PhD student at ZIEL (TUM) 
Tel.: +49 8161 71 2364
E-Mail: helen.fetzer(at)tum.de

Research Interest & Motivation

• Processing and metabolization of resistant starch
• Fiber-associated alterations of the human gut microbiota
• Food technology and processing

• in vitro digestion of macronutrients

  My personal motivation to dedicate myself to science is based on the desire to create knowledge and pass it on to the next generation.

Professional Career

08/2022-01/2023
Master‘s Thesis, Nofima (Ås, Norway), Department of Food & Health 

10/2020-02/2021
Bachelor‘s Thesis, Max Rubner-Institute (Karlsruhe, Germany), Department of Food Technology and Bioprocess Engineering

Education

Since 2023
PhD Student (Dr. rer. nat.), ZIEL – Institute for Food & Health, Technical University of Munich

2021-2023
Master (M.Sc.) in Food Processing, University of Applied Sciences Fulda

2017-2021
Bachelor (B.Sc.) in Food Technology, University of Applied Sciences Weihenstephan-Triesdorf

Project

Functionalization of resistant starch

Resistant starch (RS) is a fraction of starch that resists digestion in the small intestine of healthy individuals and passes into the large intestine, providing a substrate for bacterial fermentation. The fermentation of RS to short-chain fatty acids (SCFA) by the gut microbiota plays a critical role in promoting gut health. It is hypothesized that people who eat a “Western” diet have a lower microbial capacity to metabolize RS to SCFA than people who eat a traditional, high-fiber diet, such as in sub-Saharan Africa. We are conducting a human study (RESISTAR) to test this hypothesis. 
In the field of food technology, the various types of RS are playing an increasingly important role. The development of innovative food applications using RS is not only due to the unique techno-functionality, such as the low water holding capacity and the high-water binding capacity but also to the good organoleptic properties, such as the good mouthfeel due to the small particle size and the neutral taste. In particular, RS type 3, formed by retrogradation and produced using various food processing techniques, offers great potential as a novel and “invisible” source of dietary fiber in Western food products.
In the framework of a highly interdisciplinary team, we aim to explore the functionalization of RS from the perspective of food technology and the gut microbiome. 

PhD student at German Institute of Human Nutrition (DIfE)
Tel.: + 49 33 200 88 2464
E-Mail: annika.osswald@dife.de

Research Interest & Motivation

• Intestinal microbiology
• Microbe-Host interactions
• Microbial bile acid metabolism
• Colorectal cancer
• Gnotobiotic mouse models

Professional Career

04/2021 – 09/2022
Research Assistant, Intestinal Microbiology, German Institute of Human Nutrition 

Education

Since 10/2022
PhD student (Dr. rer. nat.), Intestinal Microbiology, German Institute of Human Nutrition

2018-2021
Master (M.Sc.) in Nutrition Science, University of Potsdam, Germany

2017-2021
Bachelor (B.Sc.) in Nutrition Science, Justus-Liebig-University Giessen, Germany

Project

Understanding the effects of gut microbial co-metabolism of bile acids on gastrointestinal health 

Intestinal bacteria are able to transform bile acids produced by the host to secondary bile acids. Deoxycholic acid is the predominant secondary bile acid in the human gut and is strongly associated with intestinal health and disease pathogenesis, e.g., for colorectal cancer. Since underlying mechanisms are still not fully understood, the aim of this project is to investigate causal relationships between deoxycholic acid, the gut microbiota and host compartments using gnotobiotic mouse models.

Publications

Wortmann E*, Osswald A*, Wylensek D, Kuhls S, Coleman OI, Ducarmon Q, Liang W, Treichel N, Schumacher F, Volet C, Matysik S, Kleigrewe K, Gigl M, Rohn S, Kleuser B, Liebisch G, Schnieke A, Bernier-Latmani R, Zeller G, Haller D, Flisikowski K, Ocvirk** S, Clavel T**. Secondary bile acid production by gut bacteria promotes Western diet-associated colorectal cancer. 2024 Jan bioRxiv. doi: doi.org/10.1101/2023.03.17.533140 

Kuhls S, Osswald A, Ocvirk S. Bile acids, bile pigments and colorectal cancer risk. Curr Opin Gastroenterol. 2022 Mar 1;38(2):173-178. doi: 10.1097/MOG.0000000000000820.

PhD student at ZIEL (TUM)
Tel.: +49 33200 88 2464
E-Mail: anika.sander(at)tum.de / anika.sander(at)dife.de 

Research Interest & Motivation

• Intestinal microbiology
• Microbe-host interactions
• Bilirubin metabolism
• Inflammatory bowel diseases
• Prevention of colorectal cancer

Professional Career

04/2021-06/2022
Research Assistant, Intestinal Microbiology, German Institute of Human Nutrition, Potsdam-Rehbruecke 

10/2019-07/2020
Master’s Thesis, Intestinal Microbiology, German Institute of Human Nutrition, Potsdam-Rehbruecke 

03/2017 – 09/2017
Bachelor’s Thesis, Clinical Research, Henkel AG & Co. KgaA, Duesseldorf 

Education

Since 2022
PhD student (Dr. rer. nat.), Chair of Immunology and Nutrition, Technical University of Munich, Munich

2018-2021
Master (M.Sc.) in Biochemistry & Molecular Biology, Potsdam University, Potsdam 

2014-2017
Bachelor (B.Sc.) in Molecular & Technical Medicine, Hochschule Furtwangen University, Villingen-Schwenningen 

Project

The influence of intestinal hyperbilirubinemia on gut microbe-host interactions

Gilbert’s Syndrome, a benign polymorphism in the UGT1A1 gene responsible for the conjugation and excretion of bilirubin in liver, leads to increased bilirubin levels in serum and colon. Studies have shown that individuals with these UGT1A1 polymorphisms have lower risks for inflammatory bowel diseases and colorectal cancer. This project aims to investigate the effects of mildly increased bilirubin levels on gut microbiota-host interactions in the context of risk factors relevant for colorectal cancer (e.g., diet, inflammation).

Publications

Mandić, A. D., Woting, A., Jaenicke, T., Sander, A., Sabrowski, W., Rolle-Kampcyk, U., von Bergen, M., Blaut, M.: Clostridium ramosum regulates enterochromaffin cell development and serotonin release. Sci. Rep. 9:1177 (2019). [Open Access]