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Probiotics and Norovirus

Helen Morton BSc (Hons), Nutritional Therapist DipION, BANT, CNHC

Norovirus, more commonly known as ‘the winter vomiting bug’, infects millions globally each year1 and tends to peak during winter. Outbreaks are particularly common in care homes, hospitals, and schools, with the elderly and young children being most at risk. That being said, even the most fit and healthy people can be hit with a stomach bug like norovirus as it’s so contagious2.

In this article, we explore how norovirus and other stomach bugs can affect your gut microbiome. We then talk you through the science behind some of the most researched strains of probiotics to support you and your family through the most common symptoms. 

What is norovirus?

This winter, the norovirus bug, which causes acute gastroenteritis, is doing the rounds across the whole of the UK, and this time there is a new strain present. The strain is called GII.17 or ‘Kawasaki’ and it appears to be a new variant. This means that even if you had Norovirus last winter, unfortunately, it’s quite possible to catch it again as you’ll likely not be immune to this new strain.

Norovirus is a nasty tummy bug that causes vomiting, hence the name ‘winter vomiting bug’, often accompanied by diarrhoea, particularly in young children and older adults4. Other typical symptoms include nausea, fatigue, cramps, body aches5 and generally feeling quite unwell. All in all, norovirus doesn’t mess around. One moment you’re fine, and the next you’re dealing with violent nausea, vomiting, and diarrhoea, leaving sufferers feeling wiped out and run down for some time afterwards.

Norovirus causes vomiting and diarrhea
Vomiting and diarrhoea are typical symptoms of norovirus

Dehydration due to the rapid loss of fluids caused by vomiting and diarrhoea is a key symptom to watch out for, especially in vulnerable groups like young children and older adults. Dehydration occurs when the body loses more water and electrolytes (such as sodium and potassium) than it can replace. To reduce the risk of dehydration it’s essential to stay well-hydrated with small, frequent sips of water. Oral rehydration solutions from a pharmacy can be very useful as they contain the necessary salts the body needs. In severe cases or if symptoms persist, seeking medical attention is advised.

As there are currently no specific medications or treatments for stomach bugs like norovirus, it’s a case of riding the storm as best you can. The usual focus on hydration and managing symptoms like diarrhoea applies – this is where probiotics can help.

Are probiotics helpful for norovirus?

Probiotics are live beneficial bacteria and yeasts crucial in maintaining a healthy gut microbiome. A balanced gut microbiome is essential for overall gut health and immune function9. However, norovirus infection can significantly disrupt this balance by causing loss of beneficial bacteria and damage to the gut lining10 due to inflammation and diarrhoea.

S. boulardii is a well-researched probiotic yeast with strong evidence supporting its use in managing diarrhoea for both adults and children11.  The friendly yeast Saccharomyces boulardii has over 50 years of research supporting its use worldwide, making it the best choice during acute stages of norovirus diarrhoea. 

For best results begin taking S. boulardii as soon as symptoms start and continue until stools return to normal. For added protection, you may wish to continue taking S.boulardii for up to one month after symptoms have passed. The Lactobacillus strain Lactobacillus acidophilus NCFM® also has also been shown to help reduce loose stools associated with diarrhoea and improve bowel regularity13 in addition to being a colonising bacteria that improves overall gut health12.

Pairing S. boulardii with a high-quality colonising probiotic can enhance recovery. This is because S. boulardii does not stay for long in the gut, instead it does it’s job to remove pathogens from the digestive tract as it passes through. This process helps to restore a healthy balance to your gut microbiome. Strains like Lactobacillus acidophilus NCFM® and Bifidobacterium lactis Bi-07® have been shown to work well in combination with S. boulardii12.

There is much research to back the use of probiotics during a bout of diarrhoea and upset stomach, including a review by the NHS14 which concluded that certain probiotic strains, such as the ones mention above, can be helpful.

Best probiotics after norovirus

Even after acute symptoms subside, norovirus can impact the gut microbiome for a period of time3. This can leave individuals at risk of ongoing digestive issues, including post-infectious Irritable Bowel Syndrome (IBS)15. 

For long-term recovery after norovirus:

  • Continue probiotics for at least one month post-infection to restore gut health and prevent lingering issues.
  • Incorporate prebiotic-rich foods such as bananas, oats, and garlic to feed probiotic bacteria and enhance recovery.
  • S. boulardii is generally safe, but consult a healthcare professional if you are immunocompromised, pregnant, or taking medications.
     

By combining effective probiotics like Saccharomyces boulardii with targeted bacterial strains, individuals can restore gut health, reduce symptoms, and recover more effectively following a norovirus infection.

How does norovirus spread?

Norovirus spreads very easily2 through contact with infected people, contaminated food, water, or surfaces6. The virus can also become airborne in tiny droplets when an infected person vomits7, making it highly contagious and able to spread like wildfire. Touching surfaces contaminated with the virus - like door handles or kitchen counters - and then touching your mouth is a common way to become infected. Always wash your hands thoroughly with warm water and soap!

Unfortunately, antibacterial gels and wipes have no effect against this type of bug. Instead, use warm water & soap to keep the virus at bay8. Due to the highly contagious nature of the norovirus, it is best to stay at home if you experience any of the common symptoms. This includes keeping children at home until they are 48 hours symptom free, to avoid spreading the virus to other children at school or nursery.

Key summary

With growing evidence supporting their role in recovery, the question remains: are probiotics good for norovirus? While not a magic bullet, probiotics such as Saccharomyces boulardii offer a simple, accessible way to support gut health during and after a norovirus infection.

You may also be interested in reading these articles on our Probiotics Learning Lab:

Probiotics for Flatulence

Taking Probiotics with Antibiotics

Best Probiotics for Women

References

  1. https://www.cdc.gov/norovirus/data-research/index.html#:~:text=Norovirus%20worldwide,children%20under%205%20years%20old
  2. Winder, N., Gohar, S., & Muthana, M. (2022). Norovirus: An Overview of Virology and Preventative Measures. Viruses, 14(12), 2811. https://doi.org/10.3390/v14122811
  3. Cannon, J. L., Seabolt, M. H., Xu, R., Montmayeur, A., Suh, S. H., Diez-Valcarce, M., Bucardo, F., Becker-Dreps, S., & Vinjé, J. (2022). Gut Microbiome Changes Occurring with Norovirus Infection and Recovery in Infants Enrolled in a Longitudinal Birth Cohort in Leon, Nicaragua. Viruses, 14(7), 1395. https://doi.org/10.3390/v14071395
  4. Tegegne, D., Gelaw, A., Zerefaw, G. et al. Prevalence and associated factors of norovirus infections among patients with diarrhoea in the Amhara national regional state, Ethiopia. BMC Infect Dis 24, 1053 (2024). https://doi.org/10.1186/s12879-024-09988-5
  5. Carlson, K.B., Dilley, A., O’Grady, T. et al. A narrative review of norovirus epidemiology, biology, and challenges to vaccine development. npj Vaccines 9, 94 (2024). https://doi.org/10.1038/s41541-024-00884-2
  6. Sakon, N., Sadamasu, K., Shinkai, T., Hamajima, Y., Yoshitomi, H., Matsushima, Y., Takada, R., Terasoma, F., Nakamura, A., Komano, J., Nagasawa, K., Shimizu, H., Katayama, K., & Kimura, H. (2018). Foodborne Outbreaks Caused by Human Norovirus GII.P17-GII.17-Contaminated Nori, Japan, 2017. Emerging infectious diseases, 24(5), 920–923. https://doi.org/10.3201/eid2405.171733
  7. Jones R.M., Brosseau L.M. Aerosol transmission of infectious disease. J. Occup. Environ. Med. 2015;57:501–508. doi: 10.1097/JOM.0000000000000448
  8. Assab, R., & Temime, L. (2016). The role of hand hygiene in controlling norovirus spread in nursing homes. BMC infectious diseases, 16, 395. https://doi.org/10.1186/s12879-016-1702-0
  9. Montalban-Arques A et al (2015) Selective Manipulation of the Gut Microbiota Improves Immune Status in Vertebrates, Frontiers in Immunology. 6:512
  10. Nelson, A. M., Walk, S. T., Taube, S., Taniuchi, M., Houpt, E. R., Wobus, C. E., & Young, V. B. (2012). Disruption of the human gut microbiota following Norovirus infection. PloS one, 7(10), e48224. https://doi.org/10.1371/journal.pone.0048224
  11. McFarland L, Karakan T, Karatas A (2021) Strain-specific and outcome-specific efficacy of probiotics for the treatment of irritable bowel syndrome: A systematic review and meta-analysis. eClinicalMedicine, 41: 101154
  12. Magro, D.O., et al., (2014). ‘Effect of yogurt containing polydextrose, Lactobacillus acidophilus NCFM and Bifidobacterium lactis HN019: a randomized, double-blind, controlled study in chronic constipation’. Nutrition Journal, 13:75.
  13. Li Z, Zhu G, Li C, Lai H, Liu X, Zhang L. Which Probiotic Is the Most Effective for Treating Acute diarrhoea in Children? A Bayesian Network Meta-Analysis of Randomized Controlled Trials. Nutrients. 2021 Nov 29;13(12):4319. doi: 10.3390/nu13124319. PMID: 34959871; PMCID: PMC8706888.
  14. nhs.uk. (2018). Probiotics 'Ease Upset Stomachs'. [online] Available at: <https://www.nhs.uk/news/medication/probiotics-ease-upset-stomachs/> [Accessed 7 October 2018].
  15. Lekha Saha. (2014). Irritable bowel syndrome: Pathogenesis, diagnosis, treatment, and evidence-based medicine. World J Gastroenterol.. 20 (22), 6759–6773.
     
Article Published: 20 Dec 2024