Project description:Pancreatic cancer is the 3rd most prevalent cause of cancer related deaths in United states alone, with over 55000 patients being diagnosed in 2019 alone and nearly as many succumbing to it. Late detection, lack of effective therapy and poor understanding of pancreatic cancer systemically contributes to its poor survival statistics. Obesity and high caloric intake linked co-morbidities like type 2 diabetes (T2D) have been attributed as being risk factors for a number of cancers including pancreatic cancer. Studies on gut microbiome has shown that lifestyle factors as well as diet has a huge effect on the microbial flora of the gut. Further, modulation of gut microbiome has been seen to contribute to effects of intensive insulin therapy in mice on high fat diet. In another study, abnormal gut microbiota was reported to contribute to development of diabetes in Db/Db mice. Recent studies indicate that microbiome and microbial dysbiosis plays a role in not only the onset of disease but also in its outcome. In colorectal cancer, Fusobacterium has been reported to promote therapy resistance. Certain intra-tumoral bacteria have also been shown to elicit chemo-resistance by metabolizing anti-cancerous agents. In pancreatic cancer, studies on altered gut microbiome have been relatively recent. Microbial dysbiosis has been observed to be associated with pancreatic tumor progression. Modulation of microbiome has been shown to affect response to anti-PD1 therapy in this disease as well. However, most of the studies in pancreatic cancer and microbiome have remained focused om immune modulation. In the current study, we observed that in a T2D mouse model, the microbiome changed significantly as the hyperglycemia developed in these animals. Our results further showed that, tumors implanted in the T2D mice responded poorly to Gemcitabine/Paclitaxel (Gem/Pac) standard of care compared to those in the control group. A metabolomic reconstruction of the WGS of the gut microbiota further revealed that an enrichment of bacterial population involved in drug metabolism in the T2D group.
Project description:Persistent mucosal inflammation and microbial infection are characteristic of Chronic Rhinosinusitis (CRS). Though mucosal microbiota dysbiosis is a characteristic feature of other chronic inflammatory diseases, the relationship between sinus microbiota composition and CRS is unknown. Here we demonstrate, using comparative microbiome profiling of a cohort of CRS patients and healthy subjects, that the sinus microbiota of CRS patients exhibit significantly reduced bacterial diversity. Characteristic of this community collapse is the depletion of multiple, phylogenetically distinct, Lactic Acid Bacteria and the concomitant increase in relative abundance of a single species, Corynebacterium tuberculostearicum. Recapitulating the conditions observed in our human cohort in a murine model confirmed the pathogenic potential of C. tuberculostearicum and the critical necessity for a replete mucosal microbiota to protect against this species. Moreover, we provide evidence that Lactobacillus sakei, identified from our comparative microbiome analyses as a potentially protective species, affords defense against C. tuberculostearicum sinus infection, even in the context of a depleted sinus bacterial community. These studies demonstrate that sinus mucosal health is highly dependent on the composition of the resident microbiota, and identifies a new sino-pathogen and a strong bacterial candidate for therapeutic intervention. A total of 14 samples were profiled for microbiome composition: 7 from non-sinusitis patients, and 7 from patients with clinically diagnosed chronic sinusitis.
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 mammalian gut harbors a diverse microbial community (gut microbiota) that mainly consists of bacteria. Their combined genomes (the microbiome) provide biochemical and metabolic functions that complement host physiology. Maintaining symbiosis seems to be a key requirement for health as dysbiosis is associated with the development of common diseases. Previous studies indicated that the microbiota and the hostM-bM-^@M-^Ys epithelium signal bidirectional inducing transcriptional responses to fine-tune and maintain symbiosis. However, little is known about the hostM-bM-^@M-^Ys responses to the microbiota along the length of the gut as earlier studies of gut microbial ecology mostly used either colonic or fecal samples. This is of importance as not only function and architecture of the gut varies along its length but also microbial distribution and diversity. Few recent studies have begun to investigate microbiota-induced host responses along the length of the gut. However, these reports used whole tissue samples and therefore do not allow drawing conclusions about specificity of the observed responses. Which cells in the intestinal tissue are responsible for the microbially induced response: epithelial, mesenchymal or immune cells? Where are the responding cells located? We used using extensive microarray analysis of laser capture microdissection (LCM) harvested ileal and colonic tip and crypt fractions from germ-free and conventionally-raised mice to investigate the microbiota-induced transcriptional responses in specific and well-defined cell populations of the hostM-bM-^@M-^Ys epithelium. Ileum and colon segments were dissected from germ-free and conventionally-raised 10-12 weeks old female C57Bl/6 mice, washed and frozen as OCT blocks. Cryosections were prepared from these OCT blocks and tip/crypt fractions isolated using laser capture microdissection. To investigate the microbiota-induced transcriptional responses specific for specific subpopulations of intestinal epithelial cells, tip and crypt fractions of ileal and colonic epithelium of germ-free and conventionally-raised 10-12 weeks old female C57Bl/6 mice were harvested using laser capture microdissection and probed in an extensive microarray analysis.
Project description:This study demonstrates the usefulness of the API by generating a baseline gut microbiota profile of a healthy population and estimating reference intervals for the functional abundance of manually selected KEGG pathways. API facilitates microbiome research by providing dynamic and customizable tools for estimating reference intervals for gut microbiota functional abundances. Through the API, researchers can rapidly generate gut microbiota functional profiles of healthy populations to use as a baseline for comparison. The API also allows users to manually select specific KEGG pathways and estimate reference intervals for the functional abundance of those pathways. By generating these customized reference intervals, researchers can better understand the expected range of gut microbiota functions in healthy individuals. API enables microbiome studies to go beyond simple taxonomic profiling and delve deeper into the functional potential of gut microbiome communities. In summary, API represents a valuable tool for microbiome researchers that enhances the ability to elucidate connections between gut microbial functions and human health.
Project description:The mammalian gut harbors a diverse microbial community (gut microbiota) that mainly consists of bacteria. Their combined genomes (the microbiome) provide biochemical and metabolic functions that complement host physiology. Maintaining symbiosis seems to be a key requirement for health as dysbiosis is associated with the development of common diseases. Previous studies indicated that the microbiota and the hostM-bM-^@M-^Ys epithelium signal bidirectional inducing transcriptional responses to fine-tune and maintain symbiosis. However, little is known about the hostM-bM-^@M-^Ys responses to the microbiota along the length of the gut as earlier studies of gut microbial ecology mostly used either colonic or fecal samples. This is of importance as not only function and architecture of the gut varies along its length but also microbial distribution and diversity. Few recent studies have begun to investigate microbiota-induced host responses along the length of the gut. However, these reports used whole tissue samples and therefore do not allow drawing conclusions about specificity of the observed responses. Which cells in the intestinal tissue are responsible for the microbially induced response: epithelial, mesenchymal or immune cells? Where are the responding cells located? Furthermore, the gut microbiota has been implicated in epigenetic regulation of the hostM-bM-^@M-^Ys transcriptional profile. We used using extensive microarray analysis of laser capture microdissection (LCM) harvested ileal and colonic tip and crypt fractions from germ-free mice before and during the time course of colonization with a normal microbiota (on days 1, 3, 5 and 7) to investigate the microbiota-induced transcriptional responses and their kinetics in specific and well-defined cell populations of the hostM-bM-^@M-^Ys epithelium. Ileum and colon segments were dissected from germ-free 10-12 weeks old female C57Bl/6 mice and on day 1, 3, 5 and 7 after colonization, washed and frozen as OCT blocks. Cryosections were prepared from these OCT blocks and tip/crypt fractions isolated using laser capture microdissection. To investigate the microbiota-induced transcriptional responses specific for specific subpopulations of intestinal epithelial cells and their kinetics, tip and crypt fractions of ileal and colonic epithelium of germ-free 10-12 weeks old female C57Bl/6 mice before and during the time course of colonization with a normal microbiota (on days 1, 3, 5 and 7) were harvested using laser capture microdissection and probed in an extensive microarray analysis.
Project description:Mammalian species have co-evolved with intestinal microbial communities that can shape development and adapt to environmental changes, including antibiotic perturbation or nutrient flux. In humans, especially children, microbiota disruption is common, yet the dynamic microbiome recovery from early-life antibiotics is still uncharacterized. Using a mouse model mimicking pediatric antibiotic use, we found that therapeutic-dose pulsed antibiotic treatment (PAT) with a beta-lactam or macrolide altered both host and microbiota development. Early-life PAT accelerated total mass and bone growth, and resulted in progressive changes in gut microbiome diversity, population structure, and metagenomic content, with microbiome effects dependent on the number of courses and class of antibiotic. While control microbiota rapidly adapted to a change in diet, PAT slowed the ecological progression, with delays lasting several months in response to the macrolide. This study identifies key markers of disturbance and recovery, which may help provide therapeutic targets for microbiota restoration following antibiotic treatment. C57BL/6J mice received three antibiotic courses: at days 10-15, 28-31, and 37-40 of life, amoxicillin or tylosin.Livers were collected at age 22 weeks, RNA was extracted, and transcriptional differences were measured by microarray analysis.
Project description:The human colon contains an extensively diverse microbial ecosystem and one of the most numerous communities of immune cells. Studies have highlighted dynamic crosstalk between immune cells and commensals. While studies have demonstrated increasing diversity of microbiota from stomach to stool, whether and how immune cell heterogeneity and microbiota diversity change across the colon is undefined. Furthermore, whether these changes are co-depended in the healthy colon is unknown. Here, tissue samples are collected from caecum, transverse colon, sigmoid colon and mLN of cadaveric donors by the Cambridge Biorepository of Translational Medicine (CBTM). We use single cell RNA sequencing (10X genomics) to assess the dynamics of immune cell populations across the colon and in matching lymph nodes. Associated microbiome 16S sequencing data is available.
Project description:The human colon contains an extensively diverse microbial ecosystem and one of the most numerous communities of immune cells. Studies have highlighted dynamic crosstalk between immune cells and commensals. While studies have demonstrated increasing diversity of microbiota from stomach to stool, whether and how immune cell heterogeneity and microbiota diversity change across the colon is undefined. Furthermore, whether these changes are co-depended in the healthy colon is unknown. Here, tissue samples are collected from caecum, transverse colon, sigmoid colon and mLN of cadaveric donors by the Cambridge Biorepository of Translational Medicine (CBTM). We use single cell RNA sequencing (10X genomics) to assess the dynamics of immune cell populations across the colon and in matching lymph nodes. Associated microbiome 16S sequencing data is available.