Project description:Opioids such as morphine have many beneficial properties as analgesics, however, opioids may induce multiple adverse gastrointestinal symptoms. We have recently demonstrated that morphine treatment results in significant disruption in gut barrier function leading to increased translocation of gut commensal bacteria. However, it is unclear how opioids modulate the gut homeostasis. By using a mouse model of morphine treatment, we studied effects of morphine treatment on gut microbiome. We characterized phylogenetic profiles of gut microbes, and found a significant shift in the gut microbiome and increase of pathogenic bacteria following morphine treatment when compared to placebo. In the present study, wild type mice (C57BL/6J) were implanted with placebo, morphine pellets subcutaneously. Fecal matter were taken for bacterial 16s rDNA sequencing analysis at day 3 post treatment. A scatter plot based on an unweighted UniFrac distance matrics obtained from the sequences at OTU level with 97% similarity showed a distinct clustering of the community composition between the morphine and placebo treated groups. By using the chao1 index to evaluate alpha diversity (that is diversity within a group) and using unweighted UniFrac distance to evaluate beta diversity (that is diversity between groups, comparing microbial community based on compositional structures), we found that morphine treatment results in a significant decrease in alpha diversity and shift in fecal microbiome at day 3 post treatment compared to placebo treatment. Taxonomical analysis showed that morphine treatment results in a significant increase of potential pathogenic bacteria. Our study shed light on effects of morphine on the gut microbiome, and its role in the gut homeostasis.
Project description:Metagenomic and metaproteomic analyses were utilized to determine the composition and function of complex air-water interface biofilms sampled from the hulls of two ships that were deployed in different geographic locations.
Project description:The community composition (in terms of abundance, distribution and contribution of diverse clades) of bacteria involved in nitrogen transformations in the oxygen minimum zones may be related to the rates of fixed N loss in these systems. The abundance of both denirifying and anammox bacteria, and the assemblage composition of denitrifying bacteria were investigated in the Eastern Tropical South Pacific and the Arabian Sea using assays based on molecular markers for the two groups of bacteria. The abundance and distribution of bacteria associated with the fixed N removal processes denitrification and anammox were investigated using quantitative PCR for genes encoding nitrite reductase (nirK and nirS) in denitrifying bacteria and hydrazine oxidase(hzo) and 16S rRNA genesin anammox bacteria. All of these genes had depth distributions with maxima associated with the secondary nitrite maximum in low oxygen waters. NirS was mch more abundant than nirK, and much more abundant than the 16S rRNA gene from anammox bacteria. The ratio of hzo:16S rRNA for anammox was low and variable implying greater unexplored diversity in the the hzo gene. Assemblage composition of the abundant nirS-type denitrifiers was evaluated using a funcitonal gene microarray. Of the nirS archetypes represented on the microarray, very few occurred speficically in one region or depth interval, but the assemblages varied significantly. Community composition of denitrifiers based on microarray analysis of the nirS gene was most different between geographical regions. Within each region, the surface layer and OMZ assemblages clustered distinctly. Thus, in addition to spatial and temporal variation in denitrificaiton and anammox rates, both microbial abundance and community composition also vary between OMZ regions and depths.
Project description:The community composition (in terms of abundance, distribution and contribution of diverse clades) of bacteria involved in nitrogen transformations in the oxygen minimum zones may be related to the rates of fixed N loss in these systems. The abundance of both denirifying and anammox bacteria, and the assemblage composition of denitrifying bacteria were investigated in the Eastern Tropical South Pacific and the Arabian Sea using assays based on molecular markers for the two groups of bacteria. The abundance and distribution of bacteria associated with the fixed N removal processes denitrification and anammox were investigated using quantitative PCR for genes encoding nitrite reductase (nirK and nirS) in denitrifying bacteria and hydrazine oxidase(hzo) and 16S rRNA genesin anammox bacteria. All of these genes had depth distributions with maxima associated with the secondary nitrite maximum in low oxygen waters. NirS was mch more abundant than nirK, and much more abundant than the 16S rRNA gene from anammox bacteria. The ratio of hzo:16S rRNA for anammox was low and variable implying greater unexplored diversity in the the hzo gene. Assemblage composition of the abundant nirS-type denitrifiers was evaluated using a funcitonal gene microarray. Of the nirS archetypes represented on the microarray, very few occurred speficically in one region or depth interval, but the assemblages varied significantly. Community composition of denitrifiers based on microarray analysis of the nirS gene was most different between geographical regions. Within each region, the surface layer and OMZ assemblages clustered distinctly. Thus, in addition to spatial and temporal variation in denitrificaiton and anammox rates, both microbial abundance and community composition also vary between OMZ regions and depths. Two color array (Cy3 and Cy5): the universal standard 20-mer oligo is printed to the slide with a 70-mer oligo (an archetype). Environmental DNA sequences (fluoresced with Cy3) within 15% of the 70-mer conjugated to a 20-mer oligo (fluoresced with Cy5) complementary to the universal standard will bind to the oligo probes on the array. Signal is the ratio of Cy3 to Cy5. Three replicate probes were printed for each archetype. Two replicate arrays were run on duplicate targets.
Project description:An important goal for many nutrition-based microbiome studies is to identify the metabolic function of microbes in complex microbial communities and its impact on host physiology. This research can be confounded by poorly-understood effects of community composition and host diet on the metabolic traits of individual taxa. Here, we investigated these multi-way interactions by constructing and analyzing metabolic models comprising every combination of five bacterial members of the Drosophila gut microbiome (from single taxa to the five-member community of Acetobacter and Lactobacillus species) under three nutrient regimes. We show that the metabolic function of Drosophila gut bacteria is dynamic, influenced by community composition and responsive to dietary modulation. Furthermore, we show that ecological interactions such as competition and mutualism identified from the growth patterns of gut bacteria are underlain by a diversity of metabolic interactions, and show that the bacteria tend to compete for amino acids and B vitamins more frequently than for carbon sources. Our results reveal that in addition to fermentation products such as acetate, intermediates of the tricarboxylic acid (TCA) cycle including 2-oxoglutarate and succinate are produced at high flux and cross-fed between bacterial taxa suggesting important roles for TCA cycle intermediates in modulating Drosophila gut microbe interactions and the potential to influence host traits. These metabolic models provide specific predictions of the patterns of ecological and metabolic interactions among gut bacteria under different nutrient regimes, with potentially important consequences for overall community metabolic function and nutritional interactions with the host.
Project description:An important goal for many nutrition-based microbiome studies is to identify the metabolic function of microbes in complex microbial communities and its impact on host physiology. This research can be confounded by poorly-understood effects of community composition and host diet on the metabolic traits of individual taxa. Here, we investigated these multi-way interactions by constructing and analyzing metabolic models comprising every combination of five bacterial members of the Drosophila gut microbiome (from single taxa to the five-member community of Acetobacter and Lactobacillus species) under three nutrient regimes. We show that the metabolic function of Drosophila gut bacteria is dynamic, influenced by community composition and responsive to dietary modulation. Furthermore, we show that ecological interactions such as competition and mutualism identified from the growth patterns of gut bacteria are underlain by a diversity of metabolic interactions, and show that the bacteria tend to compete for amino acids and B vitamins more frequently than for carbon sources. Our results reveal that in addition to fermentation products such as acetate, intermediates of the tricarboxylic acid (TCA) cycle including 2-oxoglutarate and succinate are produced at high flux and cross-fed between bacterial taxa suggesting important roles for TCA cycle intermediates in modulating Drosophila gut microbe interactions and the potential to influence host traits. These metabolic models provide specific predictions of the patterns of ecological and metabolic interactions among gut bacteria under different nutrient regimes, with potentially important consequences for overall community metabolic function and nutritional interactions with the host.
Project description:An important goal for many nutrition-based microbiome studies is to identify the metabolic function of microbes in complex microbial communities and its impact on host physiology. This research can be confounded by poorly-understood effects of community composition and host diet on the metabolic traits of individual taxa. Here, we investigated these multi-way interactions by constructing and analyzing metabolic models comprising every combination of five bacterial members of the Drosophila gut microbiome (from single taxa to the five-member community of Acetobacter and Lactobacillus species) under three nutrient regimes. We show that the metabolic function of Drosophila gut bacteria is dynamic, influenced by community composition and responsive to dietary modulation. Furthermore, we show that ecological interactions such as competition and mutualism identified from the growth patterns of gut bacteria are underlain by a diversity of metabolic interactions, and show that the bacteria tend to compete for amino acids and B vitamins more frequently than for carbon sources. Our results reveal that in addition to fermentation products such as acetate, intermediates of the tricarboxylic acid (TCA) cycle including 2-oxoglutarate and succinate are produced at high flux and cross-fed between bacterial taxa suggesting important roles for TCA cycle intermediates in modulating Drosophila gut microbe interactions and the potential to influence host traits. These metabolic models provide specific predictions of the patterns of ecological and metabolic interactions among gut bacteria under different nutrient regimes, with potentially important consequences for overall community metabolic function and nutritional interactions with the host.
Project description:An important goal for many nutrition-based microbiome studies is to identify the metabolic function of microbes in complex microbial communities and its impact on host physiology. This research can be confounded by poorly-understood effects of community composition and host diet on the metabolic traits of individual taxa. Here, we investigated these multi-way interactions by constructing and analyzing metabolic models comprising every combination of five bacterial members of the Drosophila gut microbiome (from single taxa to the five-member community of Acetobacter and Lactobacillus species) under three nutrient regimes. We show that the metabolic function of Drosophila gut bacteria is dynamic, influenced by community composition and responsive to dietary modulation. Furthermore, we show that ecological interactions such as competition and mutualism identified from the growth patterns of gut bacteria are underlain by a diversity of metabolic interactions, and show that the bacteria tend to compete for amino acids and B vitamins more frequently than for carbon sources. Our results reveal that in addition to fermentation products such as acetate, intermediates of the tricarboxylic acid (TCA) cycle including 2-oxoglutarate and succinate are produced at high flux and cross-fed between bacterial taxa suggesting important roles for TCA cycle intermediates in modulating Drosophila gut microbe interactions and the potential to influence host traits. These metabolic models provide specific predictions of the patterns of ecological and metabolic interactions among gut bacteria under different nutrient regimes, with potentially important consequences for overall community metabolic function and nutritional interactions with the host.