The Hidden Side of Laundry: More Than Just Clean Clothes

Laundry removes visible dirt — but textiles may still carry complex microbial communities.

Laundry as a Microbial Ecosystem

Laundry is not just cleaning — it is managing a changing microbial ecosystem.

Throughout the wear–wash–dry cycle, fabrics interact with:

• Human skin microorganisms
• Environmental microorganisms
• Washing machine microbes

What Happens to Fabrics During Daily Use?

During daily use:

• Skin microorganisms attach to fibres.
• Sweat and organic residues accumulate.

What Happens During Washing and Drying?

During washing and drying, some microorganisms are removed, while others may be introduced from the washing environment, including:

• Washing-machine rubber seals
• Detergent drawers
• Sump and drain areas
• Filters and hoses
• Washing-machine biofilms
• Influent water

As a result, the textile microbiome is reshaped.

Laundry does not simply remove microbes — it changes the textile ecosystem.

How Microbes Create Laundry Odour

Textile odour is primarily associated with microbial metabolism of organic residues accumulated during wear.

Microorganisms break down:

• Sweat-derived compounds
• Skin lipids (sebum)
• Organic residues retained within textile fibres

This process produces volatile organic compounds (VOCs) that contribute to unpleasant textile odours.

Why Humidity Brings Odour Back

Microbial activity depends strongly on moisture.

Dry Conditions:

• Less available water
• Reduced microbial activity

Humid Conditions:

• Prolonged moisture retention
• Support microbial growth
• Promote odour regeneration

The Washing Machine as a Source of Textile Microbes

Washing machines contain microbial communities influenced by:

• Moisture retention
• Detergent residues
• Organic material accumulation

During washing, microorganisms from the washing machine environment can transfer to textiles.

Why Can Some Microbes Persist After Washing?

Some bacteria can form biofilms — structured communities protected by a self-produced matrix.

Biofilms help microorganisms:

• Attach to textile fibres
• Resist environmental stress
• Persist after repeated laundering

Laundry Hygiene Is a Dynamic Microbial Ecosystem

Laundry hygiene depends on interactions between:

• Textile microbial communities
• Textile fibre structure
• Moisture during drying
• Odour-producing microbial activity

Washing does not necessarily eliminate all microorganisms; it can reshape the microbial environment of textiles.

From Laundry Science to Better Textile Hygiene

Supporting longer-lasting textile hygiene involves considerations that extend beyond the wash cycle.

The wear–wash–dry cycle shows that cleaning does not always mean complete microbial removal. Microorganisms can persist, interact with textile surfaces, and contribute to odour and hygiene challenges.

Reference

Díez López, C., et al. (2025). Unravelling the Hidden Side of Laundry: Malodour, Microbiome and Pathogenome. BMC Biology.