Justifying a species being able to eat alien food

How could, lets say us, be able to eat a roasted alien critter without falling sick? (Taking in mind this alien is carbon based), or an alien who finds us appettizing

Perhaps futuristic sanitizing technologies that remove all germs from the food would be aviable at the time, but would't other obstacles besides alien organisms be present and in need to be sorted before ingestion?

Well as long as the ingredients are all protein, carbohydrates, and fat, then you can eat some exotic steak meal that came from some animal native another star system.

The human digestive system is pretty good at ignoring the stuff that it can't use but which isn't actually toxic to it. If the food is stuff that a human can't digest or metabolize, they'll just shit it out.

It's possible that germs wouldn't be much of a problem because of differences in biology. For instance, viruses can reproduce inside human cells because virus RNA is very similar to DNA; if aliens had a non-DNA way of encoding their genes, Earth viruses would be useless.

(The catch is that there simply aren't that many possible ways to encode genes; extra base pairs and the like are pure nonsense. And if their chemical makeup was so different that it couldn't be broken down into sugars, they would have no nutritional value.)

The only problems I can see is if the food has something poisonous in it like arsenic. Or if the food lacked one or two amino acids. But if the humans supplemented their diets with some earth food then there'd be no trouble.

There could be any number of ways it could go wrong.

• The body cannot break it down, and it just passes through, making it worthless to eat (that's be creepy, actually, to see the food you ate come out in semi perfect condition)
• The acids in your stomach have a bad counterreaction
• The stuff in the food is either irrelevant to your health or bad for it, once again, resulting in a lack of nutrition.
• Parasite
• It causes harmless out effects. Skin changes color, maybe you start to smell, stuff like that.
• You get the equivalent of eating a rock. Not gonna kill you in small quantities but...why?

Simply make it so that all life uses the same proteins, just with different encoding if it has a different origin.

Since the digestive system only cares about the proteins, not the encoding, there are No Biochemical Barriers.

I'm not a biology major but I believe that so long as it's not toxic, it just comes right back out the other end. Also, germs and viruses shouldn't be a problem because even with Earth-life, it rarely is able to cross specie boundaries.

I think the real issue is that you won't gain any useful nutrients from eating alien food.

The main trouble is enzymes. The human digestive system has evolved enzymes to break down specific things - for example, the reason we can't digest plant fibre is that we have no enzyme to break cellulose. It's not poisonous, though, just indigestible.

So, yeah, I'd agree that it would probably be realistic to have alien food be not very nutritious, basically full of dietary fibre with a small amount able to be broken down.

CATSUP

Hmm, an interesting thought occurred to me. Cows and other herbivores can digest cellulose because their gut is full of micro-organisms that DO have an enzyme for it.

If you're talking futuristic technology that allows humans to eat alien food, perhaps a sort of drink or pill would be available that populates your stomach with alien microbes to break it down for you. Doubtless this would create its own immune system problems, but it's a thought.

The problem is, those germs might backfire horrifically in two ways:

• The difference between a cow's germs and those germs we ingest is that while a cow's system might just treat them as part of the body, ours would consider them as intrusive organisms and deal with them accordingly.
• People with weak inmune systems might get severly ill as they can't produce the antibodies necesary to fight these alien microorganisms

But how about instead of bacteria, just the enzyme that bacteria produce? I like the idea of making these creatures' meat to be made of the same proteins as our animals, but in different coding. Perhaps you'll be pooping colors or not be able to get as much nutrition from it as a native would but it wouldn't harm you as long as it it well prepared.

edited 14th Oct '10 9:37:32 PM by heartlessmushroom

Those pills already exist — that's exactly what Beano and Lactaid are — enzyme supplements.

edited 14th Oct '10 10:04:28 PM by Madrugada

Would it backfire if applied at an early age? If you're a baby then your body doesn't know what is foreign and what is not yet... not for everything anyways.

It's not a case of your body knowing. It "do you have the enzymes and assorted other chemicals necessary". That's not something that you can learn.

Yeah, my post was out of order, it was in reference to the bacteria being rejected as a foreign component of the body.

There's always John Ringo's approach to it—since alien food doesn't provide nutrients, but does provide the illusion of being full, when eaten together with human food it's the perfect way to stick to a diet.