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Scientists solve the mystery of why smelly armpits smell the way they do

Donna Coutts, July 28, 2020 8:45AM Kids News

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Underarm body odour may have been around for longer than humans, but it can be very unpleasant for those around you. media_cameraUnderarm body odour may have been around for longer than humans, but it can be very unpleasant for those around you.

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Scientists have solved the mystery of smelly armpits.

And they now understand that the substances and processes that make armpits smell predate* Homo sapiens* and may have had an important role in communication between our ancestors.

Researchers from the University of York in the UK discovered a unique substance within armpit bacteria that is responsible for the very recognisable odour some people call BO, short for body odour.

The substance is an enzyme, which is a type of molecule* that speeds up chemical reactions in living things.

The same team of researchers had previously shown that it is just a few types of bacteria that causes body odour.

This new research highlights how particular bacteria have evolved a specialised enzyme to produce some of the key molecules we recognise as BO when we smell it.

Co-lead researcher Dr Michelle Rudden said in a statement released by the University of York that this was a key discovery that will help people be less smelly, offering an alternative to merely masking bad smells, such as with strongly perfumed products.

“Solving the structure of this BO enzyme has allowed us to pinpoint the molecular step inside certain bacteria that makes the odour molecules. This is a key advancement in understanding how body odour works, and will enable the development of targeted inhibitors* that stop BO production at source without disrupting the armpit microbiome*.”

Human armpits — particularly in teenagers and adults — host a diverse community of bacteria that is part of your natural skin microbiome. This research highlights Staphylococcus hominis as one of the main microbes* behind body odour.

Furthermore, the researchers say that this BO enzyme was present in Staphylococcus hominis long before Homo sapiens was a species, suggesting that body odour existed prior to the evolution of modern humans, and may have had an important role in societal* communication among ancestral* primates.

The University of York scientists worked with Unilever scientists on this project. Unilever makes personal products such as deodorant and soap, among other things.

Unilever co-author Dr Gordon James said in a statement: “This research was a real eye-opener. It was fascinating to discover that a key odour-forming enzyme exists in only a select few armpit bacteria — and evolved there tens of millions of years ago.”

The results are published in the journal Scientific Reports.

media_cameraA key odour-forming enzyme exists in only a select few armpit bacteria and evolved there tens of millions of years ago.

GLOSSARY

  • predate: came before
  • Homo sapiens: human species name
  • molecule: smallest particle of a substance that has the properties of that substance
  • inhibitors: things to stop of slow down something happening
  • microbiome: community or colony of microorganisms on a surface or in a place
  • microbes: plural word for microorganisms
  • societal: relating to or within a society
  • ancestral: belonging to or inherited from ancestors

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QUICK QUIZ

  1. Which university are the researchers from?
  2. Do all types of bacteria cause smelly armpits?
  3. What is Staphylococcus hominis?
  4. Is it a new enzyme? How long has it been around?
  5. How is this research relevant to Unilever?

LISTEN TO THIS STORY

CLASSROOM ACTIVITIES
1. Body odour issues
Work with a fellow classmate and list some of the issues body odour (or BO as some adults refer to it) creates for teenagers and adults in today’s society.

For example: Might be ridiculed or given unkind nicknames due to their smell

Now list some of the reasons why people may have this odour or don’t know how to stop the odour.

If they developed a way to stop the odour, would this solve the problems you’ve listed above? Why or why not?

Time: allow 15 minutes to complete this activity
Curriculum Links: English, Personal and social

2. Extension
How do you think our ancestral primates might have used body odour to communicate or identify each other? If you closed your eyes and had a family member close, do you think you could identify who it is? How?

Time: allow 10 minutes to complete this activity
Curriculum Links: English, Critical and Creative thinking

VCOP ACTIVITY
Opener Operation
After reading the article, with a partner, highlight all the openers you can find in blue. Discuss if they are powerful and varied openers or not. Why do you think the journalists have used a mix of simple and power openers? Would you change any, and why?

HAVE YOUR SAY: Is it important to you that scientists solve the mystery of smelly armpits?
No one-word answers. Use full sentences to explain your thinking. No comments will be published until approved by editors.

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