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Choose your favourite friendly bacteria supplement(s) and tell us how often you want us to deliver. We'll take care of the rest.
£8.99
(inc. VAT)Pack size
FREE UK delivery on orders over £40.
Gluten free
During pregnancy
During breastfeeding
Vegan
Optibac One Week Flat is an affordable, 7-day course of friendly bacteria in easy-to-take sachets. It's gluten-free and therefore may be suitable for those with bloating.
One Week Flat can be taken occasionally for 7 consecutive days once a month or on an ongoing basis.
Customer feedback collected via independent review platform Trustpilot. See more One Week Flat reviews for more customer opinions collected via our own website.
Natural food supplement suitable for adults and children (from 4 years onwards) with the following recommendations:
We highly recommend you take One Week Flat for 7 consecutive days. Many consumers like to take this course once a month. However, it can be taken on an ongoing basis or as desired.
All questions answered by probiotic experts Dr. Kate Stephens PhD (Food and Microbial Sciences) BSc (Hons) Medical Microbiology and Kerry Beeson BSc (Nutritional Medicine) Nutritional Therapist.
Definitely! Friendly gut bacteria are not gender specific. This means that One Week Flat is suitable to be taken by everyone over the age of 4 years: women, men, and trans and non-binary people too!
It is recommended to take One Week Flat every day for at least one week. After that the rest is down to personal preference. One Week Flat can be used in the short term, as a week-long course for those who are looking for an affordable way to complement their natural gut bacteria every now and then. Equally, it can be used on an ongoing basis. There is no ‘right’ or ‘wrong’ way to take it. Here are some of the ways that our loyal One Week Flat customers take this supplement:
One Week Flat has a fairly ‘neutral’ taste and most people find it easy and pleasant to take. You may notice a slight natural sweetness which comes from the Fructooligosaccharide (FOS) fibres, but you can rest assured that the supplement contains no added flavourings, sugar, or sweeteners.
One Week Flat is gluten-free, so is fine to be taken by those with food-related bloating. It is also suitable to be taken by those with lactose intolerance1,2,3. This high-quality supplement contains 4 well-researched strains of friendly bacteria combined with 0.3g FOS fibres. Individual responses to a supplement can vary, but the majority of our customers get on well with this formulation, and purchase on a regular basis.
One Week Flat contains just 7.72 calories per sachet, and 0g fat. Most of the carbohydrate in the supplement comes from the FOS fibres which are not digested, and therefore have almost no calorific content.
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 food supplement and is not intended to prevent, treat or diagnose any medical conditions. 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.
1. Rampengan et al., (2010), ‘Comparison of efficacies between live and killed probiotics in children with lactose malabsorption’. Southeast Asian Journal of Tropical Medicine and Public Health 41: 474-481
2. D. H. Juers, B. W. Matthews and R. E. Huber, “LacZ β-galactosidase: Structure and function of an enzyme of historical and molecular biological importance,” Protein Science, vol. 21, no. 12, pp. 1792-1807, 2012.#
3. Oak SJ, Jha R. The effects of probiotics in lactose intolerance: A systematic review. Crit Rev Food Sci Nutr. 2019;59(11):1675-1683. doi: 10.1080/10408398.2018.1425977. Epub 2018 Feb 9. PMID: 29425071.
Maltodextrin (natural source); Fructooligosaccharides (FOS 0.3g); Live cultures: Bifidobacterium bifidum Rosell-71, Lactobacillus casei Rosell-215, Lactococcus lactis Rosell-1058 and Lactobacillus acidophilus/helveticus Rosell-52
Each sachet guarantees 5 billion live cultures + 0.3g FOS fibres.
Following the taxonomic updates by a global team of scientists and published in April 2020, a reclassification has been advised for the L. casei species. The casei strain in the Optibac One Week Flat product is now also known as Lacticaseibacillus casei Rosell-215.
To find out more about friendly bacteria supplements and bloating, visit the Probiotics Learning Lab.
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?This product is a total game changer. I’ve tried all the opti bac products but this one seemed to agree with me the most and I now take these daily. The opti bac team have been great with their customer care and have been committed to helping me find a product that works for me. Thank you!
Used to get so bloated whenever i had my period. I take a course once a month, starting a 2 or 3 days before my period is due
I was living with serious bloating when I discovered One Week Flat. I use it regularly now and that bloating no longer happens! I no longer live in England, but I was delighted to find that I could buy it locally. (EU)
Free standard UK delivery is automatically applied at the checkout when you spend £40.
Allow 4-10 working days (Monday - Friday) for delivery; no deliveries on Saturdays
Allow 1-3 working days (Monday - Friday) for delivery; no deliveries on Saturdays
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.
We offer an excellent worldwide delivery service. For more details, please take a look at our delivery FAQ.