Shifts in the Bacterial Community of Supragingival Plaque Associated With Metabolic-Associated Fatty Liver Disease

Abstract

Metabolic-associated fatty liver disease (MAFLD), also known as the hepatic manifestation of metabolic disorders, has become one of the most common chronic liver diseases worldwide. The associations between some oral resident microbes and MAFLD have been described. However, changes to the oral microbial community in patients with MAFLD remain unknown. In this study, variations to the supragingival microbiota of MAFLD patients were identified. The microbial genetic profile of supragingival plaque samples from 24 MAFLD patients and 22 healthy participants were analyzed by 16S rDNA sequencing and bioinformatics analysis. Clinical variables, including indicators of insulin resistance, obesity, blood lipids, and hepatocellular damage, were evaluated with laboratory tests and physical examinations. The results showed that the diversity of the supragingival microbiota in MAFLD patients was significantly higher than that in healthy individuals. Weighted UniFrac principal coordinates analysis and partial least squares discriminant analysis showed that the samples from the MAFLD and control groups formed separate clusters (Adonis, P = 0.0120). There were 27 taxa with differential distributions (linear discriminant analysis, LDA>2.0) between two groups, among which Actinomyces spp. and Prevotella 2 spp. were over-represented in the MAFLD group with highest LDA score, while Neisseria spp. and Bergeyella spp. were more abundant in the control group. Co-occurrence networks of the top 50 abundant genera in the two groups suggested that the inter-genera relationships were also altered in the supragingival plaque of MAFLD patients. In addition, in genus level, as risk factors for the development of MAFLD, insulin resistance was positively correlated with the abundances of Granulicatella, Veillonella, Streptococcus, and Scardovia, while obesity was positively correlated to the abundances of Streptococcus, Oslenella, Scardovia, and Selenomonas. Metagenomic predictions based on Phylogenetic Investigation of Communities by Reconstruction of Unobserved States revealed that pathways related to sugar (mainly free sugar) metabolism were enriched in the supragingival plaque of the MAFLD group. In conclusion, as compared to healthy individuals, component and interactional dysbioses were observed in the supragingival microbiota of the MAFLD group.

Ecological shifts of salivary microbiota associated with metabolic-associated fatty liver disease

“…(Liu et al, 2015) are generally Gram-negative microorganisms comprising mainly non-pathogenic species in the oral cavity. Previously, we also demonstrated a higher abundance of Neisseria in the supragingival plaque among healthy individuals compared to those with MAFLD (Zhao et al, 2020). Capnocytophaga is a genus of Gram-negative anaerobic bacteria reportedly linked with improved oral health and reduced caries experience (Schoilew et al, 2019).…”

“…shtml ). The specific criteria are consistent with the previous study (Zhao et al, 2020). UPARSE (version 7.1, http://drive5.com/uparse/) was used to cluster the sequences into operational taxonomic units (OTUs) with a threshold of 97% similarity.…”

“…MAFLD was diagnosed based on ultrasonographic findings and the exclusion of known etiologic factors of chronic liver disease as well as excessive alcohol consumption. The exclusion criteria were similar to a previous study as follows (Zhao et al, 2020):…”

“…It plays an essential role in physiological, metabolic, and immunological functions, which include nutrient digestion, metabolic regulation, immune response, and antibacterial activity ( Kilian et al., 2016 ). In addition to oral diseases, oral microbiota dysbiosis has also been closely linked with metabolic disorders, including MAFLD ( Zhao et al., 2020 ; Peng et al., 2022 ). An animal study demonstrated that the endotoxemia from Porphyromonas gingivalis was a remarkable risk factor for NAFLD pathogenesis, and the altered glucose/lipid metabolism may facilitate disease progression( Sasaki et al., 2018 ).…”

Bidirectional association between polycystic ovary syndrome and periodontal diseases

“…Numerous observational and interventional studies have linked IR to PDD ( 49 ). IR was positively correlated with the abundances of Granulicatella , Veillonella , Streptococcus , and Scardovia in supragingival plaque by 16s rDNA sequencing in patients with metabolism-associated fatty liver disease ( 50 ). A previous study has demonstrated that IR was associated with the abundance of 22 individual taxa in human subgingival plaque ( 51 ).…”