【Abstract】Objective To explore the relationship between gut microbiota distribution and the nutritional status and quality of life in elderly patients undergoing maintenance hemodialysis (MHD). Methods From February 2021 to February 2023,156 chronic renal failure patients who received regular MHD in the Affiliated Dazu′s Hospital of Chongqing Medical University were selected as the study subjects. Fresh fecal samples were collected, and the patients were divided into a normal group (n=53) and a dysbiosis group (n=103) according to the results of gut microbiota smear examination. The real-time fluorescence quantitative polymerase chain reaction (PCR) of the bacterial 16S rDNA gen was performed, and the two groups were compared in the quantitative results of fecal Bifidobacterum, Lactobacillus, Escherichia coli, and Enterococcus. The nutritional status indicators, including body mass index (BMI), hemoglobin (Hb), albumin (Alb), and scores on mini-nutritional assessment (MNA), were collected for both groups. The quality of life was evaluated using kidney disease quality of life short form (KDQOL-SF)1.3. Pearson correlation analysis was conducted to analyze the correlation between quantitative findings of gut microbiota and the nutritional status and quality of life in MHD patients. ResultsAmong 156 MHD patients, 53 (33.97%) were of normal gut microbiota, 67 (42.95%) of Degree Ⅰ gut microbiota dysbiosis, 31 (19.87%) of Degree Ⅱ gut microbiota dysbiosis, and 5 (3.21%) of Degree Ⅲ gut microbiota dysbiosis. The Bifidobacterium count [(6.73±1.09) vs (9.45±1.26) lg CFU/g] and Lactobacillus count [(7.14±0.86) vs (9.92±1.03) lg CFU/g] in the dysbiosis group were lower, while the Escherichia coli count [(8.75±1.12) vs (8.06±0.94) lg CFU/g] and Enterococcus count [(9.68±1.05) vs (9.13±1.27) lg CFU/g] were higher than those in the normal group, with all differences being statistically significant (P<0.05 for all). The BMI [(20.34±3.51) vs (21.68±3.27) kg/m2], Alb [(28.53±4.29) vs (31.47±4.05) g/L], MNA score [(21.36±4.27) vs (25.14±3.98) points] and 36-item short-form (SF-36) score [(52.64±9.13) vs (58.71±9.48) points] in the dysbiosis group were lower than those in the normal group, with all differences being statistically significant (P<0.05 for all). Pearson product-moment coefficient analysis showed that BMI, Alb, MNA score and SF-36 score were positively correlated with intestinal Bifidobacterium count (r=0.417,0.309,0.461,0.382; P<0.05) and Lactobacillus count (r=0.463,0.357,0.507,0.417; P<0.001), and were negatively correlated with intestinal Escherichia coli count (r=-0.389, -0.426, -0.435, -0.354; P<0.001) and Enterococcus count (r=-0.326, -0.512,-0.548, -0.496; P<0.001). Conclusion The nutritional status and quality of life in elderly MHD patients are poor, and both are closely related to the gut microbiota count.