Grammenos Ioannis is a Gastroenterologist who maintains a private practice in Nea Ionia. Simultaneously, he serves as a Specialist Scientific Collaborator at the Central Clinic of the Athens Medical Center. He graduated with honors from the Medical School of the University of Rome and specialized in Gastroenterology - Hepatology at the 2nd Internal Medicine Clinic of the General Hospital of Athens "Evangelismos." Furthermore, he holds a PhD with a dissertation titled "The absorption of fructose and sorbitol in normolactasic and hypolactasic healthy adults." He also has a notable research portfolio with scientific publications in conferences and scientific journals. Finally, the doctor has participated in numerous medical conferences both in Greece and abroad.