Once you get past the initial ick-factor of toothbrush sharing, it's worth considering whether there are any actual harms.

Whether we like it or not, our mouths are home to a unique microbiome.

As Norman and Tegan explain, it's influenced by what we eat, who we kiss – and yes, who we might share a toothbrush with.

References

• Armed to the Teeth—The Oral Mucosa Immunity System and Microbiota
• Assessment of Microbial Contamination of a Toothbrush Head with and without a Protective Cover: An Ex Vivo Study