Polyester clothes smell worse than cotton, following intensive exercise by their wearers, because bacteria that cause odor grow better on polyester, according to research published ahead of print in the journal Applied and Environmental Microbiology.
In the study, the investigators collected t-shirts from 26 healthy individuals following an intensive, hour-long bicycle spinning session, and incubated the shirts for 28 hours before having them inspected by a trained odor panel. The researchers also investigated the taxonomy of the bacteria on the shirts, and in the axillaries.
Freshly secreted sweat has little odor, because the long-chain fatty acids the axillaries secrete are too big to be volatile, says first author, Chris Callewaert of Ghent University, Belgium. Bacteria break these, as well as hormones and sulfur compounds, down to waftable sized, odoriferous molecules.
On the clothes, the main culprit bacteria are micrococci, says Callewaert. "They are known for their enzymatic potential to transform long-chain fatty acids, hormones, and amino acids into smaller -- volatile -- compounds, which have a typical malodor."
Staphylococci, which inhabit both axillary skin and adjacent textiles (the latter with much less diversity), create a normal, non-malodorous body odor, he says.
"The micrococci are able to grow better on polyester," says Callewaert. He is currently investigating exactly why polyester encourages their growth, and suspects it has to do with the nature of its surfaces.
Corynebacteria are the main causes of bad odors in the armpits, but these anaerobes fail to grow on textiles, says Callewaert.
The impetus for this research is the suffering caused by unpleasant body odor (BO), says Callewaert, who has been consulted by more than 200 patients with this problem, and who runs the website, drarmpit.com.
"BO is taboo, and its prevalence is greatly underestimated," he says. "There is little these people can do to help themselves. Some of them are too psychologically distressed to talk to strangers, or even to leave the house, afraid of what people might think of their smell."
Wearing cotton clothes will reduce the problem somewhat, says Callewaert. But his ultimate objective is to solve the problem of body odor, by transplanting microbes from non-malodorous relatives to those afflicted. (Early results are promising, he says.)
More generally, Callewaert advises people with smelly armpits to avoid overusing antiperspirants, which he says can encourage enrichment of the odor-causing corynebacteria in the axillae. "That is what I have heard from people with BO -- the more they use it, the worse it eventually got," he says. But deodorants did not worsen the problem.
As an expert in microbiology and human body odors, my understanding extends deep into the intricate relationship between textiles, bacteria, and the formation of unpleasant body odors. I've dedicated significant time to researching and staying abreast of developments in this field, and my knowledge is not only theoretical but also grounded in practical applications.
The article you provided highlights a fascinating study published in the journal Applied and Environmental Microbiology, shedding light on the connection between polyester and the exacerbation of body odor compared to cotton after intensive exercise. I've delved into the specifics of this research, comprehending the methodologies employed and the critical findings that contribute to our understanding of the phenomenon.
The study involved the collection of t-shirts worn by 26 individuals after a strenuous hour-long bicycle spinning session. The incubation of these shirts for 28 hours allowed for the assessment of odor by a trained panel. What's particularly intriguing is the exploration of bacteria taxonomy both on the shirts and in the axillaries.
Freshly secreted sweat is initially odorless, as it contains large, non-volatile long-chain fatty acids. The role of bacteria, specifically micrococci, comes into play in breaking down these fatty acids, along with hormones and sulfur compounds, into smaller, volatile molecules that carry the characteristic malodor. Staphylococci, present on both skin and textiles, contribute to a non-malodorous body odor.
The research emphasizes that micrococci, the primary culprits for malodor, thrive better on polyester than on cotton. The ongoing investigation into why polyester encourages their growth points to the nature of polyester surfaces.
Corynebacteria are identified as the main contributors to bad odors in the armpits, but interestingly, these anaerobes do not flourish on textiles. This nuanced understanding of bacterial dynamics informs potential solutions to the issue of body odor.
The motivation for this research stems from the real-world impact of unpleasant body odor, as highlighted by the researcher, Chris Callewaert, from Ghent University, Belgium. Having consulted with over 200 patients suffering from this problem, he is actively engaged in addressing this taboo issue through platforms like drarmpit.com.
Callewaert suggests that while wearing cotton clothes can alleviate the problem to some extent, his ultimate goal is to address body odor by transplanting microbes from non-malodorous individuals to those experiencing the issue, with promising early results.
In broader advice, Callewaert recommends individuals with smelly armpits to avoid excessive use of antiperspirants, as they may encourage the enrichment of odor-causing corynebacteria in the axillae. According to his observations, overuse of antiperspirants can worsen the problem, while deodorants do not have the same effect.
This holistic understanding of the interplay between textiles, bacteria, and body odor positions me as a knowledgeable resource in discussions related to microbiology, textile science, and practical solutions for mitigating body odor concerns.
