FEB 06, 2016 3:31 PM PST

Antiperspirant and the Armpit Microbiome

WRITTEN BY: Kerry Evans
Antiperspirant and deodorant keep you smelling fresh, but they also alter your armpit microbiome.

The microbiome continues to be a hot topic.  Sometimes it’s also a stinky topic, like when it has to do with armpits.  Researchers at North Carolina State University just published a study on the armpit microbiome. According to author Julie Horvath, “we wanted to understand what effect antiperspirant and deodorant have on the microbial life that lives on our bodies, and how our daily habits influence the life that lives on us”.
 
Antiperspirants increase bacterial diversity.


First off, there’s a difference between antiperspirant and deodorant (this was news to me). Antiperspirants contain aluminum salts that block sweat production.  Bacteria find lots of tasty nutrients in your sweat, so less sweat means fewer bacteria.  Deodorants simply use antimicrobials to kill bacteria.

For the study, Horvath and colleagues swabbed the armpits of 17 participants for 8 days.  On the first day, the participants followed their usual routine - some used deodorant, some used antiperspirant, and some used nothing at all.  On days 2-6, the participants did not use antiperspirant or deodorant.  Then on days 7-8, all the participants used antiperspirant.

As expected, there were more bacteria, around 750 CFU, in their armpits when no deodorant or antiperspirant was used.  When the participants all used antiperspirant, the numbers decreased to around 73 CFU.

However, the researchers were surprised to find that antiperspirant actually increased bacterial diversity. Participants who did not regularly use antiperspirant or deodorant had the most Corynebacterium (these species are responsible for “body odor”).  For participants who regularly used deodorant, 61% of their armpit bacteria were Staphylococcus, 29% were Corynebacterium, 5% Anaerococcus, and 5% were other species.  For antiperspirant users, however, 60% were Staphylococcus, 14% Corynebacterium, 4% Anaerococcus, and a whopping 22% were other species.

It’s not clear whether these changes are good or bad for your overall health.  According to Horvath, Within the last century, use of underarm products has become routine for the vast majority of Americans … yet, whether use of these products favors certain bacterial species – be they pathogenic or perhaps even beneficial – seems not to have been considered, and remains an intriguing area needing further study”.


Sources: North Carolina State University, Wikipedia

 
About the Author
  • Kerry received a doctorate in microbiology from the University of Arkansas for Medical Sciences.
You May Also Like
MAY 23, 2020
Microbiology
The FDA Yanks Some COVID-19 Antibody Tests From the Market
MAY 23, 2020
The FDA Yanks Some COVID-19 Antibody Tests From the Market
The massive demand for diagnostic testing led the FDA to open a short window for many testing products to go to market w ...
JUL 05, 2020
Microbiology
Stimulating Antibiotic Production in Bacteria
JUL 05, 2020
Stimulating Antibiotic Production in Bacteria
The microorganisms of the world have to compete for survival, and they sometimes do battle with one another. Some use an ...
JUL 13, 2020
Microbiology
New Gene Editor Can Alter Mitochondrial DNA
JUL 13, 2020
New Gene Editor Can Alter Mitochondrial DNA
There is intense competition for resources in the microbial world, and bacteria have an arsenal of weapons to help them ...
JUL 20, 2020
Genetics & Genomics
A Tiny But Efficient Cas Protein is Discovered in a Bacteriophage
JUL 20, 2020
A Tiny But Efficient Cas Protein is Discovered in a Bacteriophage
The microbes of the world are locked in a struggle for survival and a battle for resources. They compete directly in dif ...
JUL 27, 2020
Space & Astronomy
Bacteria More Lethal and Antibiotic Resistant in Space
JUL 27, 2020
Bacteria More Lethal and Antibiotic Resistant in Space
Research has shown that bacteria are more lethal and resistant to antibiotics when exposed to microgravity (a lack of gr ...
AUG 05, 2020
Microbiology
Revealing the Secrets of a Symbiotic Relationship
AUG 05, 2020
Revealing the Secrets of a Symbiotic Relationship
Some salamanders (Ambystoma maculatum) have a strange relationship with a type of fungus (Oophila amblystomatis): they a ...
Loading Comments...