Saliva contains an enzyme, "lysozyme". This enzyme, whether from saliva or other sources, is recognized for bactericidal activity. Not all lysozyme molecules are identical, however, so one must be careful in extrapolating all data from lysozyme from one source to lysozyme from another source.

Lysozyme from chicken egg, human milk and human neutrophils have both been shown to have anti-HIV activity in the test tube (Lee-Huang et al, Proc Natl Acad Sci USA 96(6)(1999)2678-2681). While human saliva is generally credited with some anti-HIV activity, such that infection from swallowing saliva is considered less risky than 'taking' saliva up the vagina or rectum, HIV has nonetheless been known to be caught by the oral route.

Regarding bile, a compound, biliverdin, has been shown to have anti-HIV and anti- (one type of) herpes (HHV-6) activities in the test tube (Mori et al, Jpn J Cancer Res 82(7)(1991)755-757; Nakagami et al, Microbiol Immunol 36(4)(1992)381-390). A compound, Virulizin, is currently under study in Canada for HIV disease (noted at www.catie.ca). Virulizin is an extract from bovine (cow) bile, and I believe it may provide some benefit via stimulation of the macrophages of the immune system, rather than direct antiviral activity per se.

I've not checked whether lysozyme is available as a supplement. In the hen's egg, it's degraded by cooking, and one would not want to risk eating raw eggs under any circumstance. I believe there are bile supplements, but whether these contain any antiviral activity is very questionable without study to indicate such.

I have not done a comprehensive study of these areas. There may be other information available. Perhaps some of the information I've given here is "additional" to what you already have.

Q#2: Saliva and Kissing

How much bacteria is in saliva? I know that people transfer saliva when they kiss but can swallowing it cause any damage? (May, 2000)

A: Charlie Smigelski, RD responds:

I do not have an exact count for how many bacteria and viral particles there are in saliva.

There was a brief report from a medical meeting about four months ago that tried to change the notion of a "theoretical" minimal risk of oral transmision of HIV to a "quantified amount" of transmision risk. The study was criticized on a number of aspects, starting with how reliable were the sexual practice stories of the subjects in the study.

How this all relates, is about whether there are things in saliva that kill the virus, and whether there are enough viral particles in saliva, to alter transmission risk. (See Chester's response to Q#1 above.) The bottom line is:

1. A life without any kissing and an exchange of saliva may be more harmful to a human being than the small risk of transmission via kissing.

2. Oral sex seems to cause some slight risk of transmission of the virus. The amount of risk is not numerically quantifiable yet.

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