For Those On Antibiotics

10 capsules


(inc. VAT)

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Gluten free

Gluten free

During pregnancy

During pregnancy

No dairy

No dairy

During breastfeeding

During breastfeeding

See full ingredients list

Who is it for?

For Those On Antibiotics is for anyone looking to buy a high-quality friendly bacteria supplement developed & proven especially to be taken alongside a course of antibiotics.

for those on antibiotics press

Optibac Probiotics Strains

  • Lactobacillus rhamnosus Rosell-11
  • Bifidobacterium lactis Lafti B94
  • Lactobacillus acidophilus/helveticus Rosell-52
  • Product Description

  • How To Use

  • Ingredients

  • Help & Advice

  • Reviews

  • Delivery & Returns

  • Product Description

    Friendly bacteria to take with antibiotics

    Perfect for anyone looking to buy a natural friendly bacteria supplement to take alongside a course of antibiotics.

    Key benefits

    • Suitable alongside antibiotics – contains three friendly bacteria strains which have been studied in clinical trials on friendly bacteria and antibiotics
    • Scientifically proven – shown to survive stomach acidity and reach the gut alive, even when you take these friendly bacteria with antibiotics
    • Highly researched – all three strains have been shown to complement the natural gut bacteria
    • Specific strain action - L. rhamnosus Rosell-11 and L. acidophilus/helveticus Rosell-52 have also been shown to increase immune cell activity
    • For daily use – designed for daily use with a typical 10-day course of antibiotics, or can be used for longer periods alongside long-term antibiotics
    • Easy to take – each easy-to-swallow capsule contains 4.5 billion live bacterial cultures; take on the go with no need for refrigeration 
    • A more natural option – vegan and gluten free, with absolutely no artificial flavourings or colourings, and suitable from 1 year of age including during pregnancy
    • Highly recommended – from the UK’s most trusted & recommended brand of friendly bacteria supplements, as determined in an independent survey of 1000 British women+

    Product reviews

    Customer feedback collected via independent review platform Trustpilot. See more For Those On Antibiotics reviews for more customer opinions collected via our own website.

  • How To Use

    Recommended use

    Food supplement suitable for adults and children, from 1 year onwards, with the following recommendations:

    • Take 1 capsule daily with food, preferably with breakfast, every day during your antibiotic course and for a few days afterwards or until the pack has been completed.
    • Can be taken at the same time as antibiotics - strains in this product have been clinically trialled alongside antibiotics and found to reach the gut alive.
    • Drink plenty of water with your course of live cultures.
    • For anyone unable to swallow capsules, open and mix contents of the capsule with a cool meal or beverage.

    Storage instructions

    • Store in a cool, dry place below 25°C and out of direct sunlight.


    Live cultures 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, infants with short bowel syndrome, or patients with open wounds following major surgery; unless under a doctor's care. Keep out of reach of children.

    This is a dietary supplement and is not intended to diagnose, treat, cure or prevent any disease. Probiotic supplements should not be used as a substitute for a healthy diet and 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.

    Customer Questions

    All questions answered by probiotic experts Dr Kate Stephens PhD (Food and Microbial Sciences) BSc (Hons) Medical Microbiology and Kerry Beeson BSc (Nut. Med.) Nutritional Therapist.

    Can I take live cultures with antibiotics?

    Yes, it is absolutely fine, and advisable to take a friendly bacteria supplement whilst on antibiotics. When prescribed antibiotics, many individuals now choose to supplement their natural bacteria with a live cultures supplement. However, it’s best to select strains that have been extensively researched alongside this type of medication.

    Which friendly bacteria are best to take with antibiotics?

    It’s important to choose friendly bacteria strains that have been trialled alongside antibiotics and shown to reach the gut alive. Strains in For Those On Antibiotics have been shown to do so in numerous clinical trials, even when taken at the exact same time as antibiotic medication1. The strains in this supplement have been trialled at various life stages including in children2,3 and can be taken during long or short courses of antibiotics.

    When should I take live cultures with antibiotics?

    Like most of our range, we recommend that For Those On Antibiotics, should be taken at breakfast time. It’s fine to take this supplement with breakfast and alongside your antibiotics at the same time. If you take your antibiotics at a different time of day, then still take For Those On Antibiotics with breakfast. If you choose to take a different live cultures supplement, then note that it may be necessary to leave a two-hour gap from your medication dose. Ideally however, it’s best to take strains such as Lactobacillus acidophilus/helveticus Rosell-52, Lactobacillus rhamnosus Rosell-11 and Bifidobacterium lactis Lafti B94 which can be taken at the same time as your medicine.

    How do friendly bacteria help with antibiotics?

    When the correct strains are taken, friendly bacteria can support you whilst on the antibiotic medication4. It’s best to start taking For Those On Antibiotics right away at the start of your course but don’t worry if you miss a day or so at the beginning, just continue until the pack is complete. Many people like to continue taking live cultures once they have finished their course of medication, to maintain their support of the gut microbiome.


    1. Nagulesapillai V. Detection and Quantification of Strain Specific Probiotics in Clinical Fecal Samples of Healthy Adults on Antibiotic Treatment by Quantitative PCR. Poster presentation. 2015;1(1).
    2. Maydannik V. et al. ‘Efficiency and safety of Lacidofil in children with antibiotic-associated diarrhoea caused by Clostridium difficile.’ Pediatrics, Obstetrics & Gynaecology. 2010;2(3):53-57.
    3. Chernyshov P v. Randomized, placebo-controlled trial on clinical and immunologic effects of probiotic containing Lactobacillus rhamnosus R0011 and L. helveticus R0052 in infants with atopic dermatitis. Published online 2009. doi:10.3109/08910600903444234
    4. Evans M, Salewski RP, Christman MC, Girard SA, Tompkins TA. Effectiveness of Lactobacillus helveticus and Lactobacillus rhamnosus for the management of antibiotic-associated diarrhoea in healthy adults: A randomised, double-blind, placebo-controlled trial. British Journal of Nutrition. 2016;116(1):94-103.

  • Ingredients


    Stabiliser: potato starch; vegetarian capsule: hydroxypropyl methylcellulose; Live cultures: Lactobacillus rhamnosus Rosell-11, Bifidobacterium lactis Lafti B94, Lactobacillus acidophilus/helveticus Rosell-52; anti-caking agent: vegetable magnesium stearate; antioxidant: ascorbic acid

    Each capsule guarantees 4.5 billion live cultures.


    • Vegetarian
    • Vegan
    • No dairy
    • Gluten free
    • Yeast free
    • Suitable during pregnancy
    • Suitable during breastfeeding
    • GMO free
    • Free from artificial flavourings, colourings and preservatives
    • No chemicals or parabens
    • Sugar free

    Following the taxonomic updates advised by a global team of scientists and published in April 2020, a reclassification has been proposed for the L. rhamnosus species. The L. rhamnosus strain in For Those On Antibiotics may therefore now also be known as Lacticaseibacillus rhamnosus Rosell-11.

  • Help & Advice

    Talk to our experts

    If you have a specific question or need some advice on which product to choose please contact our Nutrition Team on +44 (0) 1264 318 881 or click on the link below for our contact form.

    Need help choosing a product?
  • Reviews

    Customer reviews

    • I regularly use this product if my clients have to go onto antibiotics I have, on occasion, used this myself too - as well as S Boulardii. Great products from Optibac.

      Nicola Warran - 29th June 2022

    • did the optibac antibiotics due to having a combination of very strong gram negative antibiotics. Optibac was great, kept all the nasty side effects away. Would highly recommend

      Emma Protheroe - 6th December 2021

    • I frequetly use " For those on antibiotics ". This product makes me feel better. I really see a change. I also contacted the customer service dpt to get some info. Very fast reply with all the needed information. Great prouct and great service !

      Stephan B. - 15th November 2021

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  • Delivery & Returns


    Free UK Delivery over £40 

    Free standard UK delivery is automatically applied at the checkout when you spend £40.

    Standard 2nd class: £2.50

    Allow 4-10 working days (Monday - Friday) for delivery; no deliveries on Saturdays

    1st class (Tracked): £3.95

    Allow 1-3 working days (Monday - Friday) for delivery; no deliveries on Saturdays

    Express Next Day (Tracked): £6.95

    Order before 2pm for guaranteed next working day delivery to most of the UK*. Orders placed on Friday will be delivered on Monday (next working day). Requires signature.
    *Express delivery may exclude the Channel Islands, Herm Island, Isle of Man, Isle of Wight, Northern Irish postcodes BT18 & upwards, Sark, Scottish borders and offshore and a small number of remote mainland destinations as determined by our delivery courier. 

    Good to know

    • We'll send you an email to confirm once your parcel has been dispatched.
    • For delivery queries, please call us on +44 (0)1264 339 770 or email
    • Orders placed before 2pm will be dispatched on the same working day.
    • Delivery within the UK and Northern Ireland has a fixed price, regardless of the size and weight of your order. 
    • Delivery times are estimates and not guaranteed unless otherwise stated.



    International Delivery

    We offer an excellent worldwide delivery service. For more details, please take a look at our delivery FAQ.