[dbingham]

There are many bacteria that are not the sort that are going to attack your immune system, defective or not. No matter how much you wash or use antibiotics you never eradicate bacteria from your environment. Rather, you select for the bacteria most resistant to the chemicals you apply to them.

The bacteria in the sorts of microbiomics discussed in this article are (usually) totally symbiotic. They aren't going to harm you, they are going to help you. They are going to be a secondary immune system and provide you a layer of protection. Removing them is actually more dangerous for you than encouraging them. In removing them, you create a vacuum that is easier for harmful and parasitic organisms to invade.

Edit: I haven't actually seen the research (and it might not have been done yet) on the specific species mentioned in the article. So I edited to speak more generally.

The idea many of us have been indoctrinated with that all microorganisms are potentially harmful invaders is not only completely false, that belief has lead us as a society to take action that was potentially very harmful to us. There's an entire ecosystem down there, and much of it evolved in symbiosis with us. We provide them a home, and in return they protect and clean us. They don't want to destroy their home, they would die, too.

We could learn a thing or two from them in that regard.

[jamesaguilar]

I don't think this is accurate. Many bacteria that are symbiotic with immuno-normal humans are parasitic and harmful to immunocompromised humans.

That said, it's unclear that regular washing with soap removes the kinds of bacteria that have the potential to be harmful -- I know for sure that skin is constantly covered with bacteria, with and without washing. So I don't know if GP's objection is realistic.

[dbingham]

Yes, there are some species that are only symbiotic in the right circumstances, but are very harmful if they escape their niches. But there are also thousands of species that are evolved for very specific niches with in our bodies and cannot survive outside of those niches. When in those niches, they are helpful. When outside of them, they are harmless. Immunocompromised or not.

But you're right, I don't actually have the evidence to say whether the bacteria discussed with in the article are of the sort that are always harmless or of the sort that can be very harmful in the wrong circumstance. I'll edit the comment. I do think it is likely that they are largely harmless, because of the ammonia based metabolism. That would be pretty limiting. Also, their apparent fragility.

[jrabone]

We provide them a home, and in return they protect and clean us. They don't want to destroy their home, they would die, too.

Sorry but that is absolute, unmitigated rubbish. I spent 2 weeks in intensive care, with a surgical scar from my sternum to my groin which de-hisced (burst open) because my own bacteria tried to kill me.

While they might be symbiotic in the right place (eg. the gut), they'll kill you pretty quickly if they get out.

[dbingham]

You are over generalizing while also making appeals to emotion based upon your (admittedly terrifying, painful and difficult) experience. I'm sorry you had to go through that and hope life gets better for you.

But applying that emotional appeal to this argument is not valid. Yes, some bacteria are symbiotic in certain environments but extraordinarily dangerous if they escape into other parts of the body. There are particular gut bacteria that are especially notable in that regard. But there are thousands of species of bacteria that live in all parts of our body. The vast majority of these are harmless or even helpful, period. If they find themselves in an environment that isn't the specific niche they evolved for, they die.

While I haven't seen the research on the particular species discussed in the article, it is entirely possible (I would say likely) that it is one of those. Rather than one of the species that can wreck havoc if it escapes its proper environment.

[jrabone]

For hopefully the last time, I'm not talking about the bacteria in the product. All human beings defecate. Many (most?) clean themselves afterwards with their hands. If you do not practise adequate hygiene with a surfactant-based cleanser, those faecal bacteria are still stuck to the skin afterwards and transfer to anything you touch, where they may be picked up by someone else who is not in a position to deal with them. This is not an appeal to emotion, it is a fact which I happen to have had personal experience of.

[dllthomas]

And again, the article doesn't speak clearly to handwashing specifically. It would seem that ideally, if someone believes in this kind of thing, the appropriate behavior when faced with handling something likely loaded with bad bacteria (which cleaning after defecation would include) would be to subsequently clean your hands with soap and hot water, and then reapply the N. eutropha.

[dllthomas]

By stating that the gut is the "right place" for these particular bacteria, you are begging the question. It is unquestionably the case that there are bacteria in our gut flora that we definitely do not want anywhere but the gut. It does not follow that this applies to all bacteria.

Compare pathology of the bacterium under discussion (http://microbewiki.kenyon.edu/index.php/Nitrosomonas_eutroph...) with one that more clearly doesn't belong anywhere but the gut (http://microbewiki.kenyon.edu/index.php/Escherichia_coli).