Project description:The gut microbiome is intricately coupled with immune regulation and metabolism, but its role in Coronavirus Disease 2019 (COVID-19) is not fully understood. Severe and fatal COVID-19 is characterized by poor anti-viral immunity and hypercoagulation, particularly in males. Here we define multiple pathways by which the gut microbiome protects mammalian hosts from SARS-CoV-2 intranasal infection, both locally and systemically, via production of short-chain fatty acids (SCFAs). SCFAs reduced viral burdens in the airways and intestines by downregulating the SARS-CoV-2 entry receptor, angiotensin-converting enzyme 2 (ACE2), and enhancing adaptive immunity in male animals. In order to identify other mechanisms by which SCFAs influence the outcome of SARS-CoV-2 infection, we performed RNA-seq on lungs from male GF mice given control or SCFA water for two weeks. We identified a novel role for the gut microbiome in regulating systemic coagulation response by limiting megakaryocyte proliferation and platelet turnover via the Sh2b3-Mpl axis. Taken together, our findings have unraveled novel functions of SCFAs and fiber-fermenting gut bacteria that might be leveraged as pan-coronavirus therapeutics to dampen viral entry and hypercoagulation and promote adaptive anti-viral immunity.
Project description:Analysis of breast cancer survivors' gut microbiota after lifestyle intervention, during the COVID-19 lockdown, by 16S sequencing of fecal samples.
Project description:The gut microbiome is intricately coupled with immune regulation and metabolism, but its role in Coronavirus Disease 2019 (COVID-19) is not fully understood. Severe and fatal COVID-19 is characterized by poor anti-viral immunity and hypercoagulation, particularly in males. Via 16S sequencing of antibiotic-treated mice, we found that Clostridia species protect mammalian hosts from SARS-CoV-2 intranasal infection, both locally and systemically, via production of short-chain fatty acids (SCFAs). SCFAs reduced viral burdens in the airways and intestines by downregulating the SARS-CoV-2 entry receptor, angiotensin-converting enzyme 2 (ACE2), and enhancing adaptive immunity in male animals. In order to identify other mechanisms by which SCFAs influence the outcome of SARS-CoV-2 infection, we performed RNA-seq on lungs from male GF mice given control or SCFA water for two weeks. We identified a novel role for the gut microbiome in regulating systemic coagulation response by limiting megakaryocyte proliferation and platelet turnover via the Sh2b3-Mpl axis. Taken together, our findings have unraveled novel functions of SCFAs and fiber-fermenting gut bacteria that might be leveraged as pan-coronavirus therapeutics to dampen viral entry and hypercoagulation and promote adaptive anti-viral immunity.
Project description:Hematopoietic stem cell (HSC) aging is accompanied by hematopoietic reconstitution dysfunction, including loss of regenerative and engraftment ability, myeloid differentiation bias and elevated risks of hematopoietic malignancies. Gut microbiota, a key regulator of host health and immunity, has been recently reported to impact hematopoiesis. However, there is currently no empirical evidence elucidating the direct impact of gut microbiome on aging hematopoiesis. To assess these potential effects, we performed fecal microbiota transplantation (FMT) from young mice to aged mice and observed an increment in both the absolute number and the engraftment ability of HSCs. Single cell RNA sequencing depicted overall transcriptional changes of HSCs as well as the bone marrow microenvironment and indicated that gut microbiota from young mice enhanced cell cycle activity of HSCs, attenuated canonical inflammatory signals and mitigated inflammation-associated phenotypes in aging hematopoiesis. Integrated microbiome-metabolome analysis uncovered that FMT reshaped gut microbiota construction and metabolite landscape, while the administration of Lachnospiraceae and tryptophan-associated metabolites promoted the recovery of hematopoiesis and rejuvenated aged HSCs. Together, our results highlighted the paramount importance of the gut microbiota in HSC aging and provided a strong rationale to limit hematopoietic exhaustion and treat hematologic disorders.
Project description:The relationship between retinal disease, diet, and the gut microbiome has shown increasing importance over recent years. In particular, high-fat diets (HFDs) are associated with development and progression of several retinal diseases, including age-related macular degeneration (AMD) and diabetic retinopathy. However, the complex, overlapping interactions between diet, gut microbiome, and retinal homeostasis are poorly understood. Using high-throughput RNA-sequencing (RNA-seq) of whole retinas, we compare the retinal transcriptome from germ-free (GF) mice on a regular diet (ND) and HFD to investigate transcriptomic changes without influence of gut microbiome. After correction of raw data, 53 differentially expressed genes (DEGs) were identified, of which 19 were upregulated and 34 were downregulated in GF-HFD mice. Key genes involved in retinal inflammation, angiogenesis, and RPE function were identified. Enrichment analysis revealed that the top 3 biological processes affected were regulation of blood vessel diameter, inflammatory response, and negative regulation of endopeptidase. Molecular functions altered include endopeptidase inhibitor activity, protease binding, and cysteine-type endopeptidase inhibitor activity. Human and mouse pathway analysis revealed that the complement and coagulation cascades are significantly affected by HFD. This study demonstrates novel data that diet can directly modulate the retinal transcriptome independently of the gut microbiome.
Project description:We report the first case series of ICI associated colitis successfully treated with fecal microbiota transplantation (FMT), with reconstitution of the gut microbiome and a relative increase in the proportion of regulatory T cells (Tregs) within the colonic mucosa. These preliminary data provide evidence that modulation of the gut microbiome may abrogate ICI-associated colitis.
Project description:We discovered an enrichment of linoleic acid, ether lipid, glycerolipid, and glycerophospholipid metabolism among the SARS-CoV-2 infected group, suggesting a link to SARS-CoV-2 entry and replication in host cells.The identified differences provide a new insight to enrich our understanding of SARS-CoV-2-related changes in gut microbiota, their metabolic capabilities, and potential screening biomarkers linked to COVID-19 disease severity.
Project description:Application of a mass spectrometry -based approach to assess the gut microbiota composition and the associated metaproteomic functionality in patients with intestinal COVID-19 infection