PracticalDermatology

Probiotics are living gut bacteria that are beneficial to the body and may have a potential role in autoimmune conditions of the skin, such as psoriasis. Every person’s collection of microbes is collectively referred to as a microbiome. Although bacteria are the most prominent components, this collection of microorganisms also includes viruses, fungi, and protozoa that inhabit and colonize the gastrointestinal tract.

Thanks to a laundry list of potential health benefits—from aiding digestion to cooling inflammation—probiotics are a hot commodity, and they will continue to grow even hotter. The global probiotic cosmetics product market is forecast to grow at a compound annual growth rate (CAGR) of more than seven percent from 2021 to 2030, according to recent market research from Report Ocean.¹

Probiotics in Psoriasis: What do we know?

A 2019 study aimed to identify differences in stool microbial composition of patients with psoriasis compared to their psoriasis-free counterparts and showed that psoriasis patients displayed a lower diversity and different relative abundance of certain bacteria.²

Although data on probiotic supplementation in psoriasis treatment are limited, recent research suggests that probiotics may improve psoriasis. The intestinal microbiota is known to have a critical function in the maturation and homeostasis of the immune system.

Probiotic Lactobacillus strains are involved in immune responses and allergic diseases in humans. For example, Lactobacillus johnsonii activates dendritic cells and thereby reduces the secretion of key T helper 2 (Th2) cytokines, such as interleukin (IL) -4, IL-5, and IL-13, which play an important role in inducing allergic disease.

The oral administration of Bifidobacterium infantis 35624 for six to eight weeks reduced plasma C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-alpha), and IL-6 in psoriasis patients, potentially via regulatory T cells. These data demonstrate that the immunomodulatory effects of the microbiota in humans are not limited to the mucosal immune system but extend to the systemic immune system.

One interventional study that characterized the gut microbiome of psoriasis patients after treatment with probiotics showed no significant change in the microbiota. There was, however, a substantial reduction in the severity of psoriasis in the treated group: 66.7 percent of patients achieved PASI 75, compared with 41.9 percent of patients in the placebo group.³ Although the authors found a significant difference in the clinical presentation of psoriasis, a limitation of the study was that topical corticosteroid use was not prohibited.

A systematic review published in 2021 examining the association between patients with psoriatic disease and the oral and/or gut microbiome included 23 out of an initial total of 1,643 studies: one interventional and 22 observational studies. The results showed an increased presence of Candida in the oral cavity, and all studies examining the gut microbiota identified an altered microbiome in patients with psoriatic disease. Overall, the results were heterogeneous.⁴

An ongoing Phase 2, double-blind, randomized, placebo-controlled study that began in November 2021 is evaluating a proprietary strain of Lactobacillus gasseri KBL697, developed by KoBioLabs, in patients with moderate plaque-type psoriasis (NCT04911751).⁵

Reason for Optimism

More research is needed in order for us to better understand which strains of probiotics may be beneficial for people with psoriasis and in what amount. Given the low risk of adverse events and encouraging preliminary data, there’s reason for optimism about the potential of probiotics in psoriasis.

1. Report Ocean. Probiotic Cosmetic Products Market by Products Type, By distribution Type, By Region: Global Opportunity Analysis and Industry Forecast 2021-2030. https://reportocean.com/industry-verticals/sample-request?report_id=Pol221

2. Hidalgo-Cantabrana C, Gómez J, Delgado S, et al. Gut microbiota dysbiosis in a cohort of patients with psoriasis. Br J Dermatol. 2019 Dec;181(6):1287-1295.

3. Navarro-López V, Martínez-Andrés A, Ramírez-Boscá A, et al. Efficacy and Safety of Oral Administration of a Mixture of Probiotic Strains in Patients with Psoriasis: A Randomized Controlled Clinical Trial. Acta Derm Venereol. 2019 Nov 1;99(12):1078-1084.

4.Todberg, Tanja & Kaiser, Hannah & Zachariae, Claus & Egeberg, Alexander & Halling, Anne-Sofie & Skov, Lone. (2021). Characterization of Oral and Gut Microbiota in Patients with Psoriatic Diseases: A Systematic Review. Acta Dermato Venereologica. 101.

5. Groeger D, O’Mahony L, Murphy EF, et al. Bifidobacterium infantis 35624 modulates host inflammatory processes beyond the gut. Gut Microbes. 2013;4(4):325-339.