Modification of human scent glands

Hello all.  I'm afraid I wasn't entirely aware of the nature of this discussion board when I signed up for membership.  I am a biochemical engineering student who spends most of his time modifying moss, plants, and bacteria in my lab at home.  I have never considered the idea of modifying a human being except in one respect, which, if possible, I would like to investigate for my senior thesis.  I came to the idea while I was in the shower.  Humans spend thousands of dollars over the course of their lifetimes on products like deodorant, perfume, cologne, etc.  All of these products are designed to cover up the natural human body odor that we all find so repulsive.  Human body odor is caused by bacteria present in the scent glands located in the armpits, the back of the ears, and the groin.  The individual scent that each person carries is determined by that individual's histocompatibility complex, the matrix of immune responses that determines which bacteria are killed and which are not. I have, in the past, engineered bacteria in my garage that smells like strawberries and am working on other scents as well.  If successful, a simple alteration of the individual micro biome will make the purchase of perfumes and the like unnecessary.  The problem I am facing is this.  Every person's histocompatibility complex is different.  Totally different bacteria are producing your BO than are producing mine.  The modifications would have to be 100% personalized which makes distribution more difficult.  Any ideas?


  • I actually was under the impression, that immune reactions were mainly within the body while those bacteria live on the surface. I also thought, that they were mostly the same strands and the differences in BO were more in the chemical compounds we release through the skin those bacteria then are living off.
  • edited December 2012
    Hmm. Can many products be made to target each of those types of bacteria, and then be shoved into one pill? Are any essential? I like the idea a lot! 

    Beer scent would be an awesome prank.
  • @DirectorX:  I think we've just found the beginnings of Diabolical Plot #35.

    I agree with @Ben; I thought that the bacteria themselves were pretty much the same strain.

  • Would this affect androstadienone and other pheromones?
  • @DirectorX:  I doubt it.
  • I think the simplest method of transmission would be to add an anti-biotic resistance gene in with the with the plasmid carrying the gene for the desired scent, similar to the way that selection is promoted in lab cultures, then put the subject on a cycle of antibiotics, killing off the natural bacteria and giving the engineered strain an initial selection advantage.  It shouldn't interfere with androstadeinone or any naturally occurring scent chemicals in the body other than those produced as bacterial waste.  Concerning allergic reactions and the like, I believe that my concerns over this issue may be able to be resolved through animal testing, however I don't know enough about the laws concerning such things to know how I should proceed while still keeping everything legal.  Any biomedical law enthusiasts out there?
  • rewaking this old thread....

    putting a person on antibiotics would mostly kill the bacteria inside a person. This has it's on slew of problems and is not an ideal way to implement this situation. one would need a topical antibiotic to open the niche on the skin for the bacteria to grow well.

    more importantly, antibiotics linked to an engineered mutation tend to have the annoying side effect of getting kicked when they are no longer under antibiotic stress. this would cause our scent strain to get kicked as well as soon as the person stopped their regime of antibiotics.

    i've been thinking about this as well, and basically, you need to make the accompanying mutation not a resistance, but a beneficial trait that is constantly in use so that it works better than the existing bacteria.

    i have an idea about this. if anyone is still interested in this thread, we can discuss this further.
  • I'm interested. 

    Some of us were thinking a phage might do the trick. Thoughts?
  • tl;dr: you need to infect as many hosts as possible.

    our recombination technology is basically stolen from natural bacteria, who have this stuff built into their system. mutations that don't thrive get kicked out or remixed and broken.

    the issue is, the bacteria doesn't care if it smells good or not. there is no evolutionary pressure to keep the mutation, as skin bacteria have already dominated the largest growth medium on dry land.

    a phage would be the most elegant way to effect this change, but again, the alteration wouldn't stick unless there was a reason to make it stick. all transgenic bacteria projects are always kept in sterile environments and regularly checked to make sure they haven't kicked the mutations we give them

    as the person who has this tweaked bacteria is surrounded by other bacteria, they would need to stop bathing as to not open up any available niches for outside factors. even so, this would not last long. touching anything would lead to contamination.

    now, if your bacteriophage worked really well, you could try to infect as many people as possible in the hopes that you could just kinda push the balance towards better smelling bacteria. but again, our love of attacking our skin flora with surfactants and disinfectants make a push like that hard to stick.

    i've been struggling with the same issues in my research on altering gut bacteria. basically, humans are delicately balanced ecosystems and 
    they are really good at returning to a balanced state unless you scorch earth the system repeatedly (soaps and antibiotics). 

    my suggestion is maybe tweak the metabolism a bit, link that to your scent mutation and then apply repeatedly, to as many surfaces and people as possible. after testing to see if there are any detrimental side effects of course ;)
  • I think what would be far simpler, as I have personally modified my gut flora over the years to deal with some issues, would be to simply bombard the skin ecosystem with several strains of bacteria all of which carry the new scent. throough horizontal gene transfer the genes will get spread around, even as you wash the old off. In theory if you continued to bombard yourself with the new bacteria enough new dna is in the eco system that even by random chance it will survive as long as the dominant bacteria randomly end up with the dna which is fairly likely. this is akin to how seaweed is meant to be consumed. by eating it fresh from the ocean you bring bacteria carrying the genes needed to break it down. this dna can be found in your gut flora long after any trace of the original bacteria species is gone. If you could develop or select a common family of bacteria and modify a batch you could spread around the new dna and make the adjustment permanent. 
  • Modifying your own scent is actually quite easy I have been doing it for years. there are two main factors to deal with when looking to get rid of body odor.

    First is the bacteria on the skin, I use alcohol to kill the bacteria (can get a little tingly in your sensitive area but works fine for me. after that apply an probiotic cream this causes a more pleasant bacteria to take hold in your smelly areas, most of the bacteria in probiotic creams to not really release an odor or at lease one that is noticable.

    Secondly is your personal secretions. This is more difficult but is directly related to what you consume. if you a smoker who only eats salted meats its going to stink, get used to to or change you habits.  the best way I have found to see and immediate change in the sweat odor is to drink A LOT of waters and white cranberry juice/ pineapple juice. 

    This is just from my personal experience /trial and error. also anti bacterial soaps just make things worse and before you clean yourself with alcohol it works best if you wash your bedding and all you clothes so that the bacteria that you are attempting to rid yourself of doesn't find its way back to you.  
  • @drjaaz  again the issue becomes, you fill up an ecosytem with a plasmid or whatever, and you hope that it gets passed around through horizontal transfer, but why? I mean what is the evolutionary pressure that causes this thing to be swapped and saved long enough to stick into a niche?
  • Bacteria are odd creatures. A lot of times they will share their dna, even if it doesn't seem useful at the time. After randomly culturing a large group of peoples microfloura, they found that some of the bacteria had incredible uses or were resistant to things they've never encountered or simply had dna that unless they were in very specific circumstances would do them no good. here's selection pressure, hosts that smell better attract a mate more easily and as such allow the bacteria to be spread around and  further spread their genetics. that alone is selection pressure. which could be sufficient to keep the things going
  • The thing is, I think if host interaction with others of the same species for bacterial propagation due to low levels of scent was a thing, bacteria wouldn't be so smelly ;) you have to realize, on their level, we really don't matter that much and we have a tendency to rut about regardless of scent or cleanliness. Think about the middle ages... bleugh. I know it was just an example, but it's important to think about these things from the bacteria level. Down there, it's a strange place.

    Still, wouldnt hurt to try :)

  • I figure if we are only modifying our own normal bacteria to smell better I can't see many things going horribly wrong. So i figure it would be a easy enough thing to try out. And if it sticks it could make for a great product. Imagine that, a little bottle you get at the drug store that changes how you smell
  • There was a company awhile back that claims to have removed the need to shower by cultivating some species of bacteria on the skin that feed on whatever body odor is made of.  If we could cultivate this bacteria ourselves that might be interesting, or even far away prospects of genemodding for specific smells?

  • ok so it's just like i said, the product basically goes along these lines: mist yourself with bacteria culture every day and don't shower. this particular bacteria eats ammonia byproducts that produce annoying smells and instead produce odorless byproducts. but like glims said they die off quickly so you have to reapply. So perhaps we go both ways. create a bacteria that both breaks down ammonia and produces a nice smell. you'd smell great. if you did this to a species native to your micro biome though it'd have a better chance of eventually sustaining itself without the addition daily. 
  • @drjaaz The issue I see with making a more resilient strain, or because its bacteria just selective breeding for more resilient strains, is that that would basically mean breeding/modding for faster replication cycles. That can be incredibly dangerous given that when we have open wounds, they already get infected from surface bacteria. But like all things. Maybe a dietary change can be applied to make a more hospitable environment? I mean the only issue with things like trying to modify bacteria , is population control. It could be done though, and with enough foresight, safely so.
  • if you want to continue in a gland modification process I don't know terribly much about it but I have heard that we put off a pheromone in our sweat that attracts the opposite sex.  If you wanna work on something gland related figure out how to make the body produce a ridiculous amount of that pheromone so it no longer matters if you stink. you'd be like the guy in those AX commercials. 
  • That would be interesting but how much test cells such as Saccharomyces cerevisie or e coli do you need to carry the gene of interest.
  • thats an odd question. i would suggest having roughly 10e7 cells per ml. Takes about a day to grow them up to that. if you arent working with at least that many cells, it will be a pain to do the insertion.

    luckily,number of cells is not an issue.
  • SO presumably you'd use pcr to isolate the dna that contains the protein you want in the new bacteria, and repeat until you have all of the segments you want, bind everything into a plasmid, insert into your cultured bacteria, select for the bacteria containing the new gene and colonize them. then just up the bacteria count until you have enough to use and store. yes?
  • pretty much. thos i would actually build the plasmid out of biobricks and do the insert. makes it easier to control things.
  • Review for me but I did remember this though. I did think about eukaryotic cell carrying the gene of interest that supposedly carried the human scent gene at first though. Not so much on E.coli. but i will have to go back to the cell biology books for details.
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