Let me try to address several points that have been raised upthread, some of which are good, but represent an incomplete understanding or representation of the underlying microbiology and immunology.

It is true that we are exposed constantly to non-pathogenic environmental bacteria. However, the major concern in food preparation is actually exposure to pathogenic bacteria, which can result either from person-to-person transmission by an infected individual using substandard hygiene practices, or from raw/undercooked food that is contaminated with pathogenic bacteria (food poisoning), usually from animal or human feces. Obviously the last can result from inadequate hygiene practices as well. For more information on foodborne illnesses, see: http://www.cdc.gov/nczved/dfbmd/disease_listing.html

Adaptive immunity results from exposure to antigens (often proteins) that are, in the present context, produced by microorganisms. Exposure to environmental bacteria may or may not provide future protection against pathogenic bacteria, depending on the specificity of the antigens produced by the respective bacteria and the resulting antibodies and T cells produced by the human immune system. Exposure to various environmental antigens is thought to be important to proper development of the immune system during early childhood (hygiene hypothesis). Insufficient exposure results in misregulation of the immune system, leading to increased incidence of allergic and autoimmune diseases. However, I am not aware of studies pertaining to deficits in adaptive immunity resulting from insufficient exposure to environmental antigens during adulthood, as has been implied here, but if anyone is, please post a reference and I will be happy to revise my statement.

On a related note, somewhat OT to the current discussion, but nonetheless interesting, the potential public health risk of antibacterial soaps is controversial (although I personally err on the side of caution and avoid them for the reasons stated below). The hypothesis is that their use could lead to the emergence of antibiotic-resistant bacteria, either through direct selection of resistant strains or through depletion of competing environmental or commensal bacteria. However, the antibacterial agent used in most soaps, triclosan, is a general antiseptic that is not used to treat human infections. Further, it has multiple modes of action, making the development of specific resistance unlikely, and there has been no evidence for increased incidence of antibiotic-resistant bacteria in households using antibacterial soaps. All that said, the limited benefit of antibacterial soaps relative to thorough hand-washing (≥30 seconds) suggests that there is little downside to discontinuing their use. For more information, see: http://www.ncbi.nlm.nih.gov/pubmed/1...ubmed_RVDocSum

As a result, I prefer to use ≥60% ethanol-based hand sanitizers, such as Purell. You can, indeed, also sanitize your drink with alcohol, it just needs to be a really stiff one (straight vodka may actually not be enough : http://www.cdc.gov/ncidod/EID/vol12no03/05-0955.htm).

Finally, it bears saying - no hypochondria (or hysteria) is necessary. Whatever practices are effective for each of us personally are just fine...as long as you're not preparing food for someone else!