From: olivercranglejr@gmail.com   
      
   Thought Experiment - Who Are We Really? Manipulating the human microbiome has   
   ethical implications.   
      
      
      
      
   BACTERIAL FINGERPRINT: There is the possibility that microbial DNA may   
   contain even more information about a person than does their human   
   DNA.Lucy Reading-Ikkanda   
   We are human beings. Normally, one might take this to mean that, at   
   least on a biological level, we are defined by our own genome. But   
   living in and on the human body is an ecosystem of microorganisms that   
   outnumber our own cells by at least a factor of ten. It is estimated   
   that there are 100 times as many microbial genes as human genes   
   associated with our bodies. Taken together, these microbial   
   communities are known as the human microbiome. Recent technological   
   and scientific advances, mainly in the field of metagenomics, are   
   rapidly enriching our knowledge of the genomes and functions of many   
   of these microbial communities.   
      
   The ultimate aim of much of this research is to discover how   
   perturbations of the microbiome might be related to various diseases,   
   including inflammatory bowel disease, asthma, and obesity. Other   
   research is currently investigating the potential role of microbes in   
   anxiety, depression, and autism. These findings have the potential to   
   change the landscape of medicine. And they also have important   
   philosophical and ethical implications.   
      
   A key premise of some microbiome researchers is that the human genome   
   coevolved with the genomes of countless microbial species. If this is   
   the case, it raises deep questions about our understanding of what it   
   really means to be human. Typically, we draw a distinction between   
   environmental and genetic factors in understanding human traits and   
   the development of disease. What precisely is meant by "environmental"   
   varies dramatically across disciplines. Irrespective of how   
   environmental factors are conceptualized in a given study, a common   
   focus is their interaction with stable genetic factors. Traditionally,   
   the microbial communities in and around us would be counted towards   
   the environmental, rather than the genetic side of this equation.   
   Given recent findings from human microbiome research, however, this   
   classification may need to be reconsidered. If the microbiome, on a   
   species level, coevolved with the human genome and, on an individual   
   level, is a unique and enduring component of biological identity, then   
   the microbiome may need to be thought of more as "a part of us" than   
   as a part of the environment.   
      
   Ethics of DNA manipulation   
      
      
      
   The human microbiome may need to be thought of more as "a part of us"   
   than as a part of the environment.   
      
   There are practical ethical implications associated with these   
   somewhat philosophical considerations. Over the past few decades a   
   strong ethical position has emerged regarding manipulation of the   
   human genome. In most jurisdictions it is deemed unethical (and   
   illegal) to alter a human genome in such a way that these changes   
   might be passed on to offspring. There are several arguments   
   supporting this position, an important one being to safeguard the   
   right of the child to an "open future." Because the consequences of   
   even ostensibly benign genetic manipulations cannot be predicted with   
   certainty, it is currently deemed unethical to make choices on behalf   
   of a child as it might lead to permanent changes to its biological   
   identity. This reasoning underlies the prohibition in many countries   
   against manipulation of germ-line DNA. An important question thus   
   arises about how permanent certain changes to the human microbiome   
   might be, especially to the microbiomes of infants and children, and   
   whether such changes could be transmitted to offspring.   
      
      
      
      
      
   Planning for the future   
      
      
   We alter the mix of our microbial genomes all the time, through   
   changes in our diet and surroundings and, significantly, every time we   
   take antibiotics. It is currently not known how permanent these and   
   other changes to the microbiome are. Certainly some changes are very   
   transient, with the microbiome eventually returning to a fairly stable   
   state. However, it is unclear just how stable the microbiome really is   
   across a person's lifespan. There seems to be an emerging scientific   
   consensus that there is a critical period in infancy and early   
   childhood during which the microbiome initially develops and gains a   
   certain degree of stability. Neonates emerge from a sterile uterine   
   environment and are immediately colonized by microbes from the baby's   
   environment, beginning with the birth canal or, in the case of   
   cesarean section, the mother's skin, which hosts a significantly   
   different bacterial community. It is thus possible that, starting with   
   the mode of birth, early childhood exposure or lack of exposure to   
   certain microbial communities may have important implications for   
   health and illness later in life. For example, researchers in British   
   Columbia are currently investigating the possible role of early   
   childhood use of antibiotics in later development of asthma.   
      
      
      
      
      
   More important in the context of ethical considerations is the   
   possibility that if the adult microbiome is indeed relatively stable,   
   then such early childhood manipulations of the microbiome may be used   
   to engineer permanent changes that will be with the child throughout   
   life. There is thus the potential that an infant's microbiome may be   
   "programmable" for optimal health and other traits. For example, might   
   we program a baby's microbiome to decrease chances of becoming obese?   
   Or might we program it such that the person will always have a dislike   
   of alcohol? While such manipulation is likely to be motivated by many   
   good intentions, it does raise the familiar specter of "designer"   
   babies, and the ethical problem of making choices for infants and   
   children that may permanently affect their biological identity.   
      
   The issue of how stable an individual's microbiome is over time also   
   raises other ethical questions. For example, because human DNA is a   
   unique identifier of individuals, there are many safeguards for   
   ensuring the confidentiality of genetic data. In many jurisdictions   
   laws have been enacted to prohibit insurance companies from taking the   
   results of genetic tests into account in calculating premiums. There   
   is also much controversy about the possibility of law enforcement   
   agencies acquiring genetic data collected for health research. Some   
   early studies suggest that a person's microbiome may also be a unique   
   identifier. And there is the possibility that microbial DNA may   
      
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