According to UCSF, the normal stomach acid pH ranges between 1.5 to 3.5.
However, most probiotic strains flourish in the intestinal and colon environment where the pH is between 6 to 7.
These values indicate that probiotic supplements lacking the right species or appropriate coatings to protect susceptible strains are nearly ineffective.
Therefore, here are some key points that you should consider for buying products that offer high value for money.
Effect Of Stomach Acid On Probiotics
Our stomach is the first line of defense against infections and diseases, and it releases gastric acid as a key player in its protective mechanism.
This stomach acid impairs the metabolism and growth of microorganisms by oxidizing or destroying their cells’ essential biomolecules, such as cholesterol, proteins, and fatty acids.
Correspondingly, scientific experiments report that gastric juice with a pH of less than 3.0 can kill most bacteria within 15 minutes; without selectively sparing the good bacterial strains.
In this way, our stomach safeguards our health with every meal, but you need to put in extra effort to boost it.
For that, the first thing you need to do is to incorporate probiotics that survive stomach acid.
Generally, Bacillus species are the most resilient to stomach acid, followed by Lactobacillus species which demonstrated a higher resistance to stomach acid than Bifidobacterium species.
Apart from that, there is mixed evidence regarding the ability of Streptococcus thermophilus to bypass gastric acid.
In this regard, one study reports that it can withstand low pH for only 40 minutes.
Does Stomach Acid Kill All Bacteria?
No, some bacteria have developed certain adaptive mechanisms to evade stomach acid.
For instance, pathogens like Escherichia coli, Salmonella Typhimurium, and Helicobacter pylori may go past the stomach protection and into the intestines, where they induce infections like gastroenteritis.
Similarly, certain probiotic bacteria can also regulate their internal processes in such a way that they hold out in the stomach acid. Here are some examples.
– The cells of Lactic Acid Bacteria may form a gradient.
The Lactobacillus and Bifidobacterium species can maintain a different internal and external environment inside their cells.
For this purpose, they possess certain enzymes that can carry out proton expulsion from inside the cells to outside, which increases the intracellular pH in low pH conditions.
Hence, the cellular functions keep going on normally.
– The Bacillus spores promote survival.
Bacillus species can form resistant spores in unfavorable conditions.
These dormant cells can circumvent stomach acid, and they germinate in the intestines and colonize the colon.
In this way, they will improve the gut microbiome diversity and improve your immune modulation and digestion.
Which Probiotics Can Survive Stomach Acid?
Now that you know how good bacteria bear the hostile stomach environment. So, this section will specifically provide you with some of their names to support your product search.
Fortunately, scientists have specifically tested the survival rate of certain bacteria in stomach acid by utilizing artificial human GIT models or by doing real-time sampling.
Alternatively, they have also performed lab studies in which bacteria were exposed to stomach acid with a pH ranging from 1.5 to 3.0 for about 3 hours.
As a result, they have identified the following bacteria as the hardiest probiotic species:
- B. bifidium, B. longum (strain 1941) and B. pseudolongum (strain 20099), B. breve (strain M-16 V)
- L. bulgaricus, L. rhamnosus GG, L. plantarum, L. acidophilus (strains 2401 and 2409)
- Lactococcus lactis
- Spores of Bacillus species (B. subtilis and B. coagulans)
How To Help Probiotics Survive Stomach Acid?
There are certain unwritten rules for taking susceptible probiotic bacteria that can increase their chances of reaching the intestines alive.
However, if you are taking industrially produced supplements, then good manufacturers already employ various tactics to ensure the viability of the bacteria in their product.
So, here are some strategies that prevent probiotics from getting lost in harsh stomach fluid.
Opt for High Viable Cell Count
After numerous studies, researchers recommend that an effective supplement should contain at least 108–109 viable probiotics CFU per dose to impart considerable benefits.
Therefore, considering the losses in stomach acid, according to the NIH, good supplements contain high 1 to 10 billion CFUs per dose or as high as 50 billion CFUs per dose.
Additionally, the adoption of ideal manufacturing practices may also ensure that the product contains the exact viable CFUs as mentioned on the label.
For instance, probiotic bacteria such as those belonging to the Lactobacillus and Bifidobacterium genus thrive in anaerobic conditions.
So, if oxygen gets dissolved in the product during the manufacturing process, it may threaten the vitality of these bacteria.
Therefore, look for supplements that are made in FDA-approved facilities and those that conform to the GMP standards because they are less likely to have any discrepancies.
Look for Protective Coatings
Probiotics delivered in capsule form effectively slide out of the stomach environment than those that are compressed in tablets or in powder forms.
Moreover, if you are looking for an easy hack to identify the better supplement, then look for the ‘non-refrigerated’ label.
These products contain probiotics encapsulated in coverings that shield them from extreme conditions like heat, humidity, and acidic pH.
Therefore, the probiotic bacteria can escape the stomach environment in one piece and arrive in optimal quantities in the intestines and colon.
For instance, probiotics passing stomach acid in the MAKtrek delivery system are 250 times more likely to arrive safely at the intestines than their unprotected counterparts.
Similarly, probiotics can be enclosed in vegan HPMC or gelatin capsules because they prevent moisture penetration and are acid resistant.
Related post: 7 Best Non-refrigerated Probiotics
Try Pairing Probiotics with Prebiotics
The presence of prebiotics is another desirable feature that you should look for in probiotic supplements.
The reason is that fiber like inulin or polydextrose feeds the bacteria and helps to retain their viable numbers in the product.
Choose Acidic pH Resistant Species
The stomach provides ground for only the ‘survival of the fittest,’ and its pH can fall as low as 1.5 during fasting.
In comparison, even the desirable aciduric (able to tolerate acidic environment) probiotic species like L. acidophilus struggle to endure pH 2 or below.
One way in which you can tackle this issue is by taking probiotic supplements with or after food.
This practice holds significance because the American Physiological Society reports that the gastric pH can increase to as much as 4.5 after a meal and will take approximately 3 to 4 hours to drop back to approximately pH 1.
All in all, manufacturers should ideally prefer adding probiotic strains that can withstand pH 3.0 or lower.
However, another clever way to introduce probiotics in the gut is in the form of Bacillus spores that are resistant to environmental stresses.
Plus, research supports the addition of S. thermophilus to Bifidobacterium species, as it helps reduce oxygen pressure and enhances the viability of the latter species.
Practices That Should Be Paired With Probiotic Intake
Manufacturers usually publish the instructions for taking their probiotic supplements, but there are no such guidelines in the case of probiotic foods.
Here are some practices that you may adopt to preserve the viability and effectiveness of the beneficial bacteria in products that don’t come with directions.
- As mentioned before, you should prefer taking probiotics after meals.
- Probiotics are best taken at night because gut motility is reduced at that time which may enhance their chances of colonization.
- Avoid consuming probiotics with acidic and hot drinks such as tea, fruit juices, or coffee, as it may kill the beneficial bacteria.
Best Probiotics That Survive Stomach Acid
To save you time, here are my top non-refrigerated product recommendations that encompass ample acid-tolerant strains and prebiotics.
1. Culturelle Digestive Daily Probiotic – Best For Improving Gut Health
It uses HPMC capsules, contains inulin fiber, and has an FDA-verified Lactobacillus rhamnosus GG strain.
2. YourBiology Probiotics – Best For Women’s Health
It delivers probiotics with MAKtrek technology and contains fructo-oligosaccharide pre-biotic.
Plus, two out of its four stains can inherently resist low pH; these are L. acidophilus and L. Plantarum.
3. Biotics 8 probiotics – Best for Men’s Health
It encapsulates the bacterial strains in HPMC capsules and contains chicory root fiber.
Moreover, three out of its five Lactobacillus species are acid-tolerant, namely L. plantarum, L. acidophilus, and L. rhamnosus.
Do probiotics in kefir survive stomach acid?
Yes, studies prove that the bacteria in kefir are resistant to digestion. For instance, it contains L. acidophilus, B. bifidum, S. thermophilus, Lactobacillus delbrueckii subsp. bulgaricus and Lactococcus lactis.
Do kombucha probiotics survive stomach acid?
Yes, researchers have isolated various lactic acid bacteria and Bacillus coagulans from Kombucha, which are resistant to stomach acid. Nonetheless, the yeast species in it can get killed in acidic pH.
Does stomach acid kill probiotics in yogurt?
No, most of the probiotic strains in yogurt survive in the stomach as it is fermented with S. thermophilus and L. bulgaricus bacteria.
Do probiotics in sauerkraut survive stomach acid?
Yes, some probiotic species in sauerkraut that survive the stomach acid include L. brevis and L. plantarum.
How are probiotics alive in a pill?
Capsules are mostly made up of a tough film made of gelatin or Hydroxypropyl methylcellulose that serves as a barrier between inside contents and extreme environments. Hence, the probiotics remain alive in them.