Holly Novak

Background: Atopic Dermatitis (AD) is a complex skin condition caused by combination of genetics, immunity, and environmental factors that weaken the skin barrier.¹ It affects 1 in 10 people.¹ AD typically begins in early childhood for about 80% of those affected. Patients with AD commonly have a filaggrin mutation that leads to skin barrier weakness.¹ Immune responses mount to particles that invade the weakened barrier by increasing inflammation via IL-4 & IL-13 (which elevate the TH2 response).¹ Common clinical features of AD are pruritic, red, scaling lesions.¹ Distribution of lesion varies with age.¹ AD is diagnosed based on clinical criteria. The SCORing Atopic Dermatitis (SCORAD) method is common. AD currently has no cure, and all treatments are for symptom management. AD can severely impact quality of life.

Objective: In this narrative literature review, we examined if certain probiotics improve signs/symptoms of atopic dermatitis.

Search Methods: Conducted PubMed search from 2019-2023 using keywords “Atopic Dermatitis” “Probiotics” “Inflammation.”

Results: Ingestion of Lactococcus Lactis strain 11/19-B1 reduced severity of AD in mice models and humans by suppressing T cells causing inflammation (Th1, Th2, Th17).⁵  L. rhamnosus reduced symptoms of AD after treatment for 8 weeks. Lactobacillus rhamnosus 0900/0908 and Lactobacillus casei showed a significant decrease in SCORAD scores after three months.⁷ A mix of Lactobacillus rhamnosus, Lactobacillus acidophilus, Lactobacillus paracasei, and Bifidobacterium lactis decreased SCORAD from the third month of treatment and beyond. Probiotics group patients taking this mix needed less applications of topical immunosuppressants.⁸ This study showed the clinical benefit in reducing AD is related to treatment length.⁸ Lactococcus lactis KR-050L extract (LLK) experiment suggests that LLK reduces AD symptoms by inhibiting keratinocytes and mast cell activation. ⁹ LLK given to in vitro and in vivo models of AD caused decreased expression of pro-inflammatory chemokines and cytokines by down-regulating p38 MAPK, STAT1, and nuclear translocation of NF-κB in keratinocytes. ⁹ LLK reduced serum IgE, ear thickness, and immune cell infiltration in vivo. It also inhibited mast cell infiltration and serum histamine levels in mice. ⁹

Conclusions: Several strains of probiotics have proven to reduce SCORAD in patients with AD. ^6,7,8 Probiotics are not a curative treatment, but could be used successfully as an adjunct treatment in patients with AD.⁸ It is noted that effectiveness of probiotics on reducing AD depends on the length of treatment. Probiotics are a potential route to examine for developing new drugs due to their action of reducing IgE and immune cell infiltration.

Works Cited:

1. Frazier W, Bhardwaj N. Atopic Dermatitis: Diagnosis and Treatment. Am Fam Physician. 2020;101(10):590-598.
2. Mandlik DS, Mandlik SK. Atopic dermatitis: new insight into the etiology, pathogenesis, diagnosis and novel treatment strategies. Immunopharmacol Immunotoxicol. 2021;43(2):105-125. doi:10.1080/08923973.2021.1889583
3. Bylund S, Kobyletzki LB, Svalstedt M, Svensson Å. Prevalence and Incidence of Atopic Dermatitis: A Systematic Review. Acta Derm Venereol. 2020;100(12):adv00160. Published 2020 Jun 9. doi:10.2340/00015555-3510
4. Chovatiya R, Paller AS. JAK inhibitors in the treatment of atopic dermatitis. J Allergy Clin Immunol. 2021;148(4):927-940. doi:10.1016/j.jaci.2021.08.009
5. Suzuki T, Nishiyama K, Kawata K, et al. Effect of the Lactococcus Lactis 11/19-B1 Strain on Atopic Dermatitis in a Clinical Test and Mouse Model. Nutrients. 2020;12(3):763. Published 2020 Mar 14. doi:10.3390/nu1203076
6. Wu YJ, Wu WF, Hung CW, et al. Evaluation of efficacy and safety of Lactobacillus rhamnosus in children aged 4-48 months with atopic dermatitis: An 8-week, double-blind, randomized, placebo-controlled study. J Microbiol Immunol Infect. 2017;50(5):684-692. doi:10.1016/j.jmii.2015.10.003
7. Cukrowska B, Ceregra A, Maciorkowska E, et al. The Effectiveness of Probiotic Lactobacillus rhamnosus and Lactobacillus casei Strains in Children with Atopic Dermatitis and Cow’s Milk Protein Allergy: A Multicenter, Randomized, Double Blind, Placebo Controlled Study. Nutrients. 2021;13(4):1169. Published 2021 Apr 1. doi:10.3390/nu13041169
8. de Andrade PDSMA, Maria E Silva J, Carregaro V, et al. Efficacy of Probiotics in Children and Adolescents With Atopic Dermatitis: A Randomized, Double-Blind, Placebo-Controlled Study. Front Nutr. 2022;8:833666. Published 2022 Jan 26. doi:10.3389/fnut.2021.833666
9. Jin M, Lee S, Choi YA, et al. Lactococcus lactis KR-050L extract suppresses house dust mite induced-atopic skin inflammation through inhibition of keratinocyte and mast cell activation. J Appl Microbiol. 2019;126(1):230-241. doi:10.1111/jam.14116