Project description:During the COVID-19 pandemic, facemasks have played a pivotal role in preventing person-person droplet transmission of viral particles. However, prolonged facemask wearing causes skin irritations colloquially referred to as ‘maskne’ (mask + acne), which manifests as acne and contact dermatitis and is mostly caused by pathogenic skin microbes. Previous studies revealed that the putative causal microbes were anaerobic bacteria, but the pathogenesis of facemask-associated skin conditions remains poorly defined. We therefore characterized the role of the facemask-associated skin microbiota in the development of maskne using culture-dependent and -independent methodologies. Metagenomic analysis revealed that the majority of the facemask microbiota were anaerobic bacteria that originated from the skin rather than saliva. Previous work demonstrated direct interaction between pathogenic bacteria and antagonistic strains in the microbiome. We expanded this analysis to include indirect interaction between pathogenic bacteria and other indigenous bacteria classified as either ‘pathogen helper (PH)’ or ‘pathogen inhibitor (PIn)’ strains. In vitro screening of bacteria isolated from facemasks identified both strains that antagonized and promoted pathogen growth. These data were validated using a mouse skin infection model, where we observed attenuation of symptoms following pathogen infection. Moreover, the inhibitor of pathogen helper (IPH) strain, which did not directly attenuate pathogen growth in vitro and in vivo, functioned to suppress symptom development and pathogen growth indirectly through PH inhibitory antibacterial products such as phenyl lactic acid. Taken together, our study defines a mechanism by which indirect microbiota interactions under facemasks control symptoms of maskne by suppressing a skin pathogen for the first time.
Project description:A healthy rumen is crucial for normal growth and improved production performance of ruminant animals. Rumen microbes participate in and regulate rumen epithelial function, and the diverse metabolites produced by rumen microbes are important participants in rumen microbe-host interactions. SCFAs, as metabolites of rumen microbes, have been widely studied, and propionate and butyrate have been proven to promote rumen epithelial cell proliferation. Succinate, as an intermediate metabolite in the citric acid cycle, is a final product in the metabolism of certain rumen microbes, and is also an intermediate product in the microbial synthesis pathway of propionate. However, its effect on rumen microbes and rumen epithelial function has not been studied. It is unclear whether succinate can stimulate rumen epithelial development. Therefore, in this experiment, Chinese Tan sheep were used as experimental animals to conduct a comprehensive analysis of the rumen microbiota community structure and rumen epithelial transcriptome, to explore the role of adding succinate to the diet in the interaction between the rumen microbiota and host.
Project description:Coronary artery disease (CAD) is a widespread heart condition caused by atherosclerosis and influences millions of people worldwide. Early detection of CAD is challenging due to the lack of specific biomarkers. The gut microbiota and host-microbiota interactions have been well documented to affect human health. However, investigation that reveals the role of gut microbes in CAD is still limited. This study aims to uncover the synergistic effects of host genes and gut microbes associated with CAD through integrative genomic analyses.
Project description:Coronary artery disease (CAD) is a widespread heart condition caused by atherosclerosis and influences millions of people worldwide. Early detection of CAD is challenging due to the lack of specific biomarkers. The gut microbiota and host-microbiota interactions have been well documented to affect human health. However, investigation that reveals the role of gut microbes in CAD is still limited. This study aims to uncover the synergistic effects of host genes and gut microbes associated with CAD through integrative genomic analyses.
Project description:Morphine causes microbial dysbiosis. In this study we focused on restoration of native microbiota in morphine treated mice and looked at the extent of restoration and immunological consequences of this restoration. Fecal transplant has been successfully used clinically, especially for treating C. difficile infection2528. With our expanding knowledge of the central role of microbiome in maintenance of host immune homeostasis17, fecal transplant is gaining importance as a therapy for indications resulting from microbial dysbiosis. There is a major difference between fecal transplant being used for the treatment of C. difficile infection and the conditions described in our studies. The former strategy is based on the argument that microbial dysbiosis caused by disproportionate overgrowth of a pathobiont can be out-competed by re-introducing the missing flora by way of a normal microbiome transplant. This strategy is independent of host factors and systemic effects on the microbial composition. Here, we show that microbial dysbiosis caused due to morphine can be reversed by transplantation of microbiota from the placebo-treated animals.
Project description:The intestinal microbiota plays a crucial role in protecting the host from pathogenic microbes, in modulating immunity and in regulating metabolic processes. We use the simplified human intestinal microbiota (SIHUMIx) consisting of eight bacterial species to study potential synergistic effects with a particular focus on detecting novel proteins with less than 100 amino acids (= sProteins), some of which may contribute to regulate the simplified human intestinal microbiota. Although several studies have shown that sProteins carry out a wide range of important functions, they are still often missed in genome annotations, and little is known about their structure and function in individual microbes and especially in microbial communities. In this study, we created a multi-species integrated proteogenomics search database (multi-species iPtgxDB) to enable a comprehensive identification of novel sProteins. Six of the eight SIHUMIx species, for which no complete genomes were available, were first sequenced and de novo assembled. Several proteomics approaches including two earlier optimized sProtein enrichment strategies were applied prior to mass spectrometric analysis to specifically increase the chances for novel sProtein discovery. Searching the MS/MS data against the multi-species iPtgxDB enabled us to identify 31 novel sProteins, of which the expression of 30 was supported by metatranscriptomics data. Using synthetic peptides, we were able to validate the expression of 25 novel sProteins. Importantly, when comparing the expression of these novel sProteins in single strain cultivations to the multi-species community grown in a bioreactor, we found that six of them were only identified in the SIHUMIx community, indicating a possible important role of sProteins in the organization of microbial communities. Furthermore, in silico prediction suggested that two of these novel sProteins have a potential antimicrobial function. We outline an integrated experimental and bioinformatics workflow for the discovery of novel sProteins in microbial communities that can be generically applied to other microbial communities. The further analysis of novel sProteins uniquely expressed in the multi-species community is expected to enable new insights into the structure, regulation and function of bacterial communities such as those of the human intestinal tract.
Project description:The role of gut microbiota in modulating host tRNA modifications and expression has not yet been studied. In this experiment, we applied DM-tRNA-seq and normal tRNA-seq to obtain and infer the cytosolic and mitochondrial tRNA modifications and expression of four tissues (brain, intestine, kidney, and liver) in the specific pathogen-free (SPF) and germ-free (GF) mice, respectively. In conclusion, we confirmed that the modifications and expression of both cytosolic and mitochondrial tRNAs were influenced by not only tissue-specific but also microbiota-dependent manners. The present study facilitates comprehensive insights and better understanding into the interactions between the gut microbiota and the tRNA modifications and expression among host tissues
Project description:The human intestinal microbiota may play a role in the development of overweight and obesity. However, associations between saliva microbiota and body mass index (BMI) have been sparsely studied, although the oral cavity is the major gateway for microbes into the body. The aim of this study was to identify associations between the saliva microbiota and BMI categories in Finnish children aged 9-14 years.
Project description:Within the human gut reside diverse microbes coexisting with the host in a mutually advantageous relationship. We comprehensively identified the modulatory effects of phylogenetically diverse human gut microbes on the murine intestinal transcriptome. Gene-expression profiles were generated from the whole-tissue intestinal RNA of mice colonized with various single microbial strains. The selection of microbe-specific effects, from the transcriptional response, yielded only a small number of transcripts, indicating that symbiotic microbes have only limited effects on the gut transcriptome overall. Moreover, none of these microbe-specific transcripts was uniformly induced by all microbes. Interestingly, these responsive transcripts were induced by some microbes but repressed by others, suggesting different microbes can have diametrically opposed consequences.
Project description:Anal cancer is a leading neoplasia in people with immune impartments populations, and the lack of an accurate screening test challenges its prevention. Because the bacteria living in the anal epithelium the anal microbiota seems to influence and be influenced by cancer development, specific patterns of anal microbes could help in the diagnosis of precancerous anal lesions. We aimed to discover microbial biomarkers of anal precancer in high-risk populations. We discovered 12 proteins, previously reported to be associated with cancer progression, that were more abundant in the anal bacterial from subjects with precancerous lesions.