You’ve probably been told that probiotics are good for eczema. Every pharmacy shelf says so. Immune support, gut balance, clearer skin. And honestly, it sounds right — eczema does involve the immune system, a lot of the immune system sits in the gut, so feeding the gut should settle the skin.
Here’s the part nobody mentions at the counter.
Probiotics aren’t like vitamins, where most brands do roughly the same job. Probiotics talk to your immune system directly, and what they say depends on the exact strain in the bottle (not the first part of the probiotic name, but the last part).
Take Lactobacillus reuteri. Two bottles, same name on both.
- One holds a strain that makes histamine — the chemical behind the itch and the redness.
- The other one doesn’t.
Same label, totally different effects on your skin.
That’s why one person takes a probiotic for two months and feels nothing, while another starts one and watches their skin get worse.
So let’s go through the probiotic strains for eczema one at a time. The ones to avoid, the ones that are safe, the few that actually bring histamine down, and the products you’ll find them in.
Three things to know before we start:
- Some Lactobacillus strains make histamine. <– Those are the ones to skip.
- If you take a blend and get a flare, you’ll never know which strain caused it.
- Some products contain inulin, which sets off a reaction in certain babies.
FEATURED — HOW TO READ YOUR PROBIOTIC LABEL
Is BioGaia Safe for Eczema?
Yes. BioGaia’s paediatric range uses Lactobacillus reuteri DSM 17938 — a strain with no evidence of histamine production. That remains true for Protectis drops and Protectis Junior chewables.
There is one reuteri strain flagged as a histamine producer. It is ATCC PTA 6475. It is not used in BioGaia’s paediatric line. Parents who’ve read that “reuteri produces histamine” are reading about 6475.
What it doesn’t mean. No histamine risk is not the same as a benefit. DSM 17938’s strongest evidence is in infant colic and gut function, not skin. If your child is on it and the skin is settled, there’s no histamine reason to stop. If you’re starting it hoping to clear eczema, keep expectations modest.
Most labels aren’t as transparent as BioGaia. There are many probiotic brands that print a species name — Lactobacillus reuteri — and stop. That tells you almost nothing, because within a single species one strain can produce histamine and another can lower it.
The rest of this webpage is a strain-by-strain guide on which strain does what. For each strain: whether it produces histamine, what the eczema evidence actually shows, and what to look for on the label.
Probiotic Strain Safety Chart (Avoid, Safe, Histamine-Lowering)
| Strain | hdc gene | Verdict | Where you’ll see it |
|---|---|---|---|
| L. reuteri ATCC PTA 6475 | Present | Avoid | Adult gut and oral formulas — check the strain code |
| L. parabuchneri (multiple strains) | Present | Avoid | Aged cheese, artisanal ferments — not on supplement labels |
| L. casei TISTR 389 | Present | Avoid | Fermented milk drinks, general blends — code rarely printed |
| L. delbrueckii subsp. bulgaricus TISTR 895 | Present | Avoid | Standard yoghurt starter culture |
| L. reuteri DSM 17938 | Not detected | Likely safe | BioGaia Protectis drops, BioGaia Protectis Junior |
| L. rhamnosus GG (also LR06, Rosell-11) | Absent | Safe — GG lowers histamine | LactoGG |
| S. boulardii CNCM I-745 | N/A (yeast) | Safe — cannot produce histamine | Sold as S. boulardii capsules and sachets |
| L. plantarum LP115 | Absent | Safe — lowers histamine | Multi-strain blends |
| L. plantarum D-1033, LP01, 299v, 6595, HEAL9, HEAL19 | Absent | Safe | 299v is available single-strain |
| L. gasseri | Absent | Safe | Paediatric and general-purpose blends |
| L. salivarius LS01 | Absent | Safe | Oral and gut health formulas |
| B. infantis and B. longum | Absent | Safe — lower host histamine | Infant formulations |
| B. longum 04, Rosell-175 | Absent | Safe | Multi-strain blends |
| B. bifidum BGN4 | Absent | Safe — prevention evidence only | Pregnancy and early-infant products |
| B. breve B632, BR03 | Absent | Safe | Infant formulations |
| B. animalis subsp. lactis BA05, BS01 | Absent | Safe | Most children’s products |
Not detected means no functional hdc gene has been found, but the strain hasn’t been screened as thoroughly.
Absent means screened and confirmed negative. Neither produces histamine on current evidence.
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.
References
- Priyadarshani WMD, Rakshit SK. Screening selected strains of probiotic lactic acid bacteria for their ability to produce biogenic amines (histamine and tyramine). International Journal of Food Science & Technology, 2011.
https://ifst.onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2621.2011.02717.x - Saccharomyces boulardii (CNCM I-745) ameliorates ovalbumin-induced atopic dermatitis by modulating NF-κB signaling in skin and colon. Archives of Dermatological Research, 2025.
https://pubmed.ncbi.nlm.nih.gov/40009233/ - Cavaliere G, Costanzi E, Cenci-Goga B, Misuraca M, Traina G. Potential role of probiotic strain Lactiplantibacillus plantarum in control of histamine metabolism. Biology, 2025;14(6):734.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12189723/ - Dev S, Mizuguchi H, et al. Suppression of histamine signaling by probiotic Lac-B: a possible mechanism of its anti-allergic effect. Journal of Pharmacological Sciences, 2008;107(2).
https://www.jstage.jst.go.jp/article/jphs/107/2/107_08028FP/_article - Lim ES. Inhibitory effect of bacteriocin-producing lactic acid bacteria against histamine-forming bacteria isolated from myeolchi-jeot. Fisheries and Aquatic Sciences, 2016.
https://link.springer.com/article/10.1186/s41240-016-0040-x - Wang IJ, Wang JY. Children with atopic dermatitis show clinical improvement after Lactobacillus exposure. Clinical & Experimental Allergy, 2015;45(4).
https://pubmed.ncbi.nlm.nih.gov/25600169/
Why Some Strains Cause Flares: The Histamine Problem
The chart above splits on a single question: does this strain make histamine? Everything else follows from that, so it is worth two minutes on why.
Not every flare comes from something you put on the skin or ate. Some start internally, with histamine.
Histamine has normal jobs in digestion and immune defence, but it’s also the chemical behind allergic reactions. The body keeps it in check with an enzyme called diamine oxidase (DAO), which breaks down the excess before it causes trouble.
Two things upset that balance: low DAO activity, or more histamine entering the system. When histamine builds up, the immune system runs hot — more itching, more redness, more inflammation.
Certain probiotic strains carry the gene for histidine decarboxylase (hdc), the enzyme that converts histidine into histamine. Those strains produce histamine as they metabolise. Taken daily, especially at high doses or stacked in a blend, they add to the load rather than reducing inflammation.
In someone with sensitive skin or existing histamine intolerance, that extra load can be enough to tip a flare.
The hdc gene is carried at strain level, not species level. That’s the whole reason this page is organised strain by strain.
4 Probiotic Strains That Produce Histamine (Avoid These)
Four strains have been tested and confirmed to make histamine. If your child has sensitive skin, these are the ones to keep out of the bottle.
1. Lactobacillus reuteri ATCC PTA 6475
Avoid. This strain makes histamine as it goes about its normal business — not a side effect, just what it does.
It is also the reason reuteri has such a confusing reputation. A different reuteri strain, DSM 17938, shows no histamine production at all — that is the one in BioGaia. Same species on the label, opposite answer.
On a label: if it says Lactobacillus reuteri with no code after it, you don’t know which one you have. Treat it as unknown, not safe.
2. Lactobacillus parabuchneri
Avoid. Several strains of this species make histamine, and it is one of the main reasons aged cheese builds up so much of it.
You will almost never see it named on a supplement label. It turns up in fermented dairy and in artisanal products that aren’t standardised.
Worth knowing: if flares follow aged cheese fairly reliably, this species is a reasonable suspect — and no supplement change will fix it.
3. Lactobacillus casei TISTR 389
Avoid this particular strain. TISTR 389 makes histamine. But another casei strain, LC03, doesn’t — it has been screened and came back clear.
So Lactobacillus casei on its own is not a verdict either way. It is a species with members on both lists.
On a label: casei is common in fermented milk drinks and general blends, and most of them print no strain code at all. Without the code, you cannot tell which casei you are buying.
4. Lactobacillus delbrueckii subsp. bulgaricus TISTR 895
Avoid this strain. TISTR 895 generates histamine during fermentation.
This one matters less for supplements than for food. L. bulgaricus is one of the two standard yoghurt starter cultures, so it is in a great deal of fermented dairy — and yoghurt packaging essentially never names the strain.
Worth trying: if you are chasing a histamine-driven flare pattern, take fermented dairy out for a fortnight before you assume the supplement is to blame.
9 Probiotic Strains That Are Safe for Eczema
So that’s what to avoid. But which strains are safe for your child?
These nine have been screened and confirmed clear. They aren’t equally useful, though — some are simply harmless, a few actively bring histamine down — so I’ve said which is which rather than filing them all under “safe”.
1. Saccharomyces boulardii CNCM I-745
Safe — and the one to start with if probiotics have caused flares before.
This one isn’t a bacterium at all. It is a yeast, which means it has no machinery for making histamine. Not “tested and found clear” — structurally incapable of it.
In mice with eczema-like skin disease, it reduced lesions, scratching and inflammation, apparently by calming inflammatory signalling in both the gut and the skin.
Two practical points: antibiotics don’t kill yeast, so it can be taken right through a course. And it is the safest first move when you don’t yet know what your child reacts to.
2. Lactobacillus rhamnosus GG
Safe — and the most studied probiotic in eczema, by a distance.
LGG doesn’t make histamine, and it appears to help the body clear its own. If you want a single strain with the deepest research behind it, this is it.
This is the strain most parents end up buying, so it has a page of its own: Lactobacillus rhamnosus GG for children — what the trials dosed at each age, and how the products carrying it compare.
Be realistic about what that research shows: the results are better for preventing eczema in at-risk infants than for treating eczema that has already arrived. The safety picture is consistent either way.
On a label: LR06 and Rosell-11 are related rhamnosus strains, also screened clear.
3. Lactobacillus reuteri DSM 17938
Likely safe. No evidence it produces histamine.
This is the BioGaia strain, which is why it comes up so often. Being precise about the claim matters here: no evidence of histamine production is not the same as evidence it helps eczema. Its real research base is infant colic and gut function, not skin.
Reasonable position: unlikely to make eczema worse, not a treatment for it.
4. Lactobacillus plantarum
Safe — and several strains actively lower histamine.
LP115 interferes with histamine metabolism, so it reduces the load rather than adding to it. D-1033, LP01, 299v, HEAL9, HEAL19 and 6595 have all been screened clear.
Where it fits: a sensible second choice after boulardii if you want a bacterial strain but blends have caused trouble before. 299v is sold on its own, which makes it easy to trial cleanly.
5. Lactobacillus salivarius LS01
Safe. Screened and confirmed clear.
You’ll usually meet it in oral and gut health formulas rather than anything aimed at skin, and almost always as one strain inside a blend.
On a label: LS01 being safe doesn’t make the product safe. Read the other names in the blend before you decide.
6. Lactobacillus gasseri
Safe on histamine — but that’s all we can say.
Gasseri has been screened and doesn’t produce histamine. What it doesn’t have is any standalone trial in eczema. It appears inside multi-strain mixtures, where nothing can be credited to it individually.
Being straight about it: not flagged, not cleared for benefit. No reason to pay extra for a product because it contains gasseri.
7. Bifidobacterium infantis and Bifidobacterium longum
Safe — and these two push histamine down rather than up.
In a rat study, a mixture of the two did the opposite of the histamine producers: it lowered allergy-like behaviour, reduced the histamine-making enzyme, and reduced histamine in the nasal lining.
So instead of adding bacterial histamine, they appear to turn down the body’s own production. That is an anti-allergic effect, not a neutral one.
On a label: B. longum Rosell-175 and 04 are also clear. B. bifidum BGN4 has prevention evidence when given in pregnancy and early infancy — which is not the same as treating eczema already present.
8. Bifidobacterium breve (B632, BR03)
Safe. Neither strain makes histamine.
B. breve is one of the dominant bacteria in a breastfed baby’s gut, which is why it turns up in so many infant formulas.
A useful rule: as a whole genus, Bifidobacterium is the safer place to start for histamine-sensitive skin. No confirmed histamine producer has been found in it.
9. Bifidobacterium animalis subsp. lactis (BA05, BS01)
Safe. Both strains screened clear.
This is one of the most common probiotics on the shelf and sits in a large share of children’s products. On the histamine question it is simply a non-issue.
Worth knowing: “B. lactis” on a label is a shortened name — the full one is Bifidobacterium animalis subsp. lactis. Different strains within it have very different evidence, so the code still matters.
What to Take Away
Four things worth remembering the next time you pick up a bottle.
1. The front of the bottle is the species. The code after it is the strain. Lactobacillus reuteri tells you nothing on its own. DSM 17938 tells you everything.
2. No code means unscreened, not unsafe. But you cannot assess what you cannot identify — so don’t start an unlabelled product in the middle of a flare.
3. If probiotics have burned you before, start with S. boulardii. It is a yeast. It cannot make histamine, whatever the dose.
4. One strain at a time, for six to eight weeks, with a symptom log. In a ten-strain blend a flare tells you nothing about which strain caused it — and you are left unable to rule any of them in or out for the next product.
I would rather tell you a strain is unstudied than pretend the absence of a warning is a recommendation.
Frequently Asked Questions
How do I choose a probiotic without triggering a flare?
- Read for the strain code, not the species. You want “L. rhamnosus GG” or “DSM 17938”, not just “Lactobacillus rhamnosus”. No code on the label means no information — email the manufacturer or pick a different product.
- Start with one strain. Single-strain, or two at most. See multi-strain blends above.
- Start low, increase slowly. Build up over several days rather than starting at the full dose. This gives you a chance to spot early itching or redness before it becomes a flare, and it gives the immune system time to adjust.
- If histamine sensitivity is confirmed, or previous probiotics have caused flares, start with S. boulardii. It’s a yeast, so it cannot produce histamine at all.
- Check the excipients too. Some paediatric products contain inulin, which triggers a reaction in a subset of infants independently of the bacteria in the product.
- Give it a fair trial, then stop. Four to six weeks with no change is an answer. Rotating through products indefinitely just adds variables.
Is a Multi-Strain Probiotic Bad for Eczema?
Multi-strain blends aren’t inherently harmful, but they’re the wrong choice while you’re still working out what a child or adult reacts to. Three reasons:
You can’t trace a flare. If a ten-strain blend triggers itching, you’ve learned nothing about which strain did it — and you’ve now got ten strains you can’t rule in or out for the next product.
Histamine load stacks. One hdc-positive strain in a blend of eight is still contributing histamine daily. Sitting alongside seven neutral strains doesn’t neutralise it.
Most blends don’t disclose strain codes. They’ll list “Lactobacillus casei, Lactobacillus reuteri, Bifidobacterium breve” with no codes — and as this page shows, the species name doesn’t settle the question. Casei can be either. Reuteri can be either.
The practical approach: start single-strain, or two strains maximum, from the safe list above. Once the skin is stable and you know what’s tolerated, a blend becomes a reasonable option.
My product's strain isn't listed here — is that bad?
Almost certainly not. An unscreened strain isn’t a dangerous strain, it’s an unknown one. If a product’s strain doesn’t appear anywhere on this page, the most likely explanation is that nobody has gene-tested it yet — not that it failed a test.
What that does mean is you can’t assess it. If your child’s skin is settled, that’s usually fine. If you’re in the middle of a flare and trying to work out the cause, an unidentifiable strain is one variable too many.
Are there probiotic strains that fight histamine-producing bacteria?
Yes, and they’re an interesting case. Five strains — MCL11 through MCL15 — produce an antibacterial compound that suppresses histamine-forming bacteria directly. So they don’t merely avoid adding histamine, they work against the organisms that make it.
The catch is availability. They’re used mostly in food fermentation rather than sold as consumer supplements. MCL15 is the one worth looking for if you ever see it named on a label.
Is Lactobacillus fermentum safe for eczema?
Partly answered. LF08 and LF10 have been screened and are confirmed not to produce histamine.
GM090 is the one to be careful about — it has never been formally gene-tested. It was used in a paediatric eczema trial of 220 children with no sign of aggravation, which is reassuring, but a trial without a flare is not the same as a screen showing the gene is absent.
GM090 appears in some multi-strain children’s products, so it’s worth knowing which category it sits in: not flagged, not cleared.
