On Aug 31, 2016, at 4:14 PM, Richard Aiken <xxxxxx@gmail.com> wrote:

On Wed, Aug 31, 2016 at 2:56 PM, Bruce Johnson <xxxxxx@pharmacy.arizona.edu> wrote:

At the very least they would have had whatever evolved out of their gut flora...

You know, it just occurred to me . . . 

Vilani gut flora would have been under constant siege by the VIlani diet. That is, the contaminant levels would have probably kept the flora levels consistently very low. Given this constant low-level stress, it's possible that those few gut flora that mutated into lethal form killed their hosts too quickly to allow colonization of other human guts. 

Gut flora, mutation and pathogenicity don’t work that way. We only notice the lethality of pathogens when they kill lots of people, but we’re host to a gazillion ones that make us only a little sick. Heck Zika is asymptomatic, or very nearly so in a lot of people. Same for West Nile Virus, and any of a number of other diseases. The bacterial cause of stomach ulcers was hotly disputed until Barry Marshall applied Koch’s Postulates on himself http://discovermagazine.com/2010/mar/07-dr-drank-broth-gave-ulcer-solved-medical-mystery

Given the staggering adaptability of bacteria, and the tendency of gut bacteria to swap useful genes between species like gorram Pokemon cards, I doubt the Vilani diet would have been all that much of a problem. Indeed, I’d expect that after a sizeable number of generation Vilani would have less trouble digesting native foodstuffs BECAUSE their gut flora had adapted to metabolize the stuff.

A LOT of the biology  in Traveller is wrong. The susceptibility of the Vilani to terrestrial diseases is surprisingly not. (and the death toll would have been vastly lower, save for the fact that it happened during a series of wars.)

-- 
Bruce Johnson
University of Arizona
College of Pharmacy
Information Technology Group

Institutions do not have opinions, merely customs