Study finds gut health key to combating skin diseases, eyes probiotics as potential treatment

In a recent study published in the International Journal of Molecular Sciences, a team of Polish researchers conducted a review to understand the connection between the gut microbiome and dermatological diseases and examined the use of probiotics to correct gut microbiome dysbiosis as a treatment for various skin diseases.

Study: The Role of the Gut Microbiome and Microbial Dysbiosis in Common Skin Diseases. Image Credit: Kateryna Kon / Shutterstock

Background

While dermatological diseases are largely non-fatal, they still contribute substantially to the global public health burden, notwithstanding the impact of skin diseases on mental health and the quality of working and daily life due to discomfort and social stigma. Genetic and environmental factors often cause skin diseases. However, increasing research suggests that the gut microbiome, which plays a significant role in the progression of various types of diseases, also contributes to the development and progression of dermatological diseases.

Nucleic acid sequencing has been extensively used to explore bacterial genes, understand microbiome composition, abundance, and diversity, and understand the pivotal role the gut microbiome plays in human health and homeostasis. Gut microbiome dysbiosis has been found to significantly affect the development and progression of various chronic diseases. Determining the contribution of microbiome dysbiosis in the pathogenesis and progression of dermatological diseases could help find novel therapeutic avenues for skin diseases.

Gut microbiome function

In the present review, the researchers discussed the assembly and composition of the gut microbiome and its role in human health. The review reported that the gut microbiome consists of over 10¹⁴ microorganisms, cumulatively weighing the same as the human liver. Furthermore, over three million of the bacterial genes from the gut microbiome are responsible for synthesizing numerous metabolites, some of which are essential for human health.

The studies examining the assembly and composition of the gut microbiome largely indicated that the gut microbiota is acquired as early as the prenatal developmental stages, and the microbiome profile is established by the age of five or six, which continues into adulthood. Bacteroidetes and Firmicutes are the two most dominant taxa of bacteria in the healthy human gut microbiome, with individual differences in the microflora proportions and compositions being present.

Antibiotic use, genetics, diet, and lifestyle factors such as smoking, stress, improper sleep, exercise, and body mass index are known to affect the gut microbiota profile. Diets composed mainly of fats, processed food, and sugars and low in fiber are known to push the gut microbiome towards an inflammatory profile.

Dermatological diseases and the gut microbiome

The review also included a detailed examination of the role of the gut microbiome in numerous dermatological diseases, including atopic dermatitis, psoriasis, acne, and alopecia areata. Studies have reported that the chronic nature of atopic dermatitis, especially the persistence of pruritis despite medication, has been known to lower the quality of life significantly and is linked to an increased risk of depression and anxiety. The review found that gut microbiome dysbiosis is strongly associated with atopic dermatitis.

Results from genome-wide association studies have shown that bacterial taxa such as Bifidobacteriaceae, Bifidobacteriales, Bifidobacterium, Christensenellaceae, Clostridia, Mollicutes, and Tenerticutes exhibit a negative correlation with the risk of atopic dermatitis, while Anaerotruncus, Bacteroides, and Bacteroidaceae exhibit a positive correlation.

Furthermore, in cases where atopic dermatitis developed in adulthood, the alpha diversity of the gut microbiome was lower. The species richness and proportion of taxa also differed between atopic dermatitis patients with and without gastrointestinal symptoms. Additionally, the lowering of alpha diversity was also associated with a higher risk of atopic dermatitis, severity, remission, and age of onset of the disease.

Genomic examinations of stool samples from psoriasis patients have found lower species diversity in their gut microbiome and significant dysbiosis as compared to healthy controls. Furthermore, while the microbiomes of psoriasis patients and healthy controls both comprised Actinobacteria, Proteobacteria, Firmicutes, and Bacteroidetes, the abundance of Proteobacteria and Bacteroidetes was substantially lower, and that of Actinobacteria and Firmicutes was significantly higher in the gut microbiome of psoriasis patients.

The review also discussed the findings from numerous studies on the link between the gut microbiome and the development, symptoms, severity, and progression of acne, and alopecia areata.

Conclusions

To summarize, the review examined numerous studies investigating the connection between the gut microbiome and dermatological diseases such as atopic dermatitis, psoriasis, acne, and alopecia areata. The findings indicate that gut microbiome dysbiosis at various stages in life is significantly associated with the development, severity, and progression of skin diseases.

Furthermore, while the research on the use of probiotics to alleviate the symptoms of various skin diseases is limited, the review found that some studies have found positive results, highlighting the need to further explore the potential use of probiotics as a therapeutic avenue for skin diseases.