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View Full Version : Anti-bacterial soaps may do more harm than good



Angela
18-04-16, 18:44
This isn't the first time I've read about this. Maybe there's something to it.

See:
http://arstechnica.com/science/2016/04/mounting-data-suggest-antibacterial-soaps-do-more-harm-than-good/

It apparently isn't that these chemicals don't kill microbes, it's that the 30 seconds that we use them isn't long enough to get the benefit, or more of a benefit than hot water and soap without the chemicals.

Also, they do have their downsides, besides just taking in more chemicals.

"There are specific circumstances in which those antimicrobials can be useful, civil engineer Patrick McNamara of Marquette University in Milwaukee told Ars. Triclosan, for instance, may be useful to doctors scrubbing for minutes at a time before a surgery or for hospital patients who can’t necessarily scrub with soap but could soak in a chemical bath. Triclosan and triclocarban do kill off bacteria during long washes. But most people only clean their hands for a few seconds. “There’s evidence that there is no improvement with using soaps that have these chemicals relative to washing your hands under warm water for 30 seconds with soaps without these chemicals,” he said."

"A 2014 study (http://mbio.asm.org/content/5/2/e01015-13) led by microbiologist Blaise Boles of the University of Michigan in Ann Arbor tested 90 adults and found that 41 percent (37 people) had triclosan-laced boogers. Antimicrobial-snot paradoxically doubles your odds of having the potentially-infectious Staphylococcus aureus bacteria up your nose.In rats exposed to triclosan, Dr. Boles and his colleagues found that triclosan exposure made it more difficult, not less, for the rodents to fend off Staph invasions. Triclosan seems to make the bacteria “stickier”—better able to adhere to proteins and surfaces. That stickiness could be why Staph is so good at hunkering down in the schnoz, setting the stage for future infections.
Other researchers have been looking at how triclosan and other antimicrobials may alter microbial communities further down from the nose—in the gut.
Microbiologist Thomas Sharpton of Oregon State University and his colleagues are currently studying triclosan’s effect on the gut microbiomes of zebrafish, a model organism for vertebrate development. Their preliminary data (http://biorxiv.org/content/early/2016/02/14/039669.full-text.pdf+html) suggest that the antimicrobial causes swift, sweeping changes in the zebrafish gut microbiome, altering both diversity and community structure."

I've been a habitual user of those hand sanitizers they sell, mostly for when I'm out. Using hand rails etc. etc. when using public transportation, or even using public bathrooms skeeves me out, but I guess it's time to go cold turkey and throw it out.

LeBrok
19-04-16, 02:37
I'm usually sceptical of any new product which is hard to understand or see how well it works, like hand sanitizers or new antibacterial cleaning agents. Always advertised as 99.9% bacteria killed.
First of all, we don't want to kill good bacteria with bad ones. Good bacteria is friendly or even symbiotic to us, inside our bodies, on our skin or any surface. Killing good bacteria makes room, on any surface, for bad guys to spread quickly. To add to the pain, using just one cleaning agent, can make bacteria resistant to it and spread everywhere. Same as antibiotic resistant bacteria. We should use "cocktail" of agents at the same time to kill them. Leaving them astronomical chance to develop bunch of mutations at once to survive all the poisons.
The best example is HIV virus. Not actual bacteria, but hard to kill pathogen anyway. There is not one medication to kill it off, not even close. But using few disruptive to the virus drugs, the cocktail, to attack it from many sides, kills it off (or it goes into deep deep remission), and people can lead normal life with HIV these days.

Maciamo
19-04-16, 08:40
Even if antibacterial soaps could kill all bacteria, it would be pointless. The skin normally harbours the benign staphylococcus epidermis, which protects us against more dangerous bacteria, notably its cousin staphylococcus aureus (although numerous subspecies exist and some are much worse than others). If soaps and antibacterial agents left your hands germ-free, the skin would be left without protection and the vacuum could fill up with opportunistic pathogens.



I'm usually sceptical of any new product which is hard to understand or see how well it works, like hand sanitizers or new antibacterial cleaning agents. Always advertised as 99.9% bacteria killed.

Even if 0.01% of bacteria survived, they would quickly proliferate as bacteria divide every 20 minutes in average (some species as fast as every 7 minutes), so that after a few hours they would already have recovered their original number.


The best example is HIV virus. Not actual bacteria, but hard to kill pathogen anyway. There is not one medication to kill it off, not even close. But using few disruptive to the virus drugs, the cocktail, to attack it from many sides, kills it off (or it goes into deep deep remission), and people can lead normal life with HIV these days.

The reason why HIV is hard to eradicate is that it is a retrovirus that insert itself in the host's DNA. The only way to get rid of it is to cut out the virus's DNA sequence from the host's genome, using gene editing techniques like CRISPR. It should become standard procedure in a few years' time.