Are bamboo toothbrushes antibacterial?

Where the claim comes from

You’ll often read that bamboo is naturally resistant to bacteria, usually with a mention of a 2012 study. That study exists. It tested extracts of one bamboo species, made with water and two lab solvents, against a single bacterium, E. coli. One extract showed weak activity and another strong activity, and the authors wrote that the results indicate the active agents sit in the bamboo’s lignin.

That’s a real finding, but it’s a long way from a toothbrush. It tested extracts in the lab, not a solid handle that has been cut, dried and finished, and not anything in a bathroom or a mouth. The authors said the results “indicate”; they didn’t say they proved anything about bamboo products.

What other lab tests found

The studies differ in the bamboo species, how it was prepared and how it was tested, and their results don’t agree.

• One powder study: an effect. A 2022 study found that powder from two Japanese bamboo species held back E. coli and S. aureus in culture, while ethanol extracts of the same bamboo did poorly.
• A fibre and powder study: none. A 2012 conference paper found bacteriostatic rates of zero for bamboo fibre, bundles and powder against the microbes it tested, and its authors concluded the fibre had no natural effect.
• Plain timber: no inhibition zone. In a 2018 study, uncoated bamboo used as a control showed no inhibition zone against E. coli and was fully covered by two moulds.

None of these lab tests used a toothbrush handle. We couldn’t find one that did.

Bamboo fabric and bristles

Bamboo fabric, and toothbrush bristles sold as bamboo, can be viscose (rayon), a fibre made from bamboo as a raw material. The US Federal Trade Commission says there’s no trace of the original plant in finished rayon, and that anyone claiming rayon keeps antimicrobial properties from bamboo needs competent and reliable evidence, not other people’s say-so. In a 2020 lab test of five toothbrush bristle types, bamboo-viscose bristles showed no particular antimicrobial effect. One 2012 test did find regenerated bamboo fibre active against one bacterium, which its authors said may largely come from the chemicals used to make it.

What toothbrush studies show

A few small studies have compared bamboo and plastic brushes, and they point in different directions. They used different brands and small samples, and most sampled bristles or heads.

• A 2024 study with 10 people per group found fewer bacterial colonies on bristles from bamboo-handled brushes than from one plastic brand. Both brushes had plastic bristles, so the study can’t show whether the bamboo had anything to do with it.
• A small 2021 study, which alone among those we found swabbed handles, found fewer microbes on bamboo handles than plastic ones. It had only 10 brushes per group, and its introduction stated the result before testing it.
• Another 2021 study, of 50 people, found yeast on 76% of the bamboo brushes and 48% of the plastic ones; the authors called the difference not statistically significant.
• A 2024 pilot found the most bacteria on bamboo brushes kept in a bathroom with a toilet, and linked it to water building up in the head.

Why drying matters

Bamboo is prone to mould because of its starch and sugar, and a head that stays damp is where problems start. Rinse the brush well, shake it out, and let it dry upright in open air before it goes anywhere enclosed. We cover the details in why bamboo toothbrushes go mouldy and how to clean a toothbrush.

Where we fit

Our handles are bamboo, with sterilised horse hair bristles woven into the head. We don’t claim the bamboo does anything to bacteria, because we haven’t seen good evidence that a finished handle does. It needs the same drying habit as any bamboo brush.

The short version

• No lab study we found has tested a finished bamboo toothbrush handle.
• Lab results on bamboo disagree, and the studies differ in species, preparation and test.
• The often-quoted 2012 study tested extracts against one bacterium; it didn’t prove anything about brushes.
• Toothbrush studies are small and point both ways.
• Bamboo goes mouldy easily: dry it well, whatever else you read.