Clinical evaluation of paraprobiotic-associated Bifidobacterium lactis CCT 7858 anti-dandruff shampoo efficacy: A randomized placebo-controlled clinical trial.

OBJECTIVE: The microbiome plays an important role in a wide variety of skin disorders. Hence, dysbiosis in the skin and/or gut microbiome is associated with an altered immune response, promoting the development of skin diseases, such as atopic dermatitis, psoriasis, acne vulgaris and dandruff. Studies have shown that paraprobiotics may be promising for the treatment of skin disorders through microbiota modulation and immunomodulation. So, the objective is to develop an anti-dandruff formulation using a paraprobiotic (Neoimuno) as active ingredient. METHODS: Randomized, double-blind, placebo-controlled clinical trial was performed in patients who had any degree of dandruff. A total of 33 volunteers were recruited and randomly divided into two groups: placebo or treated. (1% Neoimuno). The ingredient used was Neoimuno (Bifidobacterium lactis strain CCT 7858). Combability analysis and perception questionnaire were applied before and after treatment. Statistical analyses were performed. RESULTS: No adverse effects were reported by patients throughout the study. Through the combability analysis, a significant decrease in the number of particles was verified after 28 days of shampoo use. Regarding perception, there was a significant difference for the cleaning variables and improvement of the general appearance 28 days after the intervention. There were no significant differences for the itching and scaling parameters, as well as the perception parameters at 14 days. DISCUSSION: Topical application of the paraprobiotic shampoo containing 1% Neoimuno was able to significantly improve the feeling of cleanliness and general aspects of dandruff, in addition to reducing scalp flakiness. Thus, with the results obtained through the clinical trial, Neoimuno presents itself as a natural, safe and effective ingredient in the treatment of dandruff. The efficacy of Neoimuno in dandruff was visible within 4 weeks.

OBJECTIF: Le microbiome joue un rôle important dans une grande variété de troubles cutanés. Ainsi, la dysbiose du microbiome cutané et/ou intestinal est associée à une réponse immunitaire altérée, favorisant le développement de maladies cutanées, telles que la dermatite atopique, le psoriasis, l'acné vulgaire et les pellicules. Des études ont montré que les paraprobiotiques peuvent être prometteurs pour le traitement des troubles cutanés par la modulation du microbiote et l'immunomodulation. Ainsi, l'objectif est de développer une formulation antipelliculaire utilisant un paraprobiotique (Neoimuno) comme principe actif. MÉTHODES: Un essai clinique randomisé, en double aveugle et contrôlé par placebo a été réalisé chez des patients présentant des pellicules de n'importe quel degré. Au total, 33 volontaires ont été recrutés et divisés au hasard en deux groupes: placebo ou traité. (1% Neoimuno). L'ingrédient utilisé était le Neoimuno (souche Bifidobacterium lactis CCT 7858). Une analyse de combabilité et un questionnaire de perception ont été appliqués avant et après le traitement. Des analyses statistiques ont été effectuées. RÉSULTATS: Aucun effet indésirable n'a été signalé par les patients tout au long de l'étude. Grâce à l'analyse de combabilité, une diminution significative du nombre de particules a été vérifiée après 28 jours d'utilization du shampooing. Concernant la perception, il y avait une différence significative pour les variables de nettoyage et d'amélioration de l'aspect général 28 jours après l'intervention. Il n'y avait pas de différences significatives pour les paramètres de démangeaison et de desquamation, ainsi que les paramètres de perception à 14 jours. DISCUSSION: L'application topique du shampooing paraprobiotique contenant 1% de Neoimuno a pu améliorer significativement la sensation de propreté et les aspects généraux des pellicules, en plus de réduire la desquamation du cuir chevelu. Ainsi, avec les résultats obtenus grâce à l'essai clinique, Neoimuno se présente comme un ingrédient naturel, sûr et efficace dans le traitement des pellicules. L'efficacité de Neoimuno sur les pellicules a été visible en 4 semaines.

Ketoconazole beyond antifungal activity: Bioinformatics-based hypothesis on lipid metabolism in dandruff and seborrheic dermatitis.

The role of Malassezia yeasts in dandruff and seborrheic dermatitis is unclear; however, antifungal therapy with ketoconazole is commonly used. We propose that ketoconazole shifts skin lipid profile, affects Malassezia lipid metabolism and favours biotin-producing bacteria. Biotin regulates inflammatory response and cell proliferation, contributing to symptom improvement.

Galleria mellonella as a Novelty in vivo Model of Host-Pathogen Interaction for Malassezia furfur CBS 1878 and Malassezia pachydermatis CBS 1879.

Malassezia furfur and Malassezia pachydermatis are lipophilic and lipid dependent yeasts, associated with the skin microbiota in humans and domestic animals, respectively. Although they are commensals, under specific conditions they become pathogens, causing skin conditions, such as pityriasis versicolor, dandruff/seborrheic dermatitis, folliculitis in humans, and dermatitis and otitis in dogs. Additionally, these species are associated with fungemia in immunocompromised patients and low-weight neonates in intensive care units with intravenous catheters or with parenteral nutrition and that are under-treatment of broad-spectrum antibiotics. The host-pathogen interaction mechanism in these yeasts is still unclear; for this reason, it is necessary to implement suitable new host systems, such as Galleria mellonella. This infection model has been widely used to assess virulence, host-pathogen interaction, and antimicrobial activity in bacteria and fungi. Some advantages of the G. mellonella model are: (1) the immune response has phagocytic cells and antimicrobial peptides that are similar to those in the innate immune response of human beings; (2) no ethical implications; (3) low cost; and (4) easy to handle and inoculate. This study aims to establish G. mellonella as an in vivo infection model for M. furfur and M. pachydermatis. To achieve this objective, first, G. mellonella larvae were first inoculated with different inoculum concentrations of these two Malassezia species, 1.5 × 106 CFU/mL, 1.5 × 107 CFU/mL, 1.5 × 108 CFU/mL, and 11.5 × 109 CFU/mL, and incubated at 33 and 37°C. Then, for 15 days, the mortality and melanization were evaluated daily. Finally, the characterization of hemocytes and fungal burden assessment were as carried out. It was found that at 33 and 37°C both M. furfur and M. pachydermatis successfully established a systemic infection in G. mellonella. M. pachydermatis proved to be slightly more virulent than M. furfur at a temperature of 37°C. The results suggest that larvae mortality and melanization is dependent on the specie of Malassezia, the inoculum concentration and the temperature. According to the findings, G. mellonella can be used as an in vivo model of infection to conduct easy and reliable approaches to boost our knowledge of the Malassezia genus.

New perspectives on dandruff and seborrheic dermatitis: lessons we learned from bacterial and fungal skin microbiota.

The human body is inhabited by complex microbial communities, which positively impact different aspects of our health, and might also be related to the development of diseases. Progress in technologies, particularly sequencing methods and bioinformatics tools, has been crucial for the advances in this field. Microbial communities from skin can modulate immune response and protect the host against pathogens, and there are also data supporting their association with several skin conditions; including dandruff and seborrheic dermatitis. For decades, they have been thought to be related to Malassezia yeasts; however, the microbial role has not been elucidated, and their etiology remains poorly understood. This review discusses the recent findings in dandruff and seborrheic dermatitis and their relation to the skin microbiota. Data provided new perceptions to aid in the understanding of these skin disorders, broadening our view of their etiology and the possible roles of microbial communities in symptom development.

High prevalence of Demodex spp. infestation among patients with posterior blepharitis: correlation with age and cylindrical dandruff. / Alta prevalencia de infestación por Demodex spp. en pacientes con blefaritis posterior: correlación con edad y caspa cilíndrica.

OBJECTIVE: To determine prevalence of Demodex spp. and infestation index (II) by the parasite among patients of different ages with blepharitis and to assess association with occurrence of cylindrical dandruff (CC). MATERIALS AND METHODS: Prospective study including patients diagnosed with posterior blepharitis between 2013 and 2015, without previous acaricide treatment, was conducted by Fundación Oftalmológica Los Andes (Chile). Four eyelashes were randomly extracted from each eyelid for parasite detection. The II was calculated as the ratio between the total number of demodex specimens found in the total number of eyelashes removed. A semi-quantitative determination of the CC was performed. RESULTS: A total of 178 patients (91 men, 87 women), with a mean age of 58.49±20.66 years, were included. It was found that 83.7% of patients were infested with Demodex folliculorum with a mean II of 0.96±0.84 mites/eyelash. The II was significantly higher in patients over 50 years (p<.0001). Patient age and II showed a Pearson correlation coefficient (R2) of 0.12 (p<.0001). CC was observed in 71.4% of patients, with those over 50 years-old showing significantly higher values. A positive correlation was also observed between the amount of CC and the II (R2=.33; p<.0001). CONCLUSIONS: The prevalence of infestation by Demodex folliculorum is high in patients with posterior blepharitis. The II by the parasite is positively correlated with age and with the occurrence of CC on the eyelid border.

Dysbiotic Bacterial and Fungal Communities Not Restricted to Clinically Affected Skin Sites in Dandruff.

Dandruff is a prevalent chronic inflammatory skin condition of the scalp that has been associated with Malassezia yeasts. However, the microbial role has not been elucidated yet, and the etiology of the disorder remains poorly understood. Using high-throughput 16S rDNA and ITS1 sequencing, we characterized cutaneous bacterial and fungal microbiotas from healthy and dandruff subjects, comparing scalp and forehead (lesional and non-lesional skin sites). Bacterial and fungal communities from dandruff analyzed at genus level differed in comparison with healthy ones, presenting higher diversity and greater intragroup variation. The microbial shift was observed also in non-lesional sites from dandruff subjects, suggesting that dandruff is related to a systemic process that is not restricted to the site exhibiting clinical symptoms. In contrast, Malassezia microbiota analyzed at species level did not differ according to health status. A 2-step OTU assignment using combined databases substantially increased fungal assigned sequences, and revealed the presence of highly prevalent uncharacterized Malassezia organisms (>37% of the reads). Although clinical symptoms of dandruff manifest locally, microbial dysbiosis beyond clinically affected skin sites suggests that subjects undergo systemic alterations, which could be considered for redefining therapeutic approaches.