Browsing by Person "Zimmermann, Julia"

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Einfluss verschiedener Getreidearten und Herstellungsverfahren auf den Gehalt immunogener Substanzen in Brot sowie in vivo auf die Verträglichkeit an der Maus und im Menschen
(2022) Zimmermann, Julia; Bischoff, Stephan C.
There are three medical conditions that are triggered by consumption of cereals. Celiac disease, wheat allergy and non-celiac wheat sensitivity (NCWS). While the underlying triggers and mechanisms of the first two entities have been extensively studied, there is still uncertainty in this regard for NCWS. Symptoms are nonspecific and diagnostic markers are lacking. Besides bacterial fermentable carbohydrates (FODMAPs), selected cereal proteins such as gluten or α-amylase trypsin inhibitors (ATIs) are in the focus of research as triggers. The aim of the present work was firstly to investigate the influence of the choice of cereal (common wheat, spelt, rye) and the production of bread (degree of milling and choice between yeast and sourdough) on the presence of potentially immunogenic proteins based on proteomic analysis. In a second step, the tolerability of selected breads should be investigated in a transgenic mouse model with intestinal inflammation and in a human study in patients with NCWS and subjective spelt tolerance. This was to narrow down possible triggers of NCWS and to investigate underlying mechanisms. Within the project, protein composition of bread and flour samples was analyzed based on a quantitative proteomics method (nano-UHPLC-ESI-MS based). In addition, a list of known and potentially immunogenic cereal proteins was generated based on Pfam annotation, which was used for the analysis of allergens in flour and bread. This showed that neither the absolute number nor the abundance of these allergenic proteins were dependent on the degree of milling of the flour or the fermentation process of the dough, which means that they are not selectively degraded during bread production. However, such proteins were identified in higher numbers and higher relative amounts in spelt and wheat samples compared to rye samples. Furthermore, different bread types from the proteome analysis were investigated in a mouse model with intestinal inflammation. This did not demonstrate better tolerability of rye bread compared to spelt and wheat bread. Instead, there was a trend for sourdough bread to have less negative effects on intestinal inflammation compared to yeast dough bread. It also turned out that inflammation was increased independently of gluten. No differences were found between wheat and spelt in either the proteomic analysis or the animal studies in this project. However, in a subgroup of NCWS patients, spelt bread is subjectively better tolerated than wheat bread, which could be due to both genetics and the different production of wheat and spelt bread. In order to verify the phenomenon and identify underlying mechanisms, if any, a clinical study was conducted in patients of this subgroup. The aim of the blinded study was to investigate whether spelt bread is actually better tolerated than wheat bread and whether the production process (16h dough or 1h dough + baking agent) has an influence. After each bread (4 days each + 3 days washout), gastrointestinal symptoms were assessed using the Irritable Bowel Syndrome Severity Scoring System (IBS-SSS) questionnaire. Extraintestinal symptoms and various blood and stool parameters were also analyzed. It was found that spelt bread was not better tolerated compared to wheat bread after blinded consumption and that FODMAP-rich bread was not worse tolerated compared to FODMAP-poor bread.
High-resolution proteomics reveals differences in the proteome of spelt and bread wheat flour representing targets for research on wheat sensitivities
(2020) Afzal, Muhammad; Pfannstiel, Jens; Zimmermann, Julia; Bischoff, Stephan C.; Würschum, Tobias; Longin, C. Friedrich H.
Wheat consumption can trigger celiac disease, allergic reactions and non-celiac wheat sensitivity (NCWS) in humans. Some people with NCWS symptoms claim a better tolerability of spelt compared to bread wheat products. We therefore investigated potential differences in the proteomes of spelt and bread wheat flour using nano LC–ESI–MS/MS on a set of 15 representative varieties for each of the two species. Based on the bread wheat reference, we detected 3,050 proteins in total and for most of them the expression was mainly affected by the environment. By contrast, 274 and 409 proteins in spelt and bread wheat, respectively, had a heritability ≥ 0.4 highlighting the potential to influence their expression level by varietal choice. We found 84 and 193 unique proteins for spelt and bread wheat, respectively, and 396 joint proteins, which expression differed significantly (p ≤ 0.05) when comparing both species. Thus, about one third of proteins differed significantly between spelt and bread wheat. Of them, we identified 81 proteins with high heritability, which therefore might be interesting candidates for future research on wheat hypersensitivities.
No difference in tolerance between wheat and spelt bread in patients with suspected non-celiac wheat sensitivity
(2022) Zimmermann, Julia; Longin, Friedrich H.; Schweinlin, Anna; Basrai, Maryam; Bischoff, Stephan C.
Individuals with suspected non-celiac wheat sensitivity (NCWS) often report better tolerance of spelt (Triticum aestivum ssp. spelta) compared to wheat (Triticum aestivum ssp. aestivum) bakery products. This experience has neither been validated nor explained on a molecular level. Therefore, we performed blinded wheat and spelt bread challenge in this patient group. Twenty-four adults with a history of NCWS but suspected spelt tolerance were challenged in a single-blinded crossover design over six weeks with six different study breads each at 300 g per day for 4 days followed by a washout phase of 3 days. Study breads comprised spelt and wheat breads made either after a traditional (T) or a current (C) recipe, resulting in four bread types plus a gluten-free bread with 1.5% added oligosaccharides (+FODMAP) and a gluten-free bread with 5% added wheat gluten (+Gluten). The main outcome parameter was the Irritable Bowel Syndrome—Severity Scoring System, which was higher than self-estimated by the participants after spelt bread consumption (p = 0.002 for T; p = 0.028 for C) and lower for wheat bread (p = 0.052 for T; p = 0.007 for C), resulting in no difference between wheat and spelt bread tolerance. The +FODMAP bread was better tolerated than both T breads (p = 0.003 for spelt; p = 0.068 for wheat) and equally well tolerated as both C breads and +Gluten breads after normalization to the washout scores. Neither signs of inflammation nor markers for intestinal barrier integrity were influenced. Our data do not confirm, on an objective basis, the differences in expected symptoms resulting from wheat and spelt products, suggesting a strong nocebo effect for wheat and a placebo effect for spelt.