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Gut Microbiome and Plaque Psoriasis: How Your Gut Bacteria Affect Symptoms

Plaque psoriasis isn’t just a skin condition—it’s increasingly understood as an immune-driven inflammatory disease, and your gut microbiome may play a meaningful role in shaping how that inflammation behaves. Billions of microbes live in your digestive tract, influencing immune signaling, gut barrier function, and the balance of pro- and anti-inflammatory pathways that can affect psoriasis symptoms.

Research suggests that when the microbiome is less diverse or skewed in certain directions, the immune system may become more prone to overreact. Shifts in specific gut bacteria can influence how your body processes dietary components, produces short-chain fatty acids (key for gut and immune health), and regulates inflammatory responses throughout the body. In some people, these gut–immune changes can correlate with flare frequency, severity, and overall symptom burden.

The good news: supporting a healthier gut microbiome is a practical, lifestyle-focused opportunity that may help complement standard psoriasis care. By improving fiber intake, eating a microbiome-friendly variety of whole foods, staying consistent with anti-inflammatory dietary patterns, and reducing factors that can disrupt gut bacteria, you may help create a gut environment that supports immune balance—ultimately aiming for calmer skin and fewer flare-ups.

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Plaque psoriasis

Plaque psoriasis is a chronic, immune‑driven skin condition defined by well‑defined, scaly plaques most often on the scalp, elbows, knees, and lower back. It involves dysregulated T‑cell activity and inflammatory cytokines such as TNF‑α, IL‑17, and IL‑23, with systemic inflammation that can contribute to fatigue, metabolic risk, and, in some people, psoriatic arthritis.

In recent understanding, the gut–skin axis links the skin manifestations to the gut microbiome. Dysbiosis—reduced microbial diversity and shifts toward pro‑inflammatory taxa—can alter T‑cell differentiation and cytokine balance, diminishing short‑chain fatty acids like butyrate that support barrier integrity and immune tolerance. Increased intestinal permeability can amplify inflammatory signaling that drives plaque formation and may relate to systemic symptoms beyond the skin.

Testing, such as that offered by InnerBuddies, can illuminate gut microbiome patterns and metabolite profiles that influence psoriasis activity, guiding personalized diet and lifestyle strategies (e.g., plant‑forward, high‑fiber patterns) to improve barrier function and SCFA production. While microbiome results do not replace dermatologic care, they may help explain fatigue, joint involvement, and flare risk, and support a more tailored approach to managing the gut–skin inflammatory axis.

  • Loss of butyrate-producing taxa Faecalibacterium prausnitzii, Roseburia spp., and Eubacterium rectale group reduces SCFA production and weakens gut barrier, fueling plaque psoriasis inflammation.
  • Declines in Bifidobacterium spp. and Akkermansia muciniphila impair gut barrier integrity and immune tolerance, potentially worsening skin inflammation.
  • Rise of pro-inflammatory taxa Streptococcus spp., Staphylococcus spp., Enterococcus spp., and Escherichia coli/Shigella group is linked to increased TNF-α and IL-17 signaling in psoriasis.
  • Enrichment of Bacteroides spp., Ruminococcus gnavus group, Collinsella, and Prevotella is associated with dysbiosis and activation of IL-23/IL-17 and TNF-α inflammatory pathways.
  • Reduced capacity for SCFA biosynthesis (butyrate, acetate, propionate) due to taxonomic shifts removes anti-inflammatory cues and supports keratinocyte hyperproliferation.
  • Dysbiosis-driven increased intestinal permeability (leaky gut) allows microbial components to trigger Toll-like receptor–mediated inflammatory cascades fueling plaque formation.
  • Gut–skin axis mediates systemic effects (fatigue, metabolic risk) and can contribute to psoriatic arthritis through microbiome-driven immune spillover.
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Psoriasis

Plaque psoriasis is a chronic, immune-mediated condition characterized by well-defined, scaly plaques, most commonly on the scalp, elbows, knees, and lower back. It involves an imbalance in inflammatory signaling—often driven by dysregulated T-cell activity and cytokines such as TNF-α, IL-17, and IL-23. While skin symptoms are the hallmark, systemic inflammation can also affect overall wellbeing and, in some people, contribute to fatigue, metabolic risk, and joint symptoms (psoriatic arthritis).

  • Raised, scaly red or silvery patches of skin (plaques)
  • Itching and burning sensations in affected areas
  • Skin dryness and tightness over plaques
  • Cracking, bleeding, or pain in inflamed lesions
  • Thickened or ridged nails (nail psoriasis involvement)
  • Joint pain or swelling (psoriatic arthritis symptoms in some people)
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Plaque psoriasis

Plaque psoriasis is especially relevant for people who develop chronic, well-defined scaly plaques—often on the scalp, elbows, knees, and lower back—along with symptoms like itching, burning, dryness, tightness, and sometimes cracking or bleeding. If your plaques repeatedly flare up and subside, leaving persistent redness or thickened skin, this can help explain the immune-driven nature of the condition and why symptom management may need to be consistent rather than occasional.

It’s also relevant if you experience nail changes (thickened, ridged, or pitted nails) or skin discomfort that goes beyond appearance—such as pain in inflamed areas or burning sensations. Because plaque psoriasis is linked to broader inflammatory signaling (including pathways involving TNF-α, IL-17, and IL-23), some people also notice fatigue or feeling run-down during flares, even when the skin symptoms seem to be the main issue.

This is particularly relevant for individuals who want to understand connections between plaque psoriasis and overall health, including people at risk for metabolic issues or those with possible psoriatic arthritis symptoms (joint pain, stiffness, or swelling). For many, the gut–immune relationship matters: changes in the gut microbiome can influence immune activity, which may affect how inflammatory pathways behave—making microbiome-informed approaches potentially valuable for those looking for additional support alongside standard dermatology care.

Plaque psoriasis is one of the most common autoimmune skin conditions. In most populations, overall psoriasis affects roughly 2–3% of adults worldwide, and plaque psoriasis accounts for the majority of cases (commonly estimated at about 80–90% of psoriasis). This means that, on a population level, a few in every 100 people may experience the characteristic raised, scaly plaques that define plaque psoriasis.

While psoriasis is not typically considered a “rare disease,” estimates vary by geography, age, and diagnostic practices. Many studies report that the lifetime prevalence of psoriasis is around 2–4%, with plaque psoriasis representing the dominant subtype when psoriasis presents clinically. Symptoms such as itching/burning, skin tightness, cracking or bleeding in inflamed areas, nail changes, and (in a subset of patients) joint symptoms are frequently part of the overall disease burden, contributing to why prevalence data is often accompanied by measurements of quality-of-life impact.

Systemic inflammation and immune dysregulation associated with plaque psoriasis also help explain why the condition is linked to broader health risks in some individuals. Approximately 20–30% of people with psoriasis develop psoriatic arthritis at some point, which can add joint pain or swelling to the classic skin manifestations. Because inflammation can also interact with gut-related immune signaling and microbiome composition—potentially influencing disease susceptibility and severity—research into microbiome and prevalence trends continues, reinforcing that plaque psoriasis is widespread even though individual symptom patterns (including fatigue and nail/joint involvement) vary substantially.

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Gut Microbiome & Plaque Psoriasis: How Your Microbiome Affects Symptoms

Plaque psoriasis is increasingly understood as a disorder of immune regulation that involves the gut–skin axis. Research suggests that the gut microbiome can influence inflammatory signaling by shaping T-cell activity and cytokine balance, including pathways involving TNF-α, IL-17, and IL-23—processes central to psoriasis. When gut microbial diversity is reduced or the balance of beneficial versus inflammatory-associated bacteria is altered, the intestinal barrier may become more “leaky,” allowing microbial byproducts to interact with the immune system and potentially amplify skin inflammation.

Several patterns have been observed in people with psoriasis: changes in microbial composition, altered microbial metabolites, and differences in short-chain fatty acids (SCFAs) that normally help maintain immune tolerance and support gut barrier function. SCFAs like butyrate help regulate inflammation and promote a healthier immune environment; when these protective metabolites are diminished, pro-inflammatory immune responses may become more prominent. This immune shift can contribute to the development or flare of characteristic well-defined, scaly plaques, along with itching, burning, and painful cracking lesions.

Gut inflammation may also help explain why psoriasis can extend beyond the skin in some individuals, including fatigue and increased metabolic risk, and in certain cases joint involvement (psoriatic arthritis). A dysregulated gut microbiome may promote systemic inflammatory “spillover,” affecting joints and overall energy levels. Supporting gut health through diet patterns that encourage beneficial microbes (e.g., high-fiber, plant-forward nutrition) and reducing triggers that worsen intestinal irritation may therefore be relevant as part of a broader strategy to manage inflammation and potentially improve psoriasis symptoms.

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Gut Microbiome and Plaque psoriasis

  • Gut microbial imbalance (dysbiosis) alters immune tone: changes in community composition can shift T-cell differentiation and cytokine balance, promoting psoriasis-relevant inflammatory pathways (including IL-23/IL-17 and TNF-α signaling).
  • Reduced short-chain fatty acids (SCFAs) weaken immune tolerance and barrier defense: lower levels of protective metabolites like butyrate can impair regulatory T-cell (Treg) function and favor pro-inflammatory immune responses that drive plaque formation.
  • Increased intestinal permeability (“leaky gut”) amplifies immune activation: when the gut barrier is compromised, microbial products (e.g., lipopolysaccharide and other byproducts) can reach immune cells more readily, increasing systemic and skin-directed inflammation.
  • Microbial metabolite signaling influences inflammatory pathways: gut-derived metabolites (beyond SCFAs) can modulate innate and adaptive immune signaling, affecting the inflammatory cascade that supports keratinocyte hyperproliferation and scaling.
  • Pattern-recognition receptor activation by microbial components: altered exposure to microbial antigens can stimulate innate immune receptors (e.g., Toll-like receptors), increasing cytokine production and reinforcing the psoriatic inflammatory loop.
  • Immune “spillover” from gut to skin and joints: systemic inflammatory mediators generated in response to gut immune activation can contribute to distant manifestations, including fatigue and psoriatic arthritis in susceptible individuals.

Plaque psoriasis is increasingly viewed as an immune-regulation problem in which the gut–skin axis plays an important role. In many people, the gut microbiome shifts away from a healthy, diverse balance (dysbiosis), which can alter how immune cells “decide” between tolerance and inflammation. This includes effects on T-cell differentiation and cytokine signaling, particularly pathways tied to IL-23/IL-17 activity and TNF-α–driven inflammatory responses that are central to psoriasis plaque formation.

A key part of this connection involves gut barrier support and immune tolerance, which are strongly influenced by microbial metabolites. Beneficial short-chain fatty acids (SCFAs)—especially butyrate—help strengthen the intestinal barrier and support regulatory T-cell (Treg) function. When SCFA-producing bacteria decline, protective metabolites drop, making it harder for the immune system to stay in a tolerant, anti-inflammatory state. The result can be a greater tendency toward pro-inflammatory immune signaling that favors the development and persistence of scaly, inflamed skin lesions.

When barrier defenses weaken, intestinal permeability can increase, allowing microbial byproducts to interact more readily with immune cells. Microbial components such as lipopolysaccharide and other antigens can trigger pattern-recognition receptors (e.g., Toll-like receptors), boosting cytokine production and reinforcing the inflammatory loop that promotes keratinocyte hyperproliferation. In addition, immune activation can “spill over” systemically—potentially contributing to psoriasis symptoms beyond the skin, such as fatigue and, in some individuals, psoriatic arthritis.

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Microbial patterns summary

In plaque psoriasis, studies commonly report a shift in gut microbial composition that reduces overall diversity and alters the balance between bacteria associated with immune regulation and those linked to inflammatory signaling. Rather than a single “psoriasis microbe,” the pattern is often one of dysbiosis—changes in relative abundances that can affect how intestinal immune cells are trained. This altered microbial ecosystem can influence T-cell differentiation and cytokine balance, including pathways involving IL-23/IL-17 and TNF-α, which are central to psoriatic plaque formation.

A recurring feature in gut–skin axis research is altered microbial metabolism, particularly reduced production of protective short-chain fatty acids (SCFAs) like butyrate. SCFAs help maintain the intestinal barrier and promote regulatory T-cell (Treg) activity, supporting immune tolerance. When SCFA-producing bacteria decline, barrier integrity can weaken and anti-inflammatory signaling may drop, making it easier for pro-inflammatory immune programs to dominate and potentially contribute to both onset and flares of psoriatic lesions.

Dysbiosis can also increase intestinal permeability, allowing microbial byproducts to interact more directly with the immune system. Components such as lipopolysaccharide and other antigenic signals can activate pattern-recognition receptors (e.g., Toll-like receptors), amplifying cytokine production and reinforcing inflammatory feedback loops that drive keratinocyte hyperproliferation. Because inflammation can extend beyond the gut, these gut-mediated immune changes may also relate to systemic symptoms (such as fatigue) and, in some individuals, joint involvement seen in psoriatic arthritis.


Low beneficial taxa

  • Faecalibacterium prausnitzii
  • Roseburia spp.
  • Eubacterium rectale (Eubacterium hallii group)
  • Coprococcus spp.
  • Butyrivibrio spp.
  • Bifidobacterium spp.
  • Akkermansia muciniphila


Elevated / overrepresented taxa

  • Streptococcus spp.
  • Staphylococcus spp.
  • Enterococcus spp.
  • Escherichia coli (Shigella/E. coli group)
  • Bacteroides spp. (higher relative abundance in dysbiosis)
  • Ruminococcus gnavus group
  • Collinsella spp.
  • Prevotella spp.


Functional pathways involved

  • Short-chain fatty acid (SCFA) biosynthesis—especially butyrate, acetate, and propionate production (via fermentation of dietary fibers)
  • Tryptophan metabolism and aryl hydrocarbon receptor (AhR) signaling (indole/indole-3-acetic-acid–related pathways influencing mucosal immune balance)
  • Bacterial lipopolysaccharide (LPS) and other pathogen-associated molecular pattern (PAMP) sensing pathways that activate Toll-like receptors (TLR4/TLR2) and downstream NF-κB signaling
  • Intestinal barrier integrity and epithelial tight-junction regulation (SCFA-dependent maintenance of mucus layer and barrier function; reduced barrier → higher permeability)
  • Th17 and IL-23/IL-17 axis modulation (microbial signals promoting Th17 differentiation and cytokine amplification)
  • Regulatory T-cell (Treg) induction and immune tolerance pathways (butyrate-driven Foxp3+ Treg programming and IL-10/TGF-β–related signaling)
  • TNF-α–linked inflammatory signaling cascades (microbiome-driven systemic inflammatory feedback that supports keratinocyte hyperproliferation)


Diversity note

In plaque psoriasis, gut–skin axis research commonly finds that gut microbial diversity tends to be reduced, alongside broader shifts in community structure (dysbiosis) rather than a single consistent “psoriasis-causing” organism. This altered ecosystem often corresponds with changes in the relative abundance of bacteria linked to immune regulation versus bacteria more associated with inflammatory signaling, which can affect how the intestinal immune system is educated and maintained.

A key pattern is dysregulated microbial metabolism, particularly a decline in short-chain fatty acid (SCFA) production such as butyrate. SCFAs normally support intestinal barrier integrity and help promote anti-inflammatory immune pathways, including regulatory T-cell (Treg) activity. When SCFA-producing microbes decrease, the gut lining may become more vulnerable to permeability changes, making it easier for microbial byproducts to interact with immune cells and reinforce inflammatory signaling.

These diversity and metabolic shifts may also contribute to a “leakier” intestinal barrier, allowing microbial antigens and inflammatory triggers to more readily stimulate pattern-recognition pathways. That immune amplification can help sustain pro-inflammatory cytokine programs central to psoriasis biology (notably IL-23/IL-17 and TNF-α), potentially contributing not only to skin plaque formation and flare susceptibility but also to the systemic inflammatory spillover seen in some individuals, including fatigue and joint symptoms.


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Why generic solutions fail

  • Issue with generic solutions

    Generic “gut health” approaches often fail for plaque psoriasis because the condition is not driven by gut symptoms alone; it involves immune regulation through the gut–skin axis. While many people try broad probiotics or generic supplements, the relevant issue is usually a specific pattern of dysbiosis (often reduced diversity and altered balance of immune-modulating microbes) paired with impaired microbial metabolites such as short-chain fatty acids (SCFAs) that support barrier integrity and regulatory T-cell (Treg) function. Without restoring SCFA production and improving immune tolerance signaling, interventions may do little to affect the cytokine pathways commonly implicated in psoriasis (e.g., IL-23/IL-17 and TNF-α).

    Generic strategies also tend to overlook gut barrier and inflammatory “context.” If intestinal permeability is increased and microbial byproducts can interact more easily with the immune system, simply adding a single product may not meaningfully shift pattern-recognition receptor activation or downstream inflammatory amplification loops. Additionally, psoriasis severity and flare patterns vary widely across individuals, and factors like diet composition, fiber intake, medication use, and baseline microbiome structure strongly influence whether any intervention can support the right immune milieu. A one-size-fits-all regimen may therefore miss the key drivers—metabolic outputs, barrier function, and immune re-training—that determine whether gut changes translate into skin improvement.

    Finally, many generic plans ignore that psoriasis is often systemic and may include fatigue and, in some cases, psoriatic arthritis—signs that inflammation may be spilling beyond the gut. Approaches that target only symptom relief (e.g., transient constipation or bloating) without addressing the immune pathways and metabolite shifts linked to psoriatic plaques are less likely to produce consistent results. For some people, indiscriminate probiotic dosing or highly restrictive diets can even worsen intolerance or reduce beneficial substrates, further delaying improvements that depend on restoring a supportive microbial ecosystem.

  • Common mistakes

    • Treating plaque psoriasis as a “gut symptom only” problem and using generic gut-soothing steps (or anti-bloating/anti-constipation tactics) without targeting gut–skin immune regulation (e.g., IL-23/IL-17 and TNF-α axis).
    • Using broad probiotics without regard to specific dysbiosis patterns or SCFA-producing capacity—so they fail to restore butyrate/other SCFA outputs that support barrier integrity and Treg (immune tolerance) function.
    • Ignoring intestinal barrier context (increased permeability): adding a supplement that doesn’t reduce pattern-recognition receptor stimulation (e.g., LPS/TLR signaling) may not meaningfully dampen downstream inflammatory feedback loops.
    • Assuming “more is better” with microbiome interventions—over-supplementing or indiscriminately dosing probiotics/prebiotics can reduce microbial substrate availability, worsen intolerance, or shift the ecosystem in unhelpful directions.
    • Skipping baseline personalization (diet composition, fiber intake, medication use, initial microbial diversity)—leading to one-size-fits-all regimens that don’t match the individual’s starting microbiome/metabolite landscape.
    • Over-relying on highly restrictive diets without ensuring adequate fiber diversity—potentially lowering fermentable substrates needed for SCFA production and weakening the microbial outputs that support immune tolerance.
    • Focusing on single organisms or single biomarkers while neglecting functional outcomes (metabolites, barrier markers, T-cell training) that are more directly linked to psoriasis flare biology.
    • Failing to consider systemic inflammation and co-morbid psoriatic arthritis—using gut-only strategies when inflammation may be spilling beyond the intestine, limiting the impact on overall disease activity.

What to do

  • General support strategies

    For plaque psoriasis, general support strategies increasingly focus on improving immune regulation through the gut–skin axis. A key goal is to foster a healthier gut microbiome and strengthen intestinal barrier function, since microbial imbalance and reduced microbial diversity can tilt immune signaling toward inflammation. Diet patterns that emphasize high fiber and a plant-forward intake help support beneficial bacteria and increase microbial metabolites such as short-chain fatty acids (SCFAs), including butyrate. These compounds help reinforce gut barrier integrity and promote immune tolerance, which may help calm downstream inflammatory pathways linked to psoriasis-related cytokines.

    Alongside fiber-forward nutrition, many people benefit from minimizing dietary patterns that can aggravate gut irritation or worsen dysbiosis. Limiting highly processed foods, excessive added sugars, and other common pro-inflammatory dietary drivers may reduce intestinal stress and help maintain a more stable microbial ecosystem. Some individuals also find that reducing potential personal triggers (such as certain alcohol or high-sugar intake) supports more consistent symptom control. In general, the focus is on creating a gut environment that discourages inflammatory microbes and supports microbes associated with anti-inflammatory signaling.

    Because psoriasis can sometimes involve systemic inflammation beyond the skin, gut-focused habits may complement overall lifestyle strategies that influence inflammatory load. Prioritizing regular, minimally processed meals; maintaining adequate hydration; and considering gentle, sustainable dietary changes rather than extreme restrictions can help promote long-term microbiome stability. For added support, individuals with persistent symptoms may also discuss clinician-guided approaches such as targeted supplementation (when appropriate) and screening for related issues (e.g., gut intolerance, metabolic risk, or joint symptoms), since comprehensive care can address both skin inflammation and systemic contributors.

  • Lifestyle recommendations

    • Adopt a high-fiber, plant-forward diet (variety of fruits, vegetables, legumes, whole grains) to support beneficial gut microbes and SCFA production (e.g., butyrate).
    • Increase prebiotic sources (garlic, onions, leeks, asparagus, bananas, oats) and consider probiotics/fermented foods (e.g., yogurt with live cultures, kefir, sauerkraut) if tolerated.
    • Minimize ultra-processed foods, added sugars, and excess saturated fats, as these can promote dysbiosis and worsen inflammatory signaling.
    • Reduce alcohol intake and avoid smoking, both of which are associated with worse psoriasis control and greater systemic inflammation.
    • Prioritize gut-friendly habits: avoid unnecessary NSAID overuse when possible, manage constipation, and address reflux or chronic GI irritation with clinician guidance.
    • Manage stress through consistent sleep, relaxation practices (e.g., mindfulness, breathing exercises), and regular exercise, since stress can affect immune regulation and flare frequency.

  • Nutrition recommendations

    • Adopt a high-fiber, plant-forward diet (aim for multiple servings/day of vegetables, legumes, whole grains, nuts, seeds) to support beneficial gut microbes and increase SCFAs like butyrate that help maintain immune tolerance and gut barrier integrity.
    • Prioritize probiotic- and fermentation-friendly foods (e.g., yogurt/kefir with live cultures, fermented vegetables like sauerkraut/kimchi, tempeh, miso) to help rebalance gut microbiota and modulate inflammatory signaling relevant to plaque psoriasis.
    • Increase omega-3 intake (fatty fish such as salmon/sardines 2x/week, or chia/flax/walnuts) to support a more anti-inflammatory cytokine profile and may complement immune regulation pathways involving TNF-α/IL-17/IL-23.
    • Choose minimally processed, whole-food carbohydrates over refined sugars and ultra-processed foods to reduce gut dysbiosis and downstream inflammatory signaling that can worsen psoriasis activity.
    • Support barrier function with adequate protein and polyphenol-rich foods (e.g., extra-virgin olive oil, berries, cocoa, green tea, herbs/spices, colorful vegetables) which can help promote beneficial metabolites and reduce inflammatory stress.
    • Limit common gut irritants/triggers for some individuals—especially excess alcohol, high-sugar diets, and frequent processed foods; consider reducing if you notice flares after specific foods and discuss with your clinician.

  • Supplement considerations

    For plaque psoriasis, supplement strategies that support gut–skin immune balance are often centered on restoring healthier microbial diversity, improving intestinal barrier function, and reducing pro-inflammatory signaling. Because changes in gut microbiota composition and downstream immune pathways (notably TNF-α, IL-23/IL-17–linked inflammation) have been observed in psoriasis, nutrients that encourage a more tolerance-promoting immune environment—such as those that support short-chain fatty acid (SCFA) production—may be particularly relevant. Compounds that act as substrates for beneficial microbes (e.g., prebiotic fibers) and those that provide anti-inflammatory SCFA-like effects (such as butyrate in appropriate formulations) are commonly considered to help reinforce the gut barrier and modulate immune reactivity.

    Probiotics and postbiotics are another focus area, with the goal of shifting microbial metabolites and reducing gut immune activation. Evidence varies by strain and product, but in general, supplements containing carefully selected probiotic strains (or postbiotic metabolites) may help support a steadier gut barrier and a cytokine profile less dominated by inflammatory cascades. In parallel, omega-3 fatty acids are frequently discussed because they can dampen systemic inflammation and may complement gut-mediated immune effects, potentially benefiting overall inflammatory burden alongside skin symptoms.

    Individuals with psoriasis should also consider that deficiencies and diet-related factors can influence outcomes, so targeted supplementation may be helpful when warranted by labs or clinical history. Vitamin D is commonly evaluated, given its role in immune regulation and skin barrier function. Magnesium may support general metabolic and inflammatory pathways, and antioxidants may help counter oxidative stress that can accompany chronic inflammation. As psoriasis therapies vary widely, it’s important to choose supplements thoughtfully—especially if using immunomodulating medications—since the safest approach is to prioritize gut-supporting, evidence-informed options and monitor response rather than relying on a single “universal” product.

  • Retesting / monitoring note

    For plaque psoriasis, retesting is most useful when it changes clinical decision-making—such as when a new gut-support strategy (e.g., fiber-forward diet, specific probiotic/fermented foods, or elimination of likely dietary triggers) is started or when symptoms flare. A practical approach is to recheck after a sufficient interval for the gut microbiome and its metabolites (including short-chain fatty acids like butyrate) to shift; many people consider a window of about 8–12 weeks, aligned with the time needed for microbial composition and barrier-related signaling to meaningfully adapt.

    Retesting should also be timed to account for confounders that can mask or mimic microbial changes, including antibiotic or corticosteroid use, bowel disruptions, major diet changes, infections, and active systemic inflammation. If the goal is to link gut findings to skin outcomes, retest during periods of relative clinical stability (or document PASI/BSA changes at the same time) so that immune signaling patterns can be interpreted in context—particularly the TNF-α/IL-23/IL-17 axis that’s commonly implicated in psoriasis inflammation.

    Finally, retesting is best approached as a targeted “response check” rather than repeated testing without a plan. If results and symptom trends move in the same direction, the current gut-focused approach can be maintained and retesting can be spaced out (e.g., every several months) only if you need further optimization. If results and symptoms diverge, reassessing adherence, gastrointestinal triggers, medication timing, and whether additional evaluation for comorbid gut inflammation or psoriatic arthritis is warranted can provide more actionable next steps than simply repeating the same test.

The importance of gut microbiome testing

  • Why testing matters

    Gut microbiome testing matters in plaque psoriasis because it may help clarify whether an individual’s symptoms are being influenced by gut–skin immune signaling. Research increasingly points to immune dysregulation involving pathways such as TNF-α, IL-23, and IL-17, and the gut microbiome can shape these responses by altering T-cell activity and the balance of pro- and anti-inflammatory cytokines. When the microbiome shows reduced diversity or an imbalance between “beneficial” and pro-inflammatory taxa, the intestinal barrier can become more permeable, allowing microbial byproducts to interact more strongly with the immune system and potentially intensify skin inflammation.

    Testing can also be useful because it provides insight into microbial metabolites—especially short-chain fatty acids (SCFAs) like butyrate—that support intestinal barrier integrity and help maintain immune tolerance. Lower SCFAs can remove a key anti-inflammatory influence, making it easier for pro-inflammatory immune pathways to dominate and contribute to plaque formation and flare-ups. While gut effects don’t replace dermatologic care, microbiome results can help explain why some people experience broader inflammatory symptoms (e.g., fatigue or metabolic risk) or are more prone to joint involvement, suggesting a potential “systemic spillover” component.

    Finally, microbiome testing may guide more personalized dietary and lifestyle strategies aimed at improving microbial balance, barrier function, and SCFA production. By identifying patterns that correlate with gut irritation or reduced fiber-fermenting capacity, clinicians and patients can tailor nutrition toward plant-forward, high-fiber intake and other supportive habits. In this way, gut testing can move psoriasis management beyond one-size-fits-all recommendations and help target modifiable drivers linked to the gut–skin axis.

  • How InnerBuddies helps

    InnerBuddies can help people with plaque psoriasis by assessing gut microbiome patterns that may influence the gut–skin immune axis. Plaque psoriasis is increasingly linked to immune dysregulation, with inflammatory pathways such as TNF-α, IL-23, and IL-17 playing central roles. Because gut microbes shape T-cell activity and cytokine balance, your test results can reveal whether your microbiome shows signs of reduced diversity or an imbalance between bacteria associated with immune tolerance versus those linked to inflammatory signaling—offering a potential explanation for why flares may be more likely in certain periods.

    The InnerBuddies results can also provide insight into the metabolic “signals” your gut environment is producing—particularly those related to short-chain fatty acid (SCFA) production like butyrate. SCFAs support intestinal barrier integrity and help keep immune responses in check. When SCFA-producing capacity is diminished, the gut barrier may become more permeable, allowing microbial byproducts to interact more strongly with the immune system and potentially amplify skin inflammation. Seeing these microbiome and functional tendencies can help connect gut conditions (like sensitivity or occasional digestive symptoms) to psoriasis activity, including broader inflammatory symptoms that some individuals experience.

    Finally, InnerBuddies testing may support more personalized dietary and lifestyle strategies aimed at improving microbiome balance and barrier-supporting metabolite output. By identifying patterns that suggest low fiber-fermenting potential or a microbiome configuration that may be less supportive of immune tolerance, you and your clinician can tailor plant-forward, high-fiber nutrition and other gut-supportive habits. While gut testing doesn’t replace dermatologic care, it can add actionable context—helping target modifiable drivers that may contribute to flare frequency, symptom intensity, and overall inflammatory risk.

Medical Evidence

  • Scientific evidence level

    2 [weak/emerging but inconsistent for gut–plaque psoriasis links; intervention and clinical utility are not established]

  • Clinical relevance note

    Current clinical relevance is low. While the gut microbiome is a plausible modulator of systemic immune pathways implicated in plaque psoriasis, the human evidence does not yet reach the threshold for actionable use. Associations between gut microbial signatures and psoriasis presence/severity are reported, but reproducibility is limited, confounding is difficult to fully remove (notably medications, diet, and disease-related changes that can alter the microbiome), and reverse causality cannot be excluded.

    At present, measuring the gut microbiome has no validated clinical role for plaque psoriasis (no established predictive biomarker, no clinically validated stratification algorithm, and no demonstrated monitoring strategy that changes outcomes). Microbiome-targeted interventions have not yet provided consistent, adequately powered randomized evidence with clinically meaningful endpoints and robust microbiome-informed stratification. Therefore, the most evidence-aligned interpretation is that the gut microbiome is a potential contributor and biomarker candidate, but clinical application is premature.

Title Journal Year Link
Probiotics and prebiotics for psoriasis: a systematic review and meta-analysis Journal of the European Academy of Dermatology and Venereology 2022 View →
Gut microbiota in psoriasis: a systematic review and meta-analysis Journal of Dermatological Science 2021 View →
Gut microbiota signatures are associated with response to anti-TNF-α and anti-IL-17 in patients with psoriasis Gut 2020 View →
Role of the gut microbiota in the pathogenesis of psoriasis Nature Reviews Immunology 2018 View →
Dysbiosis of gut microbiota in patients with psoriasis Scientific Reports 2015 View →

Frequently Asked Questions

    Qu'est-ce que le psoriasis en plaques et en quoi diffère-t-il des autres types de psoriasis ?
    Le psoriasis en plaques est la forme la plus courante, caractérisée par des plaques rouges bien définies et des écailles. D'autres formes incluent le psoriasis nail, guttate, inverse ou pustuleux, qui peuvent sembler différents ou apparaître ailleurs.
    Comment le microbiome intestinal pourrait-il influencer les symptômes du psoriasis ?
    Des résultats suggèrent que le microbiome intestinal peut influencer les signaux immunitaires liés au psoriasis, pouvant affecter le risque de poussées. C'est une pièce d'un puzzle complexe.
    Qu'est-ce que l'axe intestin–peau ?
    L'axe intestin–peau décrit comment la santé intestinale et les microbes intestinaux peuvent influencer l'inflammation cutanée via des signaux immunitaires et des métabolites.
    Que mesure le test InnerBuddies ?
    Le test InnerBuddies mesure la composition du microbiome intestinal et des signaux métaboliques associés (par ex. la production de SCFA) qui peuvent être liés à l'équilibre immunitaire.
    Qu'est-ce que les acides gras à chaîne courte (SCFA) et pourquoi sont-ils importants ?
    Les SCFA sont des métabolites produits lorsque les bactéries intestinales fermentent les fibres alimentaires. Ils aident à soutenir la barrière intestinale et à réguler les réponses immunitaires.
    Que signifie un microbiome intestinal dysbiotique pour le psoriasis ?
    Un microbiome intestinal dysbiotique pourrait être lié à un état immunitaire plus pro-inflammatory, ce qui pourrait être lié à l'activité du psoriasis; les résultats varient.
    Les tests intestinaux peuvent-ils prédire les poussées de psoriasis ou les symptômes articulaires ?
    Ils peuvent donner du contexte sur l'inflammation, mais ne prédisent pas avec certitude les poussées ou les symptômes articulaires.
    Comment dois-je me préparer à un test du microbiome intestinal ?
    Suivez les instructions du kit et les conseils de votre médecin ; des étapes typiques incluent éviter les antibiotiques ou certains compléments avant l'échantillonnage, si recommandé.
    Combien de temps faut-il pour obtenir les résultats et comment sont-ils rapportés ?
    Les délais varient; les résultats sont généralement fournis via un portail sécurisé avec l'interprétation d'un professionnel.
    Les résultats des tests du microbiome sont-ils concluants pour les décisions de traitement ?
    Non; les résultats du microbiome constituent un contexte et ne doivent pas, à eux seuls, dicter le traitement.
    Quels changements de mode de vie ou d'alimentation sont généralement recommandés pour la santé intestinale et le psoriasis ?
    Des schémas courants incluent une alimentation riche en fibres et axée sur les plantes pour soutenir la diversité intestinale ; en discuter avec un médecin.
    Le test est-il sûr et privé et comment les données sont-elles gérées ?
    Les tests réputés protègent la vie privée; le traitement des données est décrit dans la politique ; demandez des détails.

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