• Permissive microbiome characterizes human subjects with a neurovascular disease cavernous angioma | Nature Communications
    https://www.nature.com/articles/s41467-020-16436-w

    Cavernous angiomas (CA) are common vascular anomalies causing brain hemorrhage. Based on mouse studies, roles of gram-negative bacteria and altered intestinal homeostasis have been implicated in CA pathogenesis, and pilot study had suggested potential microbiome differences between non-CA and CA individuals based on 16S rRNA gene sequencing. We here assess microbiome differences in a larger cohort of human subjects with and without CA, and among subjects with different clinical features, and conduct more definitive microbial analyses using metagenomic shotgun sequencing. Relative abundance of distinct bacterial species in CA patients is shown, consistent with postulated permissive microbiome driving CA lesion genesis via lipopolysaccharide signaling, in humans as in mice. Other microbiome differences are related to CA clinical behavior. Weighted combinations of microbiome signatures and plasma inflammatory biomarkers enhance associations with disease severity and hemorrhage. This is the first demonstration of a sensitive and specific diagnostic microbiome in a human neurovascular disease.

    AXE #INTESTIN-#CERVEAU : Désordre intestinal et hémorragie cérébrale ? | santé log
    https://www.santelog.com/actualites/axe-intestin-cerveau-desordre-intestinal-et-hemorragie-cerebrale

    C’est une « drôle » d’association, découverte par cette équipe de l’Université de Chicago : les patients atteints d’une maladie cérébrale hémorragique [angiome caverneux, héréditaire ou non] présentent aussi des #microbiomes intestinaux très désordonnés.

    [..,]

    En substance, l’analyse identifie [dans les selles de] ces patients une communauté bactérienne « très perturbée » : « Les patients atteints d’angiome [caverneux] cérébral présentent tous le même microbiome distinctif, qu’ils aient hérité de la mutation ou qu’ils aient développé une lésion sporadique. Ce déséquilibre bactérien produit des molécules de lipopolysaccharides (LPS), qui voyagent via le sang vers le cerveau et se fixent à la paroi des vaisseaux sanguins du cerveau, entraînant le développement de lésions »

    Le #microbiome est une cause de lésions plutôt qu’un effet, concluent les chercheurs.

    • Donc l’intolérance au lactose n’est pas seulement une mode destinée à montrer sa singularité ?

      Intéressant... Je n’avais aucune idée que ça pourrait varier si vite.

      "This combination of physical traits has been previously noted in other European hunter-gatherers, suggesting that this phenotype was widespread in Mesolithic Europe and that the adaptive spread of light skin pigmentation in European populations only occurred later in prehistory,” wrote Schroeder and his colleagues.

    • This single discarded piece of ancient chewing gum tells us that the ancient woman, who Schroeder and his colleagues have nicknamed Lola, was probably lactose intolerant, ate duck and hazelnuts, and may recently have had pneumonia. She also had blue eyes, dark brown hair, and dark skin

      #chewing_gum

      Article original :

      A 5700 year-old human genome and oral microbiome from chewed birch pitch
      Theis Z. T. Jensen, Jonas Niemann, Katrine Højholt Iversen, Anna K. Fotakis, Shyam Gopalakrishnan, Åshild J. Vågene, Mikkel Winther Pedersen, Mikkel-Holger S. Sinding, Martin R. Ellegaard, Morten E. Allentoft, Liam T. Lanigan, Alberto J. Taurozzi, Sofie Holtsmark Nielsen, Michael W. Dee, Martin N. Mortensen, Mads C. Christensen, Søren A. Sørensen, Matthew J. Collins, M. Thomas P. Gilbert, Martin Sikora, Simon Rasmussen & Hannes Schroeder
      Nature Communications 10:5520 (2019)
      https://www.nature.com/articles/s41467-019-13549-9

      A rajouter à la compilation #archéologie :
      https://seenthis.net/messages/633249

      #histoire #préhistoire #anthropologie #civilisation #évolution #nourriture #genome #microbiome

  • New Alzheimer’s Therapy Approved in China, Delivering a Surprise but Raising Questions - Scientific American
    https://www.statnews.com/2019/11/04/a-new-alzheimers-therapy-is-approved-in-china-delivering-a-surprise-for-th

    Chinese regulators have granted conditional approval to an Alzheimer’s drug that is derived from seaweed, potentially shaking up the field after years of clinical failures involving experimental therapies from major drug companies.

    The announcement over the weekend has been met with caution as well as an eagerness from clinicians and others to see full data from the drug maker, Shanghai Green Valley Pharmaceuticals. The company said its drug, #Oligomannate, improved cognitive function in patients with mild to moderate Alzheimer’s compared to placebo in a Phase 3 trial, with benefits seen in patients as early as week four and persisting throughout the 36 weeks of the trial.

    [...]

    Instead of being designed to sweep away protein buildups in the brain, as has been the case with dozens of other experimental Alzheimer’s treatments, Oligomannate was developed to modulate the connection between the brain and the bacterial communities in the gut known as the #microbiome.

    The connection between the microbiome and overall health is the subject of a relatively new and evolving field of research, with some scientists seeking to understand how bacteria can influence the emergence of disease, including Alzheimer’s.

    #maladie_d'Alzheimer #santé #Chine

  • New surveillance tech means you’ll never be anonymous again

    Forget facial recognition. Researchers around the world are creating new ways to monitor you. Lasers detecting your heartbeat and microbiome are already being developed

    The fight over the future of facial recognition is heating up. But it is just the beginning, as even more intrusive methods of surveillance are being developed in research labs around the world.

    In the US, San Francisco, Somerville and Oakland recently banned the use of facial recognition by law enforcement and government agencies, while Portland is talking about forbidding the use of facial recognition entirely, including by private businesses. A coalition of 30 civil society organisations, representing over 15 million members combined, is calling for a federal ban on the use of facial recognition by US law enforcement.

    Meanwhile in the UK, revelations that London’s Metropolitan Police secretly provided facial recognition data to the developers of the Kings Cross Estate for a covert facial recognition system have sparked outrage and calls for an inquiry. The Information Commissioner’s Office has launched an investigation into the legality of the program. But the scandal comes at the same time as a landmark ruling by the High Court in Cardiff that said the use of facial recognition by South Wales police is legal. (The decision is likely to be appealed).

    Facial recognition is only the tip of the creepy surveillance iceberg, however. If strict regulation is brought in to govern the use of facial recognition, it is possible we may simply see a switch to one, or several, of the other forms of surveillance technologies currently being developed. Many are equally if not more invasive than facial recognition – and potentially even harder to regulate. Here’s a look at some of what might be coming down the pipeline.

    How you walk

    The rapidly growing field of behavioural biometrics is based on recognising individuals from their patterns of movement or behaviour. One example is gait recognition, which may well be the next surveillance technology to hit the mainstream, especially if facial recognition comes under tight regulation. The technique is already being trialled by police in China, which frequently leads the field when it comes to finding new ways to monitor its people, whether they like it or not.

    There are a few different ways of recognising an individual from the way they walk. The method being trialled by Chinese police is based on technology from a company called Watrix, and relies on the use of video surveillance footage to analyse a person’s movements as they walk. In a recently granted patent, Watrix outlines a method of using a deep convolutional neural network to train an AI system capable of analysing thousands of data points about a person as they move, from the length of their stride to the angle of their arms, and use that to recognise individuals based on their ’gait record’. Watrix claims that its systems achieve up to 94 per cent accuracy, and that it holds the world’s largest database of gait records.

    The vision-based methods of gait recognition being developed by Watrix and others can be used to identify people at a distance, including in crowds or on the street, in a similar way that facial recognition can – which could make it a quick and easy substitute if regulation is brought in against facial recognition. Increasingly, many video surveillance systems are collecting multi-modal biometrics. That means they may be using facial recognition and gait recognition simultaneously, which at least in theory should both increase the accuracy and tackle issues like identifying people facing away from the cameras.

    Another method for identifying people by their walk relies on sensors embedded in the floor. Researchers from the University of Manchester used data from 20,000 footsteps belonging to 127 individuals to train a deep residual neural network to recognise 24 distinct factors, like the person’s stride cadence and the ratio of time on toe to time on heel (the people did not need to take off their shoes, as the system analyses movement rather than shape of the foot). Using this system, they were able to identify individuals with over 99 per cent accuracy in three ’real world’ scenarios: the workplace, the home environment, and airport security checkpoints.

    According to the researchers, the benefits of this kind of identification over vision-based systems are that it is less invasive, and less prone to disruption from objects or other people obscuring the camera’s view. Of course, another way of saying that it is less invasive is that it is harder for people to detect when it’s being used on them. People might notice when they’re being watched by cameras, but they’re much less likely to be aware of sensors in the floor.

    Heartbeat detection

    Your heartbeat and your breathing pattern are as unique as your fingerprint. A small but growing number of remote sensing technologies are being developed to detect vital signs from a distance, piercing through skin, clothes and in some cases even through walls.

    In June, the Pentagon went public with a new laser-based system capable of identifying people at a distance of up to 200m. The technology, dubbed Jetson, uses a technique known as laser doppler vibrometry to detect surface movement caused by your heartbeat.

    The eventual goal is to be able to identify a target within five seconds based on their cardiac signal, or ’heartprint.’ At the moment, however, the Pentagon’s system has a number of limitations: the target needs to be standing still, needs to be wearing light clothing (thick clothing, like a heavy coat, can interfere with the signal), and most importantly there needs to be a clear line of sight between the laser and the target.

    Coats, walls, even rocks and rubble are no obstacle for another nascent surveillance technology, however. Researchers are hard at work developing radar-based systems capable of tracking vital signs for a range of purposes, from non-invasive monitoring of patients and aiding in medical diagnoses to finding survivors in search and rescue operations.
    Monitoring indoor movements

    But why bother installing new radars when we’re already bathed in a different sort of radiation pretty much all the time? Wi-Fi can also be used to locate individuals, identify their position in the room and whether they’re sitting or standing, and even track vital signs.

    Until recently, it was thought a dedicated Wi-Fi network was required, in part because the technique depends on knowing the exact position of the Wi-Fi transmitters. In 2018, however, a group of researchers at the University of California built an app which allowed them to figure out the exact location of existing Wi-Fi transmitters in a building. With that information, they were able to use normal smartphones and existing ambient Wi-Fi networks to detect human presence and movement from outside the room. “With more than two Wi-Fi devices in a regular room, our attack can detect more than 99 per cent of user presence and movement in each room tested,” the researchers claim.

    Some research groups want to go further than just using Wi-Fi to identify people. Based on movement and vital signs, they claim it is possible to monitor the subject’s emotional state and analyse their behavioural patterns. These researchers have formed a company to market a ’touchless sensor and machine learning platform for health analytics’, which they claim has been deployed in over 200 homes and is being used by doctors and drug companies.

    Beyond the potential benefits for healthcare and emergency responders, however, the technology also has obvious applications for surveillance. Technology which is capable of building up a profile of a person’s heartbeat and breathing in order to watch for abnormalities in a health context is readily adaptable to being used to identify one person from another. Radar-based security surveillance systems capable of detecting people are already on the market, It’s only a matter of time, and perhaps not even very much time, before the ability to identify individual people is layered on top.
    Tracking your microbial cells

    Every person emits around 36 million microbial cells per hour, and human microbiomes are unique for a certain period of time (a 2015 study found that around 80 per cent of people could be re-identified using their microbiome up to a year later). This means that the constant trail of microbial traces we leave behind us, as well as those we pick up from our surroundings, can be used to help reconstruct a picture of a person’s activities and movements, like where they walked, what objects they touched and what environments they have been in.
    Monitoring your scent

    Identifying people by smell is actually one of the oldest police tricks in the book, but doing it with computers instead of bloodhounds is still in its infancy in comparison with facial and fingerprint recognition. The field of odor biometrics may be useful for individual authentication but is not well suited to mass surveillance – separating exactly who smells like that in a crowd can be tricky, as anyone who has been stuck in public transport on a hot day probably knows.
    Bum detection

    Then there are the identification techniques designed for very specific use cases. One pioneering suggestion from a team of Japanese researchers for an anti-theft system for cars was based on using 360 sensors to measure the unique shape of the driver’s rear end. Despite achieving a 98 per cent accuracy rate in trials, tragically this important security innovation does not seem to have gone any further than lab testing.
    The regulation problem

    Trying to regulate surveillance technologies one by one is likely to be futile. The surveillance industry is simply developing too fast, and it is too easy to switch from one kind of surveillance to another. The difference between a facial recognition system and one based on behavioural biometrics may simply be a matter of swapping the software on an existing camera network, for example.

    Increasing cooperation between government agencies and the private sector also means that regulations like San Francisco’s, which limits only government use of certain types of surveillance, are insufficient according to Katina Michael, a professor in the School for the Future of Innovation in Society and School of Computing, Informatics and Decision Systems Engineering at Arizona State University.

    Amazon is perhaps the prime example for this blurring of the lines between private and government surveillance. Amazon has previously come under criticism for selling facial and emotion-recognition systems to police. More recently, it has been revealed that Amazon is partnering with hundreds of law enforcement agencies in the US, including giving them access to surveillance data gathered through its Ring home doorbell in return for police actively marketing the devices to the community.

    “Fundamentally, we need to think about democracy-by-design principles,” Michael says. “We just can’t keep throwing technologies at problems without a clear roadmap ahead of their need and application. We need to assess the impact of these new technologies. There needs to be bidirectional communication with the public.”

    Surveillance changes the relationship between people and the spaces they live in. Sometimes, that change is for the better; there are real benefits from increased security, and the insights which can be gained into how people use public places can be used to help shape those places in the future. At the same time, however, we need to ask ourselves whether the future society we want to live in is one which constantly watches its citizens – or, more likely, one in which citizens are never totally sure when, how and by whom they’re being watched.

    https://www.wired.co.uk/article/surveillance-technology-biometrics
    #surveillance #laser #microbiome #battements_cardiaques #coeur #comportement #mouvement #marche #respiration #corps #vibrométrie #doppler_vibrometry

    ping @etraces

    • Another method for identifying people by their walk relies on sensors embedded in the floor. Researchers from the University of Manchester used data from 20,000 footsteps belonging to 127 individuals to train a deep residual neural network to recognise 24 distinct factors, like the person’s stride cadence and the ratio of time on toe to time on heel (the people did not need to take off their shoes, as the system analyses movement rather than shape of the foot). Using this system, they were able to identify individuals with over 99 per cent accuracy in three ’real world’ scenarios: the workplace, the home environment, and airport security checkpoints.

      According to the researchers, the benefits of this kind of identification over vision-based systems are that it is less invasive, and less prone to disruption from objects or other people obscuring the camera’s view. Of course, another way of saying that it is less invasive is that it is harder for people to detect when it’s being used on them. People might notice when they’re being watched by cameras, but they’re much less likely to be aware of sensors in the floor.

  • Le #microbiote intestinal bientôt sauvegardé dans une grande #bibliothèque
    https://www.courrierinternational.com/article/interview-le-microbiote-intestinal-bientot-sauvegarde-dans-un

    Les bactéries présentes dans notre intestin sont essentielles pour notre santé, mais du fait de l’urbanisation et de l’utilisation d’antibiotiques, le microbiote humain, autrefois d’une grande diversité, tend à s’appauvrir. Eric Alm veut y remédier. Biologiste au Massachusetts Institute of Technology [MIT, près de Boston], il a mis sur pied le Global Microbiome Conservancy [Société de conservation du #microbiome planétaire], organisme à but non lucratif. Son but : prélever des échantillons de selles auprès de peuples indigènes et isolés en vue de constituer une collection de leurs hôtes intestinaux, avant qu’ils ne disparaissent.

  • #Exercise Alters Our #Microbiome. Is That One Reason It’s So Good for Us? - The New York Times
    https://www.nytimes.com/2018/01/03/well/move/exercise-microbiome-health-weight-gut-bacteria.html

    Most of these changes were not shared from one person to the next. Everyone’s gut responded uniquely to exercise.

    But there were some similarities, the researchers found. In particular, they noted widespread increases in certain microbes that can help to produce substances called short-chain fatty acids. These fatty acids are believed to aid in reducing inflammation in the gut and the rest of the body. They also work to fight insulin resistance, a precursor to diabetes, and otherwise bolster our metabolisms.

    Most of the volunteers had larger concentrations of these short-chain fatty acids in their intestines after exercise, along with the #microbes that produce them.

    These increases were greatest, though, among the volunteers who had begun the experiment lean compared to those who were obese, the scientists found.

    And perhaps not surprisingly, almost all of the changes in people’s guts dissipated after six weeks of not exercising. By and large, their microbiomes reverted to what they had been at the study’s start.

    #microbiote

  • Fiber Is Good for You. Now Scientists May Know Why. - The New York Times
    https://www.nytimes.com/2018/01/01/science/food-fiber-microbiome-inflammation.html

    ... our bodies make a limited range of enzymes, so that we cannot break down many of the tough compounds in plants. The term “dietary fiber” refers to those indigestible molecules.

    But they are indigestible only to us. The gut is coated with a layer of mucus, atop which sits a carpet of hundreds of species of bacteria, part of the human #microbiome. Some of these microbes carry the enzymes needed to break down various kinds of dietary fiber.

    The ability of these bacteria to survive on fiber we can’t digest ourselves has led many experts to wonder if the #microbes are somehow involved in the benefits of the fruits-and-vegetables diet. Two detailed studies published recently in the journal Cell Host and Microbe provide compelling evidence that the answer is yes.

    #fibres #microbiote #aliments #nutrition

  • New images of complex microbiome environments visualized by Berkeley Metagenomics Lab and Stamen…
    https://hi.stamen.com/uc-berkeley-metagenomics-lab-releases-new-images-of-complex-microbiome-en

    What is metagenomics?

    A metagenome is a collection of DNA sequences from the organisms present in an environment at the time a sample is taken. Metagenomics is the study of these genomic sequences. Metagenomics has been around in various forms since the early 2000s. Initially, the approach was referred to as “community genomics” because the sequencing approaches were used to study natural microbial communities. It wasn’t until the mid 2000s that it acquired its “meta” label. In the first studies, both genome reconstruction-based approaches and analyses of collections of genes without organism affiliation were used. Both of these methods are distinct from investigations of specific marker genes that had been used previously to phylogenetically “fingerprint” environments.

    The primary difference is that genome sequences provide some insight into what all the organisms might be doing. Fingerprinting methods mostly tell us how closely organisms are related to each other.

    #recherche #microbiome #image #écosystème #adn

  • How Burgers and Fries Are Killing Your Microbial Balance
    http://nautil.us/issue/30/identity/how-the-western-diet-has-derailed-our-evolution

    So a remarkable and somewhat quixotic effort has begun to catalog and possibly preserve, before they disappear, the #microbes of people who live in environments thought to resemble humanity’s past—people whose #microbiomes may approximate an ancestral state. Researchers are motoring down rivers in the Amazon, off-roading in the East African savanna, hiking into the mountain villages of Papua New Guinea. They see themselves as rushing to catalog an ecosystem that may soon disappear.

    “It’s really our last chance to harvest a lot of these microbes from around the world,” Rob Knight, a microbiologist at the University of California, San Diego, told me. “We have to do it before it’s too late—and it’s very nearly too late.”

    He and others suspect these populations won’t retain their traditional ways much longer. Antibiotics, thought to deplete microbes, are already used frequently in some communities. And as modernization and acculturation progresses—as these peoples move toward the sanitized, indoor-dwelling, junk food-eating reality that characterizes much life in developed nations today—some human microbes, or perhaps certain configurations of those microbes, may be lost forever.

    For now, scientists are careful to characterize the quest as purely descriptive; they want to know how these human microbiomes affect our bodies. Yet a kind of microbial ark—a storage vault for potentially endangered human microbes—is perhaps implied. Martin Blaser, a microbiologist at New York University and Dominguez-Bello’s husband, argues that because Westernized peoples may have lost important microbes, we may have to repopulate ourselves with microbes derived from more traditional-living populations—from, say, Amazonian Amerindians or African hunter-gatherers.

    #microbiote #alimentation

  • Can the Bacteria in Your Gut Explain Your Mood? - The New York Times
    http://www.nytimes.com/2015/06/28/magazine/can-the-bacteria-in-your-gut-explain-your-mood.html?_r=0

    Biologists now believe that much of what makes us human depends on microbial activity. The two million unique bacterial genes found in each human #microbiome can make the 23,000 genes in our cells seem paltry, almost negligible, by comparison. ‘‘It has enormous implications for the sense of self,’’ Tom Insel, the director of the National Institute of Mental Health, told me. ‘‘We are, at least from the standpoint of DNA, more microbial than human. That’s a phenomenal insight and one that we have to take seriously when we think about human development.’’

    [...]

    At the two-minute mark, a prominent scientist in the audience did a spit take.

    ‘‘Dr. Lyte,’’ he later asked at a question-and-answer session, ‘‘if what you’re saying is right, then why is it when we give antibiotics to patients to kill bacteria, they are not running around crazy on the wards?’’

    #microbiote#santé_mentale

  • There Is No ‘Healthy’ #Microbiome
    http://www.nytimes.com/2014/11/02/opinion/sunday/there-is-no-healthy-microbiome.html

    It may be that a Hadza microbiome would work equally well in an American gut, but incompatibilities are also possible. The conquistadors proved as much. As they colonized South America, they brought with them European strains of Helicobacter pylori, a stomach bacterium that infrequently causes ulcers and stomach cancer, and these European strains also displaced native American ones. This legacy persists in Colombia, where some communities face a 25-fold higher risk of stomach cancer, most likely due to mismatches between their ancestral genomes and their H. pylori strains.

  • Notre #vagin est une fabrique d’#antibiotique
    http://m.slate.fr/story/92089/vagin-antibiotique

    Notre vagin peut nous soigner. Oui. Une étude repérée par Jezebel et publiée dans la revue Cell montre que le vagin contient une multitude de #bactéries qui produisent des molécules dont on pourrait se servir pour fabriquer des produits pharmaceutiques utiles.

    Le biologiste Michael Fischbach, qui fait partie de l’équipe qui a mené l’étude, interviewé par The Huffington Post, est enthousiaste :
    « Nous avons l’habitude de penser que les médicaments sont découverts par des compagnies pharmaceutiques, approuvés par la FDA [l’équivalent américain de l’Agence du médicament], puis qu’ils nous sont prescrits par des médecins. Ce que ces recherches prouvent, c’est que les bactéries qui vivent sur et en nous peuvent court-circuiter le processus. »

    En d’autres termes plus scientifiques, « les #bactéries_commensales produiraient des centaines de molécules ayant des caractéristiques génétiques susceptibles de servir de base à de nouveaux #médicaments », comme l’explique Le Quotidien du Médecin.

    L’étude menée par les chercheurs de l’université de Californie s’intéresse particulièrement à « une bactérie commensale du vagin, le #Lactobacillus gasseri, qui produit l’antibiotique #lactocilline très proche d’autres utilisés en pharmaceutique », contre des infections vaginales précise encore le site médical. Avec un avantage : alors que les antibiotiques « traditionnels » s’attaquent à toutes les bactéries (un effet « terre brûlée » selon l’image utilisée par The Huffington Post), l’antibiotique « naturel », lui, n’éliminerait que les pathogènes.

    Vaginal #microbe yields novel antibiotic
    Drug is one of thousands that may be produced by the human #microbiome
    http://www.nature.com/news/vaginal-microbe-yields-novel-antibiotic-1.15900

    ...Fischbach doesn’t plan to develop the antibiotic that he has discovered into a drug. Instead, he wants to find novel types of molecule that are made by the microbiome. Studying these molecules might help researchers to understand how the microbiome influences our susceptibility to disease, he says.