I met Dr Trevor Lawley at the Wellcome Trust Sanger Institute, where he is trying to grow the whole microbiome from healthy patients and those who are ill. Dr Lawley says there's growing evidence that repairing someone's microbiome "can actually lead to remission" in diseases such as ulcerative colitis, a type of inflammatory bowel disease.
And he added: "I think for a lot of diseases we study it's going to be defined mixtures of bugs, maybe 10 or 15 that are going into a patient. Microbial medicine is in its early stages, but some researchers think that monitoring our microbiome will soon become a daily event that provides a brown goldmine of information about our health. Prof Knight said: "It's incredible to think each teaspoon of your stool contains more data in the DNA of those microbes than it would take literally a tonne of DVDs to store.
Follow James on Twitter. Illustrations: Katie Horwich. But genetically we're even more outgunned. Microbial battleground. This is where it might get confusing. Their entire existence is completely free of microbes.
Goldmine of information. View comments. Related Topics. Bacteria Medical research Genetics Genome. Experiences, expectations, motivations, and emotional levels can all affect perceptions. Much of learning appears to occur by association: If two inputs arrive at the brain at approximately the same time, they are likely to become linked in memory, and one perception will lead to an expectation of the other.
Actions as well as perceptions can be associated. At the simplest possible level, behavior that is accompanied or followed by pleasant sensations is likely to occur again, whereas behavior followed by unpleasant sensations is less likely to occur again. Behavior that has pleasant or unpleasant consequences only under special conditions will become more or less likely when those special conditions occur.
The strength of learning usually depends on how close the inputs are matched in time and on how often they occur together. However, there can be some subtle effects.
For example, a single, highly unpleasant event following a particular behavior may result in the behavior being avoided ever after. On the other hand, rewarding a particular behavior even only every now and then may result in very persistent behavior. But much of learning is not so mechanical. People tend to learn much from deliberate imitation of others. Nor is all learning merely adding new information or behaviors.
Human thinking involves the interaction of ideas, and ideas about ideas, and thus can produce many associations internally without further sensory input. People's ideas can affect learning by changing how they interpret new perceptions and ideas: People are inclined to respond to, or seek, information that supports the ideas they already have and on the other hand to overlook or ignore information that is inconsistent with the ideas.
If the conflicting information is not overlooked or ignored, it may provoke a reorganization of thinking that makes sense of the new information, as well as of all previous information. Successive reorganizations of one part or another of people's ideas usually result from being confronted by new information or circumstances.
Such reorganization is essential to the process of human maturation and can continue throughout life. To stay in good operating condition, the human body requires a variety of foods and experiences.
The amount of food energy calories a person requires varies with body size, age, sex, activity level, and metabolic rate.
The normal condition of most body systems requires that they perform their adaptive function: For example, muscles must effect movement, bones must bear loads, and the heart must pump blood efficiently. Good health also depends on the avoidance of excessive exposure to substances that interfere with the body's operation.
Chief among those that each individual can control are tobacco implicated in lung cancer, emphysema, and heart disease , addictive drugs implicated in psychic disorientation and nervous-system disorders , and excessive amounts of alcohol which has negative effects on the liver, brain, and heart.
In addition, the environment may contain dangerous levels of substances such as lead, some pesticides, and radioactive isotopes that can be harmful to humans. Therefore, the good health of individuals also depends on people's collective effort to monitor the air, soil, and water and to take steps to keep them safe. Other organisms also can interfere with the human body's normal operation. Some kinds of bacteria or fungi may infect the body to form colonies in preferred organs or tissues.
Viruses invade healthy cells and cause them to synthesize more viruses, usually killing those cells in the process.
Infectious disease also may be caused by animal parasites, which may take up residence in the intestines, bloodstream, or tissues. The body's own first line of defense against infectious agents is to keep them from entering or settling in the body.
Protective mechanisms include skin to block them, tears and saliva to carry them out, and stomach and vaginal secretions to kill them. Related means of protecting against invasive organisms include keeping the skin clean, eating properly, avoiding contaminated foods and liquids, and generally avoiding needless exposure to disease. The body's next line of defense is the immune system.
White blood cells act both to surround invaders and to produce specific antibodies that will attack them or facilitate attack by other white cells. For years afterward, or even a lifetime, the immune system will be ready for that type of organism and be able to limit or prevent the disease. A person can "catch a cold" many times because there are many varieties of germs that cause similar symptoms.
Allergic reactions are caused by unusually strong immune responses to some environmental substances, such as those found in pollen, on animal hair, or in certain foods. Sometimes the human immune system can malfunction and attack even healthy cells.
Some viral diseases, such as AIDS, destroy critical cells of the immune system, leaving the body helpless in dealing with multiple infectious agents and cancerous cells. Infectious diseases are not the only threat to human health, however. Body parts or systems may develop impaired function for entirely internal reasons. Some faulty operations of body processes are known to be caused by deviant genes.
They may have a direct, obvious effect, such as causing easy bleeding, or they may only increase the body's susceptibility to developing particular diseases, such as clogged arteries or mental depression. Such genes may be inherited, or they may result from mutation in one cell or a few cells during an individual's own development. Because one properly functioning gene of a pair may be sufficient to perform the gene's function, many genetic diseases do not appear unless a faulty form of the gene is inherited from both parents who, for the same reason, may have had no symptoms of the disease themselves.
The fact that most people now live in physical and social settings that are very different from those to which human physiology was adapted long ago is a factor in determining the health of the population in general. One modern "abnormality" in industrialized countries is diet, which once included chiefly raw plant and animal materials but now includes excess amounts of refined sugar, saturated fat, and salt, as well as caffeine, alcohol, nicotine, and other drugs.
Lack of exercise is another change from the much more active life-style of prehistory. There are also environmental pollutants and the psychological stress of living in a crowded, hectic, and rapidly changing social environment. On the other hand, new medical techniques, efficient health care delivery systems, improved sanitation, and a fuller public understanding of the nature of disease give today's humans a better chance of staying healthy than their forebears had.
Good mental health involves the interaction of psychological, biological, physiological, social, and cultural systems. It is generally regarded as the ability to cope with the ordinary circumstances people encounter in their personal, professional, and social lives. Ideas about what constitutes good mental health vary, however, from one culture to another and from one time period to another. Behavior that may be regarded as outright insanity in one culture may be regarded in another as merely eccentricity or even as divine inspiration.
In some cultures, people may be classified as mentally ill if they persistently express disagreement with religious or political authorities. Ideas about what constitutes proper treatment for abnormal mental states differ also. Evidence of abnormal thinking that would be deliberately punished in one culture may be treated in other cultures by social involvement, by isolation, by increased social support, by prayers, by extensive interviews, or by medical procedures.
Individuals differ greatly in their ability to cope with stressful environments. Stresses in childhood may be particularly difficult to deal with, and, because they may shape the subsequent experience and thinking of the child, they may have long-lasting effects on a person's psychological health and social adjustment.
And people also differ in how well they can cope with psychological disturbance when it occurs. Often, people react to mental distress by denying that they have a psychological problem. Even when people recognize that they do have such a problem, they may not have the money, time, or social support necessary to seek help.
Prolonged disturbance of behavior may result in strong reactions from families, work supervisors, and civic authorities that add to the stress on the individual. Diagnosis and treatment of mental disturbances can be particularly difficult because much of people's mental life is not usually accessible even to them.
In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript. It's often said that the bacteria and other microbes in our body outnumber our own cells by about ten to one.
That's a myth that should be forgotten, say researchers in Israel and Canada. The ratio between resident microbes and human cells is more likely to be one-to-one, they calculate. A 'reference man' one who is 70 kilograms, 20—30 years old and 1.
Those numbers are approximate — another person might have half as many or twice as many bacteria, for example — but far from the ratio commonly assumed. In , molecular biologist Judah Rosner at the US National Institutes of Health at Bethesda, expressed his doubts about the claim, noting that there were very few good estimates for the numbers of human and microbial cells in the body.
Milo, Sender and Fuchs decided to re-estimate the number by reviewing a wide range of recent experimental data in the literature, including DNA analyses to calculate cell number and magnetic-resonance imaging to calculate organ volume.
The vast majority of human cells are red blood cells, they note see 'Counting human cells'. Luckey estimated that guts contain around 10 14 bacteria, by assuming that there were 10 11 bacteria in a gram of faeces, and scaling that up by the one-litre volume of the alimentary canal, which stretches from the mouth to the anus.
But most bacteria reside only in the colon which has a volume of 0. Putting together these kinds of calculations, the researchers produce a ratio for microbial to human cells for the average man of 1. Milo declined to comment on the paper, because it is in review at a scientific journal. Sender, R. Download references. You can also search for this author in PubMed Google Scholar.
Tweet Follow NatureNews. My digital toolbox: back-of-the-envelope biology Mar Microbiome science threatened by contamination Nov Sugar substitutes linked to obesity Sep
0コメント