dependent DC maturation. This finding could have implication for CD, raising the perspective of a potential therapeutic strategy alternative to a gluten free diet.

Low risk of colon cancer in patients with celiac disease.

OBJECTIVE: Celiac disease (CD) has strongly been established as associated with some site-specific gastrointestinal malignancies. On the contrary, according to the few reports available, the risk of colon carcinoma in CD patients has been described similar to that of general population. In this cohort study, we describe the risk of colon carcinoma in a group of Italian celiac patients. MATERIALS AND METHODS: The study population included all CD patients diagnosed at the Collaborating Centers of the Italian Registry of CD between 1st January 1982 and 31st December 2006. Upon diagnosis of CD and upon at every subsequent clinical control, the Collaborating Centers filled in a validated form for each CD patient reporting information about demographic data, possible occurrence of a neoplasm and adherence to a gluten-free diet. RESULTS: Out of 1757 celiac patients enrolled, 6 developed a colon carcinoma during the follow-up period (mean: 18.1 years). The standardized incidence ratio (SIR) resulted 0.29 (95% CI=0.07-0.45). Stratifying the risk for the dietary gluten intake, the SIR dropped to 0.07 (95% CI=0.009-0.27) for CD patients with a strict adherence to a gluten-free diet. CONCLUSION: We confirm the previous finding that there is low risk to develop a colon cancer in celiac patients.

Diversity of oat varieties in eliciting the early inflammatory events in celiac disease.

PURPOSE: Celiac disease (CD) is an autoimmune enteropathy, triggered by dietary gluten. The only treatment is a strict gluten-free diet. Oats are included in the list of gluten-free ingredients by European Regulation, but the safety of oats in CD is still a matter of debate. The present study examined the capability of different oat cultivars of activating the gliadin-induced transglutaminase-2 (TG2)-dependent events in some in vitro models of CD. In addition, we compared this capability with the electrophoresis pattern of peptic-tryptic digests of the proteins of the oat cultivars. METHODS: K562(S) cells agglutination, transepithelial electrical resistance of T84-cell monolayers, intracellular levels of TG2 and phosphorylated form of protein 42-44 in T84 cells were the early gliadin-dependent events studied. RESULTS: The results showed that the Nave oat cultivar elicited these events, whereas Irina and Potenza varieties did not. The ability of a cultivar to activate the above-described events was associated with the electrophoretic pattern of oat proteins and their reactivity to anti-gliadin antibodies. CONCLUSION: We found significant differences among oat cultivars in eliciting the TG2-mediated events of CD inflammation. Therefore, the safety of an oat cultivar in CD might be screened in vitro by means of biochemical and biological assays, before starting a clinical trial to definitely assess its safety.

Use of fungal proteases and selected sourdough lactic acid bacteria for making wheat bread with an intermediate content of gluten.

This study was aimed at combining the highest degradation of gluten during wheat flour fermentation with good structural and sensory features of the related bread. As estimated by R5-ELISA, the degree of degradation of immune reactive gluten was ca. 28%. Two-dimensional electrophoresis and RP-FPLC analyses showed marked variations of the protein fractions compared to the untreated flour. The comparison was also extended to in vitro effect of the peptic/tryptic-digests towards K562 and T84 cells. The flour with the intermediate content of gluten (ICG) was used for bread making, and compared to whole gluten (WG) bread. The chemical, structural and sensory features of the ICG bread approached those of the bread made with WG flour. The protein digestibility of the ICG bread was higher than that from WG flour. Also the nutritional quality, as estimated by different indexes, was the highest for ICG bread.

Early tissue transglutaminase-mediated response underlies K562(S)-cell gliadin-dependent agglutination.

INTRODUCTION: [corrected] K562(S) agglutination has been used as a rapid and economic tool for the in vitro screening of the toxicity of cereal fractions and prolamins in celiac disease (CD). A strict correlation has been reported between the toxicity of cereals and cereal fractions for celiac patients and their ability to agglutinate K562(S) cells. Whether this specificity of K562(S)-cell agglutination is caused by the activation of the same pathogenic events triggered by toxic cereal fractions in CD intestine or simply represents a bystander event of gluten toxicity is, however, unknown. METHODS: K562(S) cells were incubated in vitro with the peptic-tryptic digest of wheat gliadin. RESULTS: The agglutination of K562(S) cells by wheat gliadin peptides is orchestrated by a cascade of very early events occurring at the K562(S)-cell surface similar to those occurring at the intestinal epithelial surface. They involve a rapid increase in intracellular calcium levels that activate tissue transglutaminase (TG2), leading to a rapid actin reorganization that is pivotal in driving cell agglutination. These specific effects of toxic cereals are phenocopied by the gliadin-derived peptide p31-43, which orchestrates the activation of innate response to gliadin in CD. DISCUSSION: Our study provides the rationale for the extensive use of K562(S)-cell agglutination as a valuable tool for screening cereal toxicity.

The sourdough fermentation may enhance the recovery from intestinal inflammation of coeliac patients at the early stage of the gluten-free diet.

PURPOSE: This study aimed at investigating the effect of corn, rice and amaranth gluten-free (GF) sourdoughs on the release of nitric oxide (NO) and synthesis of pro-inflammatory cytokines by duodenal mucosa biopsies of eight coeliac disease (CD) patients. METHODS: Selected lactic acid bacteria were used as starters for the manufacture of corn, rice or amaranth sourdoughs. Chemically acidified doughs, without bacterial starters, and doughs started with baker's yeast alone were also manufactured from the same GF matrices. Pepsin-trypsin (PT) digests were produced from all sourdoughs and doughs, and used to assay the rate of recovery of biopsy specimens from eight CD patients at diagnosis. The release of NO and the synthesis of pro-inflammatory cytokines interferon-γ (IFN-γ) were assayed. RESULTS: During fermentation, lactic acid bacteria acidified and grew well (ca. log 9.0 CFU/g) on all GF matrices, showing intense proteolysis. Duodenal biopsy specimens still released NO and IFN-γ when subjected to treatments with basal medium (control), PT-digest from chemically acidified doughs and PT-digest from doughs fermented with baker's yeast alone. On the contrary, the treatment of all the biopsy specimens with PT-digests from all GF matrices subjected to sourdough fermentation significantly decreased the release of NO and the synthesis of IFN-γ. CONCLUSIONS: During manufacture of GF baked goods, the use of sourdough fermentation could be considered as an adjuvant to enhance the recovery from intestinal inflammation of coeliac patients at the early stage of the gluten-free diet.

Towards the Standardization of Intestinal In Vitro Advanced Barrier Model for Nanoparticles Uptake and Crossing: The SiO2 Case Study.

Increasing interest is being addressed to the development of a reliable, reproducible and relevant in vitro model of intestinal barrier, mainly for engineered nanomaterials hazard and risk assessment, in order to meet regulatory and scientific demands. Starting from the consolidated Caco-2 cell model, widely used for determining translocation of drugs and chemicals, the establishment of an advanced intestinal barrier model with different level of complexity is important for overcoming Caco-2 monoculture limitations. For this purpose, a tri-culture model, consisting of two human intestinal epithelial cells (Caco-2 and HT29-MTX) and a human lymphocyte B cell (Raji B), was developed by several research groups to mimic the in vivo intestinal epithelium, furnishing appropriate tools for nanotoxicological studies. However, tri-culture model shows high levels of variability in ENM uptake/translocation studies. With the aim of implementing the standardization and optimization of this tri-culture for ENM translocation studies, the present paper intends to identify and discuss such relevant parameters involved in model establishment as: tri-culture condition set-up, barrier integrity evaluation, mucus characterization, M-cell induction. SiO2 fluorescent nanoparticles were used to compare the different models. Although a low level of SiO2 translocation is reported for all the different culture conditions. a relevant role of mucus and M-cells in NPs uptake/translocation has been highlighted.

Circulating microRNAs as novel non-invasive biomarkers of paediatric celiac disease and adherence to gluten-free diet.

BACKGROUND: Celiac Disease (CD) is a multifactorial autoimmune enteropathy (with a prevalence of approximately 1% worldwide) that exhibits a wide spectrum of clinical, serological and histological manifestations. For the diagnosis of paediatric CD, the gold standard is the combination of serological tests (with high TGA-IgA values greater than 10 times the upper limit of normal) and duodenal biopsy (with a positive TGA-IgA but low titer). Therefore, a diagnostic test that totally excludes an invasive approach has not been discovered so far and the discovery of novel biological markers would represent an undoubted advantage for the diagnosis of CD and prognostic evaluation. MicroRNAs (miRNAs), small non-coding RNAs (18-22 nucleotides) that regulate gene expression at post-transcriptional level and play important roles in many biological processes, represent a novel class of potential disease biomarkers. Their presence in biological fluids (i.e., serum, plasma, saliva, urine) provides the opportunity to employ circulating miRNAs as novel non-invasive biomarkers. METHODS: In our prospective observational study, we examined the expression of circulating miRNAs in a cohort of CD patients (both at diagnosis and on gluten-free diet, respectively referred as CD and GFD) compared to healthy controls. By small RNA-Seq we discovered a set of circulating miRNAs that were further validated by qPCR with specific assays. FINDINGS: We found that out of the 13 miRNAs able to discriminate the three groups (i.e., CD, GFD and controls), three of them, namely miR-192-5p, miR-215-5p and miR-125b-5p (alone or in combination), were able to discriminate these three groups with high accuracy and specificity. INTERPRETATION: Our conclusions emphasize that these circulating miRNAs can be employed not only for the diagnosis of CD patients with a low TGA-IgA titer but also to monitor the adherence to a gluten-free diet by CD patients. In conclusion, we suggest the use of the circulating miRNAs identified in this work as a novel diagnostic and follow-up tool for paediatric CD. FUNDING: This work was supported by Fondazione Celiachia Onlus (FC) Grant n° 018/FC/2013 and by Italian Ministry of Health (Ricerca Corrente).

Evaluation of the Potential Anti-Inflammatory Activity of Black Rice in the Framework of Celiac Disease.

Inflammation and oxidative stress are two mechanisms involved in the pathogenesis of celiac disease (CD). Since the direct effect of gliadin on the intestinal epithelia is less studied, the aims of this study were the development of a specific cellular model based on the use of gliadin as a pro-inflammatory stimulus and the evaluation of the potential antioxidant and anti-inflammatory properties of extracts from different black rice in the framework of CD. The rice extracts were in vitro digested, characterized in terms of phenolic compounds and antioxidant capacity, and tested on Caco-2 cells to investigate their inhibitory effect on Reactive Oxygen Species, the NF-κB transcription and the CXC chemokines (sICAM-1, IL-8, and CXCL-10). In addition, the role of the extracts in modulating the activation of epithelial cells in CD was confirmed by applying the K562(S) agglutination test. The black rice extracts showed inhibitory effects on the production of the oxidative and the inflammatory mediators considered, with particular reference to lymphocyte-attracting CXCL-10 both before and after digestion. The presence of anthocyanins and their digestion metabolites may account for the observed anti-inflammatory activity after in vitro digestion. This work provided preliminary data supporting the use of black rice as a healthy food or ingredient of food supplements for celiacs.

Papillary cancer of thyroid in celiac disease.

BACKGROUND: Celiac disease (CD) has been established as being associated with several thyroid diseases. However, occurrence of thyroid epithelial cancer in celiac patients has been rarely described. GOAL: We describe the prevalence of thyroid carcinoma detected in a cohort of Italian celiac patients, with the aim to carry out a prospective analysis of the risk of celiac patients to develop thyroid carcinoma. METHODS: The study population included all CD patients diagnosed at the Collaborating Centers of the Italian Registry of CD between January 1, 1982 and December 31, 2006. Upon diagnosis of CD and at every subsequent clinical control, the Collaborating Centers filled in a validated form for each CD patient reporting information about demographic data, possible occurrence of a thyroid disease, and adherence to a gluten-free diet. RESULTS: Of the 1757 celiac patients enrolled, 6 developed a papillary thyroid carcinoma during the follow-up period (mean: 18.1 y). The Standardized Incidence Ratio resulted 2.55 (95% confidence interval=0.93-5.55; P<0.01). The mean age of diagnosis of CD in patients who developed thyroid carcinoma was rather low (40 y) and not statistically different from that of those who did not develop thyroid carcinoma. The number of gluten-containing diet per month did not correlate with the development of a thyroid carcinoma. CONCLUSIONS: There is a 2.5-fold increased risk of papillary cancer of thyroid for celiac patients. A prompt diagnosis of CD and a strict adherence to gluten-free diet do not seem to protect from the development of this malignancy.

Screening for celiac disease among the personnel in active service of an Italian Armed Force.

INTRODUCTION AND OBJECTIVE: Celiac disease (CD) affects the 1% of the general population worldwide. Because of its clinical variability, roughly the 70% of CD patients are not correctly diagnosed and not adequately treated. Active military personnel represent an interesting cohort for a CD screening. Upon the enrollment in the Armed Forces, a complete health check is carried out to exclude any diseases. Aim of the present work is to assess the CD prevalence among the personnel of Carabinieri Corps, an Italian armed force, through a serological screening. RESULTS AND DISCUSSION: Out of 291 militaries (281 M, 10 F age range: 18.2-61.5) enrolled, 2 resulted affected by CD (prevalence: 0.7%); 1 to have high serological anti-TG and EMA level without duodenal mucosal lesions and 1 to have high serological anti-TG, but not EMA. CONCLUSION: These results show that the CD prevalence among a cohort of Italian militaries is similar to that of the general population.

Nutrients Bioaccessibility and Anti-inflammatory Features of Fermented Bee Pollen: A Comprehensive Investigation.

We compared raw bee-collected pollen (Raw-BCP), spontaneously fermented BCP (Unstarted-BCP), and BCP fermented with selected microbial starters (Started-BCP) to deepen whether fermentation may favorably affect the nutrients bioaccessibility and functional features of BCP. Under in vitro gastrointestinal batches, the highest serum-availability of phenolic compounds was found in Started-BCP, highlighting the positive effect exerted by selected microbial starters. The same effect was not found in spontaneously fermented BCP. In colon adenocarcinoma cell line-2 (Caco-2) cells stressed by a pro-inflammatory stimulus, the treatment with Started-BCP halted the increase of pro-inflammatory mediator's level. Started-BCP counteracted efficiently the deleterious effects of inflammatory stimuli on the integrity of the Caco-2 cells monolayer and its barrier function. Started-BCP successfully counteracted the H2O2-induced intracellular accumulation of reactive oxygen species (ROS) in Caco-2 cells. A protective role against lipopolysaccharide (LPS)-induced inflammation was exerted by Started-BCP in human keratinocytes. The same protective effects on Caco-2 and keratinocyte cell lines were negligible after treatments with Raw-BCP or Unstarted-BCP.

Biotechnological re-cycling of apple by-products: A reservoir model to produce a dietary supplement fortified with biogenic phenolic compounds.

This study is an example of apple by-products (AP) recycling through a designed fermentation by selected autochthonous Lactobacillus plantarum AFI5 and Lactobacillus fabifermentans ALI6 used singly or as binary cultures with the selected Saccharomyces cerevisiae AYI7. Compared to Raw-, Unstarted- and Chemically Acidified-AP, Fermented-AP promoted the highest levels of total and insoluble dietary fibers, DPPH scavenging capacity, and free phenolics. The binary culture of L. plantarum AFI5 and S. cerevisiae AYI7 had the best effect on the bioavailability phenolic compounds as resulted by the LC-MS/MS validated method. The accumulation of phenolic acids derivatives highlighted the microbial metabolism during AP fermentation. Bio-converted phenolics were likely responsible for the increased DPPH scavenging capacity. The potential health-promoting effects of Fermented-AP were highlighted using Caco-2 cells. With variations among single and binary cultures, fermented-AP counteracted the inflammatory processes and the effects of oxidative stress in Caco-2 cells, and preserved the integrity of tight junctions.

Bioprocessed Brewers' Spent Grain Improves Nutritional and Antioxidant Properties of Pasta.

Brewers' spent grain (BSG), the by-product of brewing, was subjected to a xylanase treatment followed by fermentation with Lactiplantibacillus plantarum PU1. Bioprocessed BSG has been used as ingredient to obtain a fortified semolina pasta which can be labeled as "high fiber" and "source of protein" according to the European Community Regulation No. 1924/2006. Compared to native BSG, the use of bioprocessed BSG led to higher protein digestibility and quality indices (essential amino acid index, biological value, protein efficiency ratio, nutritional index), as well as lower predicted glycemic index. Bioprocessing also improved the technological properties of fortified pasta. Indeed, brightfield and confocal laser scanning microscopy revealed the formation of a more homogeneous protein network, resulting from the degradation of the arabinoxylan structure of BSG, and the release of the components entrapped into the cellular compartments. The extensive cell wall disruption contributed to the release of phenols, and conferred enhanced antioxidant activity to the fortified pasta. The persistence of the activity was demonstrated after in vitro-mimicked digestion, evaluating the protective effects of the digested pasta towards induced oxidative stress in Caco-2 cells cultures. The fortified pasta showed a peculiar sensory profile, markedly improved by the pre-treatment, thus confirming the great potential of bioprocessed BSG as health-promoting food ingredient.

Quorum sensing in sourdough Lactobacillus plantarum DC400: induction of plantaricin A (PlnA) under co-cultivation with other lactic acid bacteria and effect of PlnA on bacterial and Caco-2 cells.

This work aimed at showing the effect of pheromone plantaricin A (PlnA) by Lactobacillus plantarum DC400 towards other sourdough lactic acid bacteria and the potential of PlnA to protect the function of the human intestinal barrier. Growth and survival of sourdough lactic acid bacteria were differently affected by co-cultivation with L. plantarum DC400. Compared to mono-cultures, Lactobacillus sanfranciscensis DPPMA174 and Pediococcus pentosaceus 2XA3 showed growth inhibition and decreased viability when co-cultured with L. plantarum DC400. L. sanfranciscensis DPPMA174 induced the highest synthesis of PlnA. Survival of strain DPPMA174 only slightly varied by comparing the addition of PlnA to the culture medium and the co-cultivation with L. plantarum DC400. Compared to mono-culture, the proteome of L. sanfranciscensis DPPMA174 grown in co-culture with L. plantarum DC400 showed the variation of expression of 58 proteins (47 over expressed and 11 repressed). Thirty-four of them were also over expressed or repressed during growth of DPPMA174 with PlnA. Fifty-one of the above 58 proteins were identified. They had a central role in stress response, amino acid, energy and nucleotide metabolisms, membrane transport, regulation of transcription, and cell redox homeostasis. PlnA markedly increased the viability of human Caco-2/TC7 cells and the transepithelial electrical resistance.

Two prolamin peptides from durum wheat preclude celiac disease-specific T cell activation by gluten proteins.

PURPOSE: Celiac disease (CD) is a permanent intolerance to wheat prolamins and related proteins displayed by genetically susceptible individuals. Blocking or modulation of CD-specific T cell response by altered prolamin peptides are currently considered as a potential alternative to the only effective therapy of CD based on a life-long gluten-free diet. Two prolamin peptides, the 9-mer ASRVAPGQQ and the 10-mer GTVGVAPGQQ sequences, were identified by mass spectrometry in the peptic/tryptic digest of prolamins (PTP) from durum wheat (Triticum turgidum ssp. durum) cv. Adamello, and investigated for their ability to preclude the stimulation of CD-specific mucosal T cells by gluten proteins. METHODS: Gluten-specific polyclonal intestinal T cell lines from five CD children (mean age 5 years) were exposed to 50 microg/ml of a deamidated PTP from whole flour of common wheat (T. aestivum) cv. San Pastore, and tested for proliferation and production of interferon-gamma (INF-gamma) and interleukin 10 (IL-10). The same experiment was performed in the presence of 20 microg/ml of the 9-mer or the 10-mer peptide. RESULTS: T cells exposed to PTP showed a threefold increase in proliferation and INF-gamma production, and a significant (P

Megalencephalic Leukoencephalopathy with Subcortical Cysts Disease-Linked MLC1 Protein Favors Gap-Junction Intercellular Communication by Regulating Connexin 43 Trafficking in Astrocytes.

Astrocytes, the most numerous cells of the central nervous system, exert critical functions for brain homeostasis. To this purpose, astrocytes generate a highly interconnected intercellular network allowing rapid exchange of ions and metabolites through gap junctions, adjoined channels composed of hexamers of connexin (Cx) proteins, mainly Cx43. Functional alterations of Cxs and gap junctions have been observed in several neuroinflammatory/neurodegenerative diseases. In the rare leukodystrophy megalencephalic leukoencephalopathy with subcortical cysts (MLC), astrocytes show defective control of ion/fluid exchanges causing brain edema, fluid cysts, and astrocyte/myelin vacuolation. MLC is caused by mutations in MLC1, an astrocyte-specific protein of elusive function, and in GlialCAM, a MLC1 chaperon. Both proteins are highly expressed at perivascular astrocyte end-feet and astrocyte-astrocyte contacts where they interact with zonula occludens-1 (ZO-1) and Cx43 junctional proteins. To investigate the possible role of Cx43 in MLC pathogenesis, we studied Cx43 properties in astrocytoma cells overexpressing wild type (WT) MLC1 or MLC1 carrying pathological mutations. Using biochemical and electrophysiological techniques, we found that WT, but not mutated, MLC1 expression favors intercellular communication by inhibiting extracellular-signal-regulated kinase 1/2 (ERK1/2)-mediated Cx43 phosphorylation and increasing Cx43 gap-junction stability. These data indicate MLC1 regulation of Cx43 in astrocytes and Cx43 involvement in MLC pathogenesis, suggesting potential target pathways for therapeutic interventions.

Toxic, immunostimulatory and antagonist gluten peptides in celiac disease.

Celiac disease (CD) is an increasingly diagnosed, permanent autoimmune enteropathy, triggered, in susceptible individuals, by the ingestion of gluten, the alcohol - soluble protein fraction of some cereals, such as wheat, rye and barley. The main protein of wheat gluten is called gliadin, the similar proteins of rye and barley are secalin and hordein, respectively. Approximately 96% of CD patients express the HLA molecule DQ2, while the remainder mostly express the less common haplotype DQ8, reflecting the pivotal role of these molecules in the pathogenesis of CD. Because of their aminoacid sequence and tri-dimensional structure, gluten peptides selectively bind to these HLA alleles present on the surface of antigen presenting cells and then they are presented to the T lymphocytes in intestinal mucosa, thus starting the inflammatory immune response. CD is defined by the characteristic histological changes of small bowel mucosa: villous atrophy, crypts hyperplasia and T cells infiltration of the lamina propria, along with the increase of the number of intra-epithelial lymphocytes. The withdrawal of the gluten- containing food from the diet determines a complete recovery of the intestinal mucosa, whereas the reintroduction causes a relapse of the disease. This review focuses on the description of gluten peptides that elicit the mucosal immune response via the activation of innate and adaptive immunity in CD. It also describes the antagonist gluten peptides, obtained by artificial modification of gluten T epitopes or naturally occurring in the alcohol protein fraction of a cultivar of durum wheat, able to immuno-modulate the pathogenic immune response of CD.

Fermented Portulaca oleracea L. Juice: A Novel Functional Beverage with Potential Ameliorating Effects on the Intestinal Inflammation and Epithelial Injury.

P. oleracea L. contains high level of nutrients and biologically active compounds. Recently, lactic fermentation has been proposed as a biotechnological option to enrich the profile of biogenic compounds of Portulaca oleracea L. puree. This study investigated the capability of fermentation by selected lactic acid bacteria to enhance the restoring features of Portulaca oleracea juice towards intestinal inflammation and epithelial injury. Lactic acid fermentation markedly increased the total antioxidant capacity of P. oleracea juice, preserved the inherent levels of vitamins C, A, and E, and increased the bioavailability of the level of vitamin B2 and that of phenolics. The effects of fermented P. oleracea juice on a Caco-2 cell line were investigated using an in vitro model closest to the in vivo conditions. Fermented P. oleracea juice strongly decreased the levels of pro-inflammatory mediators and reactive oxygen species. It also counteracted the disruption of the Caco-2 cell monolayers treated with the inflammatory stimulus. We used a diversified spectrum of lactic acid bacteria species, and some effects appeared to be strains- or species-specific. Fermentation with Lactobacillus kunkeei B7 ensured the best combination for the content of bioactive compounds and the ability to counteract the intestinal inflammation and epithelial injury.