Porphyromonas gingivalis exacerbates alcoholic liver disease by altering gut microbiota composition and host immune response in mice

The gut-liver axis in fatty liver disease: role played by natural products

Fatty liver disease, a condition characterized by fatty degeneration of the liver, mainly classified as non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD), has become a leading cause of cirrhosis, liver cancer and death. The gut-liver axis is the bidirectional relationship between the gut and its microbiota and its liver. The liver can communicate with the gut through the bile ducts, while the portal vein transports the products of the gut flora to the liver. The intestinal flora and its metabolites directly and indirectly regulate hepatic gene expression, leading to an imbalance in the gut-liver axis and thus contributing to the development of liver disease. Utilizing natural products for the prevention and treatment of various metabolic diseases is a prevalent practice, and it is anticipated to represent the forthcoming trend in the development of drugs for combating NAFLD/ALD. This paper discusses the mechanism of the enterohepatic axis in fatty liver, summarizes the important role of plant metabolites in natural products in fatty liver treatment by regulating the enterohepatic axis, and provides a theoretical basis for the subsequent development of new drugs and clinical research.

Porphyromonas gingivalis as a promotor in the development of the alcoholic liver disease via ferroptosis

Alcoholic liver disease (ALD) is a liver disease caused by heavy drinking. Porphyromonas gingivalis (P.g), a major cause of periodontitis, whose antibodies are elevated in severe ALD patients in the plasma. The purpose of this study is to further study the role and the molecular mechanism of P.g in the progress of ALD. In this study, saliva of patients with ALD was collected. Then, an animal model of ALD with oral P.g administration was established, pathology of liver and spleen, intestinal microorganisms and metabolites were analyzed. The molecular mechanism of P.g on ALD was analyzed in vitro. ALD and intestinal microflora and metabolite changes were observed more serious in the alcohol and P.g groups than the alcohol group. Moreover, ferroptosis was aggravated by P.g in the liver. Meanwhile, P.g promoted ferroptosis accomplication with alcohol in vitro, which can be reversed by ferroptosis inhibitors. In conclusion, P.g aggravates ALD through exacerbation gut microbial metabolic disorder in mice with alcohol, which maybe depend on ferroptosis activation in hepatocytes. The study provides a new strategy for prevention and treatment of ALD by improving the oral micro-environment.

Exploration of potential shared gene signatures between periodontitis and multiple sclerosis

BACKGROUND

Although periodontitis has previously been reported to be linked with multiple sclerosis (MS), but the molecular mechanisms and pathological interactions between the two remain unclear. This study aims to explore potential crosstalk genes and pathways between periodontitis and MS.

METHODS

Periodontitis and MS data were obtained from the Gene Expression Omnibus (GEO) database. Shared genes were identified by differential expression analysis and weighted gene co-expression network analysis (WGCNA). Then, enrichment analysis for the shared genes was carried out by multiple methods. The least absolute shrinkage and selection operator (LASSO) regression was used to obtain potential shared diagnostic genes. Furthermore, the expression profile of 28 immune cells in periodontitis and MS was examined using single-sample GSEA (ssGSEA). Finally, real-time quantitative fluorescent PCR (qRT-PCR) and immune histochemical staining were employed to validate Hub gene expressions in periodontitis and MS samples.

RESULTS

FAM46C, SLC7A7, LY96, CFI, DDIT4L, CD14, C5AR1, and IGJ genes were the shared genes between periodontitis, and MS. GO analysis revealed that the shared genes exhibited the greatest enrichment in response to molecules of bacterial origin. LASSO analysis indicated that CFI, DDIT4L, and FAM46C were the most effective shared diagnostic biomarkers for periodontitis and MS, which were further validated by qPCR and immunohistochemical staining. ssGSEA analysis revealed that T and B cells significantly influence the development of MS and periodontitis.

CONCLUSIONS

FAM46C, SLC7A7, LY96, CFI, DDIT4L, CD14, C5AR1, and IGJ were the most important crosstalk genes between periodontitis, and MS. Further studies found that CFI, DDIT4L, and FAM46C were potential biomarkers in periodontitis and MS.

Nicotinamide employs a starvation strategy against Porphyromonas gingivalis virulence by inhibiting the heme uptake system and gingipain activities

Periodontitis is a common oral bacterial infection characterized by inflammatory responses. Its high prevalence lowers the quality of life for individuals and increases the global economic and disease burden. As microorganisms in dental plaque are responsible for this oral disease, antibacterial drug treatments are effective strategies for preventing and treating periodontitis. In this study, we investigated the inhibitory effect of nicotinamide (NAM), a vitamin B3 derivative, on the growth and virulence of Porphyromonas gingivalis, a key member of the red complex. Our findings revealed that NAM inhibited bacterial growth and gingipain activities, which played a dominant role in protein hydrolysis and heme acquisition. NAM decreased hemagglutination and hemolysis abilities and changed hemin and hemoglobin binding capacities, controlling bacterial infection through a starvation strategy by blocking access to growth-essential nutrients from the outside and reducing bacterial virulence. Several experiments in an animal model showed the effectiveness of NAM in preventing alveolar bone loss and reducing inflammatory cell infiltration, shedding light on its potential therapeutic applicability.

Gut microbiota related response of Oryzias melastigma to combined exposure of polystyrene microplastics and tetracycline

The co-existence of microplastics (MPs) and antibiotics in the coastal environment poses a combined ecological risk. Single toxic effects of MPs or antibiotics on aquatic organisms have been verified, however, the exploration of their combined toxic effects remains limited. Here, foodborne polystyrene microplastics (PS-MPs, 10 μm, 0.1 % w/w in food) and waterborne tetracyclines (TC, 50 μg/L) were used to expose an estuarine fish Oryzias melastigma for four weeks. We found that the aqueous availability of TC was not significantly altered coexisting with MPs. The fish body weight gain was significantly slower in TC alone or combined groups than the control group, consistent with the lower lipid content in livers. The body length gain was significantly inhibited by the combined presence compared to the single exposure. Both exposures led to a shift of gut microbiota composition and diversity. TC and the combined group possessed similar gut microbiota which is distinct from PS-MPs and the control group. The Firmicutes/Bacteroidetes (F/B) ratio in the TC and combined groups were significantly lower compared to the control, while the PS-MPs group showed no significant impact. Metabolomic analysis of the fish liver confirmed the shift of metabolites in specific pathways after different exposures. More, a number of gut microbiota-related metabolites on lipid metabolism was perturbed, which were annotated in arachidonic acid metabolism and linoleic acid metabolism. In all, TC modulates bacterial composition in the fish gut and disturbs their liver metabolites via the gut-liver axis, which led to the slower growth of O. melastigma. More, the adverse impact was aggravated by the co-exposure to foodborne PS-MPs.

The role of oral microbiota in cancer

Cancer remains a significant global challenge, with an estimated 47% increase in cancer patients from 2020 to 2040. Increasing research has identified microorganism as a risk factor for cancer development. The oral cavity, second only to the colon, harbors more than 700 bacterial species and serves as a crucial microbial habitat. Although numerous epidemiological studies have reported associations between oral microorganisms and major systemic tumors, the relationship between oral microorganisms and cancers remains largely unclear. Current research primarily focuses on respiratory and digestive system tumors due to their anatomical proximity to the oral cavity. The relevant mechanism research mainly involves 47% dominant oral microbial population that can be cultured in vitro. However, further exploration is necessary to elucidate the mechanisms underlying the association between oral microbiota and tumors. This review systematically summarizes the reported correlations between oral microbiota and common cancers while also outlining potential mechanisms that may guide biological tumor treatment.