Posts tagged microbiome
The International Space Station (ISS) is a closed system inhabited by microorganisms originating from life support systems, cargo, and crew that are exposed to unique selective pressures such as microgravity. To date, mandatory microbial monitoring and observational studies of spacecraft and space stations have been conducted by traditional culture methods, although it is known that many microbes cannot be cultured with standard techniques. To fully appreciate the true number and diversity of microbes that survive in the ISS, molecular and culture-based methods were used to assess microbial communities on ISS surfaces. Samples were taken at eight pre-defined locations during three flight missions spanning 14 months and analyzed upon return to Earth. The results reveal a diverse population of bacteria and fungi on ISS environmental surfaces that changed over time but remained similar between locations. The dominant organisms are associated with the human microbiome and may include opportunistic pathogens. This study provides the first comprehensive catalog of both total and intact/viable bacteria and fungi found on surfaces in closed space systems and can be used to help develop safety measures that meet NASA requirements for deep space human habitation. The results of this study can have significant impact on our understanding of other confined built environments on the Earth such as clean rooms used in the pharmaceutical and medical industries. https://doi.org/10.1186/s40168-019-0666-x
The first population-level study on the link between gut bacteria and mental health identifies specific gut bacteria linked to depression and provides evidence that a wide range of gut bacteria can produce neuroactive compounds. Jeroen Raes (VIB-KU Leuven) and his team published these results today in the scientific journal Nature Microbiology. In their manuscript entitled ‘The neuroactive potential of the human gut microbiota in quality of life and depression’ Jeroen Raes and his team studied the relation between gut bacteria and quality of life and depression. The authors combined faecal microbiome data with general practitioner diagnoses of depression from 1,054 individuals enrolled in the Flemish Gut Flora Project. They identified specific groups of microorganisms that positively or negatively correlated with mental health. The authors found that two bacterial genera, Coprococcus and Dialister, were consistently depleted in individuals with depression, regardless of antidepressant treatment. The results were validated in an independent cohort of 1,063 individuals from the Dutch LifeLinesDEEP cohort and in a cohort of clinically depressed patients at the University Hospitals Leuven, Belgium.
In the last few years, the microbiome (sometimes referred to as “the second genome”) has become a focus for the health conscious and for scientists alike. Studies like the Human Microbiome Project, a national enterprise to sequence bacterial DNA taken from 242 healthy Americans, have tagged 19 of our phyla (groupings of bacteria), each with thousands of distinct species. As Michael Pollan wrote in this magazine last year: “As a civilization, we’ve just spent the better part of a century doing our unwitting best to wreck the human-associated microbiota… . Whether any cures emerge from the exploration of the second genome, the implications of what has already been learned — for our sense of self, for our definition of health and for our attitude toward bacteria in general — are difficult to overstate.”
A healthy adult human harbours some 100 trillion bacteria in his gut alone. That is ten times as many bacterial cells as he has cells descended from the sperm and egg of his parents. These bugs, moreover, are diverse. Egg and sperm provide about 23,000 different genes. The microbiome, as the body’s commensal bacteria are collectively known, is reckoned to have around 3m. Admittedly, many of those millions are variations on common themes, but equally many are not, and even the number of those that are adds something to the body’s genetic mix.