Naked Science Forum

Life Sciences => Cells, Microbes & Viruses => Topic started by: srollings on 12/04/2009 21:30:02

Title: Where do most bacteria reside on the body?
Post by: srollings on 12/04/2009 21:30:02
Stacey Rollings asked the Naked Scientists:
   
We have heard that 90% of the cells contained within the human body are
bacterial, not human.  

My question is, are the bacterial cells located throughout the body, or are they concentrated in areas such as the intestines and mouth?  

Love the show! (http://www.thenakedscientists.com/HTML/podcasts/)

What do you think?
Title: Where do most bacteria reside on the body?
Post by: Variola on 14/04/2009 11:37:13
Stacey Rollings asked the Naked Scientists:
   
We have heard that 90% of the cells contained within the human body are
bacterial, not human. 

My question is, are the bacterial cells located throughout the body, or are they concentrated in areas such as the intestines and mouth? 

Love the show! (http://www.thenakedscientists.com/HTML/podcasts/)

What do you think?

Without hunting throughmy books, my best guess would be the skin. I think even with the numerous folds and length of intestine, it still beats it on surface area. The skin is full of bacteria, most of it quite useful and helps to munch up any erroneous flora on the surface of our skin. Thats often why after a course of antibiotics, some people find they are prone to thrush infection, as the normal compliment of bateria have been destroyed.
Having said that the gut is jam packed with bacteria, most of it performing useful tasks of Vit K synthesis, and breakdown of foodstuffs.

Ok...Im still voting skin.... what does everyone else think??
Title: Where do most bacteria reside on the body?
Post by: RD on 14/04/2009 20:33:38
My answer is a load of crap...

Quote
The colon contains large numbers of bacteria that make up about one-third to one-half of the dry weight of the faeces..
http://tripatlas.com/Human_feces

Quote
faecal bacterial mass accounted for 44 and 35% of faecal dry weight
http://www.nature.com/ejcn/journal/v61/n2/full/1602496a.html


I doubt even a pig in rolling in "muck" would have bacteria on its skin which exceeded 1/3rd the dry mass of its daily faeces.
Title: Where do most bacteria reside on the body?
Post by: Bored chemist on 14/04/2009 21:20:56
I heard that the answer is that it depends on what you mean by "more bacteria". By weight the gut wins. By number of varieties, the mouth wins- we keep innoculating it with stuff we call food. Practically none of that is sterile so lots of different bugs get a chance to grow in the mouth and lots succeed.
I think that the skin is (in most cases, not very heavily populated by bacteria because it's fairly dry (for the most part).
Title: Where do most bacteria reside on the body?
Post by: Phil1907 on 15/04/2009 00:00:05
As was said gut then mouth - thoiugh oral flora are consistent and not variable by whatever goes in.  Skin has substantial populations.

Substnatial part of the flora isn't be cultured by conventional means.