The Gut-Skin Axis and Eczema: Why Gut Health Matters

The connection between eczema and gut health isn't a new idea, but the research confirming it has accelerated dramatically in recent years. People with atopic dermatitis consistently show different intestinal microbiota profiles compared to healthy individuals—specifically, reduced populations of beneficial Lactobacillus and Bifidobacterium species alongside increased levels of potentially harmful bacteria like Clostridium and Staphylococcus.^[2] This imbalance, known as dysbiosis, appears to both precede and perpetuate eczema symptoms.

How the Gut Communicates With the Skin

The gut-skin axis operates through several interconnected pathways. Approximately 70% of the body's immune cells reside in the gut-associated lymphoid tissue, which means that disruptions in intestinal microbial balance can trigger immune responses that manifest far from the digestive tract—including on the skin. When gut dysbiosis occurs, it can shift the immune system toward a Th2-dominant response, characterized by elevated immunoglobulin E (IgE) and pro-inflammatory cytokines like IL-4, IL-5, and IL-13—the same immunological pattern observed in atopic dermatitis.^[1]

The intestinal barrier also plays a critical role. When the gut lining becomes compromised—sometimes described as increased intestinal permeability—bacterial endotoxins and inflammatory mediators can enter the bloodstream and trigger widespread immune activation. This systemic inflammation directly impacts skin barrier function, creating a feedback loop where gut dysfunction worsens skin symptoms and damaged skin further stresses the immune system. If you're noticing signs of this kind of imbalance, our guide on Lactobacillus deficiency symptoms covers the warning signals to watch for.

Dysbiosis in Eczema Patients

The microbial differences between eczema patients and healthy individuals extend to both the gut and the skin. On the skin, atopic dermatitis lesions are characterized by an overrepresentation of Staphylococcus aureus, which correlates with disease severity and flare frequency.^[9] In the gut, healthy individuals harbor robust populations of Lactobacillus and Bifidobacterium species that help maintain immune homeostasis, while people with atopic diseases tend to show reduced abundance of these protective organisms.^[2]

This observation carries a practical implication: if the absence of certain beneficial bacteria contributes to eczema, then restoring those populations through targeted probiotic supplementation may help address the condition at its immunological root rather than only managing surface-level symptoms. That hypothesis has now been tested in dozens of clinical trials—and the results, while nuanced, are increasingly encouraging.

While this article focuses specifically on eczema and atopic dermatitis, probiotics influence a wide range of skin conditions through the gut-skin axis. For a broader look at how gut microbial balance affects skin health overall, see our complete guide on probiotics for skin health and the gut-skin axis.

How Probiotics Address Eczema at the Source

Probiotics don't treat eczema the way a topical corticosteroid does—by suppressing inflammation at the skin's surface. Instead, they work through the gut-skin axis to modulate the underlying immune dysregulation that drives atopic dermatitis. Understanding these mechanisms helps explain both why probiotics can be effective and why strain selection matters so much.

Rebalancing Th1/Th2 Immune Responses

Atopic dermatitis is fundamentally an immune-mediated condition driven by an overactive Th2 response. Probiotics—particularly Lactobacillus and Bifidobacterium species—help restore balance by promoting Th1 responses and increasing regulatory T cell activity. In clinical studies, probiotic supplementation has been shown to reduce Th2 cytokines (IL-4, IL-5) while maintaining or increasing Th1 cytokines (IFN-γ, IL-12), effectively recalibrating the immune system away from the allergic phenotype that characterizes eczema.^[5][10]

Strengthening Intestinal Barrier Function

By enhancing tight junction protein expression and stimulating mucin production, probiotics help strengthen the gut barrier. When the intestinal lining is intact, fewer inflammatory triggers enter the bloodstream—which means less systemic inflammation reaching the skin. Several of the Lactobacillus species studied for eczema, including L. rhamnosus and L. plantarum, have demonstrated the ability to upregulate tight junction proteins and reduce markers of intestinal permeability.^[1]

Modulating IgE Production

Elevated serum IgE is a hallmark of atopic dermatitis, and several probiotic strains have shown the capacity to reduce total and allergen-specific IgE levels. In a trial involving children with eczema, L. plantarum IS-10506 supplementation for 12 weeks led to significantly lower IL-4 levels (a key driver of IgE production) compared to placebo, while increasing regulatory Foxp3+ T cell markers.^[5] This immunomodulatory effect helps explain why probiotics appear most effective in allergen-sensitized patients—those whose eczema has a strong allergic component.

Reducing Staphylococcal Colonization

One of the more intriguing findings from probiotic-eczema research is that oral probiotic supplementation can alter skin microbial communities. In a randomized placebo-controlled trial of L. salivarius LS01 in adults with atopic dermatitis, the probiotic group showed a statistically significant decrease in fecal staphylococci levels by the end of treatment—and this microbial shift correlated with clinical improvement.^[10] Since S. aureus colonization on the skin drives eczema flares, reducing its systemic presence may be one pathway through which oral probiotics improve skin outcomes.

Best Probiotic Strains for Eczema: What the Research Shows

Not all probiotic strains affect eczema equally. The clinical literature reveals significant differences between species—and even between strains within the same species—in their ability to reduce SCORAD scores, prevent eczema development, and modulate the immune responses that drive atopic dermatitis. Here are the strains with the strongest published evidence, all of which are included in MicroBiome Restore's formulation.

Probiotics for Eczema in Children: Prevention and Treatment Evidence

Childhood eczema is where probiotic research has produced some of its most compelling results. The evidence falls into two distinct categories—prevention (reducing the likelihood that eczema develops in the first place) and treatment (reducing severity in children who already have it)—and both carry meaningful implications for parents and clinicians.

Prevention: Reducing Eczema Risk Before It Starts

The strongest prevention evidence comes from studies where probiotics are administered to mothers during late pregnancy and/or to infants in early life. A 2025 umbrella meta-analysis encompassing 38 prior meta-analyses and over 127,000 participants found that probiotic supplementation significantly reduced the incidence of atopic dermatitis in children (RR = 0.74, 95% CI: 0.70–0.79).^[3] The protective effect was confirmed across multiple subgroup analyses, including studies that supplemented pregnant mothers, infants, or both.

The most striking individual prevention trial involved L. rhamnosus HN001. Mothers received the probiotic from 35 weeks of gestation through 6 months postpartum (if breastfeeding), and infants continued supplementation until age 2. The probiotic group showed half the cumulative eczema prevalence of placebo by age 2, and this protection extended to at least age 4—a full two years after supplementation stopped.^[4] This finding suggests that early probiotic exposure may produce lasting changes in immune development that persist well beyond the supplementation period.

The prenatal/postnatal combination of B. bifidum, B. lactis, and L. acidophilus also demonstrated significant prevention efficacy, cutting eczema prevalence at one year from 40% to 18.2% in high-risk infants.^[15] For parents exploring infant gut health support, our guide on probiotics for infants provides additional strain-specific information.

Treatment: Reducing Eczema Severity in Children

For children who already have atopic dermatitis, the treatment evidence is robust across multiple strains. A meta-analysis of single-strain Lactobacillus interventions involving 14 clinical trials and 1,124 children found that probiotic supplementation statistically significantly reduced the SCORAD index compared to placebo (mean difference: −4.50; 95% CI: −7.50 to −1.49; p = 0.003).^[8]

The magnitude of improvement varies by strain and population. The 220-child RCT by Wang and Wang demonstrated that L. paracasei, L. fermentum, and their combination all produced significant SCORAD reductions compared to placebo (p < 0.001), with benefits persisting 4 months after discontinuing treatment.^[14] Notably, the study also documented improvements in family quality of life scores—a reminder that childhood eczema affects the entire household.

An important finding from the multicenter RCT by Cukrowska et al. is that probiotics appear most effective in allergen-sensitized children. While both probiotic and placebo groups showed improvement over time, the probiotic group was 6 times more likely to achieve meaningful SCORAD improvement among sensitized patients (OR 6.03, 95% CI 1.85–19.67, p = 0.001).^[12] This suggests that probiotic supplementation may be especially valuable for children whose eczema has a strong allergic component.

Probiotics for Eczema in Adults: Clinical Findings

Adult-onset or persistent eczema presents unique challenges. Hormonal fluctuations, chronic stress, environmental exposures, and years of potential antibiotic use can all contribute to gut dysbiosis that perpetuates atopic dermatitis. While fewer large-scale trials have focused exclusively on adults compared to children, the existing evidence provides clear direction on which probiotic approaches show the most promise.

Meta-Analytic Evidence

A 2022 meta-analysis of six randomized controlled trials (n = 241 adult AD patients) found that probiotics were effective in treating adults with atopic dermatitis, producing a statistically significant decrease in SCORAD scores (Mean Difference −7.90, 95% CI −7.25 to −6.92; p < 0.05).^[2] Quality of life measures also improved significantly in the probiotic groups.

The network meta-analysis by Chen et al. went further, ranking the relative effectiveness of different probiotic preparations. The combination of L. salivarius LS01 and B. breve BR03 achieved the highest probability of being the best supplementation for adult AD (SUCRA 95.2%) in both short-term and long-term outcomes. The combination of L. salivarius LS01 and S. thermophilus ST10 ranked second for short-term outcomes (SUCRA 75.6%).^[7]

Individual Trial Highlights

Lactobacillus salivarius LS01 was studied in a 16-week RCT with 38 adults with moderate-to-severe AD. The probiotic group showed significant improvement in SCORAD, quality of life (DLQI), and fecal microbiota composition. Importantly, the treatment modulated Th1/Th2 cytokine balance—reducing the Th2-skewed immune profile characteristic of eczema—and significantly decreased intestinal staphylococci levels.^[10]

Lactobacillus plantarum IS-10506 was tested in a double-blind, placebo-controlled trial with 30 adults with mild-to-moderate AD. The probiotic group (2×10¹⁰ CFU/day) showed significantly lower SCORAD scores by week 8, along with decreased IL-4 and IL-17 and increased regulatory Foxp3+ expression.^[6]

A three-strain mixture of B. lactis CECT 8145, B. longum CECT 7347, and L. casei CECT 9104 was evaluated in a 12-week randomized, double-blind, placebo-controlled trial published in JAMA Dermatology. The probiotic group showed significant SCORAD reduction and notably decreased their use of topical corticosteroids compared to placebo.^[17]

For adults whose eczema may be connected to broader gut health concerns, addressing underlying digestive issues alongside probiotic supplementation can enhance results. Our evidence-based guide covers probiotics for SIBO for those dealing with bacterial overgrowth, and the article on probiotics after antibiotics addresses post-antibiotic microbiome recovery—both of which can compound eczema symptoms when left unaddressed.

Multi-Strain and Synbiotic Approaches to Eczema

If individual strains each offer distinct benefits—L. rhamnosus for prevention, L. plantarum for immune rebalancing, L. salivarius for adult AD, L. fermentum for childhood severity—does combining multiple strains produce better outcomes than any single organism alone? The evidence increasingly says yes.

The Multi-Strain Advantage

The 2025 umbrella meta-analysis found that multi-strain probiotics and synbiotics significantly decreased SCORAD scores in children, while Bifidobacterium alone or prebiotics alone did not achieve statistical significance for severity reduction.^[3] This finding aligns with results from several individual trials where multi-strain formulations outperformed single organisms.

The JAMA Dermatology trial demonstrated that a three-strain combination (B. lactis, B. longum, and L. casei) reduced both SCORAD scores and topical steroid dependence in moderate AD—an outcome not typically achieved with single-strain interventions at equivalent dosages.^[17] Similarly, the combination of L. rhamnosus and L. reuteri in the Rosenfeldt trial showed benefits that were most pronounced in allergen-sensitized patients, with 56% of the probiotic group reporting improvement compared to only 15% on placebo.^[16]

The biological rationale is straightforward: different strains target different aspects of eczema pathology. Some primarily influence Th2 cytokine suppression, others enhance regulatory T cell activity, and still others reduce intestinal permeability or alter microbial colonization patterns. A multi-strain formulation can address multiple pathways simultaneously. For a detailed comparison of supplementation strategies, our guide on single vs. multi-strain probiotics explores when each approach makes sense.

Why Prebiotics Amplify Probiotic Benefits for Eczema

Synbiotics—formulations that combine probiotics with prebiotics—have shown enhanced efficacy for eczema outcomes compared to probiotics alone. The umbrella meta-analysis confirmed that synbiotic interventions significantly reduced both AD incidence and SCORAD severity.^[3] Prebiotics provide the fermentable substrates that beneficial bacteria need to colonize the gut and produce short-chain fatty acids (SCFAs)—metabolites that play a central role in immune regulation and barrier function.

MicroBiome Restore includes nine organic prebiotics designed to fuel the probiotic strains it delivers: Jerusalem artichoke (rich in inulin), maitake mushroom, fig fruit, bladderwrack, Norwegian kelp, oarweed, acacia gum, maltodextrin (for strain shelf stability), and pullulan capsules that themselves serve as a prebiotic substrate. This synbiotic design reflects the evidence showing that combining prebiotics with probiotics consistently produces stronger outcomes than either component alone.

Choosing and Using Probiotics for Eczema: A Practical Guide

Translating clinical trial results into an effective personal strategy requires understanding not just which strains to look for, but how to use them, how long to expect before seeing results, and what other factors influence success.

Timeline: When to Expect Results

The clinical trials reviewed above provide a useful framework for setting expectations. Treatment-focused studies typically demonstrate measurable SCORAD improvement within 4–8 weeks, with continued benefit through 12–16 weeks of consistent supplementation. The 8-week L. rhamnosus trial showed significant severity reduction by the final assessment.^[11] The 16-week L. salivarius LS01 trial documented progressive improvement in both clinical scores and quality of life throughout the treatment period.^[10]

Importantly, the Wang and Wang trial with L. fermentum and L. paracasei showed that benefits persisted for at least 4 months after discontinuing the probiotic—suggesting that sustained supplementation may produce lasting changes in gut microbial ecology and immune regulation rather than merely temporary symptom suppression.^[14]

A reasonable expectation: begin looking for reductions in itch intensity and flare frequency within 4–8 weeks, with more substantial improvements in overall skin appearance and SCORAD components emerging between 8–16 weeks of daily supplementation.

What to Look for in a Probiotic Supplement for Eczema

Strain specificity matters more than CFU count. The evidence is clear that some strains significantly reduce eczema severity while others show minimal effect. Prioritize products that include the strains with the strongest clinical evidence: L. rhamnosus, L. plantarum, L. salivarius, L. fermentum, B. bifidum, and B. lactis are well-supported by multiple trials.

Multi-strain formulations outperform single-strain products. Meta-analyses consistently show that combining Lactobacillus and Bifidobacterium species produces more reliable and larger reductions in eczema severity than any individual strain.^[3][8]

Prebiotic inclusion enhances efficacy. Synbiotic formulations—probiotics combined with prebiotics—have demonstrated superior outcomes for eczema compared to probiotics alone.^[3]

Clean formulation protects the microbiome you're trying to build. Common supplement additives like microcrystalline cellulose and flow agents have raised concerns about potential disruption to gut microbiota—counterproductive in a supplement designed to restore microbial balance. MicroBiome Restore uses no titanium dioxide, no microcrystalline cellulose, and no magnesium stearate.

Complementary Strategies for Eczema Management

Probiotic supplementation works best as part of a comprehensive approach to eczema management rather than a standalone intervention. Several lifestyle and dietary factors can support the gut-skin axis alongside probiotic use:

Dietary fiber fuels SCFA production—the same metabolites that mediate many of probiotics' immune-regulatory benefits. Increasing intake of fruits, vegetables, and whole grains provides the fermentable substrates that beneficial bacteria need to thrive.

Stress management directly impacts the gut-skin axis. Psychological stress alters gut microbiota composition, increases intestinal permeability, and elevates inflammatory markers—all of which can trigger or worsen eczema flares.^[2]

Appropriate use of topical treatments remains important. Probiotics address eczema from the inside by modulating immune responses and gut health, while topical emollients, moisturizers, and prescribed treatments manage the skin barrier externally. The two approaches are complementary, not competitive—and the JAMA Dermatology trial notably found that probiotic supplementation reduced the need for topical corticosteroids, suggesting that internal support can decrease reliance on external treatments over time.^[17]

Minimizing unnecessary antibiotic exposure protects the Lactobacillus and Bifidobacterium populations that support skin health. When antibiotics are medically necessary, concurrent or post-course probiotic supplementation can help restore microbial balance faster. See our probiotics after antibiotics guide for evidence-based recovery protocols.

Frequently Asked Questions

Conclusion

The relationship between gut health and eczema is no longer speculative—it's supported by umbrella meta-analyses encompassing over 127,000 participants, dozens of randomized controlled trials, and a growing understanding of the biological pathways that connect intestinal microbiota to skin immune function. Specific probiotic strains, particularly Lactobacillus rhamnosus, Lactobacillus plantarum, Lactobacillus salivarius, Lactobacillus fermentum, Bifidobacterium bifidum, and Bifidobacterium lactis, have demonstrated the ability to reduce eczema incidence by up to 50% in prevention studies and produce clinically meaningful reductions in SCORAD severity scores in treatment trials.

The evidence also makes clear that not all probiotic supplements are equally suited for eczema support. Multi-strain formulations combining Lactobacillus and Bifidobacterium species consistently outperform single-strain products. Synbiotic approaches—pairing probiotics with prebiotics—show enhanced efficacy. And the specific strains matter enormously: a supplement containing well-studied species like L. rhamnosus, L. plantarum, and L. salivarius is fundamentally different from one built on less-researched organisms.

At BioPhysics Essentials, we formulated MicroBiome Restore to reflect this research. Our 26-strain synbiotic includes the Lactobacillus and Bifidobacterium species that carry the strongest evidence for eczema and atopic dermatitis support, paired with organic prebiotics that fuel their activity—all in a formulation free from the fillers and flow agents that can undermine the gut health you're working to rebuild. Because when it comes to eczema, the most effective path to calmer skin may start with a healthier gut.