What benefits do bacteria on your skin provide?

[Q_Goest]

Wikipedia suggests a typical human has ~ one trillion bacteria on their skin. That’s orders of magnitude more than a cell phone and many many orders of magnitude more than a toilet seat.

They typically don't cause disease and may offer benefits. It kind of bothers me that there’s this common belief that microbes are bad and the more sterile our skin is, the healthier we will be. There seems to be a push to reduce bacteria of all kinds on our skin.

Here’s one example I know of regarding beneficial bacteria and acne. This is from Science:

When [the researchers] sequenced the genomes of each strain and compared them, they discovered that two of the strains, RT4 and RT5, were found predominantly in people with acne—and that one strain, RT6, was found almost exclusively in people with clear skin. Because this "good" strain contains genes known to fight off bacterial viruses and other potentially harmful microbes, the researchers suspect that it may actively ward off the "bad" strains that are associated with disease, thereby keeping skin healthy.

"Just like good strains of bacteria in yogurt, for example, are good for the gut, these good strains of P. acnes could be good for the skin," says Li, whose team reports the findings today in the Journal of Investigative Dermatology.

Maybe if you have acne, you should rub faces with someone with healthy skin. Preferably someone of the opposite sex.

Anyway, I bet there are a lot of benefits to having the right bacteria on your body. Wikipedia states that most bacteria are in the epidermis or hair follicles so perhaps they are difficult to wash off. Hopefully the good bacteria don’t get destroyed by that anti-bacterial stuff in those dispensers, but I don’t know.

Not too sure where I’m going with this but I’d be interested in comments, especially around the benefits these bacteria have on our skin and our health in general. What bacteria are they and what benefits can they provide?

 

[Q_Goest]

My nephew send me this regarding dirty dogs. I guess these examples are all part of the larger hygiene hypothesis. I’m sure there must be numerous examples of studies out there like this.

 

[SteamKing]

Skin bacteria are OK as long as they stay on your skin. In some people, if skin bacteria get inside the body thru a cut in the skin, they can develop some nasty diseases, like necrotising fasciitis, or flesh-eating disease.

http://en.wikipedia.org/wiki/Necrotizing_fasciitis

The bacteria responsible for this disease are quite benign as long as they remain on, not in, the skin.

 

[Enigman]

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC120688/
http://www.nlm.nih.gov/medlineplus/druginfo/natural/790.html

 

[Q_Goest]

Hi SteamKing,

Skin bacteria are OK as long as they stay on your skin. In some people, if skin bacteria get inside the body thru a cut in the skin, they can develop some nasty diseases, like necrotising fasciitis, or flesh-eating disease.

http://en.wikipedia.org/wiki/Necrotizing_fasciitis

The bacteria responsible for this disease are quite benign as long as they remain on, not in, the skin.

There are problems of course with cuts to the skin and harmful bacteria getting inside. We don't need to invoke flesh eating bacteria to see the problem with infections, only that the body has a reaction to bacteria that enter our bodies that way. Sterilizing our environment and our skin might help to get rid of these bacteria, but wouldn't it be better to steralize the area of the wound instead? I think the point is that we need various types of bacteria both on our skin and in our gut to remain healthy.

 

[Q_Goest]

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC120688/
http://www.nlm.nih.gov/medlineplus/druginfo/natural/790.html

I had to laugh a bit at that first one, but it brings up a point about couples or any group of people in close physical contact. I would suspect that there's a need to 'swap' these good bacteria between people and I wonder if the most likely way that happens is through close, physical contact. I've heard something about gut bacteria being transmitted to babies on birth - the reason god put the playground and the septic tank so close together.

The gastrointestinal tract of a normal fetus is sterile. During birth and rapidly thereafter, bacteria from the mother and the surrounding environment colonize the infant's gut. Immediately after vaginal delivery, babies may have bacterial strains derived from the mothers' feces in the upper gastrointestinal tract.[25] Infants born by caesarean section may also be exposed to their mothers' microflora, but the initial exposure is most likely to be from the surrounding environment such as the air, other infants, and the nursing staff, which serve as vectors for transfer.[26] The primary gut flora in infants born by caesarean delivery may be disturbed for up to six months after birth, whereas vaginally born infants take up to one month for their intestinal microflora to be well established.[27] After birth, environmental, oral and cutaneous bacteria are readily transferred from the mother to the infant through suckling, kissing, and caressing.

Ref: http://en.wikipedia.org/wiki/Gut_flora#Acquisition_of_gut_flora_in_human_infants

 

[SteamKing]

Hi SteamKing,

There are problems of course with cuts to the skin and harmful bacteria getting inside. We don't need to invoke flesh eating bacteria to see the problem with infections, only that the body has a reaction to bacteria that enter our bodies that way. Sterilizing our environment and our skin might help to get rid of these bacteria, but wouldn't it be better to steralize the area of the wound instead? I think the point is that we need various types of bacteria both on our skin and in our gut to remain healthy.

No one disputes this. However, sterilization is not always 100% effective. I'm just pointing out that even beneficial bacteria can be harmful when, for whatever reason, they wind up out of place in the body.

 

[johnnymorales]

I had to laugh a bit at that first one, but it brings up a point about couples or any group of people in close physical contact. I would suspect that there's a need to 'swap' these good bacteria between people and I wonder if the most likely way that happens is through close, physical contact. I've heard something about gut bacteria being transmitted to babies on birth - the reason god put the playground and the septic tank so close together.


Ref: http://en.wikipedia.org/wiki/Gut_flora#Acquisition_of_gut_flora_in_human_infants

Left unsaid is how this happens during vaginal birth. LOL

Women almost always defecate during labor as their ability to control their anal sphincter is severely compromised and completely overwhelmed by their concentrated effort to push the baby out.

As a result no matter how hard attendants try to keep the environment neat and tidy by the time the baby is born he or she will get a sufficient dose to ensure proper colonic colonization.

Considering most pediatricians know this, I'm sure only cursory efforts are made to tidy things up during a labor to ensure a baby gets properly dosed.