Microbial life is everywhere - a largely invisible world of astonishing metabolic diversity that helped to create the biosphere and that continues to support life on earth. In fact, there are more bacterial cells inside your gut and on your skin than there are cells in your entire body. So, we are not only living in a microbial world… we are microbial worlds!”
This Curation Blog aims to be a comprehensive and entertaining source of microbial news.
Recent evidence suggests that the gut microbiota plays an important role in human metabolism and energy homeostasis and is therefore a relevant factor in the assessment of metabolic health and flexibility. Understanding of these host–microbiome interactions aids the design of nutritional strategies that act via modulation of the microbiota. Nevertheless, relating gut microbiota composition to host health states remains challenging because of the sheer complexity of these ecosystems and the large degrees of interindividual variation in human microbiota composition.
We assessed fecal microbiota composition and host response patterns of metabolic and inflammatory markers in 10 apparently healthy men subjected to a high-fat high-caloric diet (HFHC, 1300 kcal/day extra) for 4 weeks. DNA was isolated from stool and barcoded 16S rRNA gene amplicons were sequenced. Metabolic health parameters, including anthropomorphic and blood parameters, where determined at t=0 and t=4 weeks. A correlation network approach revealed diet-induced changes in Bacteroides levels related to changes in carbohydrate oxidation rates, whereas the change in Firmicutes correlates with changes in fat oxidation. These results were confirmed by multivariate models. We identified correlations between microbial diversity indices and several inflammation-related host parameters that suggest a relation between diet-induced changes in gut microbiota diversity and inflammatory processes.This approach allowed us to identify significant correlations between abundances of microbial taxa and diet-induced shifts in several metabolic health parameters. Constructed correlation networks provide an overview of these relations, revealing groups of correlations that are of particular interest for explaining host health aspects through changes in the gut microbiota.
UT Arlington researchers focusing on the Amazon recently found that widespread conversion from rainforest to pastureland has significant effects on microorganism communities that may lead to a reduction in the region's role as a reservoir for...
The role of our intestinal microbiota reaches far beyond fermentation of indigestible food components. Apart from immunological functions, they have a major impact on our metabolic and perhaps even mental health. Dutch research organization TNO is exploring this exciting field, known as host-microbiota interactions, and is developing and integrating a range of advanced models, techniques and trials. The insights generated will support manufacturers in the development of functional foods targeted at, for example, obesity.
The intestinal microbiota is frequently referred to as “an extra organ in the human body”. This is not surprising, given that our intestines contain up to 100 trillion bacteria, about 10 times more than there are cells in the body. The intestinal microbiota exert a wide range of functions: from playing a key role in the fermentation of indigestible food leftovers, to producing components that benefit intestinal epithelial cells and help inhibit attachment of pathogenic bacteria to the intestinal wall.
‘The intestinal microbiota affect not only our immune system, but also our metabolic and mental health’...
Francisella tularensis is a facultative intracellular bacterium in the class Gammaproteobacteria. This strain is of interest because it is the etiologic agent of tularemia and a highly virulent category A biothreat agent. Here we describe the draft genome sequence and annotation of Francisella tularensis subsp. holarctica BD11-00177, isolated from the first case of indigenous tularemia detected in The Netherlands since 1953. Whole genome DNA sequence analysis assigned this isolate to the genomic group B.FTNF002–00, which previously has been exclusively reported from Spain, France, Italy, Switzerland and Germany. Automatic annotation of the 1,813,372 bp draft genome revealed 2,103 protein-coding and 46 RNA genes.
The diversity on our bodies is, like any biological diversity, fascinating and full of awe and we want to share the joy of discovering it, one body part at a time. You give us a sample, we will grow and identify the bacteria, and you get the results. Meet your personal ecosystem, in color! With time we will not only grow the microbes off of your parts, we will sequence them, to know the easy to cultivate species but also all the rest. The life on us knows no celebrity, or rather it knows them as well as it knows the rest of us. Lady Gaga may live the wild life, but she also hosts it.
Rival colonies of the bacteria Paenibacillus dendritiformis can produce a lethal chemical that keeps competitors at bay. When competing colonies get too close poisons are unleashed, creating a toxic no-man's land in between.
It is increasingly apparent that the microbial ecosystems in the mammalian gastrointestinal tract play an intricate role in health and disease. There is a growing interest in the development of targeted strategies for modulating health through the modification of these microbiota.
Ecologists are faced with the challenge of understanding the structure and function of ecosystems, the component parts of which interact with each other in complex and diffuse ways. The human gut microbiota, with its high species richness and diversity (up to 1000 bacterial species per individual) including members of all three domains of life, situated in the dynamic environment of the gastrointestinal tract, is probably among the most complex ecosystems on this planet.
In order to elucidate the mechanistic foundations, and physiological significance, of beneficial or pathogenic relationships between the gut microbiota and their hosts, researchers require tractable model ecosystems that allow to recapitulate and investigate host–microbe and microbe–microbe interactions. This review discusses ex vivo gastrointestinal models systems that can be used to gain mechanistic insights into the emergent properties of the host–microbial superorganism.
Gut Bacteria Conspired in Melamine Poisonings - ScienceNOW
Guus Roeselers's insight:
Remember the 2008 melamine contamination of formula in China? Nearly 300,000 infants got sick, at least six died. Now, a study in rats implicates toxicity arises from gut microbiota converting melamine to cyanuric acid.
"...Women's gut microbe populations change as pregnancy advances, becoming more like those of people who might develop diabetes. These changes, which do not seem to damage maternal health, correspond with increases in blood glucose and fat deposition thought to help a mother nourish her child...."
We live in a microbial world; both from an evolutionary, biochemical, and an ecological perspective. Our bodies are no exception. The mammalian gut harbors microorganisms (the microbiota) of vast phylogentic, genomic, and metabolic diversity, and recent years have seen a rapid development in the techniques for studying these complex microbial ecosystems. It is increasingly apparent that the GIT microbiota plays an intricate role in human health and disease. In the spirit of ideas worth spreading, TEDx is a program of local, self-organized events that bring people together to share a TED-like experience.
Hydrothermal fractures around Martian impact craters may have been a habitable environment for microbial life, according to new research that determined that water temperatures on the Red Planet ranged from 50°C to 150°C sufficiently warm enough to...