Probiotics in Capsules vs in Liquid?

In a dialog with a reader, this question came up. In the US, most probiotics are in capsules and thus assumed to be the right way (repeat something enough and it becomes “fact”/Urban Legend). Often manufacturers will accent their special capsules that “prevents the probiotics being killed in transit”.

The problem with this probiotic view is that there is lots of contradictory examples showing that it is wrong. In fact, one could suggest that it is so wrong that it destroys or reduces the effectiveness of the probiotic to put the probiotic into capsules.

Probiotics in Liquid that persists

Both Symbioflor-1 and Symbioflor-2 comes suspended in liquid and is added to a glass of water. Both have been proven to persists. How can that be if the transit destroys it???? Or this study, Persistence of Supplemented Bifidobacterium longum subsp. infantis EVC001 in Breastfed Infants, “Mothers were trained by lactation consultants to mix the contents of the sachet in 5 ml of expressed breast milk and feed this to the infant. ” I see no capsules!!

Similar, Mutaflor is available as a suspension (i.e. in a liquid).

Evidence that Capsules Work?

The typical evidence is simple, when given in acid harden capsules, the probiotic can be detected in the stool later in the day (the same day!). Not detecting it was the motivation for developing the capsules. There are many other reasons that none could be detected — including sourcing the probiotics from pigs and chickens.

The diagram below may illustrate their proof… note that most of the digestive system never sees the probiotic.

How they “prove” that the capsule is needed (Image adapted from

Non-holistic thinking of the Microbiome

I have written previously how the mouth and throat acts as a reserve of the bacteria in your gut. This applies to the entire digestive system. Upstream areas restocks downstream areas. Often the amount in the upstream may be very small because the environment is hostile, but when some colonies moves downstream – they bloom in a friendlier environment. Often probiotics companies have simplistic understandings of the digestive system — their purpose is not research or knowledge, but making a profit.

To make a profit means selling to the public that their product is superior (more sales), and ideally worth a premium (more profit).

Two more cases of probiotics transiting the entire system

The first one is easy, probiotic gummies. The second one comes from Custom Probiotics, my favorite source because I can get single strains with no additives. They do sell capsules (after all, there is a demand for capsules). Their instructions for the rest of their products are below. Incidentally, they are the cheapest source for BCFU per dollar, and all of their strains are formally identified):

Bottom Line

A simple experiment may demonstrate the difference for many people(not all). Take your capsules, open them and take it as directed by custom probiotics, shown above, for 1-2 weeks. What differences do you observe?