Nutrition and atopic dermatitis

Abstract

Atopic dermatitis (AD) is a chronic eczematous disease characterized by T helper 2 (Th2)-shifted allergic immunity, skin barrier impairment, and pruritus. Oral intake of certain nutrients could help regulate AD. In patients with AD, serum 25-hydroxyvitamin D levels are reduced, and oral vitamin D supplementation improves AD. Vitamin D increases regulatory T (Treg) cells which promote tolerance to allergens and prevent allergic inflammation, inducing the expression of filaggrin and cathelicidin in keratinocytes. Vitamin A strengthens Treg cells by inducing the expression of Forkhead box P3, and inhibits mediator release from mast cells or eosinophils. Serum levels of linolenic acid and its metabolite, dihomo--linolenic acid, are reduced in patients with AD, and oral -linolenic acid improves AD through anti-inflammatory prostaglandin D1 or E1 derived from dihomo--linolenic acid. Eicosapentaenoic acid and docosahexaenoic acid ameliorate AD by suppressing the production of leukotriene B4, increasing ceramides in the stratum corneum, or through their metabolites, resolvin E1 and D1, resolving inflammation. Probiotics, Lactobacillus or Bifidobacteria, improve the intestinal permeability barrier, and induce Treg cells. Serum, hair, and erythrocyte zinc levels are reduced in patients with AD. Zinc induces Forkhead box P3 expression and increases Treg cells, and zinc-finger protein A20 suppresses the nuclear factor-B-3 dependent expression of inflammatory cytokines or cell-adhesion molecules. Oral supplementation of the above nutrients might play therapeutic or preventive roles for AD.

Bacterial Metabolites and Inflammatory Skin Diseases

“…SCFAs such as butyrate that were heavily discussed surrounding AD also play a role in psoriasis via their induction of differentiation of thymic T regulatory cells and naïve CD4+ T cells into peripheral Tregs by histone deacetylase inhibition [ 79 , 80 , 81 ]. T regs in psoriasis patients have been reported to have reduced suppressive activity that normalizes with sodium butyrate administration and IL-10 levels and expression of Foxp3, IL-17, and IL-6 in psoriatic skin lesions [ 82 , 83 ]. Sodium butyrate also enhances keratinocyte differentiation and mRNA of filaggrin and transglutaminase A, while promoting cornified envelope formation of keratinocytes and downregulating their proliferation [ 82 , 84 ].…”

“…T regs in psoriasis patients have been reported to have reduced suppressive activity that normalizes with sodium butyrate administration and IL-10 levels and expression of Foxp3, IL-17, and IL-6 in psoriatic skin lesions [ 82 , 83 ]. Sodium butyrate also enhances keratinocyte differentiation and mRNA of filaggrin and transglutaminase A, while promoting cornified envelope formation of keratinocytes and downregulating their proliferation [ 82 , 84 ]. SCFAs can be produced by Cutibacterium acnes for homeostasis and act via G-protein-coupled receptors (GPCRs) [ 79 , 85 ].…”

Oral probiotics increased the proportion of Treg, Tfr, and Breg cells to inhibit the inflammatory response and impede gestational diabetes mellitus

“…Wang’s findings also revealed that acetic acid, propionic acid, and butyric acid in the circulation of women with GDM influence placental immune metabolism, exhibiting potential anti-diabetic and anti-inflammatory properties (Wang et al 2022a , b , c , d , e ). In addition, this study found that oral probiotics reduced leptin levels and prevented GDM by increasing the ratio of Treg, Tfr, and Breg cells, suppressing the inflammatory response, and maintaining normal pregnancy in mice (Kanda et al 2021 ).…”

The Administration of Probiotics against Hypercholesterolemia: A Systematic Review

“…Authors have also analyzed the increased circulation of 25-hydroxyvitamin D in serum during L. reuteri NCIMB administration and found that the level of vitamin D was increased at the end of the study. The increased vitamin D level improves the proper intestinal colonization of probiotics, prevents pathogenic bacterial invasion, reduces chronic inflammation, and maintains enterocyte cell integrity [45,64,65]. Women who consumed yogurt containing L. acidophilus 145 and B. longum 913 regularly for six months had higher HDL-c levels and improved LDL-c/HDL-c ratio [52].…”