Patients with
nonalcoholic fatty liver disease (
NAFLD) have symptoms of a gut microbiota disorder with abnormal
amino acid and
glycolipid metabolism. This study was designed to analyze the characteristics of gut microbiota in patients with
NAFLD, predict the gut microbiota phenotype, explore its role in the diagnosis of
NAFLD, and establish its significance in
disease progression.The characteristics of the gut microbiota in
NAFLD patients (n = 28, 45.8 ± 14.2 years, male/female = 18/10) and healthy subjects (n = 20, 49.6 ± 4.8 years, male/female = 14/6) during March-May 2020 were analyzed using
16S rRNA sequencing technology and the phenotypes with large differences were predicted using the Tax4Fun method. The metabolites in the fecal samples of the patients were analyzed using mass spectrometry, and their correlation with different microorganisms was examined. The accuracy of the gut microbiota in diagnosing
NAFLD was investigated by receiver operating characteristic curve analysis.We found that the microbial diversity and Bacteroides/Firmicutes (BF) ratio changed significantly (P < .05) in the feces of
NAFLD patients. Phenotypic prediction showed that there were significant differences in the phenotypes of
amino acid,
glucose, and lipid metabolism of gut microbiota in the
NAFLD group (P < .05). receiver operating characteristic curve analysis revealed that combination of Bacteroides and the BF ratio resulted in 88% and 100% sensitivity and specificity, respectively, when used for
NAFLD diagnosis. Metabolomics and bioinformatics analysis revealed changes in the metabolism of
nicotinate,
nicotinamide, and
pyrimidine; signaling pathways of
calcium and
oxytocin; pancreatic secretion with metabolites such as
uracil,
xanthine, and
biliverdin; and
enzymes such as
xanthine dehydrogenase and
xanthine oxidase (P < .05).Therefore, the phenotypic changes may be a potential marker for
NAFLD and we considered that a combined analysis of Bacteroides and BF ratio had good diagnostic accuracy for
NAFLD.