Under the motto “Researching Nutrition. Strengthening Health”, on September 15, 2022, the German Institute of Human Nutrition Potsdam-Rehbrücke (DIfE) celebrated 30 years since its founding. For this special occasion, the Institute organized a scientific symposium followed by a summer fete. Around 50 guests from the the realms of politics, academia, and society , as well as former employees, gathered to celebrate the anniversary together with the DIfE.

Since its founding in 1992, as a member of the Leibniz Association, the DIfE has conducted fundamental research in the fields of nutrition and health, applying a wide spectrum of scientific, medical, and epidemiological methodologies. “Thanks to the continuous sharpening of our profile and the exceptional commitment shown by all DIfE employees, over the last three decades, we have managed to develop into a nationally and internationally recognized, successful, and modern institute in the field of nutrition and health sciences,” explained  Prof. Tilman Grune, scientific director of the DIfE, at the opening of the symposium.

A Jewel in the Crown of the Leibniz Association
This is evident not only in its more than 3700 publications but also in the many other milestones that the DIfE has reached. In his welcoming address, Prof. Andreas Radbruch, spokesperson for the Life Sciences Section of the Leibniz Association, explained: “With its focus on research into the molecular principles of healthy nutrition, the DIfE is an integral component of Section C of the Leibniz Association, which is comprised of 24 life science institutes. The DIfE makes a crucial contribution to the field of health, especially the question of how nutrition influences our health and can cause disease, and how a healthy diet can help prevent disease. Over the last 30 years, the DIfE has developed into the jewel in the crown of the Leibniz Association”.

Well-Connected into the Future
This was followed by a second welcoming address by Tobias Dünow, state secretary at the Ministry of Science, Research and Culture of Brandenburg: “We have known for a long time that what and how much we eat has a significant impact on our health – the risk of developing common diseases such as type 2 diabetes or cardiovascular diseases depends greatly on our diet. But how does the brain make decisions on food selection – and can they be changed? Thanks to its excellent experimental and application-oriented fundamental research and exceptional networking – including with the University of Potsdam – the DIfE works on exactly these types of future questions and plays a major role in promoting nutrition and health sciences in Brandenburg. The DIfE is also a major player in the field of scientific communication. The crises in recent years have shown that this is something we need more of – more science, more facts, more solutions, more discourse. With this in mind, I would like to congratulate the DIfE on its anniversary – I look forward to the next 30 years of its research findings and contributions to discourse!”.

Joint Presentations of Socially Relevant Nutritional Research Topics
The Institute was able to attract five researchers to the scientific symposium for whom the DIfE played an important role in their respective careers. “I am delighted to hear that our former scientists fondly remember their time as doctoral or post-doctoral candidates at the DIfE. They have successfully found national or international posts in the field of nutrition research and continue to engage in scientific exchange with the DIfE,” said Prof. Grune during his presentation of the speakers. Together with young scientists active at the DIfE, the speakers proceeded to present their research work on current socially relevant nutrition topics focusing on intestinal microbiota, micronutrients, neuroscience, obesity and its sequalae, and nutritional epidemiology.

The speakers of the symposium from left to right: Dr. Sören Ocvirk, Prof. Dr. Thomas Clavel, Prof. Dr. Tilman Grune, Prof. Dr. Marc Birringer, Dr. Thomas Ambrosi, Dr. Franziska Jannasch, Dr. Heike Vogel, Prof. Dr. Ina Danquah, Dr. Rachel Lippert und Prof. Dr. Paul Pfluger. © DIfE

Gut Bacteria Influence the Risk of Colorectal Cancer
First up were Prof. Dr. Thomas Clavel of Aachen University Hospital and Dr. Sören Ocvirk of the research group Intestinal Microbiology.

Under the title “Gut microbiome: You never eat alone”, both lectured on the huge variety of microorganisms that colonize the human gut and their wide-reaching effects on health – which remain largely unknown. The around 100 billion microorganisms in the gut have numerous nutritional effects on human metabolism: Primary bile acids are produced in the liver and then transported to the small intestine to help promote fat absorption. The gut bacteria then transform the primary bile acids into secondary bile acids.

However, the production of certain types of secondary bile acids, which often accompany a very fatty “Western” diet, is suspected of increasing the risk of colorectal cancer. In an ongoing joint research project, Thomas Clavel, who investigated the degradations of lignans by gut microbiota as a doctoral candidate at the DIfE from 2002 to 2006, and Sören Ocvirk focus on the influence of gut bacteria and secondary bile acids on the colorectal cancer risk. Both scientists stressed to those present “Make sure you give your gut microbiome the food it needs: It needs a lot of fiber and less red meat!”.

What do Dietary Patterns have to do with Chronic Diseases?
The next lecture focused on the topic “Dietary Patterns in a Global Context – Does a One-Size-Fits-All Solution Exist?” and was presented by Prof. Dr. Ina Danquah of the Heidelberg Institute of Global Health and Franziska Jannasch of the Department of Molecular Epidemiology. Dietary patterns provide an alternative to the investigation of individual types of foods as they take the complexity of human diets into consideration. The two scientists presented the methodological generation and analysis of the correlations between dietary patterns and the onset of chronic diseases, such as type 2 diabetes and cardiovascular diseases, published in various national, European, and global studies. Ina Danquah, who was a research associate at the DIfE from 2010 until 2019 while researching type 2 diabetes in African population groups, argued that clarifying the correlations between dietary patterns and chronic diseases will enable future adjustment of dietary recommendations. “The heterogeneity of the various study populations limits the ability to derive a “healthy dietary pattern for all,” stressed Danquah. “However, the results do point to a plant-based diet with less meat consumption, which also offers the most promising perspectives in the context of sustainability and climate protection.

The Role of the Brain in the Regulation of Body Weight
The third joint lecture was given by Prof. Dr. Paul Pfluger of Helmholz Center Munich and Dr. Rachel Lippert, head of the junior research group Neural Circuits on the topic of “Why are we getting fat? Is it all in the head?” More than half of the adult population of Germany is overweight or obese. All of these individuals are at a greater risk of developing cardiovascular diseases, type 2 diabetes, and cancer. Weight loss is therefore an essential therapeutic objective; however, it is very difficult to achieve. Paul Pfluger, who was a doctoral candidate at the DIfE from 2001 to 2004, aims to better understand the mechanisms that prevent sustainable weight loss and those that cause obesity in the first place. This is an important step in the development of therapeutic options in the future. “Overweight and obesity are all in the head,” says Pfluger. “The same applies to the failure to lose weight. However, lack of willpower is not the reason but rather numerous, still poorly understood, neuronal circuits and primitive mechanisms that protected our ancestors from starvation. These include, for example, the maternal environment, how the diet of a pregnant woman can influence the still developing brain of her baby, and how neurons develop and interconnect with one another to generate signals to trigger hunger and behaviors,” added Pfluger. In our age of abundance, it is essential to understand and combat these mechanisms.

What Vitamins and Nutrients Reveal About Health and Disease
In the fourth lecture, Prof. Dr. Marc Birringer of Fulda University of Applied Sciences and Prof. Dr. Tilman Grune, standing in for Dr. Daniela Weber of the Department of Molecular Toxicology, who was unable to attend at short notice, took the audience on a “Search for clues in the world micronutrients”.

Micronutrients and their metabolites have very specific duties, e.g., enzyme cofactors for energy metabolism or as antioxidants. They often circulate through the body and organs in very low concentrations and complex device-based analysis is necessary to detect and quantify them. During their lecture, the two scientists placed a special focus on the challenges of valid analysis of vitamins A, E, K, B12 and carotenoids and their metabolites. “Although some of the vitamins and micronutrients presented here were identified over 100 years ago, new research findings have exposed new correlations to inflammatory processes and age- and dietary-related diseases,” explained Birringer, who was active at the DIfE from 1999 to 2002, researching, among other things, human vitamin E metabolism. Grune stated that lifestyle and dietary changes may result in an additional need for micronutrients. Vitamin B12 is an essential vitamin for those adhering to a vegan diet and vitamin A is a risk marker for cardiac disease.

New Strategies to Combat Osteoporosis and Obesity
The last scientific lecture of the day dealt with “obesity genes” and unexpected fat accumulation and was presented by Dr. Thomas Ambrosi from Stanford University School of Medicine and Dr. Heike Vogel, head of the research group Genetics of Obesity.

Ambrosi, who from 2013 until 2017 was a doctoral candidate at the DIfE researching the function of bone marrow fat during aging and when consuming a fatty diet using bone stem cells, explained that six million people in Germany suffer from osteoporosis. This disease results in a severe loss of bone mass with increased susceptibility to bone fracture. People who are overweight and/or have type 2 diabetes are at increased risk of osteoporosis. Until now, there have been few measures in place for the prevention and treatment of osteoporosis. “Using stem cell-based research approaches, my aim is to develop alternative therapeutic strategies to improve skeletal health and thus overall quality of life," Ambrosi said.

Heike Vogel has set herself the aim of discovering the “obesity gene”. By crossbreeding thin and fat mice, she was able to identify new puzzle pieces in the complex search for disease-triggering genes, for example, the obesity gene Ifif202b, which promotes abdominal fat accumulation. However, our genes alone are not responsible for the onset of obesity. Diet and lifestyle also play important roles. An effective dietary strategy is the 16/8 intermittent fasting approach. “Using mouse models, we were able to show that a 16-hour pause from eating improves sensitivity to the blood sugar-reducing hormone insulin and protects against the development of hepatic steatosis,” explained Vogel. These findings result in a better understanding of the processes that cause obesity, insulin resistance, and diabetes and also provide valuable starting points for the development of new treatments.

After the end of the official part, Dr. Birgit Schröder-Smeibidl, administrative director of the DIfE, thanked the speakers for their fascinating lectures and invited all those present to end the special day in the relaxed atmosphere of the summer fete.