Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 7, 2023; 29(25): 4036-4052
Published online Jul 7, 2023. doi: 10.3748/wjg.v29.i25.4036
Fractal nature of human gastrointestinal system: Exploring a new era
Fabio Grizzi, Marco Spadaccini, Maurizio Chiriva-Internati, Mohamed A A A Hegazi, Robert S Bresalier, Cesare Hassan, Alessandro Repici, Silvia Carrara
Fabio Grizzi, Mohamed A A A Hegazi, Department of Immunology and Inflammation, IRCCS Humanitas Research Hospital, Rozzano 20089, Milan, Italy
Fabio Grizzi, Cesare Hassan, Alessandro Repici, Department of Biomedical Sciences, Humanitas University, Pieve Emanuele 20072, Milan, Italy
Marco Spadaccini, Cesare Hassan, Alessandro Repici, Silvia Carrara, Division of Gastroenterology and Digestive Endoscopy, Department of Gastroenterology, IRCCS Humanitas Research Hospital, Rozzano 20089, Milan, Italy
Maurizio Chiriva-Internati, Robert S Bresalier, Departments of Gastroenterology, Hepatology & Nutrition, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, United States
Author contributions: Grizzi F and Carrara S contributed to study conception and design; Grizzi F, and Carrara S contributed to writing of article; Spadaccini M, Chiriva-Internati M, Hegazi AAAM, Hassan C, Bresalier RS, and Repici A critically reviewed the manuscript; all the authors contributed to editing, reviewing and final approval of article.
Conflict-of-interest statement: The Authors have no conflict of interest to declare.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Fabio Grizzi, PhD, Senior Scientist, Head Histology Core, Department of Immunology and Inflammation, IRCCS Humanitas Research Hospital, 56 Via Manzoni, Rozzano 20089, Milan, Italy.
Received: March 28, 2023
Peer-review started: March 28, 2023
First decision: May 4, 2023
Revised: May 26, 2023
Accepted: June 13, 2023
Article in press: June 13, 2023
Published online: July 7, 2023

The morphological complexity of cells and tissues, whether normal or pathological, is characterized by two primary attributes: Irregularity and self-similarity across different scales. When an object exhibits self-similarity, its shape remains unchanged as the scales of measurement vary because any part of it resembles the whole. On the other hand, the size and geometric characteristics of an irregular object vary as the resolution increases, revealing more intricate details. Despite numerous attempts, a reliable and accurate method for quantifying the morphological features of gastrointestinal organs, tissues, cells, their dynamic changes, and pathological disorders has not yet been established. However, fractal geometry, which studies shapes and patterns that exhibit self-similarity, holds promise in providing a quantitative measure of the irregularly shaped morphologies and their underlying self-similar temporal behaviors. In this context, we explore the fractal nature of the gastrointestinal system and the potential of fractal geometry as a robust descriptor of its complex forms and functions. Additionally, we examine the practical applications of fractal geometry in clinical gastroenterology and hepatology practice.

Keywords: Fractals, Geometry, Gastroenterology, Esophagus, Stomach, Colon, Pancreas, Liver, Time-series, Shape, Behavior

Core Tip: Utilizing fractal analysis to estimate the fractal dimension is a potent tool for investigating the geometrical properties of the gastrointestinal system. This approach has the potential to improve diagnostic and prognostic rates, leading to better patient care and a deeper understanding of the underlying pathophysiological mechanisms.