Comparative analysis of intestinal flora characteristics in patients with alcoholic fatty liver and metabolism associated fatty liver based on 16S rDNA sequencing

Abstract

Abstract: Objective To analyze the changes in intestinal flora in patients with alcoholic fatty liver disease (AFLD) and metabolism-associated fatty liver disease (MAFLD) and to explore the differences in intestinal flora between them. Methods Forty-five patients who visited Inner Mongolia Baogang Hospital from June 2023 to June 2024 were selected as the study subjects, including 15 patients in the AFLD group, 15 patients in the MAFLD group and 15 patients in the normal control group (NC group), and the data on the changes in the diversity of the bacterial flora between the groups were obtained to analyze the differences in gut microorganisms among AFLD, MAFLD patients and healthy control patients, and to detect the alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglycerides (TG), total cholesterol (TC), and lipopolysaccharide (LPS) at the same time. The body mass index (BMI) was calculated and compared and analyzed. Results Compared with the NC group, the levels of serum LPS were elevated in patients in the AFLD and MAFLD groups (all P<0.05), and LPS was significantly higher in the AFLD group than in the MAFLD group (P>0.05). For the analysis of intestinal flora: (i)Alpha diversity: there was no significant difference in Shannon index (P=0.15), Simpson index (P=0.06) in AFLD, MAFLD and control group, and there was a difference in gut microbial community among the three groups in Beta diversity analysis. (ii) Species composition analysis: at the phylum level, the abundance of Pseudomonadota in AFLD and MAFLD groups was higher than that in NC group, and the abundance of Verrucomicrobiota was higher in AFLD than that in MAFLD group. At the family level, the abundance of Enterobacteriaceae, Veillonellaceae and Streptococcaceae in AFLD and MAFLD groups were all elevated, and that of Lachnospiraceae Bifidobacteriaceae and Barnesiellaceae were all reduced and the abundance of Lachnospiraceae was significantly lower in the AFLD group than in the MAFLD group. (iii)Analysis of variance among the three groups: when the LAD score was >3.5, Bacteroidota, Verrucomicrobiota, Acidaminococcaceae, Escherichia, and Phascolarctobacterium in the AFLD group were the differential species compared to the NC group. In the MAFLD group, Bacillota, Faecalibacterium, Oscillospiraceae, Veillonellaceae and Blautia were the differential species. And compared with the AFLD and MAFLD groups, Eubacteriales, Clostridia, Lachnospiraceae and Bifidobacteriaceae were the differential species in the NC group. (iiii) KEGG analysis: Compared with the NC group, the intestinal flora of the AFLD and MAFLD groups were significantly down-regulated in lipid metabolism and carbohydrate metabolism pathways, while the intestinal flora of the AFLD group were significantly up-regulated in the immune system pathway. Correlation analysis: in the AFLD group and the healthy control group, Bacteroidota and Pseudomonadota were positively correlated with serum LPS, and Bacillota was negatively correlated with serum LPS; whereas in the MAFLD group and the healthy control group, Pseudomonadota was positively correlated with serum LPS, and Actinomycetota was negatively correlated with serum LPS. Conclusion Patients with AFLD and MAFLD have elevated levels of LPS, which may indicate intestinal inflammation. The inflammatory response involving LPS may be one of the causes of FLD, and LPS levels are higher in the AFLD group than in the MAFLD group, suggesting that alcohol can exacerbate the inflammatory response in AFLD. Patients with AFLD and MAFLD had intestinal dysbiosis, as evidenced by increased abundance of pathogenic bacteria (e.g., Pseudomonadota, Enterobacteriaceae, Veillonellaceae, Streptococcaceae) and decreased abundance of beneficial bacteria (e.g., Lachnospiraceae, Bifidobacteriaceae, and Barnesiellaceae), and Lachnospiraceae was significantly decreased in the AFLD group as compared to the MAFLD group, which may be related to alcohol. AFLD has an imbalance in gut microbiota, and alcohol may alter the gut microbiota, affect immune system pathways, generate inflammatory responses, and promote the occurrence and development of AFLD.

Key words: Alcoholic fatty liver disease, Metabolism-related fatty liver disease, Intestinal flora, Lipopolysaccharide

Sun Yue, Niu Haoshu. Comparative analysis of intestinal flora characteristics in patients with alcoholic fatty liver and metabolism associated fatty liver based on 16S rDNA sequencing[J]. Chinese Hepatolgy, 2026, 31(8): 1146-1151.

References

[1] Plaza-Díaz J, Solís-Urra P, Rodríguez-Rodríguez F, et al. The gut barrier, intestinal microbiota, and liver disease: molecular mechanisms and strategies to manage[J]. Int J Mol Sci, 2020, 21(21): 8351.
[2] Sharma S P, Suk K T, Kim D J. Significance of gut microbiota in alcoholic and non-alcoholic fatty liver diseases[J]. World J Gastroenterol, 2021, 27(37): 6161-6179.
[3] Chopyk D M, Grakoui A. Contribution of the intestinal microbiome and gut barrier to hepatic disorders[J]. Gastroenterology, 2020, 159(3): 849-863.
[4] Jiang N, Xiao Y, Yuan K, et al. Effect of intestinal microbiota on liver disease and its related future prospection: from the perspective of intestinal barrier damage and microbial metabolites[J]. J Gastroenterol Hepatol, 2023, 38(7): 1056-1071.
[5] 酒精性肝病防治指南(2018年更新版)[J]. 实用肝脏病杂志, 2018, 21(2): 170-176.
[6] Eslam M, Newsome P N, Sarin S K, et al. A new definition for metabolic dysfunction-associated fatty liver disease: an international expert consensus statement[J]. Journal of Hepatology, 2020, 73(1): 202-209.
[7] Shen F, Zheng R D, Sun X Q, et al. Gut microbiota dysbiosis in patients with non-alcoholic fatty liver disease[J]. Hepatobiliary Pancreat Dis Int, 2017, 16(4): 375-381.
[8] Yan A W, Fouts D E, Brandl J, et al. Enteric dysbiosis associated with a mouse model of alcoholic liver disease[J]. Hepatology, 2011, 53(1): 96-105.
[9] Park J W, Kim S E, Lee N Y, et al. Role of microbiota-derived metabolites in alcoholic and non-alcoholic fatty liver diseases[J]. Int J Mol Sci, 2021, 23(1): 426.
[10] 李梦晴, 张炜. 非酒精性脂肪性肝病血清生化指标与肠道菌群结构变化的初步研究[J]. 智慧健康, 2023, 9(13): 30-34, 39.
[11] 池欣, 孙秀, 许艺凡, 等. 酒精性脂肪性肝病患者肠道菌群特征及其临床意义[J/OL]. 中国肝脏病杂志(电子版), 2023, 15(1): 19-27. http://dx.chinadoi.cn/10.3969/j.issn.1674-7380.2023.01.004.
[12] Wang H, Yan Y, Yi X, et al. Histopathological features and composition of gut microbiota in rhesus monkey of alcoholic liver disease[J]. Front Microbiol, 2019, 10: 165.
[13] Mouzaki M, Comelli E M, Arendt B M, et al. Intestinal microbiota in patients with nonalcoholic fatty liver disease[J]. Hepatology, 2013, 58(1): 120-127.
[14] 李晓玲, 孙凤霞, 张莹雪, 等. 基于16S rRNA基因测序技术分析非酒精性脂肪性肝病大鼠的肠道菌群[J/OL]. 中国肝脏病杂志(电子版), 2023, 15(4): 39-46.http://dx.chinadoi.cn/10.3969/j.issn.1674-7380.2023.04.008.
[15] Shin N R, Whon T W, Bae J W. Proteobacteria: microbial signature of dysbiosis in gut microbiota[J]. Trends in Biotechnology, 2015, 33(9): 496-503.
[16] An L, Wirth U, Koch D, et al. The role of gut-derived lipopolysaccharides and the intestinal barrier in fatty liver diseases[J]. J Gastrointest Surg, 2022, 26(3): 671-683.
[17] Wu W, Kaicen W, Bian X, et al. Akkermansia muciniphila alleviates high-fat-diet-related metabolic-associated fatty liver disease by modulating gut microbiota and bile acids[J]. Microb Biotechnol, 2023, 16(10): 1924-1939.
[18] Di Vincenzo F, Del Gaudio A, Petito V, et al. Gut microbiota, intestinal permeability, and systemic inflammation: a narrative review[J]. Intern Emerg Med, 2024, 19(2): 275-293.
[19] Caussy C, Tripathi A, Humphrey G, et al. A gut microbiome signature for cirrhosis due to nonalcoholic fatty liver disease[J]. Nat Commun, 2019, 10(1): 1406.