Gut Microbiome: A Predictor of Long-Term Pancreatitis Complications

A Europe-wide study led by the University Medical Center Göttingen (UMG) shows that the microbial composition of the gut, known as the gut microbiome, can predict long-term complications following severe acute pancreatitis. To this end, the gut microbiome was analyzed upon admission to hospital and, based on this data, a computer-assisted model was developed that links subsequent complications to microbial changes. The results were published in the journal Gut. Understanding the gut microbiome and pancreatitis Healthy humans are colonized by numerous microbes. Trillions of bacteria can be found in the gastrointestinal tract alone, which, along with fungi and viruses, make up the main component of the so-called gut microbiome. These microorganisms and their metabolic products influence various processes and functions, as well as inflammatory and immune regulation processes in the human body. Severe acute inflammation of the pancreas, also known as pancreatitis, is a life-threatening condition that requires highly specialized interdisciplinary treatment. It is often triggered by gallstones or excessive alcohol consumption. It is known that patients who have suffered from acute pancreatitis often develop complications in subsequent years, such as chronic pancreatitis, recurrent acute pancreatitis, diabetes mellitus, pancreatic cancer, or exocrine pancreatic insufficiency, in which insufficient digestive enzymes are produced to properly break down and digest nutrients, especially fats, in the gut. Study design and key findings Researchers led by Dr. Christoph Ammer-Herrmenau, resident physician at the Department of Gastroenterology, Gastrointestinal Oncology, and Endocrinology at University Medical Center Göttingen (UMG), and Prof. Albrecht Neesse, MD, Ph.D., managing senior physician at the Department of Gastroenterology, Gastrointestinal Oncology, and Endocrinology at UMG, have now investigated the role of the gut microbiome in connection with complications after discharge in acute pancreatitis in a Europe-wide study involving 15 pancreatic centers. They developed a machine-learning model based on microbiome data of 277 patients with acute pancreatitis. The bacterial composition of the gut microbiome after hospital admission and the complications that occurred within three years after discharge were fed into the model to determine correlations. The results show that early changes in the gut microbiome are significantly associated with later complications. For example, in patients who developed diabetes mellitus, eleven bacterial species were identified that were more prevalent in the gut at the time of hospital admission. For the other complications, different bacterial compositions were observed at admission. These findings will be further explored in a global follow-up study over the next three years. Methods and future directions For the study, the gut microbiome of 277 patients with acute pancreatitis was analyzed within 72 hours of hospital admission using oral and rectal swabs and correlated with complications over a period of three years after discharge from the hospital. Possible complications include the development of chronic pancreatitis, recurrent acute pancreatitis, diabetes mellitus, pancreatic cancer, or exocrine pancreatic insufficiency. Various confounding factors that influence the microbiome were included in the investigations, including age, gender, nicotine consumption, and antibiotic use. "The microbial composition of the samples was determined using genetic material, DNA, with the help of Oxford Nanopore sequencing. This method allows long DNA fragments of the bacteria to be analyzed in their entirety and then, with the help of bioinformatic methods, the bacteria to be identified precisely down to the species level," says Dr. Christoph Ammer-Herrmenau, first author of the study. "Our results show a highly significant change in the gut microbiome in patients who later developed recurrent acute pancreatitis or diabetes mellitus, or even died. Thus, the microbial composition of the gut can predict the course of long-term complications at an early stage. The patterns of metabolic pathways that we were able to identify using bioinformatic prediction models provide initial indications that microbiome-induced metabolic pathways may contribute to long-term clinical complications," says Dr. Ammer-Herrmenau.