Changes in composition and function of intestinal microbiota after cholecystectomy

To analyze the correlation of cholecystectomy and changes in intestinal microbiota composition and function by observing functional characteristics of differential microbial communities.

A cross-sectional study was conducted on the patients (PC group, n=73) undergoing cholecystectomy in our hospital from 2020 to 2021. Another 56 healthy age- and gender-matched individuals (HC group) without a history of cholecystectomy were subjected and served as the control group. Fecal specimens were collected from the 2 groups. 16S rRNA sequencing analysis was performed to examine the changes in composition and function of intestinal microbiota.

There were no statistical differences between the 2 groups in baseline indicators, such as gender, age, BMI, smoking and drinking history, blood pressure, heart rate, and comorbidities, but significant difference was observed in total bilirubin (TBIL) between them (P < 0.01). Alpha diversity analysis showed no significant difference in Chao1, Shannon, and Simpson indices between the 2 groups. Beta diversity analysis using the Bray-Curtis distance algorithm revealed a significant difference between the 2 groups at the class and genus levels (P < 0.05). The analysis of microbiota relative abundance using LEFSE showed that Enterobacteriaceae, Lactobacillales, Citrobacter, Megasphaera, Lactobacillus, Enterococcus, Akkermansia, Streptococcus, Klebsiella, and Ruminococcus_gnavus were up-regulated in the PC group, and Lachnospiraceae, Sutterellaceae, Lachnospirales, Lachnospira, and Sutterella were down-regulated. Kyoto Encyclopedia of Genes and Genomes (KEGG) functional prediction analysis indicated that significant differences were seen between the 2 groups in metabolic pathways, including ascorbic acid (vitamin C) metabolism and aldonic acid metabolism (P < 0.05), tricarboxylic acid cycle (TCA cycle) (P < 0.05), glutathione metabolism (P < 0.05), glutamic acid metabolism (P < 0.05), secondary bile acid metabolism (P < 0.05), and pentose phosphate pathway (P < 0.01).

Cholecystectomy is closely associated with the structural alterations in the composition of intestinal microbiota. Variations in microbiota composition and function may induce perturbations in TCA cycle and glutathione metabolism, glutamate metabolism, secondary bile acid metabolism, and pentose phosphate pathways.