Main Research Areas. My training and professional life has always had two major complementary emphases, namely my clinical activities as specialist in internal medicine with a focus on gastroenterology and hepatology and basic research that has always been in informed and motivated by my special interest in inflammatory bowel diseases, mucosal immunology, and the gut microbiome. Thus, it spans a variety of topics including specific aspects of immunometabolism namely the NAD+ salvage pathway with the rate-limiting enzyme nicotinamide phosphoribosyl transferase (NAMPT). We also have a longstanding interest in mucosal lipocalin 2 (Lcn2). In 2016, we showed that mucosal Lcn2 interferes with luminal iron homeostasis during chronic intestinal inflammation. Deletion of Lcn2 results in an atypical dysbiosis during chronic inflammation, aggravation of intestinal inflammation, and increased cancerogenesis driven by specific bacteria such as Alistipes spp and Robinsoniella. A few years ago, we started to plan and to execute clinical study protocols aiming at studying short- and long-term impacts of nutritional and pharmacological factors including dietary soluble fiber, plant-derived polyphenols and anthocyanins, or combinations of antibiotics on the human gut microbiome and metabolome.