If you are reading this blog, then the chances are that you have some concerns about whether or not probiotics survive to reach the gut alive. You may be confused as to whether spending money on probiotics is indeed an investment in your own good health, or if it is in fact a waste of money. I'd say that this concern about survival through stomach acidity is a very valid one, but if you read on, I hope to put your mind at rest that there are some viable, well tested and researched probiotics out there...

Choose a probiotic proven to survive to reach the gut alive

In part, the concern over the survival of probiotics through the stomach has been perpetuated by a small study1 performed at University College London back in 2014, which tested 8 probiotic products and found that only one of the probiotics tested survived gut acidity and flourished in the intestines. We reported on this study at the time, and our write up can be found here. However it is worth mentioning again that no OptiBac Probiotics products were included in this study, and that if they had been, then we believe we would have passed each test with flying colours!

So, it appears that some probiotics may not survive transit through the stomach, and some DO!

But how can we tell which is which?

pH testing of our strains:

Well, we can't speak for other brands, but we can tell you a little more about why we are so confident that our products would have excelled in the 2014 study. One reason is that each strain of bacteria that we use undergoes rigorous in-vitro pH testing2 which indicates that the strains we use do survive exposure to stomach and bile acids. Obviously the stomach is a challenging environment that exposes any probiotics taken to a low (acidic) pH; however, the exact pH changes constantly, dependent on the time of day and the presence or absence of food. We always recommend that our products are taken with breakfast each day, as stomach acid is naturally at its weakest in the mornings, and this is then buffered still further by the presence of food. To read more about the best time to take your probiotic, you may wish to read our FAQ.

We subject the strains of bacteria we use to different levels of acidity in laboratory conditions to see how well they survive. At pH 3 and above we see 95-100% survivability of our strains, and research shows that at mealtimes our stomach pH is typically at about pH 4.

Survivability of two of the strains of bacteria in 'For babies & children' (formerly 'For your child's health') at different pH's

Enteric coating and timed-release technologies:

Due to the high survival rate of the strains of bacteria that we use, we do not need to use technology like Bio-tract®, a time-release technology thought to protect the bacteria from the low pH in the stomach for our product range, though this may well be of benefit for other strains of probiotic bacteria.

Our bacterial strains also don't need a Unique Delivery System (UDS™) as used by other brands, or a special enteric coating in order to survive transit through the harsh stomach environment. Enteric coating is a special coating for capsules, which is intended to remain intact in the stomach but to dissolve in the small intestine, and which could well provide another good option for ensuring probiotics survive to reach the gut alive. On the other hand, critics of enteric coating have pointed out that it can involve the use of synthetic chemicals, as well as highlighting some doubts over whether the capsules eventually break down in the lower GI tract to release the probiotics, or if they pass through the intestines intact with their probiotic cargo still on board. Therefore, we feel that it is better to use hardy strains of bacteria that do not require this level of protection to survive transit through the stomach, in fact, all of our encapsulated products can be safely taken out of their capsules and the live cultures consumed alone!

For more about this subject, click on this link to our FAQ: 'Are your capsules enteric coated?'. You may also enjoy reading a page from our latest information section, 'Probiotic Myths - BUSTED!' - see 'The Survival Myth'.

The bacteria in our range also undergo other forms of stability testing to show how they survive at different temperatures, and which confirm that they remain viable until the date of expiry. Thanks to a sophisticated method of freeze drying known as lyophilisation, our brand offers 'fridge-free technology', which means that you don't need to refrigerate any of the products within our range.

The Ultimate Proof of Survival - Human Clinical Trials

But ultimately, what is the most conclusive proof that you're buying probiotics that reach the gut alive? How do you know that your live cultures have survived transit through the stomach and are surviving and thriving in your gut?

Quite simply, it's from measurable results obtained from credible scientific research, most importantly, human clinical trials. It's best to choose a probiotic that has been used in studies on human subjects, and which have then yielded clinically significant, measurable results that suggest the live cultures are positively influencing the health of the test subjects.

Whilst in vitro trials appear to demonstrate that certain probiotics are stomach acid resistant, the real 'proof of the pudding' are the clinical trials which show notable effects on gut health, or cholesterol levels, or vaginal health. This is the ultimate confirmation that the live cultures survive stomach acid and colonise in the intestines or vagina and offer health benefits.

It's worth noting here, then, that we have significantly more clinical trials on our finished products, than any other live cultures brand available in the UK. Click on this link to our blog: Most Researched Probiotics: Comparing Brands

In fact, we have 156 finished product clinical trials to support the use of the strains within our range. A finished product trial is one conducted on the exact formula and dosage used in each product, rather than on one or two of the strains they contain - if we included all of the clinical trials that we have on each of the bacterial strains, or different combinations of strains within each product, then the number would be much higher.

To view some of the research studies that support the formulas we use, click on this link to Our Research Pages.

And finally...YOU and your clients!

If you find a probiotic product that constantly receives positive independent reviews and feedback, then this is another indication that the live cultures it contains are surviving their journey through the stomach and thriving as part of their host's resident microflora.

After all, the only thing that is important is whether or not the product works and brings health benefits to your clients. So why not conduct your own mini human trials and see which product works best for your patients. Take a look at our probiotic myths for more information.

You can read how we collect our customer reviews, here.

Or read some actual product reviews, here.


1. Gaisford, S., & Fredua-Agyeman, M., (2014) ‘Comparative survival or commercial probiotic formulations: test in biorelevant gastric fluids and real time measurements using microcalorimetry’, Beneficial Microbes.

2. Institut Rosell Lallemand (2016), 'Resistance to Gastric Acid', General Probiotic Training 27-29

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