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One week flat
OptiBac Probiotics Probiotics http://www.optibacprobiotics.hk

For a flat stomach

Product rated 4.6 from 44 reviews

HK$ 249.00

This is a blend of probiotics (such as acidophilus) & prebiotic fibres (food for the probiotics) especially for those who suffer from bloating. This natural supplement supports your digestion & aids transit, promoting a comfortably flatter stomach.

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What's it for?

Supports a healthy balance of probiotics in the gut to promote a lighter feeling. 

Who's it for?

For those who suffer from abdominal bloating caused by trapped wind, food intolerances, PMS or stress.

Each sachet provides

5 billion live probiotic microorganisms + 0.3g prebiotic fibres.

For a flat stomach Probiotic & Prebiotic

Abdominal or stomach bloating is usually associated with food intolerances, constipation, over-eating, PMS or intestinal gas; leaving the abdomen feeling uncomfortable, full and tight.  If you have poor digestion, waste materials and the gases they produce can remain in the gut for long periods of time, often at high temperatures and pressures.  This causes bloating and stretching of the gut walls beyond their comfortable limits. 
An imbalance of bad (pathogenic) bacteria and friendly (probiotic) bacteria in the gut can result in poor digestive health, bloating, production of smelly and uncomfortable gases, and sluggish bowels. This imbalance is known as dysbiosis.

For a flat stomach is a natural probiotic & prebiotic supplement which comes in powdered sachets to be taken daily as a one-week course - once a month, or as frequently as desired. This probiotic and prebiotic can help to naturally re-balance the good bacteria in your small and large intestines, supporting healthy digestion and good intestinal passage.  Please scroll to the bottom of the page to read reviews from our customers who have tried this supplement. 

Lactococcus lactis Rosell-1058

Lactococcus lactis Rosell-1058

How does For a Flat stomach work?

Lactobacillus acidophilus Rosell-52 is a natural resident of the intestinal microflora; this strain of acidophilus has been shown to survive gastric acidity and biliary salts, and to reach the intestines without damage. Lactobacillus acidophilus naturally adheres to the gut wall, where it inhibits harmful pathogens and supports immune cells.

Bifidobacterium bifidum Rosell-71 naturally resides in the large intestine, B. bifidum supports the production of antibodies, promotes detoxification and maintains resistance to undesirable pathogenic and putrefactive bacteria which can cause gas and bloating. In the colon, B. bifidum flourishes well with Fructooligosaccharides (prebiotics) where it supports the intestines to assist natural transit, promote comfort and optimise a healthy frequency and regularity of bowel movements.

Lactobacillus casei Rosell-215 is an extensively studied species naturally residing in the intestinal flora; our strain has been researched in its ability to resist gastric acidity and bile salts in order to reach your small and large intestines where it exerts its probiotic benefits. L. casei has been shown to modulate the composition and growth of Bifidobacteria in the colon and to support regularity.

Lactococcus lactis Rosell-1058 is extracted from the kefir culture, Lactococcus lactis is renowned for its antimicrobial benefits in supporting the body against undesirable bacteria and some fungi.

Fructooligosaccharides (FOS) predominantly settles in the large intestine where it acts as a food source to stimulate the growth of your body's probiotics.  The symbiotic relationship between Bifidobacteria and prebiotics in the colon has a great impact on supporting natural intestinal health and wellbeing, reducing the unpleasant effects of bloating.

See Scientific Research on Probiotics and Bloating


As a natural food supplement 'One week flat' can be given to adults and children from 4 years old & up, with the following recommendations: Take one sachet daily with breakfast for a 7 day course, or as professionally directed.

We highly recommend you take 'One week flat' for 7 consecutive days.  Most customers take this course once a month, but it can taken as often as desired. For more information see our FAQ: How often should I take OptiBac One week flat?

For best results:

  1. Pour an inch of water into a tall glass, leaving plenty of room for swirling.
  2. Shake the sachet well before gently sprinkling in the powder.
  3. Leave powder to dissolve naturally. 
  4. Vigorously swirl the water around in the glass.
  5. Drink, wait, and enjoy the benefits!


It is not recommended to give live cultures to patients who are: severely immunosuppressed, have pancreatitis, are in the Intensive Care Unit, have blood in the stool, have central venous catheters; or to post-surgical patients with open wounds, or infants with short bowel syndrome; unless under a doctor's care.

Full Ingredients

Stabiliser: Maltodextrin; Fructooligosaccharides (FOS); live cultures: (Lactococcus lactis Rosell-1058, Lactobacillus casei Rosell-215, Lactobacillus acidophilus Rosell-52 and Bifidobacterium bifidum Rosell-71).

Each sachet guarantees 5 billion micro-organisms + 0.3g FOS fibres.


Like the rest of the OptiBac Probiotics range, this product does not require refrigeration.  

Store away from direct sunlight.

  • Vegetarian
  • No added sugars
  • Gluten free
  • Yeast free
  • Free from artificial colours
  • Flavourless
  • Suitable in pregnancy
  • Live cultures
  • FOS fibres
  • Natural bacteria

Customer Reviews — 44 Reviews

  • One week flat 5 product Howard 2014-06-21

    Posted by Howard (UK) 5 years ago

    5 stars

    "I suffered from bloating for more than 5 years, with no relief whatsoever.
    My colonics Hydrotherapist recommended OptiBac products, that were spoken highly of at Colonics seminars.
    I purchased One Week Flat, and from day one of the 7 day course, I have had no bloating since.
    I am amazed, speechless and over the moon to be free of bloating, which caused me extreme pain sometimes, it affected me walking or exercising. It affected my relationship with my wife, it gave or worsened lower back pain that I suffer from.
    I am now completely free from bloating, and at risk of sounding dramatic, it has turn my life around :))))))

  • One week flat 5 product Kat Turton 2014-06-20

    Posted by Kat Turton (Norfolk) 5 years ago

    5 stars

    "Cannot recommend this product enough. I am a chronic IBS sufferer and was going through a bad patch with coming off my pill (super, super bloated). After 3 days I noticed a massive difference and felt so much better in myself. I was expecting the sachets not to taste very pleasant but infact they did not taste of anything so taking them was easy. I've since moved on to the optibac daily which is keeping my IBS under control. Great product."

  • One week flat 5 product Annamaria 2014-06-16

    Posted by Annamaria (London) 5 years ago

    5 stars

    "I had a very bad period, my tummy hurt me and I was always going to the toilet, Everything I was eating that hurt me, I tried 'For a Flat Stomach' and now I feel better, Is there one I can use for a longer period? This one definitely worked."

    Reply from OptiBac Probiotics Hong Kong

    Great news that ‘One week flat’ worked well for you.

    You can certainly try one of our daily probiotics – ‘For every day’ or ‘For every day EXTRA Strength’, and remember it’s also fine to keep taking ‘One week flat’ at regular intervals (some of our customers like it so much they even take it every day!).

  • One week flat 5 product Laura 2014-03-05

    Posted by Laura (Hampshire) 5 years ago

    5 stars

    "I recently tried the flat stomach sachets followed by every day caps. I get bloated constantly; every food sets me off so I reluctantly looked into probiotics (as I couldn't cut out every single food group going!) and was so pleased with this product. I didn't get on so much with the capsules so have stocked up on these flat stomach sachets and notice how much they help almost immediately. Even on my period or at the end of the day, I have still been 100% more comfortable than usual! Will be sticking with courses of these from now on!"

  • One week flat 1 product Caroline 2014-02-25

    Posted by Caroline (London) 5 years ago

    1 stars

    "I took my first 7 day course of For a Flat Stomach the week before my period since that is when I usually feel the most bloated. My period started days earlier than expected and I had acne all across my forehead which I do not think I have ever had before. I did not notice any improvement whatsoever gut-wise, but I put it down to my hormones clearly being all over the place at the time. I started the second 7 day course five weeks later, this time the week after my period, but stopped taking the powder when I started bleeding and that mysterious acne reappeared. I also had stomach pains and a lot of gas. The symptoms disappeared fairly quickly after I stopped taking For a Flat Stomach. My favourite (well, used to be anyway) frozen yoghurt gives me the same symptoms. It contains chicory root, which is a prebiotic, and I am clearly very sensitive to it. Chicory root can cause miscarriage, so pregnant women are advised not to eat it, but prebiotics in supplements are supposed to be safe. My reaction to For a Flat Stomach makes me wonder, though. Having said that, I know I am not the only one who gets a lot of gas and discomfort from prebiotics, but I have not come across anyone else whilst searching the web who has experienced bleeding. If I were pregnant I would definitely avoid prebiotics anyway to be on the safe side!"

    Reply from OptiBac Probiotics Hong Kong

    Dear Caroline, I'm sorry to hear of your symptoms. Occasionally some people find they are sensitive to prebiotics, in that the bloating and gas can slightly worsen in the first few days, but usually the body adjusts and symptoms disappear. We have an FAQ looking at prebiotics in more detail if of interest. However, probiotics & prebiotics should not interact with hormones, and we have never come across prebiotics being associated with influencing the menstrual cycle at all. I would recommend you consult with your doctor about the unexpected bleeding. Just to reassure you whilst chicory is contraindicated in pregnancy due to components such as polyphenols, prebiotics are not known to have contraindications in pregnancy. I hope you find this information useful, please be in touch if you’d like any further information. - Megan, Naturopath & Herbalist