The Human Collective
21/11/10 21:02 Filed in: GenomeWeb Daily Scan
Submitted by S. Pelech - Kinexus on Sun, 11/21/2010 - 21:02.
Each individual has his or her own unique resident flora of some 10 trillion bacteria that results from the combination of a diversity of factors. These include our genetic background, where we have travelled to become exposed to the bacteria, our innate and acquired immunity systems, our diet and other environmental exposures (including soaps and deodorants). So, it is not really surprising that identical twins can have different fecal viromes based on these and other environmental factors.
The resident flora is our best protection against adventitious disease-causing bacterial invasions and the loss of this is a major risk of non-discriminate use of antibiotics. Only a couple of hundred different bacterial strains appear to be particularly pathogenic to humans, and they are able to do so because of co-evolution to specifically exploit human proteins (usually cell surface or signalling proteins). In view of this, the decision to quarantine the Apollo moon mission astronauts after their lunar expeditions was more political than science-based. Likewise, in H.G. Well's War of the Worlds story, which has been adapted once again into a relatively recent movie, it is highly unlikely that bacteria on this planet would be well suited to be harmful to alien physiology.
It is fascinating to realize that we are not just a colony of some 100 trillion interconnected mammalian cells that are directly related, but that we have a symbiosis with our bacterial flora. However, it is also worth remembering that each of our cells typically harbor over a thousand mitochondria with their own genomes. Even within the same cell, these mitochondria genomes have differences in their genetic sequences. While essential to the functioning of eukaryotic cells, these symbiotic mitochondria are believed to have a bacterial origin. Consequently, colonies of bacterial-like entities exist within our cells as well as outside them.
Link to the original blog post.
Each individual has his or her own unique resident flora of some 10 trillion bacteria that results from the combination of a diversity of factors. These include our genetic background, where we have travelled to become exposed to the bacteria, our innate and acquired immunity systems, our diet and other environmental exposures (including soaps and deodorants). So, it is not really surprising that identical twins can have different fecal viromes based on these and other environmental factors.
The resident flora is our best protection against adventitious disease-causing bacterial invasions and the loss of this is a major risk of non-discriminate use of antibiotics. Only a couple of hundred different bacterial strains appear to be particularly pathogenic to humans, and they are able to do so because of co-evolution to specifically exploit human proteins (usually cell surface or signalling proteins). In view of this, the decision to quarantine the Apollo moon mission astronauts after their lunar expeditions was more political than science-based. Likewise, in H.G. Well's War of the Worlds story, which has been adapted once again into a relatively recent movie, it is highly unlikely that bacteria on this planet would be well suited to be harmful to alien physiology.
It is fascinating to realize that we are not just a colony of some 100 trillion interconnected mammalian cells that are directly related, but that we have a symbiosis with our bacterial flora. However, it is also worth remembering that each of our cells typically harbor over a thousand mitochondria with their own genomes. Even within the same cell, these mitochondria genomes have differences in their genetic sequences. While essential to the functioning of eukaryotic cells, these symbiotic mitochondria are believed to have a bacterial origin. Consequently, colonies of bacterial-like entities exist within our cells as well as outside them.
Link to the original blog post.