Through a short amount of research it seems most blood is cleaned in the liver and most toxins are neutralized before being passed into urine or the bowels. If this is how most toxins are excreted from the body then what are some other ways of dumping toxins the liver can't destroy, assuming a race's technology has reached the point that modifying biology can be done relatively successfully? There are a few restrictions I'd like to put on answers if allowed:

  • Since we know that most toxins are already dumped through the liver let's refrain from any answers using this method. We can just assume that doing this would over-work the liver or would otherwise be untenable.
  • Secreting them out of the skin with sweat is acceptable but lets keep these types of answers to the minimum.
  • In general I'm looking for answers that the body can not already do on its own, I'm looking for a creative or otherwise interesting new way to do it

I'm aware I'm asking more than one question here but I'd also like some input on a way I think would be quite theatrical but am not sure if it is anywhere near realistic. Tissues in the nose are rather thin, so would it be realistic for the bio-engineers to add a new organ near the nasal cavity that filters blood for toxins that the liver can't sift out and then eject these toxins through the membrane with mostly plasma and maybe a few red blood cells and hemoglobin? Or is this completely ridiculous/unnecessary? Tearing the membrane in the nose causing minor bleeding is acceptable in this case. To clarify the point of this question revolves around neutralizing toxins in a humans body through biological engineering, not through other things such as nanobots. If I haven't been clear enough I will be sure to come back and clarify.

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    $\begingroup$ What's wrong with engineering a super liver? When you want to create a faster car you look at improving the engine, not stuffing some new go-fast widget under the hood. $\endgroup$
    – sphennings
    Commented May 11, 2017 at 4:18
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    $\begingroup$ If your main requirement is "not boring", this is opinion based. $\endgroup$
    – Mołot
    Commented May 11, 2017 at 6:00
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    $\begingroup$ You know, turboprop/turbofan is a jet. Blades spinning fast push the air back. $\endgroup$
    – JDługosz
    Commented May 11, 2017 at 6:37
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    $\begingroup$ @JDługosz You know a turbofan looks like a jet, right? Those things on a 747. But yes, the only difference between a turboprop and turbofan is duct that goes around the spinny thing at the front. They are both high-bypass jet engines. $\endgroup$
    – Aron
    Commented May 11, 2017 at 9:02
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    $\begingroup$ Yes. But they work by pushing air using spinning blades. “sup up a prop” is in fact a good description: give it more power and use multblade design suited for the speed. $\endgroup$
    – JDługosz
    Commented May 11, 2017 at 9:05

5 Answers 5


Stick them in your hair

Mangroves are able to survive in saltwater environments by removing the salt from the water they take in and placing it in sacrificial leaves. According to Scholander et al., 1964, this is done by maintaining an extremely high (30 atm) osmotic potential between the salty water and the xylem sap.

The practical application of this in a human would be to have an organ in contact with some place where your hair is growing that operates at such a high potential. Blood is pumped into the organ and then filtered at very high osmotic pressure back into the circulatory system. This is basically how a reverse osmosis water purifier works.

Everything filtered out would then be enmeshed in keratin and grown out in the hair. The hair is dead anyways, so any toxins in the body are effectively removed from the body.

The downside to this system is that your blood has a lot more things in it than a mangrove's xylem. You are going to lose a lot of red and while blood cells, and other useful things in this way. Perhaps the filtering organ has some sort of mechanism to exclude blood cells from entering in the first place. Alternately, the body could just be engineering to make blood cells a lot faster to replace the losses.

  • $\begingroup$ Would it be fair to equate this almost as secreting it out with hair rather than with sweat through the skin? Though this certainly is in the vein I was thinking and has the opportunity to be theatrical if applied correctly. The blood loss might be an issue I'd have to look at though. Thank you! $\endgroup$
    – William C.
    Commented May 11, 2017 at 4:37
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    $\begingroup$ "Perhaps the filtering organ has some sort of mechanism to exclude blood cells from entering in the first place. " Yes that sounds like a really good idea. Then that organ could pump all the useful chemicals back into the blood. In fact we could have TWO of these organs, for backup purposes.. $\endgroup$
    – Aron
    Commented May 11, 2017 at 9:06

A symbiont

The huge bacteria colony each of us carries in our gut (mine is large right now) does a fair bit of detoxification and metabolic modification. Sometimes that causes trouble: irinotecan for example is a chemotherapeutic that is partly metabolized by gut microbes, the end product being a more toxic chemotherapy which then causes diarrhea. Microbial metabolism of nitrogenous products can overload the body with ammonia in some circumstances.

The bioengineered ones can have some sort of commensal creature that lives in them / on them and does the detox heavy lifting.

I like the idea that this creature gets its caloric requirement from alcohol and so its maintenance requires considerable heavy drinking of alcohol and things which might contain alcohol. It could even communicate, suggesting things that the host might eat or drink. Some of its suggestions are unwise.


An enhanced immune system!

For certain toxins that flood the body on a daily basis the immune system can deal with them by producing antibodies or enzymes that neutralize or simply transport the harmful substance through the lymphatic system to ultimately be excreted by urine.


Since you're entering the realm of bio engineering modifying the immune system can happen. Note that this degree of body modification is not yet possible or even plausible.

Recognizing intoxication

The immune system contains an array of low concentration identifier substances that somehow manage to indicate the presence of toxins and alert the immune system to produce the corresponding enzymes/antibodies.


Enzymes will modify the toxin by changing it chemically and disabling the group of the substance that causes the toxic effects in the body.


Antibodies will capture and transport the toxin to be excreted harmfully before it can can do its harm in the body.


Change in Appetite

If the body has no capability to purge a toxin by itself, why not make you hungry for something containing chemicals that can? If you have a water deficiency, you get the strong urge to drink water - if you have a toxic mercury buildup, perhaps you'll get an urge to mix a cocktail of paint thinner and wood shavings, or whatever has chemicals in it that your body can then use to neutralise the toxin. I think there was a Dr. Who episode that did this where he consumes certain things to assist in his body curing himself of poisoning. Could make for an interesting hunt as the protagonist searches for the exact thing they need.


How about the lungs?

Instead of them just diffusing oxygen into the bloodstream via the alveoli, why not have them catch all the crap the liver can't, and pass it out via exhalation?

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    $\begingroup$ Cough it out? Most things that are toxic to the body are heavier than air so simple exhalation would be a hard sell. But I suppose coughing it out would be fine. Good suggestion. $\endgroup$
    – William C.
    Commented May 12, 2017 at 0:28
  • $\begingroup$ Perhaps these bio-engineered lungs are designed more easily expel mucus. When the toxins are dumped into the lungs, the lungs also excrete mucus to trap it and then a snot-and-spit hocks out a spectacular loogie. $\endgroup$ Commented Feb 5, 2018 at 14:21

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