Probiotics for Your Family’s Immunity

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

With life being so busy, now is a good time to be thinking about getting your whole family’s health in tip-top condition. Supporting the immune system, through a combination of approaches, is the best way to do this. In a 2021 survey, 62%1 of consumers indicated that having a strong immune system is their definition of 'healthy'.

Read on to find out everything you need to know about choosing the best probiotic for your family’s immune health:

The immune system 

70% of immune system is in the gut
Did you know?

Put simply, the immune system is a network of different cells, tissues, organs, and proteins which are located throughout the body. The different components of the immune system all work together to protect us against threats like physical injuries, toxins, pathogens and even stress.

But did you know that 70% of your entire immune system is based in your gut?

This means that in order to improve our immune health, it is vital to support and maintain good gut health. With that in mind, this article looks at a new way to approach the change of seasons, starting from the inside out.

Health professionals can find out more about the link between the gut and the immune system on the Probiotic Professionals site.

Are probiotics good for immune function? 

Inside everybody’s gut is a multitude of tiny micro-organisms, collectively known as the microbiome. You may like to read more about the microbiome in Dr Kate’s article all about the microbiome.

Our gut microbiome is a mixture of good, or ‘friendly’, bacteria, known as ‘probiotics’, and a small percentage of the ‘bad guys’, known as pathogens. One of the most important jobs of good gut bacteria is providing the first line of defence against ingested pathogens, such as undesirable bacteria and viruses. Another vital role of friendly bacteria colonies is the way they ‘talk’ to the immune system helping to enhance our immune responses2 and keep us healthy. You can read more here about how probiotics work.

This means that if our good gut bacteria aren’t fighting fit then we may be more at risk for picking up infections such as colds and flu. So how do we make sure our microbiome stays healthy? Our article ‘Gut health, all you need to know’ gives more tips and advice on keeping your gut healthy.

Which are the best probiotics for the immune system? 

Probiotics come in lots of different shapes and sizes: yoghurts, fermented drinks (like kombucha), and most recently, supplements. You can read here about the difference between fermented foods and probiotics. With 1 in 3 Brits now taking a daily nutritional supplement3, the probiotics industry is growing rapidly. With so many to choose from, it can be difficult to find the one to best suit your needs.

woman with a cold
Can good bacteria help with cold and flu symptoms? The research says yes.

Perhaps the most important thing to remember here is that different probiotics supplements do different things, depending on the strains of probiotic bacteria used in them. Scientists are particularly keen to understand which strains help to support our immune system best, and so there is more and more evidence growing in this area.

However, each member of your family may need a supplement which is suited to their individual needs. Read on to find out more about the different types of probiotic immune support.

Probiotics for family immune health 

Different strains of probiotic suit different people and conditions. This might depend on their individual needs or on their stage of life. Whatever you needs, you should always choose a probiotic with plenty of good quality research behind it.

The elderly population naturally have lower levels of friendly bacteria than younger members of the family. A decline in immune function is another natural characteristic of aging, and the two together can result in significant changes in the gut microbiome. So, the elderly can certainly do with a helping hand. The soil-based probiotic Bacillus coagulans Unique IS-2 has promising research in the immune response of older adults12. Likewise, a strain of Bifidobacteria called Bifidobacterium lactis BB-12®, has been shown to improve immune function in the elderly. You can read more in probiotics for older people.

At the other end of the population, teenagers are another age-group who may benefit from specific strains of probiotic to support them through their growing years. It is well known that teenagers do not always prioritise sleep over fun, which affects the body in several ways including lowered immune health. Our article probiotics for teenagers gives more guidance on how to support teenagers through these important years.

Probiotics are not usually gender-specific, but we know that some strains have particular benefits for women’s health. Research has shown that women tend to mount a stronger immune response to infections than men7. The reasons for this are unclear but it is likely to do with female sex hormones, and possibly genetics, playing a role. You can read more about here about probiotics for women.

Of course, the men in the family shouldn’t be overlooked! Men have a need to support their immune function as much as any member of the family. Sometimes even more so if their lifestyle incorporates smoking, high stress and activity levels, and a poor diet. Our article probiotics for men tells you all you need to know.

The Bacillus coagulans Unique IS-2 strain is available in both Optibac Probiotics Gut Health Gummies (suitable for older adults and teenagers alike) and Optibac Probiotics Kids Gummies.

Probiotics for colds and flu 

During the winter months we often get asked ‘do probiotics help fight colds?’, so let’s take a look at the potential benefits of probiotics for immune health. With luck, you’ve stumbled across this blog before catching a nasty cold or respiratory virus like Covid-19, however, if you’re already experiencing symptoms, and are firmly in the coughing and sneezing camp, don’t lose hope. It’s never too late to start building up your good bacteria.

In fact, research done in the U.S4 shows that taking probiotics may shorten the duration of colds.

The Chr. Hansen-sponsored study observed a group of 200 student participants, with half receiving the probiotic strains L. rhamnosus LGG® and B. lactis BB-12® probiotic formula. The researchers observed that those taking the probiotics experienced colds that lasted an average of 4 days, as opposed to 6 in the placebo group. The probiotic group also experienced a 34% reduction in cold symptom severity.

Birgit Michelsen, Chr. Hansen’s director of scientific affairs in health and nutrition commented on the significance of the study, “There have been other studies that have shown similar effects, but this shows a significant result in a key population typically under extreme stress and prone to colds and flus as a result.”

A further large scale study5 found that a different strain of probiotic also had positive effects on immune health. The 2015 study observed the effects of Lactobacillus paracasei CASEI 431® on over 1000 healthy individuals to see how the immune system responded to this strain.

Results showed that L. paracasei CASEI 431® probiotic strain reduced the duration of flu-like symptoms by 3 days (a 41% reduction) compared to placebo. This means that participants in the probiotic group experienced symptoms for a significantly reduced amount of time compared to those without probiotic supplementation.

Therefore, when looking to support your immune health, you might consider probiotic supplements containing Lactobacillus paracasei CASEI 431®.

L. paracasei CASEI 431® strain can be found in the Optibac Immune Support supplement.

For daily immunity
Optibac Immune Support contains Lactobacillus paracasei CASEI 431®

Health Professionals can read more about Lactobacillus paracasei CASEI 431® over at the Probiotics Database.

Probiotics for children’s immune health 

The younger years can be a particularly challenging time for the gut microbiome. Not only are children growing quickly, they also often dealing with factors such as school, social activities, a high-sugar diet and low-fibre diet, stress and not enough sleep. These factors can influence your child’s gut microbiome and reduce levels of friendly bacteria.

Giving your child probiotics can help give them the extra support they need. Researchers have looked extensively at the impact of probiotics on the immune systems of children.

A 2010 study6 revealed that a probiotic supplement, containing the strains Lactobacillus acidophilus Rosell-52, Bifidobacterium infantis Rosell-33, Bifidobacterium bifidum Rosell-71 and prebiotics was able to reduce the risk of occurrence of common infectious diseases in children.

Those taking the probiotic formula were 25% less likely to contract common winter diseases and their risk of absence from school due to illness was also reduced. This trial showed great results for the effects of specific probiotic strains on the immune systems of children. Therefore, when looking to support your child’s immune health, you might consider probiotic supplements containing these strains.

Another strain, Lactobacillus rhamnosus GG®, has been shown to reduce the risk and duration of upper respiratory infections in children10. In one study of 281 children, the length of time the children suffered with runny noses and sore throats was significantly shorter in those taking L. rhamnosus GG® for 3 months.

Bifidobacterium breve M-16V®Lactobacillus rhamnosus GG, and Lactobacillus rhamnosus HN001 strains can be found in Optibac Babies & Children supplement.

Health Professionals can read more about Lactobacillus acidophilus Rosell-52 over at the Probiotics Database.

For more information about the best probiotics for your child, read probiotics for kids and baby probiotics.

Babies and Children
Optibac Babies & Children contains Bifidobacterium breve M-16V®, Lactobacillus rhamnosus GG, and Lactobacillus rhamnosus HN001

In summary, whether you’re fit and healthy (and aiming to stay that way), or are already experiencing symptoms and need some TLC, probiotics can be a great addition to your daily health regime.

Do note that people who are immune-suppressed or who have weakened immune systems should speak to their doctor before taking probiotics. This is due to their interaction with the immune system. See this FAQ for more information: 'I'm severely immunosuppressed: why can't I take probiotics?'

Top tips to boost the whole family’s immune health all year round 

  • Get more sleep - a lack of sleep is known to suppress the immune system and make us more likely to succumb to bacterial and viral infections.
  • Limit sugar - sugar feeds bad bacteria. It is also known to suppress the immune system8 for up to 5 hours after its ingestion, putting us at more risk of picking up infections.
  • Vitamin D, known as the ‘sunshine’ vitamin, is a key player in immune health12
  • Vitamin C, a powerful antioxidant found primarily in fresh fruit and vegetables, is known to be effective in supporting a healthy immune system in both children and adults9.
  • Look after their gut flora - colonies of friendly bacteria in the gut are our first line of defence against ingested bacteria and viruses.
  • Consider taking a well-researched probiotic supplement, containing strains of probiotic bacteria such as Lactobacillus paracasei CASEI 431®, which may help to support a healthy immune response
  • An increase in stress hormones, such as adrenaline and cortisol, over a long period of time results in a suppression of the immune system. Relaxation, play time, and laughter really is the best medicine!
  • Practice good hygiene - regularly washing your hands and trying not to pick at warm, moist environments like noses, eyes, and ears, can help to stop the spread of diseases.
  • Covering your mouth and nose when sneezing or coughing helps to stop microbe-laden droplets from spreading to the rest of the family. Then remember to wash your hands!
woman at a window
Ticking off all the ways to keep your gut in good shape can be tough. Probiotics are a quick win!


Key takeaways

  • There are trillions of microbes living in the human gut, known as the ‘microbiome’
  • The health of the microbiome is vital to the health of the immune system
  • Our probiotic colonies can ‘talk to’ the cells of our immune system
  • These friendly bacteria help to prevent pathogen overgrowth and create a protective barrier in the gut to reduce infections

Interested in finding out more about supporting immune function? Read more:

Probiotics and Antibiotics: Can I Take Both?
Got a cold? Try probiotics!

Health professionals can head over to Probiotics Professionals to find out more about the gut bacteria’s key role in immune function and could probiotics help against COVID-19?


  2. Montalban-Arques A et al (2015) Selective Manipulation of the Gut Microbiota Improves Immune Status in Vertebrates, Frontiers in Immunology. 6:512
  3. Mintel, (2019). ‘D outshines C to become the UK’s favourite single vitamin supplement’. [Online] Available at: [Accessed 14 Oct. 2019]
  4. Smith J. et al, (2013). Effect of Lactobacillus rhamnosus LGG® and Bifidobacterium animalis ssp. lactis BB-12® on health-related quality of life in college students affected by upper respiratory infections. British Journal of Nutrition. 109(11):1999-2007. doi: 10.1017/S0007114512004138. Epub 2012 Oct 1.
  5. Jespersen L. et al., (2015), ‘Effect of Lactobacillus paracasei subsp. paracasei, L. casei 431® on immune response to influenza vaccination and upper respiratory tract infections in healthy adult volunteers: a randomized, double- blind, placebo-controlled, parallel-group study’. Am.J.Clin.Nutr., 101:1188-1196.
  6. Cazzola M. et al., (2010) ‘Efficacy of a synbiotic supplementation in the prevention of common diseases in children: a randomized, double-blind, placebo-controlled pilot study’ Therapeutic Advances in Respiratory Disease, 0(0):1-8.
  7. Klein S, Flanagan K, (2016) Sex differences in immune responses. Nature Reviews Immunology. 16:626-638.
  8. Sanchez, A et al (1973) Role of sugars in human neutrophilic phagocytosis. Am J Clin Nutr, 26(11): 1180-1184
  9. Carr A, Maggini S, (2017) Vitamin C and Immune Function, Nutrients. 9(11):1211
  10. Hojsak et al., (2010) Lactobacillus GG in the prevention of gastrointestinal and respiratory tract infections in children who attend day care centers: a randomized, double-blind, placebo-controlled trial. Clinical Nutrition, 29(3): 312-6.
  11. Upadhyaya, S. and Banerjee, G. (2011) ‘Enhancement of Natural Killer Cell Activity in Immuno-compressed Elderly Subjects by Bacillus, International Journal of Probiotics and Prebiotics, 6
  12. Aranow C (2011) Vitamin D and the immune system, Journal of Investigative Medicine. 59(6): 881–886.