Didier Merlin

Ph.D. in Cell Biology, Paris University

Didier Merlin is a Regents' Professor at Georgia State University and a Senior Research Career Scientist at the Veterans Affairs Medical Center in Decatur, Georgia. His research focuses on understanding the mechanisms of intestinal inflammation and developing innovative treatments for inflammatory bowel diseases (IBD). With over 200 peer-reviewed publications, his work has been consistently featured in high-impact journals and widely cited (as of October 3, 2024: h-index of 82, with 19,612 citations).

His lab employs a wide array of cutting-edge techniques, from nanotechnology to molecular and cell biology, to advance research in this area. Over one million people in the U.S., including many veterans, suffer from IBD, with 50,000 new cases diagnosed each year, according to the Crohn's and Colitis Foundation of America. Veterans with IBD face a much higher risk of colorectal cancer compared to the general population (2.9% vs. 0.1%, National Center for Health Statistics). The goal of his work is to improve treatment strategies and clinical care for both veterans and non-veterans with these debilitating diseases.

Research Interests

PepT1 in Intestinal Inflammation (Refs 1-4)

The role of PepT1, a member of the Proton Oligopeptide Transporter (POT) superfamily, in intestinal inflammation. Although initially thought to be unrelated to any human disease, his research has revealed that the human intestinal di- and tri-peptide transporter, hPepT1, is highly expressed in inflamed colonic epithelial cells, mediating the transport of pro-inflammatory bacterial peptides. His studies have shown that hPepT1 plays a crucial role in aggravating colitis by activating inflammatory signaling pathways. Recently, a PepT1 polymorphism has been linked to IBD, further validating his research. The ongoing hypothesis is that colonic PepT1 is a key driver in both initiating and perpetuating intestinal colitis, and understanding its function could unlock new therapeutic avenues for IBD patients.

Nanomedicine in Intestinal Inflammation (Refs 5-8)

Merlin's group is also at the forefront of nanomedicine, developing innovative strategies for targeting low-dose drugs to colon tissues. While synthetic nanoparticles have limitations in clinical use, Merlin’s lab has pioneered the use of natural nanoparticles derived from ginger, which have shown promising results in reducing colitis and colitis-associated cancer. His team has reverse-engineered these nanoparticles to develop safe and well-defined nano-lipids and scalable delivery system. They have identified novel potent anti-inflammatory compounds, such as MLY2 and MLY8, which show efficacy in human ulcerative colitis biopsies. These findings hold great potential for developing new, natural therapeutic strategies with minimal side effects.

New Diagnostic and Therapeutic Tools for IBD (Refs 9-11)

Diagnosing and monitoring IBD remains invasive and costly, relying primarily on endoscopy. Merlin’s research is advancing the use of fecal biomarkers and microRNAs (miRNAs) as a non-invasive alternative. His team is investigating the role of fecal exosomes in reflecting intestinal inflammation, offering a more accurate diagnostic tool. This work could revolutionize the early diagnosis and monitoring of IBD, moving away from traditional invasive procedures to innovative biomarker-based approaches. Moreover, the potential for fecal exosome-based therapies opens new treatment possibilities that are already progressing to clinical trials.

Merlin’s research is dedicated to developing safe, natural drugs and innovative diagnostics that will transform the care of patients with IBD, ultimately aiming for more effective and less invasive treatments.