Established in 2016, the Eco-undefinedImmunology and Microbiome Group is a dynamic and international team with expertise in microbiology, immunology, molecular genetics, public health, and bioinformatics.

Our research focuses on understanding how our changing dietary habits, especially the reduced consumption of dietary fiber, impacts susceptibility to various diseases such as inflammatory bowel diseases, multiple sclerosis and allergy, as well as to variety of gastrointestinal pathogens. We investigate the microbiome-mediated molecular mechanisms that impact our immune system via the interaction with the colonic mucus barrier, which is one of the first lines of host defense. In order to effectively address our research questions, we utilize a variety of tools and techniques from high-throughput culturing of commensal gut bacteria to next-generation sequencing, as well as immunological tools like mass cytometry (CyTOF).

Our research exploits the power of synthetic human gut microbiotas in various gnotobiotic mouse models of the multiple diseases. Importantly, we also incorporate translational approaches to shift findings from a mouse model to human cohorts in order to inform clinical care or public health measures related to dietary fiber intake and disease. The mission of our research is to pursue the “from bed to bench to bed” approach to explore the disease-based biomarkers and susceptibility factors that could be used as critical transition points between health and disease in order to harness the potential of microbiome engineering. 

 


GROUP LEADER

 
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Photo: Tim Wegner www.timwegner.de

Mahesh Desai, PhD     

Mahesh S. Desai is the Group Leader of the Eco-Immunology and Microbiome team at the Luxembourg Institute of Health and is an Adjunct Associate Professor in ‘Gut microbiome in health and disease’ at the University of Southern Denmark, Odense, Denmark. He is working as a visiting scientist at the RIKEN Centre for Integrative Medical Sciences, Yokohama, Japan. He obtained his PhD at the International Max Planck Research School, Marburg, Germany, and underwent postdoctoral training at the University of Michigan Medical School, Ann Arbor, USA. He has received several awards including Dr. Tissier’s medal from the Japan Bifidus Foundation. 

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mahesh.desai@lih.lu 

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Projects summary:

Using gnotobiotic mouse models containing fully characterized human gut bacterial communities, we intend to:

  • Study how a fiber-deprived gut microbiota resorts to host-secreted mucin glycoproteins leading to erosion of the colonic mucus barrier
  • Investigate host immune regulation in response to the fiber-deprived gut-microbiota-mediated erosion of the colonic mucus layer
  • Examine changes in host susceptibility to an intestinal pathogen (Citrobacter rodentium) during microbiota-mediated erosion of the colonic mucus layer
  • Design and test practicable prebiotic diets in order to maintain populations of fiber-degrading bacteria

 

 


POSTDOCTORAL FELLOWS

 
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Alexander Steimle, PhD      

Dr. Alex Steimle obtained his PhD in Biochemistry from the Eberhard Karls University in Tübingen, Germany with majors in Biochemistry, Analytical Chemistry and Virology. For his diploma thesis, he characterized the influence of commensal Gram-negative bacteria on the expression of MHC class II in dendritic cells of the colonic lamina propria. During his PhD at the Interfaculty Institute of Microbiology and Infection Medicine in Tübingen, Germany, he investigated the molecular mechanisms of how intestinal microbes modulate the host immune system by focusing on surface components of commensal bacteria and certain cysteine proteases of the host. After 1.5 years of Postdoc at the same institute, he joined the group as a postdoc. Here, he focuses on mucus-degrading bacteria (mucobiomes) and their impact on the progress of inflammatory bowel diseases and their influence on success of antibody-based therapies.

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Project:

  • MUCO-UC: Impact of antibody-based therapies on mucobiomes of ulcerative colitis patients

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Marie Boudaud, PhD     

Dr. Marie Boudaud obtained her PhD in Immunology from the University of Sherbrooke, QC, Canada. For her thesis, she characterized the regulation of cysteinyl-leukotriene receptor type 1 (CysLT1) expression by interleukin-33 in human peripheral blood  T cells. During her PhD, she studied lipid mediators and human peripheral blood leukocytes in order to understand mechanisms related to the pathogenesis of asthma. In May 2019, she joined the group of Dr. Mahesh Desai for a Postdoctoral fellowship to understand how a fiber-deprived diet and commensal mucolytic bacteria interact to shape the host immune responses and promote colitis development. In February 2020, Marie was awarded an H2020 postdoctoral research grant through the Marie Skłodowska-Curie actions (MSCA). 

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Project:      

  • Mucobiome-regulated immune pathways in a mouse model of inflammatory bowel diseases (IBD)

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PHD STUDENTS

 
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Mathis Wolter, MSc     

PhD Student

Mathis obtained his Master of Science in Microbiology and Genetics in 2015 from the RWTH Aaachen University in Germany. For his Master’s thesis, he characterized the Crabtree effect in Saccharomyces cerevisiae under nitrogen limited conditions using ion mobility spectrometry and 13C metabolic flux analysis. In June 2016, he joined the laboratory of Prof. Desai under the FNR CORE grant. As part of the FNR CORE grant and his PhD thesis work, Mathis collaborates with Prof. Eric Martens from the University of Michigan. As part of this collaboration, Mathis received the Fulbright scholarship to visit Prof. Martens lab. His PhD thesis aims to investigate the complex mechanisms underlying the interaction between gut microbiota, dietary fiber and gut mucus layer with a particular focus on enteric pathogen susceptibility. 

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Project:      

  • Combined low dietary fiber and mucus-degrading gut bacteria cause lethal colitis in genetically susceptible mice

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Mareike Neumann, MSc     

PhD Student

Mareike Neumann obtained her Master of Science in Anthropology in 2015 at the Johannes Gutenberg-University in Mainz, Germany. In her Master's thesis, she investigated the role of B cells in the pathogenesis of glaucoma in an animal model. In July 2016, she joined the laboratory of Prof.  Desai as part of the FNR’s AFR bilateral research grant, an international research collaboration with the RIKEN Center for Integrative Medical Science in Japan. Her PhD thesis focusses on the investigation of the complex interplay between the colonic mucus barrier, the gut microbiota and dietary fiber in the context of multiple sclerosis.

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Project:      

  • Colonic mucus foraging by commensal microbiota modulates the host immune responses

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Amy Parrish, MSc     

PhD Student

Amy Parrish holds a Master of Science in Immunology of Infectious Diseases from the London School of Hygiene and Tropical Medicine. She completed her thesis research at the Medical Research Centre Unit in The Gambia in 2016, investigating the role of NK and gamma delta T cells in Mycobacterium tuberculosis infection in patients and household contacts. In April 2017, she was successful in securing an AFR individual PhD grant from the FNR. Her thesis aims to understand the role of dietary fiber and mucus barrier dysfunction and its influence on immune tolerance breakdown in food allergy and inflammatory disorders, such as IBD. 

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Project:      

  • Mucus barrier erosion by the gut microbiome exacerbates food allergy sensitization

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Erica Grant, MPH  

PhD Student

Erica Grant completed her Master of Public Health in One Health at the University of Washington in Seattle, Department of Environmental and Occupational Health Sciences. For her thesis, she investigated microbiome sharing between humans and macaques in Thailand. In January of 2019, she joined the Desai lab through the MICROH (Microbiomes in One Health) doctoral training programme. Her research centers on  impacts of a fiber-deprived diet on a defined, humanized mouse gut microbiome in early life. Erica also manages the Luxembourgish Fiber Cohort project (LUXFICO), a translational study to investigate effects of low-fiber consumption in humans using a multi-omics approach. 

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Projects:      

  • Luxembourgish Fiber Cohort (LUXFICO) - From mouse to man: translating findings in mouse study into a human cohort
  • Gut microbiota-mediated impacts of dietary fiber deprivation in gnotobiotic mice in early life

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MASTER'S TRAINEES

 
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Hélène De Franco

Master's Trainee

Hélène De Franco completed her Bachelor's degree in Physiology and Cellular and Molecular Biology at the Université de Bordeaux, where she is currently studying for a Master’s in Nutrition and Food Sciences. She joined Prof. Desai’s lab in January 2021 as a Master’s Trainee and is writing her thesis on the impact of a high-fiber diet on fat-soluble vitamins status in humans, making use of the ongoing LUXFICO study.

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Project:      

  • Vitamins A, D, E, and total carotenoid status in the context of a high-fiber diet intervention

 

 

 

 

 

 

 


TECHNICIANS

 
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Stéphanie Willieme, MSc     

Laboratory Technician

Stéphanie Willieme graduated in Biomedical Sciences from the Université Libre de Bruxelles. She joined the Department of Infection and Immunity as a research technician in September 1999. She initially took an active part in the development, the setting and the quality control of diagnostic tests for industries. Afterwards, Stephanie was involved in the study of the immunotoxic effect of carcinogens and in the development of NGS techniques to study the B cell repertoire after immunization against carcinogens as well as DNA single mutations. In May of 2017, she joined the Desai lab as a laboratory technician where she is responsible for laboratory management and supports several research projects.

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Alessandro De Sciscio, MSc

Laboratory Technician

Alessandro De Sciscio completed his Masters in Molecular Biology, Biochemistry and Cellular at the Université Libre de Bruxelles, Department of Molecular Biology of the Gene. He performed trainings in various molecular biology labs from 2012 to 2017. He joined the Desai lab in May 2018 as a laboratory technician and coordinates work in the germ-free facility.

 

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