Hand Sanitizer and your Microbiome

By: Patience Lister

Hand sanitizer is rapidly becoming the “new” soap. If you take a brief walk around any urban centre, you will likely witness multiple people applying it to their hands. For many people, the choice to use hand sanitizer is a no brainer – after all, it’s portable, doesn’t require water, and is effective at killing different types of germs.

The downside is that overusing hand sanitizer can affect the integrity of your skin and your microbiome. Thankfully there are ways to enjoy the convenience of hand sanitizer while also protecting your overall well-being.

The science behind hand sanitizer

Hand sanitizers are categorized as alcohol based or non-alcohol based. Alcohol based sanitizers that contain 60% to 90% alcohol are effective options for killing or deactivating bacteria and viruses. The alcohol works by breaking down the proteins and dissolving the lipids or fats that form the outer layer of bacterial cells and viruses.[1] Benzalkonium chloride, an active ingredient in many non-alcohol based hand sanitizers, also works by weakening the outer lipid structure and disrupting the internal structure of many different microorganisms. Although both categories of hand sanitizer are effective, The World Health Organization recommends using alcohol based hand sanitizers to prevent most infections.[2]

Hand sanitizers may also contain substances that promote the retention of moisture, such as glycerol, propylene glycol, or aloe, to help counteract the dehydrating effect of alcohol or other key ingredients on your skin. These substances also help slow the evaporation of alcohol from your hands. Slower evaporating increases the contact time between alcohol and germs, which increases the hand sanitizer’s effectiveness.

With proper use, alcohol based hand sanitizers have been shown to reduce the risk of infections from rhinovirus, rotavirus, and norovirus by as much as 98%, depending on how contaminated your hands are.[3] When used together with respiratory hygiene practices, such as covering your mouth and nose when coughing or sneezing, frequent use of hand sanitizer has also been shown to reduce influenza A infection by 52% in schoolchildren.[4]

But as convenient and effective as hand sanitizer is, there are consequences to overusing it.

Hand sanitizer and your microbiome

We often hear about the infectious microorganisms that get picked up from touching contaminated surfaces, but your skin is also home to billions of beneficial microorganisms that don’t cause disease or harm.[5],[6] A delicate balance of bacteria, yeast, and fungi make up the microbiota of your skin. They interact closely with your immune system and are easily affected by everything that your skin is exposed to, from your clothing and cosmetics to your hygiene products.

As important as hand hygiene is, overdoing it can be damaging to your skin microbiome. Too much hand washing can wear away the skin’s fatty acids that help protect it from disease-causing microorganisms. Overusing hand sanitizer can also dry out and irritate your skin, leading to an imbalance in its microflora[J2] .[7]

Along with damage from overuse, some of the ingredients found in common hand sanitizers, such as triclosan and benzalkonium chloride, have a negative impact on your microbiome.[8],[9] Studies suggest that high exposure to triclosan may increase the risk of allergies. Animal-based studies also suggest that over time, using products that contain triclosan can alter intestinal microbiota and increase the risk of digestive disorders. In addition, exposure to benzalkonium chloride from non-alcohol based sanitizers can lead to contact dermatitis.

Despite the drawbacks of overuse, hand sanitizer plays an important role in helping to prevent infection. You can help protect your microbiome by limiting your use of hand sanitizer to times when handwashing is not available and by including live probiotic cultures in your diet.

Supporting your microbiome with probiotics

Your gut and skin microbiome depend on each other. This means that when the balance of microorganisms in your gut changes, it affects your skin. Similarly, when the microbiota of your skin is altered, it affects your immune function.[10]

Your gut microbiome influences inflammation, oxidative stress, and the lipid content of body tissues. When it is disrupted by illness, antibiotics, or exposure to damaging hand hygiene practices, it can leave you more susceptible to infection.

One of the best ways to re-establish a healthy gut microbiome and indirectly support skin health is by adding live probiotic cultures to your diet. Probiotic supplements have been successfully used to help reduce symptoms in people suffering from atopic dermatitis, acne, seborrheic dermatitis, burn wounds, and skin ulcers.

The Natural Factors line of probiotic supplements, such as Double Strength Ultimate Multi Probiotic and Critical Care Probiotic, contain live active cultures of beneficial bacteria and yeast to help maintain and re-establish a healthy gut microbiome. Depending on your age and health concerns, there are a variety of formulas with synergistic combinations of Lactobacillus, Bacillus, Enterococcus, and Saccharomyces strains to choose from.

Use hand sanitizer responsibly

Hand hygiene is a critical step in preventing infections. In addition to taking a probiotic supplement, you can support a healthy microbiome by using hand sanitizer responsibly. This means only using hand sanitizer when soap and water is not available and choosing a product that is free from synthetic fragrances, parabens, and other potential irritants. To make sure that your hand sanitizer is effective, read the label to learn the correct amount needed, cover all surfaces of your hands, and allow it to air dry naturally

[1] Golin AP, Choi D, Ghahary A. Hand sanitizers: A review of ingredients, mechanisms of action, modes of delivery, and efficacy against coronaviruses. Am J Infect Control. 2020; 48(9):1062-1067.

[2] Siddharta A, Pfaender S, Vielle NJ, et al. Virucidal activity of World Health

Organization-recommended formulations against enveloped viruses, including

Zika, Ebola, and emerging coronaviruses. Br Rep J Infect Dis. 2017; 902:902–


[3] Tamimi AH, Maxwell S, Edmonds SL, et al. Impact of the use of an alcohol-based hand sanitizer in the home on reduction in probability of infection by respiratory and enteric viruses. Epidemiol Infect. 2015; 143(15):3335-3341.

[4] Stebbins S, Cummings DAT, Stark JH, et al. Reduction in the incidence of influenza A but not influenza B associated with use of hand sanitizer and cough hygiene in schools: A randomized controlled trial. Pediatr Infect Dis J. 2011; 30(11):921-926.

[5] Schloss PD. An integrated view of the skin microbiome. Nature. 2014; 514:44-45.

[6] Grice EA, Segre JA. The skin microbiome. Nat Rev Microbiol. 2011; 9(4):244-253.

[7] Himabindu CS, Tanish B, Padma priya D, et al. Hand sanitizers: is over usage harmful? WJCMPR. 2020; 2(4):296-300.

[8] Wentworth AB, Yiannias JA, Davis MD, et al. Benzalkonium chloride: A known irritant and novel allergen. Dermatitis. 2016; 27(1):14-20.

[9] Halden RU, Lindeman AE, Aiello AE, et al. The Florence Statement on Triclosan and Triclocarban. Environ Health Perspect. 2017; 125(6):064501.

[10] Yu Y, Dunaway S, Champer J, et al. Changing our microbiome: probiotics in dermatology. Br J Dermatol. 2020; 182:8-9.

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