What form of probiotic has the greatest health benefit- Capsule or powder?

I have searched for it but the results talk about everything on probiotics except my question!
(A snapshot of my endeavors)

In my opinion it is better to use capsule since it will protect the bacteria from the acid environment in the stomach. But then I'm skeptical about that: if the powder form is useless, why does it exist?

  • @DaveL: thanks for your edit. However why do you put the image into a link instead of showing it directly? I think it will be easier for the readers to see it?
    – Ooker
    Commented Jun 3, 2015 at 15:59
  • Oh, that was a mistake. I didn't notice that changed. Thanks for pointing that out. Actually, now that I consider it, the picture isn't all that relevant and does take up a lot of space. Someone who's trying to answer the question wouldn't find that image useful.
    – Dave Liu
    Commented Jun 3, 2015 at 16:01

3 Answers 3


I cannot answer your question directly, but explaining some general considerations might help to clarify what would be a sound choosing approach.

When you say:

In my opinion it is better to use capsule since it will protect the bacteria from the acid environment in the stomach.

bear in mind that this applies to gastro-resistant capsules only:

Gastro-resistant capsules are delayed-release capsules that are intended to resist the gastric fluid and to release their active substance or substances in the intestinal fluid. Usually they are prepared by filling capsules with granules or with particles covered with a gastro-resistant coating or in certain cases, by providing hard or soft capsules with a gastro-resistant shell (enteric capsules). (Ph.Eur.5.0.)

Many manufacturers of probiotics use hard (gelatine) capsules which are not resistant to stomach acid. In fact these two sorts of capsules have to comply with different pharmacopoeial requirements:

Gastro-resistant capsules:

Disintegration. For capsules with a gastro-resistant shell carry out the test for disintegration [...] use 0.1 M hydrochloric acid as the liquid medium and operate the apparatus for 2 h, or other such time as may be authorised, without the discs. Examine the state of the capsules.The time of resistance to the acid medium varies according to the formulation of the capsules to be examined. It is typically 2 h to 3 h but even with authorised deviations it must not be less than 1 h. No capsule shows signs of disintegration or rupture permitting the escape of the contents. (Ph.Eur.5.0)

Whereas for hard capsules it says:

Use water R as the liquid medium. When justified and authorised, 0.1 M hydrochloric acid or artificial gastric juice R may be used as the liquid medium. [...] Operate the apparatus for 30 min, unless otherwise justified and authorised and examine the state of the capsules. The capsules comply with the test if all 6 have disintegrated. (Ph.Eur.5.0)

Some strains of probiotics are found to be acid resistant which can be enhanced by formulation factors other than gastro-resistant coating. On the other hand, manufacturers of probiotics in gastro-resistant capsules often state (on their websites e.g.) that they deliver more units of probiotic bacteria to the intestines than conventional dosage forms. (It may depend on the strains they use.) Some probiotics can be found in yoghourt which is definitely not gastro-resistant.

Regulatory requirements are much stricter for medicines than for supplements in most countries, so if one is concerned with the sufficient drug delivery and the accuracy of medical claims, it is useful to know that for medicines to be approved for marketing much firmer evidence about these (and other concerns) has to be submitted.

Why does powder exist as a dosage form? There may be several reasons to produce and market oral powder as a dosage form: some people have difficulties to swallow capsules, it may depend on manufacturer's production line, powders allow for individualised dosage (measuring the dose for a specific patient - but I don't think this would be necessary with probiotics), hygroscopic excipients which are incompatible with capsule shell etc.

The dose you take in powder is not more precise - even if it is sold in divided doses (each dose in one bag), because a small amount of powder can always remain on the walls. The precision of measurement is the same at best, if not in favour of the capsules.

How to chose?

Here are some of the questions that should be taken into account:

  1. Is the patient allergic/intolerant to any of the formulation's ingredients?
  2. Is there a form preferred by the patient's physician, for some medical reason?
  3. Which form is the most convenient one for you?
  4. Which form is accessible and affordable to you?
  • I can drink capsule and there is no advise from physician. I think that using capsule is more convenient for me. Thank you.
    – Ooker
    Commented Jun 4, 2015 at 12:38

If they both contain the exact same substance, then powder form may be easier to measure more precisely. However, I cannot find any studies indicating any significant difference between capsule and powder form.

Additionally, I would like to give you this link containing an interview with Dr. Stefano Guandalini, MD, Section Chief of Pediatric Gastroenterology, Hepatology, and Nutrition and Medical Director of the Celiac Disease Center at the University of Chicago.

He gives a short list of probiotics which "have been validated through clinical trials and published in peer-reviewed journals to show efficacy". For the rest, he states,

"Outside of this incredibly short list, however, there is nothing else. There is no other probiotic that has been found to be effective in rigorous, controlled clinical trials. This is not to say they aren’t working, it’s just to say we don’t have any scientific proof yet."

  • 2
    Hi Dave! I'm leaving this as a comment because I don't have a reference on hand, but, with many things, the difference between powder and capsule isn't quite as simple as that. There are situations in which a capsule is preferred in terms of the timing of delivery into your system. Also, some powders need to be mixed with liquid, and are therefore dosed differently. As for probiotics, there are many kinds, which increases the number of variables for consideration. Commented Jun 4, 2015 at 2:12
  • @Sue you don't have to have the references to write an answer. It's just strongly recommend to have one. Just go on and evaluate your thoughts
    – Ooker
    Commented Jun 4, 2015 at 7:15
  • @Sue, edited to say "may be". Thanks for the input! :)
    – Dave Liu
    Commented Jun 4, 2015 at 18:19
  • 1
    @Ooker Actually I've been doing some research and will post some thoughts tomorrow, although they'll supplement, not replace, the answers you've gotten. Thanks for the edit Dave :)) Commented Jun 5, 2015 at 21:49

I was told by a gastroenterologist at the IWK children's hospital in Halifax NS ( regarding medications my child had to take - that many things are excreted from our body when taken in capsul form before it gets a chance to work. An example the doctor gave me is when people take Metamucil capsules they do not get the effect bc the capsul goes through the system often before it is effective. The doctor recommended for someone taking Metamucil to take the powder form rather than the capsul. I would think the same idea would affect probiotic capsules. I started opening my capsule and putting the powder on my oatmeal / food and taking it that way.

  • 1
    Welcome to health SE :-). This sounds like a personal experience, and this website aims for evidence-based answers, which is why reliable references are required.
    – Lucky
    Commented Mar 6, 2017 at 15:13

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