Aim: The microbiome has been shown to be pivotal in the development of metabolic associated fatty liver disease (MAFLD). Few have examined the relationship of the microbiome specifically with steatosis grade. Therefore, our aim was to characterize the association of the microbiome with MAFLD steatosis severity while adjusting for metabolic comorbidities including diabetes.
Methods: We enrolled patients with MAFLD at the West Los Angeles Veterans Affair Hospital. All patients underwent ultrasound elastography, fasting serum collection, and fecal sampling for 16S sequencing. We examined the associations of microbial diversity and composition with advanced steatosis, defined as a CAP score of ≥ 300 dB/m, with or without the presence of metabolic comorbidities.
Results: Seventy-five patients were enrolled. African American were less likely to have advanced steatosis than either Hispanics or Whites (P = 0.001). Patients with more advanced steatosis had higher fasting serum triglyceride (192.6 ± 157.1 mg/dL vs. 122.5 ± 57.4 mg/dL), HbA1c (6.7% ± 1.4% vs. 6.1% ± 0.8%), transaminases, and were more likely to have metabolic syndrome (52.4% vs. 24.2%, P = 0.02). Advanced steatosis and diabetes were associated with altered microbial composition. Bacteroides was negatively associated with advanced steatosis while Megasphaera was positively associated with steatosis. Akkermansia was negatively associated with diabetes, while Anaerostipes and Parabacteroides were positively associated with diabetes.
Conclusion: Diabetes and metabolic syndrome are associated with hepatic steatosis severity in MAFLD patients and both advanced steatosis and comorbid diabetes are independently associated with microbiome changes. These results provide insight into the role of the gut microbiome in MAFLD associated with metabolic syndrome.
Keywords: Metabolic syndrome; advanced steatosis; diabetes; microbiome; nonalcoholic fatty liver disease; obesity; ultrasound elastography.