Above, I take a real children’s probiotic off the shelf and read the label line by line. Everything below is the same method in writing.
Here is the short version. If a label says Lactobacillus reuteri and nothing more, you cannot tell whether it is safe for your child.
- L. reuteri DSM 17938 is among the best-evidenced strains in treating paediatric eczema.
- But L. reuteri ATCC PTA 6475 produces histamine.
Same species, different strain → opposite answer. This is why the label needs to show the strain!
Why Is Chinese Doc Writing About Probiotics For Children?
At our clinic, parents bring in their children mid-flare — mostly toddlers, sometimes infants. The child is in excruciating pain, the parents have run out of answers, and somewhere along the way someone told them to try probiotics.
Then comes the same question, nearly every time: which probiotics should we use?
This page is written for that parent.
I’m Dr Mark Chern, and I treat childhood eczema with Chinese herbal medicine at Chinese Doc Singapore.
Any probiotic you want to ask us about? Ask us below.
First Rule For Safety: No Allergens
The diet is clean. The house is clean. BUT the child still flares after starting a probiotic. Search it and you get the same answer everywhere.
Some probiotics are grown on a dairy and soy base. The base is skimmed out before packaging, but traces can remain. OptiBac is one example.
The stabiliser in OptiBac is potato starch. Potato starch is uncommon as an allergen, but not harmless. It can provoke reactions like hives in children who already react to nightshades or latex.
The product below is good in that all the probiotic strains are stated clearly. Yet it is NOT SOY-FREE, but doesn’t declare that.
The brands worth trusting say it outright: no wheat, no eggs, no dairy. FloraTummys is a good example — a company willing to be that explicit is usually careful elsewhere too.
So yes, read the allergen line first.
But if you have done that, BUT your child is still flaring — then you have to check for the strains.
Part Two: The Strain Line Matters Most
Some probiotic strains produce histamine in the gut. Not in everyone, but in a child who is already histamine-loaded and easy-to-flare, it is enough to matter.
Here is a product sold on being multi-strain, from InnovixLabs.
Zoom in and the UALre-16 strain is printed. UALre-16 is short for Lactobacillus reuteri UALre-16.
Named is good — all probiotic supplements should name their strain. That said, Lactobacillus reuteri DSM 17938 is the better-evidenced strain.
Histamine is not simply bad. In some experimental models it is anti-inflammatory.
But for a child with histamine excess, more histamine in the gut can outweigh whatever else that strain is doing. That is the whole argument for reading the strain line.
The Three Things a Probiotic Label Has to Tell You
Every probiotic label is trying to tell you three things. Most manage two.
- Genus — Lactobacillus, Bifidobacterium, Saccharomyces. The family. On its own it tells you almost nothing.
- Species — reuteri, rhamnosus, casei. Narrower, still not an answer. Two strains of one species can behave in opposite directions.
- Strain code — DSM 17938, ATCC 53103, BB-12. This is the organism. Everything ever studied was studied at this level.
Written in full: Lactobacillus rhamnosus GG (ATCC 53103). Genus, species, strain. That label is making a checkable claim.
Note that the species already defines the genus for most.
So, your job is to first look for the strain code.
If there is no strain code, nothing else on the label can rescue this product, even if it is a well-known product like Garden of Life.
| STRAIN | SPECIES | VERDICT | WHAT TO DO? |
|---|---|---|---|
| DSM 17938 | L. reuteri, the paediatric strain | Safe | This is the one you want |
| UALre-16 | L. reuteri, a named commercial strain | Usable | Named, so you can check it — but DSM 17938 has the better evidence |
| ATCC PTA 6475 | L. reuteri, histamine-producing | Avoid | Put it back |
| ATCC 53103 (sold as LGG) | L. rhamnosus GG | Safe | Well studied in children |
| BB-12 | B. animalis subsp. lactis | Safe | Common in children’s blends |
| CNCM I-745 | S. boulardii — a yeast, not a bacterium | Safe | No hdc gene to worry about |
| TISTR 389 | L. casei | Avoid | Histamine-producing |
| TISTR 895 | L. delbrueckii subsp. bulgaricus | Avoid | Histamine-producing |
| L. reuteri with no code | Species only | Unknown | No information. Email the maker or choose another product |
| Proprietary blend | Undisclosed | Unknown | No information, by design |
Three species are worth committing to memory, because they turn up constantly and all three sit on the RED-FLAG histamine list:
- Lactobacillus casei
- Lactobacillus bulgaricus
- Streptococcus thermophilus.
1. Labels That Name the Strain: What Good Looks Like
Start with the two products that get it right, because they set the bar the others fail against.
NOW Probiotic-10, 25 Billion CFU
On the label: all ten strains, each with its code — L. acidophilus La-14, B. lactis Bl-04, L. plantarum Lp-115, L. casei Lc-11, L. rhamnosus Lr-32, L. paracasei Lpc-37, B. breve Bb-03, S. thermophilus St-21, L. salivarius Ls-33, B. longum Bl-05. Dairy, soy and gluten free, printed on the front.
Why it works: this is exactly what a label should do. Every organism in the capsule is identified, so every one of them can be looked up.
What looking them up finds: two of the ten — L. casei Lc-11 and S. thermophilus St-21 — belong to species associated with histamine production. So a well-labelled product is not automatically the right product. Named means checkable, not safe. The difference is that here you get to make a decision instead of a guess.
Nano Singapore, 40 Billion CFU
On the label: four strains, each with a code and its own CFU count — L. acidophilus LA85 at 5.6 billion, B. lactis BL80 at 23.2 billion, L. plantarum Lp90 at 5.6 billion, L. paracasei LC86 at 5.6 billion.
Why it works: it goes one step further than NOW. You know which organisms are in there and how much of each, so the headline 40 billion is not hiding a token sprinkle of one strain behind a mountain of another. The word proprietary blend still appears at the top of the panel — and then it discloses everything anyway.
Four named strains, none of them on the avoid list, with the amounts shown. For a histamine-sensitive child this is the clearest label of the eight.
2. Species Named But Strain Codes Missing
These labels give you the species but NOT the strain. You can see roughly what is in the capsule, and in all of these, the species alone is NOT guaranteed SAFE!
Cymbiotika Probiotic, 50 Billion CFU
On the label: 19 species, no strain codes anywhere. Among them L. bulgaricus, L. casei, L. brevis, L. helveticus, L. fermentum and L. reuteri.
The problem: five of those nineteen are species linked to histamine production, and without codes you cannot tell which strain of each you are getting. That L. reuteri could be DSM 17938 or ATCC PTA 6475 — the best case and the worst case, for the same money.
HealthVeda Organics Probiotics, 50 Billion CFU
On the label: 17 species, each with its own CFU count — and not one strain code. The list includes L. casei, L. helveticus, L. fermentum, L. reuteri and S. thermophilus.
The problem: the CFU breakdown looks like transparency. But 3 billion of an unnamed L. casei could mean an L. casei that produces histamine. Red flag!
SuperSmart Lactobacillus Reuteri, 5 Billion CFU
On the label: Lactobacillus reuteri, 200 mg, 5 billion CFU. Gluten and soy free. No strain code.
The problem: As mentioned several times already, reuteri is the species where the code matters most. You really don’t want strain to be a L. reuteri ATCC PTA 6475.
Vitamatic L. Reuteri Complex, 22 Billion CFU
On the label: one line reading L. Reuteri Complex, 22 B CFU, and underneath it three species — Lactobacillus reuteri, Lactobacillus rhamnosus, Lactobacillus acidophilus. No codes, and no split of the 22 billion between them.
The problem: the product is sold as a reuteri supplement, but nothing on the label says how much of it is reuteri. It could be 21 billion reuteri and a dusting of the other two, or the reverse. Compare that with the Nano Singapore panel above, which prints the number beside every organism.
A large CFU total is the easiest figure to put on a label. Without a breakdown it is the least useful figure on it.
3. Built on the Wrong Organism
Genesis LB Probiotic, Lactobacillus Bulgaricus, 25 Billion CFU
On the label: a single species, Lactobacillus bulgaricus, 25 billion per capsule, no strain code. And in the ingredients: contains milk and lactose.
Two problems: L. bulgaricus is a yogurt starter culture — not a clinically studied probiotic. It is on the histamine list and certainly not some thing can help childhood eczema. Add to that the label, which declares milk outright. This is yoghurt in a capsule!
Common Questions About Probiotic Labels
I am holding a bottle right now. Is this one good?
Turn it over and look for a code after the species name — letters and numbers such as DSM 17938, ATCC 53103, BB-12, CNCM I-745. Check it against the table above.
If there is a code and it is on the safe list, it is a reasonable choice. If there is a code and it is on the avoid list, put it back. If there is no code at all, the honest answer is that nobody can tell you — including the shop assistant.
What are my options if I want to keep it simple?
Single-strain, strain code printed, one of the safe entries in the table. L. reuteri DSM 17938 and L. rhamnosus GG (ATCC 53103) are the two with the most paediatric eczema evidence behind them, and both are widely sold in Singapore. For LGG specifically, see Lactobacillus rhamnosus GG for kids with eczema.
Start with one. Give it a few weeks before adding anything else, so that if something changes you know what changed it.
The label just says Lactobacillus reuteri. Is that a problem?
It is usually a red flag.
L. reuteri DSM 17938 is one of the better-studied strains for children. A manufacturer would share this if they were selling this.
L. reuteri ATCC PTA 6475 produces histamine. Would the manufacturer declare that?
Does organic, dairy-free or hypoallergenic on the front help?
It helps with a different problem. Those claims are about the formulation — the carrier, the stabiliser, the traces left from the growing medium — and they matter, as the OptiBac example shows.
But they say nothing about the organism. A certified organic, dairy-free capsule can still contain a histamine-producing strain. The two questions are separate and you have to ask both.
My child reacted. Was it the probiotic?
Possibly, and the label is where to start. Look at what is in it — strain codes first, then the allergen and excipient list.
Stop the product, let things settle, and if you restart, restart with one named strain so the next few weeks actually tell you something.
Blends Versus Single-Strain: Why Ten Strains Is Harder to Judge
A ten-strain blend sounds like better value than a single strain. BUT For a child with eczema it is usually NOT SO SAFE. For two reasons:
- You cannot tell which strain causes a flare. If the flare gets worse in week two, a single-strain bottle gives you one suspect. A ten-strain bottle gives you ten, and no way to test them apart without stopping everything and starting again.
- Blends are where unnamed strains hide. A single-strain product has one code to print and usually prints it. A blend has ten, and the label very often lists ten species with no codes at all — or worse, a total CFU count and the words proprietary blend.
One histamine-producing strain in that mix is enough to matter. Blends are acceptable, as long as they name every strain.
Starting out, one strain — or two — is easier to read, easier to stop, and easier to blame.
If the Label Does Not Name the Strain
When choosing probiotics for eczema, it helps to be precise:
- Always look for the full strain name, such as Lactobacillus rhamnosus GG, rather than just the species.
- For those with histamine sensitivity, simpler is often better: single-strain probiotics or very limited blends make it easier to notice any reactions.
- Start with a low dose and increase gradually, so you can monitor how your body responds.
- If histamine intolerance is severe, Saccharomyces boulardii, a yeast-based probiotic, may be a gentler option, as it doesn’t produce histamine.
Summary: How To Choose
Four questions, in this order, and the bottle answers all of them before you reach the price.
- Is there a strain code? Letters and numbers after the species name. No code, no information — put it back or email the maker.
- Check each code against the table above. A named strain can still be one to avoid. NOW Probiotic-10 is well labelled and contains two species on the histamine list.
- Count the strains. One or two you can judge and, if things go wrong, stop and blame. Nineteen you cannot.
- Read the allergen line. Dairy and soy from the growing medium, potato starch as a stabiliser. It is the second question, not the first — but it is still a question.
Goes back on the shelf: anything with a proprietary blend, anything built on L. bulgaricus, and any L. reuteri that will not tell you which one it is.
