Patients with chronic pancreatitis have greatly reduced gut microbiota diversity, marked gut microbiota dysbiosis, and an overgrowth of opportunistic pathogens, according to study results published in Clinical and Translational Gastroenterology.
Patients with chronic pancreatitis (N=51) were recruited between 2010 and 2017 at the University Medicine Greifswald in Germany. Data from healthy controls (n=102) were selected from the population-based Study of Health in Pomerania. Fecal samples were assessed for microbiota, in which diversity was quantified with the Shannon diversity index (H) and Simpson diversity number (N2).
Patients had alcohol-related chronic pancreatitis (n=35), idiopathic chronic pancreatitis (n=13), or chronic pancreatitis caused by a mutation in pancreatic secretory trypsin inhibitor (n=3).
Microbiota diversity was significantly lower among patients with chronic pancreatitis (median N2, 26.4; interquartile range [IQR], 20.0-38.5; median H, 4.1; IQR, 3.7-4.3) compared with those in the control group (median N2, 40.1; IQR, 28.0-57.9; median H, 4.4; IQR, 4.1-4.7; P <.001 for both).
Both patients and controls had 23 differentially expressed genera in their fecal samples. These differentially expressed genera represented 51.6% of the total microbial abundance among patients with chronic pancreatitis. Most of these taxa (n=15) were negatively associated with disease status.
Among patients with chronic pancreatitis, Enterococcus (q <.001) demonstrated the most “distinct increase in abundance” in terms of percentage. Bacteroides demonstrated the largest increase in absolute terms (mean, 27.3% vs 16.7%; q <.001). Faecalibacterium (3.8% vs 6.1%; q <.001) and Prevotella (7% vs 11.7%; q =.008) were found to have the largest absolute decreases in abundance for patients compared with controls, respectively.
Facultative pathogenic bacteria — Citrobacter, Enterobacter, Enterococcus, Enterobacteriaceae, Escherichia Shigella, Klebsiella, Pseudomonas, Proteus, Staphylococcus, and Streptococcus — were observed to have a 2.8-fold mean and 5.0-fold median increase in abundance among patients with chronic pancreatitis (P <.001). The abundance of pathogenic bacteria in samples was significantly associated with disease status (P =.002) and age (P =.022). Samples from smokers with chronic pancreatitis had a median pathogenic abundance of 2.1% (IQR, 0.6%-11.1%) compared with 0.6% (IQR, 0.3%-2.3%; P =.04) among non-smokers with chronic pancreatitis.
One limitation of this study was that dietary habits of the participants were not assessed. The investigators were unable to determine whether the observed differences of gut microbiota were due in part to differential food preferences between groups.
The study authors concluded that the composition of intestinal microbiota among patients with CP exhibited microbiota dysbiosis in which overall diversity was lower, creating an environment for facultative pathogens to thrive.
Frost F, Weiss FU, Sendler M, et al. The gut microbiome in patients with chronic pancreatitis is characterized by significant dysbiosis and overgrowth by opportunistic pathogens. Published online September 16, 2020. Clin Transl Gastroenterol. doi: 10.14309/ctg.0000000000000232