**Notes/Thanks/Other declarations**

The authors gratefully acknowledge the Bualuang ASEAN Chair Professorship grant award provided by Thammasat University. The funders had no role in any parts of this study.

**79**

**Author details**

Atiya Rungjang1

The Netherlands

, Jitlada Meephansan1

\*Address all correspondence to: h.thio@erasmusmc.nl

provided the original work is properly cited.

Thammasat University, Pathum Thani, Thailand

and Hok Bing Thio2

1 Division of Dermatology, Chulabhorn International College of Medicine,

2 Department of Dermatology, Erasmus University Medical Center, Rotterdam,

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

\*

*Skin and Gut Microbiota in Psoriasis: A Systematic Review*

*DOI: http://dx.doi.org/10.5772/intechopen.92686*

*Skin and Gut Microbiota in Psoriasis: A Systematic Review DOI: http://dx.doi.org/10.5772/intechopen.92686*

*Human Microbiome*

that the colonization of probiotic bacteria in the gut is mostly transient as they are only detectable for less than 2 weeks after cessation of intake [64]. However, a study by Maldonado-Gómez et al. demonstrated that a certain *Bifidobacterium longum* (*B. longum*) strain was able to persist for over 6 months in a subset of subjects where it was originally absent [65]. A recent, randomized, double-blind, placebo-controlled trial evaluated the effect of a probiotic mixture as co-adjutant treatment together with topical steroids in 90 patients with plaque psoriasis. The results showed a large reduction in the score of severity indexes in the probiotic group, compared with the placebo group. Gut microbiota analysis demonstrated the efficacy of the probiotic in modulation of the composition of the microbiota. After the end of the probiotic or placebo intake, patients were followed up for 6 months. The results showed a lower risk

• Topical probiotics show that after sequential applications of a donor microbiome, the recipient microbiome becomes more similar to the donor [67]. The use of topical probiotics may have special subclinical significance, for example, to improve skin defense with probiotic-containing cosmeceuticals. It has been reported that *B. longum* strains exert pro-differentiating, as well as and proregenerating, effects on primary human epidermal keratinocytes [68]. Thus, using the most suitable oral probiotic strain in combination with topical probiotics and/or prebiotics might help in the personalized treatment of skin disorders.

• Fecal microbiota transplantation (FMT) is currently being used to restore the balance of the intestinal microbiota [69, 70]. Particularly, this procedure has demonstrated >90% clinical resolution of recurrent, or refractory, *Clostridium difficile* infections [71]. Also, multiple FMTs seem to be able to induce remission in patients with IBD [72]. Due to these results, FMT is now being tested as a potential novel treatment for other gastrointestinal and extraintestinal diseases [73] as it greatly improves outcomes compared with those before treatment.

The function of microbiota may be more important in psoriasis. The metabolic activity of microbiota may become an upcoming research area in near future for identifying crucial biomarkers and new therapeutic approaches for psoriasis. Future cohort studies with standardized methodologies and proof-of-concept investigations in animal models may uncover the role of microbiota and the microbial pathway in psoriasis. This, then, may lead to the development of diagnostics and

The authors gratefully acknowledge the Bualuang ASEAN Chair Professorship grant award provided by Thammasat University. The funders had no role in any

of relapse in patients in the probiotic group [66].

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**3. Conclusion**

therapeutic opportunities.

The authors have no conflict of interest to declare.

**Notes/Thanks/Other declarations**

**Conflict of interest**

parts of this study.
