Proteomic and Metabolomic Analyses Reveal Contrasting Anti-Inflammatory Effects of an Extract of Mucor Racemosus Secondary Metabolites Compared to Dexamethasone

Fungal mycobiome dysbiosis in choledocholithiasis concurrent with cholangitis

BACKGROUND

The gut mycobiome might have an important influence on the pathogenesis of choledocholithiasis concurrent with cholangitis (CC). The aim of this study was to characterize the fungal mycobiome profiles, explore the correlation and equilibrium of gut interkingdom network among bacteria-fungi-metabolites triangle in CCs.

METHODS

In a retrospective case-control study, we recruited patients with CC (n = 25) and healthy controls (HCs) (n = 25) respectively to analyze the gut fungal dysbiosis. Metagenomic sequencing was employed to characterize the gut mycobiome profiles, and liquid chromatography/mass spectrometry (LC/MS) analysis was used to quantify the metabolites composition.

RESULTS

The Shannon index displayed a reduction in fungal α-diversity in CCs compared to HCs (p = 0.041), and the overall fungal composition differed significantly between two groups. The dominant 7 fungi species with the remarkable altered abundance were identified (LDA score > 3.0, p < 0.05), including CC-enriched Aspergillus_niger and CC-depleted fungi Saccharomyces_boulardii. In addition, the correlations between CC-related fungi and clinical variables in CCs were analyzed. Moreover, the increased abundance ratio of Basidiomycota-to-Ascomycota and a dense linkage of bacteria-fungi interkingdom network in CCs were demonstrated. Finally, we identified 30 markedly altered metabolites in CCs (VIP > 1.0 and p < 0.05), including low level of acetate and butyrate, and the deeper understanding on the complexity of bacteria-fungi-metabolites triangle involving bile inflammation was verified.

CONCLUSION

Our investigation demonstrated a distinct gut fungal dysbiosis in CCs and proposed that, beyond bacteria, the more attention should be paid to significantly potential influence of fungi and bacteria-fungi-metabolites triangle interkingdom interactions on pathogenesis of CC.

Genetic Prediction of the Phosphate-to-Glucose Ratio Mediates the Association Between CXCL5 and Vascular Dementia

BACKGROUND AND OBJECTIVES

A variety of observational studies suggest a possible connection between C-X-C Motif Chemokine Ligand 5 (CXCL5) and vascular dementia (VaD), though the exact causal relationship is still uncertain. This research aims to investigate the causal connection between CXCL5 and VaD risk through a Mendelian randomization (MR) method and to examine the phosphate-to-glucose ratio as a possible mediator.

METHODS

Using summary-level data from genome-wide association studies (GWAS), we conducted a two-sample MR analysis to investigate the genetic prediction of CXCL5 and VaD. Horizontal pleiotropy, heterogeneity, and sensitivity analyses were also performed on the MR findings. Additionally, a two-step MR was utilized to quantify the proportion of the effect of CXCL5 on VaD mediated by the phosphate-to-glucose ratio.

RESULTS

MR analysis identified that higher levels of CXCL5 (IVW: p = 0.022, OR = 1.265, 95% CI = 1.034-1.547) increase the risk of VaD. Tests for horizontal pleiotropy (p > 0.05), heterogeneity (p > 0.05), and sensitivity analyses supported these findings. There is insufficient robust evidence to suggest that genetic predispositions for VaD have any significant impact on CXCL5 (IVW: p = 0.254). The phosphate-to-glucose ratio accounted for 11.1% of increase in the risk of VaD associated with CXCL5 (95% CI = -12.3% to 34.5%).

CONCLUSION

To conclude, our research confirms a causal link between CXCL5 and VaD and shows that the ratio of phosphate-to-glucose plays a mediating role in a segment of the risk effect of CXCL5 on VaD. However, most of the effects of CXCL5 on VaD are still not well understood. Additional studies are necessary to explore other potential mediators as risk factors. In clinical settings, individuals with abnormally elevated CXCL5 may need to be monitored for an increased risk of developing VaD.

The gut mycobiome composition is linked to carotid atherosclerosis

The mycobiotic component of the microbiota comprises an integral, yet under-researched, part of the gastrointestinal tract. Here, we present a preliminary study of the possible contribution of gut mycobiota to sub-clinical atherosclerosis in a well-characterised group of obese and non-obese subjects in association with the Framingham Risk Score (FRS) and carotid intima-media thickness (cIMT). From all taxa identified, the relative abundance of the phylum Zygomycota, comprising the family Mucoraceae and genus Mucor, was negatively associated with cIMT and this association remained significant after controlling for false discovery rate. Obese subjects with detectable Mucor spp. had a similar cardiovascular risk profile as non-obese subjects. Interestingly, the relative abundance of Mucor racemosus was negatively associated both with FRS and cIMT. Partial least square discriminant analyses modelling, evaluating the potential relevance of gut mycobiota in patients stratified by mean values of cIMT, showed that even a 1 component model had a high accuracy (0.789), with a high R2 value (0.51). Variable importance in projection scores showed that M. racemosus abundance had the same impact in the model as waist-to-hip ratio, high-density lipoprotein-cholesterol, fasting triglycerides or fasting glucose, suggesting that M. racemosus relative abundance in the gut may be a relevant biomarker for cardiovascular risk.

Anti-inflammatory properties of extracts from Chimonanthus nitens Oliv. leaf

Chimonanthus nitens Oliv. (CN) is a species in the family Calycanthaceae. Its leaf is widely used to make traditional herbal tea in southern China and has a wide range of therapeutic effects. The profile of the ethanol extracts from CN leaves was identified by UPLC-QTOF-MS/MS. Forty seven compounds were determined including organic acids, phenolic acids and derivatives, flavonoids, coumarins, fatty acids and other compounds. The effect of the CN extracts on the inflammatory damage in zebrafish and in RAW 264.7 cells was investigated. The extracts demonstrated a strong ability to inhibit the recruitment of neutrophils in LPS-stimulated zebrafish, but macrophage migration was not significantly affected. Pro-inflammatory cytokines (i.e., TNF-α, IL-6 and IL-1β) were also determined by q-PCR. The extracts strongly reduced mRNA expression of TNF-α, IL-6 but not IL-1β in zebrafish model, while significantly inhibited the production of the factors in the RAW 264.7 cells. Therefore, our results suggest that the ethanol extracts of CN leaves may serve as a source of nutraceutical compounds with anti-inflammatory properties.

Characterization and control of Mucor circinelloides spoilage in yogurt

Consumer confidence in the food industry is severely affected by large-scale spoilage incidents. However, relatively little research exists on spoilage potential of members of the fungal subphylum Mucormycotina (e.g. Mucor), which includes dimorphic spoilage organisms that can switch between a yeast-like and hyphal phase depending on environmental conditions. The presence of Mucor circinelloides in yogurt may not cause spoilage, but growth and subsequent changes in quality (e.g. container bloating) can cause spoilage if not controlled. The purpose of this study was to evaluate the effects on M. circinelloides of pasteurization regimen, natamycin concentrations, and storage temperature in yogurt production, as measured by fungal proliferation and carbon dioxide production. A strain of M. circinelloides isolated from commercially spoiled yogurt showed greater yogurt-spoilage potential than clinical isolates and other industrial strains. D-values and z-values were determined for the spoilage isolate in milk as an evaluation of the fungus' ability to survive pasteurization. Natamycin was added to yogurt at 0, 5, 10, 15, and 20ppm (μg/ml) to determine its ability to inhibit M. circinelloides over the course of month-long challenge studies at 4°C, 15°C, and 25°C. Survivors were recovered on acidified PDA and carbon dioxide levels were recorded. The D-values at 54°C, 56°C, and 58°C for hyphae/sporangiospores were (in min) 38.31±0.02, 10.17±0.28, and 1.94±0.53, respectively, which yielded a z-value of 3.09°C. The D-values at 51°C, 53°C, and 55°C for yeast-like cells were (in min) 14.25±0.12, 6.87±1.19, and 2.44±0.35, respectively, which yielded a z-value of 0.34°C. These results indicated that M. circinelloides would not survive fluid milk pasteurization if contamination occurred prior to thermal treatment. CO2 production was only observed when M. circinelloides was incubated under low-oxygen conditions, and occurred only at temperatures above 4°C. Addition of 10ppm and greater of natamycin inhibited the growth and CO2 production of M. circinelloides under moderate temperature abuse when compared to the untreated control. These data suggest that yogurt spoilage (container bloating) caused by anaerobic growth of M. circinelloides is due to post-pasteurization contamination. Temperature abuse facilitated spoilage as CO2 production was observed in yogurt incubated at 15°C and 25°C, but not at 4°C. The addition of at least 10ppm of natamycin prevented M. circinelloides growth in both hyphal and yeast-like phases, as well as CO2 production in temperatures of up to 15°C for 30days.