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@tum.de / anika.sander@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]

Master Student at ZIEL (TUM)
E-Mail: jessica.holstein@tum.de

Professional Career

Since 10/2025
Master‘s Thesis, ZIEL – Institute for Food and Health, Technical University of Munich 

10/2022 – 03/2023
Bachelor‘s Thesis, Institute of Neuropathology Universitätsklinikum Freiburg

Education

Since 2023
Master (M.Sc.) in Public Health, Charité – Universitätsmedizin Berlin

2019 - 2023
Bachelor (B.Sc.) in Biology, Albert-Ludwigs-University Freiburg

Project

Investigating health-promoting effects of fiber-rich food and their fermentability by the gut microbiota