ZIEL Graduate Programme

Chair of Environmental Medicine
Faculty of Medicine, University of Augsburg

Prof. Dr. Claudia Traidl-Hoffmann

Title of the PhD thesis
Breaking down Barriers: Understanding the Role of Anaerobic Bacteria in the Skin

Description
Atopic eczema (AE) is an inflammatory skin disorder that is increasing in prevalence (Williams H., et al. 2008; Asher MI., et al. 2006). Most of the research done on this topic has focused on the disturbance of the aerobic microbial layer above the stratum corneum, but inflammation may be caused by the loss of anaerobic microbes lying beneath that skin layer (Nakatsuji T, et al 2013).  The stratum corneum is fractured in patients with AE, and this allows oxygen to reach and disrupt the environment where the anaerobic bacteria live (Tabata N, et al 1998; Nakatsuji, T et al 2013). It has been shown that skin microbiome diversity is lower in AE patients, and the diversity is significantly lower in perforated skin than with it intact. Though this change might solely result from an increase in S. aureus, it also implies the possibility that the size of the anaerobic microbiome may be drastically reduced, which indeed may be the cause of AE (Gong J, et al 2006; Reiger M, et al 2016). Anaerobic bacteria are known to have pH reducing metabolites, such as short chain fatty acids, and, compared to the healthy controls, in AE patients the skin pH is increased (Jang et al 2015).  In this project, we aim to isolate, characterize, and define the role of anaerobic bacteria in the skin, and to determine their relationship to the development of AE.

Title of the PhD thesis
Modulation of the microbial production of dietary biomarkers based on a dietary intervention

Description

Nutrition biomarkers are assumed to be a valuable and objective measure for dietary intake. Unfortunately, only few biomarkers are sufficiently validated so far ^[1]. Furthermore, biomarkers underlie inter- and intra-individual variabilities because they are often influenced by various endo- and exogenous factors such as genetic variability, lifestyle and physiological factors including for example the intestinal microbiota ^[2]. Therefore, the aim of the Food-Biomarker Alliance (FoodBAll) was the validation and systematic evaluation of (novel) biomarkers ^[3,4].

With this project we aim to continue this work on nutrition markers.  With a human intervention study the impact of dietary fibre on certain biomarkers will be investigated^. Another focus is to evaluate the plasticity of the intestinal microbiome under this treatment.

[1] E. M. Brouwer-Brolsma, L. Brennan, C. A. Drevon, H. van Kranen, C. Manach, L. O. Dragsted, H. M. Roche, C. Andres-Lacueva, S. J. L. Bakker, J. Bouwman et al., The Proceedings of the Nutrition Society, DOI: 10.1017/S0029665117003949.

[2] A. Scalbert, L. Brennan, C. Manach, C. Andres-Lacueva, L. O. Dragsted, J. Draper, S. M. Rappaport, J. J. J. van der Hooft, D. S. Wishart, The American journal of clinical nutrition, DOI: 10.3945/ajcn.113.076133.

[3] Ulaszewska MM, Weinert CH, Trimigno A, Portmann R, Lacueva CA, Badertscher R, Brennan L, Brunius C, Bub A, Capozzi F, Rosso MC, Cordero CE, Daniel H, Durand S, Egert B, Ferrario PG, Feskens EJM, Franceschi P, Garcia-Aloy M, Giacomoni F, Giesbertz P, Domínguez RG, Hanhineva K, Hemeryck LY, Kopka J, Kulling S, Llorach R, Manach C, Mattivi F, Migné C, Münger LH, Ott B, Picone G, Pimentel G, Pujos-Guillot E, Riccadonna S, Rist M, Rombouts C, Rubert J, Skurk T, Sri Harsha PSC, van Meulebroek L, Vanhaecke L, Vázquez-Fresno R, Wishard D, and Vergères G. Nutrimetabolomics: An Integrative Action for Metabolomic Analyses in Human Nutritional Studies. Mol Nutr Food Res 2018:e1800384. Doi: dx.doi.org/10.1002/mnfr.201800384

[4]     P. Giesbertz, B. Brandl, Y.-M. Lee, H. Hauner, H. Daniel, T. Skurk, Molecular nutrition & food research, DOI: 10.1002/mnfr.201900921.