Immune Support Probiotics

30 capsules |1 month's supply

Dr Sasivimol Ahmed PhD, PG Dip (Personalised Nutrition), BSc (Food Science)
A personal favourite of mine! I use it daily and all year round, it's perfect for those with busy and demanding lifestyles; especially helpful during the winter months.
Dr Sasivimol Ahmed
Dr Sasivimol Ahmed PhD, PG Dip (Personalised Nutrition), BSc (Food Science)

Who is it for?

Formulated for optimum immune health support, Optibac Probiotics Immune Support is a high-quality, extensively researched probiotic supplement with Vitamin C to help maintain a healthy immune system and digestion*.

Buy online from our UK website
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  • Vegan


  • Dairy free

    Dairy free

  • Gluten free

    Gluten free

  • GMO free

    GMO free

  • No added sugar

    No added sugar

Key benefits

Probiotics with Vitamin C for the immune system

For anyone who tends to suffer from poor immune health, and who is looking for a daily probiotic supplement with vitamin C to help support immune function and digestive health*.

  • Probiotics for immune system support Optibac Probiotics Immune Support contains 5 billion live cultures of the strain L. paracasei CASEI 431®, which helps to support immune health
  • Extensively researched L. paracasei CASEI 431® has been studied in over 20 clinical trials where it was shown to stimulate immune responses and increase immune cell activity
  • With Vitamin C for immune function With 80mg of Vitamin C per capsule, to help maintain normal function of the immune system, contribute to our resistance to infection, and reduce tiredness and fatigue
  • Also aids digestion L. paracasei CASEI 431® has also been shown to support gut health and complement the natural gut bacteria
  • Scientifically proven Shown to survive stomach acidity and reach the gut alive, where over 70% of the body’s immune cells reside
  • For daily use High-quality, daily immune support in just one easy-to-swallow capsule
  • Natural and vegan Vegan, dairy free and gluten free, with absolutely no artificial flavorings or colorings
  • The UK's most recommended brand Optibac is the brand of probiotic supplements most recommended by UK consumers

Probiotic strains

  • Lactobacillus paracasei CASEI 431®

Added nutrients

  • Vitamin C
See full ingredients list

Complements gut bacteria


General digestive

Customer Reviews

Customer reviews have been collected on our website or independently through Trustpilot where no moderation is possible. Reviews are not endorsed by us and should not be regarded as medical or health advice. For supplement advice, you can speak to one of our qualified experts. The top 3 reviews have been selected from our website, please click view all to explore more customer feedback.

Since starting these tablets my health has really improved. I was always feeling tired and tried a range of vitamins that never changed anything. I asked in my local health shop and explained how I was feeling. And was offered optibac it took 3 week's to get into my system, I'm starting into my 4 month and my whole body function is better than it ever was. Getting a full night's sleep and feel so much energy that I can get on with life. As a diabetic I suffered to keep my suger levels under control. But with always being tired I couldn't get out much. That drive my suger up and having bowl syndrome made me feel worse. These tablets has taken over and my lifestyle has improved. These really work and it's best to take one first thing in the morning. And you will start noticing a difference on week 3.

A huge thank you to OptiBac Advisor and Nutritionist Claire Foss for all her support and guidance around my digestive health and OptiBac products. Very happy to say that the gentleness of OptiBac Immunity is working well after a few weeks after many other brands did not agree my digestive system. The secret is trying different products, give them a few weeks each. I know you're eager to reduce your symptoms, but issues like this can take some time to resolve... keep going, and thanks again to Claire for her help.

Help & advice

Our team of qualified experts are available for free personalised supplement advice. If you're not sure where to start or your needs have recently changed, please get in touch.

Louise Mason
Louise Mason BA(Hons) DipCNM Nutritional Therapist, DipCNM Naturopath, mANP
  • How to use

  • Ingredients

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  • How to use

    Recommended use

    Immune Support can be given to adults and children, from 4 years upwards, with the following recommendations:

    • Take 1 capsule daily, preferably with breakfast, or as professionally directed.
    • For those  unable to swallow capsules, open and mix contents with cool drink/food .
    • May be used on an ongoing basis

    Storage instructions

    • For best results, do not remove desiccant sachet from the glass jar and close lid firmly after each use.
    • Store in a cool, dry place below 25°C and out of direct sunlight. For maximum potency, can be refrigerated after opening.


    Probiotics are not recommended for those with serious medical conditions e.g. those who are severely immunosuppressed, have pancreatitis, are in the ICU, have melaena, have a central venous catheter, short bowel syndrome, or patients with open wounds following major surgery; unless under a doctor's care. Keep out of reach of children.

    Gut health supplements are not intended to prevent, treat or diagnose any medical conditions. If taking probiotic supplements for gut health, note that these should not be used as a substitute for a varied and balanced diet and a healthy lifestyle. If you are taking any medications or have a serious medical condition, consult a doctor before use. Optibac supplements will not cause dependency and may be used on an ongoing basis.

  • Ingredients


    Vitamin C (80mg); Probiotic cultures: Lactobacillus paracasei CASEI 431®; maltodextrin, hydroxypropyl methylcellulose, vegetable magnesium stearate

    Each capsule contains 5 billion CFU.

    Optibac Immune Support Supplement fact panel


    • Vegan
    • Vegetarian
    • Dairy free
    • Gluten free
    • No added sugars
    • GMO free
    • Yeast free
    • Free from artificial flavorings, colorings and preservatives
    • No chemicals or parabens
    • Suitable during pregnancy
    • Suitable during breastfeeding

    Following the taxonomic updates published in April 2020 which are intended to be adopted globally, this strain may now also be referred to as Lacticaseibacillus paracasei subsp. paracasei CASEI-431.

    Format Capsule
    CFU 5 billion
    Added Ingredients Vitamin C
    Recommended Use 1 capsule daily
    Age Range Adult
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  • Delivery & returns

    USA standard shipping: $4.99 

    International postal order - typically deatched and delivered within 5-10 working days.
    Free standard shipping on orders over $60.

    USA express shipping: $6.99 

    We use DHL and orders are typically dispatched and delivered within 2-5 working days.

    Good to know

    • We'll send you an email to confirm once your parcel has been dispatched.
    • For delivery queries, please email
    • We are unable to ship orders to PO boxes.
    • Product prices on this website are always shown in US dollars (USD $) and exclude tax - tax is not applicable as orders are fulfilled from the UK.

    Worldwide Delivery

    • We deliver to more than 50 countries.
    • Shipping is charged at cost - please note that duties may apply.
    • Please allow 3-7 working days for delivery within Europe and 5-12 days to all other destinations. Includes order tracking.  
    • If you are located within the United Kingdom or Europe, we recommended switching to our UK website.
    • International deliveries might currently take a little longer due to the global coronavirus situation. Please refer to the webpage of our international delivery provider DHL to confirm the number of days it takes to receive your order and whether they currently ship to your country.
    • Most international delivery prices are dependent on the size and weight of your order and where it is being sent. You'll be shown the final price of shipping in the checkout, before payment, once we have your address and order details.
    • Long distance shipping and short-term exposure to high temperatures will not compromise the viability of our products. Customers living in very hot countries should store the products out of direct sunlight and refrigerate if the option is available.

    For more details regarding international orders, currency conversion and applicable tax for orders outside the USA, please take a look at our delivery FAQ.


    If you have changed your mind, you can return goods, at your cost, unopened within 14 days for refund or exchange, this does not affect your statutory rights.

Customer Questions

All questions answered by probiotic experts Dr Kate Stephens PhD (Food and Microbial Sciences) BSc(Hons) Medical Biology and Helen Morton BSc (Hons) DipION Nutritional Therapist

Yes! It’s not possible to overdose on probiotics for immune support as your gut naturally contains trillions of friendly bacteria. Live cultures have been researched for decades, and daily use is both safe and recommended, without risk of dependency or overdose1,2,3.

Read references

Various factors affect immune function, including cold weather or stress, but you can do things to help your immune system. Eat plenty of fruits and vegetables, limit alcohol intake, get a good night’s sleep, exercise daily, and wash your hands properly. As 70% of our immune system is in the gut, consider taking probiotics for immune support during the winter cold and flu season. Optibac Probiotics Immune Support offers all-round gut and immune support.

Choose highly researched probiotic supplements containing ingredients proven to support a healthy immune system and your body’s resistance to infection*, such as Vitamin C. Optibac Probiotics Immune Support contains 100% of your daily requirement of Vitamin C, along with one of the world’s most researched probiotic strains, Lactobacillus paracasei CASEI 431®, clinically trialled in thousands of people and found to support immune health1.

Read references

Vitamin C and probiotic supplements for immune support are generally safe for everyone from one year into old age1,2. However, they may not be appropriate for adults or children who are immune-compromised – read our safety information for more details. If you have a serious health condition, speak to your doctor before taking any supplement.

Read references

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