Chiral Life Concept involves the recreation of regular lifeforms as identical, but mirror-reflected (in the molecular sense), versions of themselves. It is thought that such mirror organisms can be highly incompatible with existing microbes (viruses, bacteria, protozoa, etc). Hypothetically, it is possible to recreate our entire ecosystem from the bottom-up, in chiral form. In this way, the creation of an Earth ecosystem without microbial diseases is possible. In the more distant future, Chiral Life can employed to create robust, effective and disease-free ecosystems for use on other planets.
The creation of chiral humans is the basis of Arthur C. Clarke's story "Technical Error", from The Collected Stories.
Reconstructing regular lifeforms in mirror-image form, using the mirror-image (chiral) reflection of our cellular components is achieved by replacing left-handed amino acids with right-handed ones, in order to create mirror reflections of all regular proteins. Analogically, we could get reflected sugars, DNA, etc, on which reflected enzymes would work perfectly. Finally we would get a normally functioning mirror reflection of a natural organism - a chiral counterpart organism - with which natural viruses and bacteria couldn’t interact. Electromagnetic force (chemistry) is unchanged under such molecular reflection transformation (P-symmetry). There is a small alteration of weak interactions under reflection, which can produce very small corrections, but these corrections are many orders of magnitude lower than thermal noise - almost certainly too tiny to alter any biochemistry.
Such a chiral lifeform would obviously need to be feed with reflected food, produced by reflected plants. The great advantage, though, is that such chiral organisms should enjoy a disease-free life, completely immune to all viruses and microbes (which virologists are now beginning to understand underlie a huge number of diseases).
Viruses would be completely incompatible with the reflected cellular structures; and bacteria, protozoa and fungi could not function because they would not be able to find normal sugars inside reflected organisms. The reverse sugars circulating in the chiral organism's body would be indigestible as far as normal bacteria are concerned, so any bacterium entering a chiral organism would simply starve to death. The chiral environment is absolutely hostile for normal viruses, protozoa, bacteria, etc.
In order to infect a chiral organism, existing bacteria would have to evolve their own mirror image structure from scratch. This is extremely unlikely to happen (since DNA holds the genes, the alphabet of evolution, but DNA itself is a priori to genes, and therefore untouched by the process of evolution). Terrorist acts, however, are a concern. In the case of sabotage, though, it may be easier control the spread of any terrorist-engineered chiral virus, using anti-terrorist measures already in place today.
How do we create a chiral organism, such as a reflected human? The synthesis of every molecule, a reflected zygote is difficult, because we don’t have chiral enzymes. But the real problem is creating the correct structure of membranes with specific concentrations … fill it with life. Nevertheless, with advancing nano-engineering, this could be possible in let’s say 50 years, when we could slowly transform our ecosystems, starting from the bacterium E. coli, which will act as our factory, and later plants. Finally, if all goes well, the human being.
But in such a sterile environment, would we have perfect health? Maybe the stresses created by small infections can, like small amounts of radiation, have positive long-term influence? For example, infection helps to get rid of damaged and weak cells in an organism. And the hygiene hypothesis states that the actual absence of exposure to microbes can lead to autoimmune diseases (although more probably, autoimmune diseases are due to chronic underlying infection from viruses and bacteria that have insinuated themselves deeply inside a living organism and its cells, rather than the lack of exposure to microbes; so we should eliminate autoimmune conditions in once we have shifted into chiral life).
There are other dangers too: imagine a reflected unicellular organism, which needs only light and symmetric molecules like H2O, CO2, O2. Such a chiral unicellular organism could spread, evolve, and could even overthrow plant life.
So the main rule from the beginning should be: in the case of chlorophyll organisms: only plants whose population can be controlled should be transformed!
Transformation of our ecosystem would be expensive, but in the future we may need to create completely new ecosystems for populating other planets like Mars. In these situations, the effectiveness of such an ecosystem will be very important. We would need many kinds of microorganisms. Symbiotic ones wouldn’t need to have aggressive mechanisms; aggressive microbes would only re-emerge if they evolved from zero. I cannot imagine that chiral viruses would be needed; they wouldn’t be transformed at all. Thus chiral viruses would just re-appear if they evolved from zero, like free DNA, which is unlikely. Furthermore, the last time this happened, the viruses evolved in parallel with their targets; now organisms have very advanced specific/non-specific defensive systems, which will make it hard for any chiral virus to appear and establish itself in a chiral ecosystem.
Of course, once our ecosystem is transformed, if in the distant future, we find a new major problem, we can always reverse again!
Another option, which is much easier: just switch human to chiral form, leaving the rest of the ecosystem untouched. In the near future, it is likely that we will bio-engineer some of our food, so we could just bio-engineer our own factory-made chiral foods, without needing to introduce chiral plants for our crops, or chiral animals for our meat.
This humans-only approach would be much easier and safer than converting the whole ecosystem, and we could then enjoy all of nature in its pure and natural form, without ever having to worry about parasites or infections, which we will have jumped beyond forever.