New insights into the characteristic skin microorganisms in different grades of acne and different acne sites

New clinical approach in facial mild-moderate acne: Re-stabilization of skin microbiota balance with a topical biotechnological phytocomplex

OBJECTIVES

Dysbiosis of the skin microbiota has been identified as a key factor in the development of acne. This study was aimed to evaluate the effect of a facial cream gel containing a biotechnological phytocomplex, niacinamide and succinic acid on the bacterial diversity of subjects with mild-moderate acne and its clinical benefits due to microbiota changes.

METHODS

Open-label, clinical study in 44 subjects with mild-moderate acne treated with a facial cream gel for 8 weeks. Bacterial diversity was analyzed by 16S rRNA gene sequencing of skin samples. Clinical effects were evaluated using the IGA acne severity scale, biometric measurements, and safety.

RESULTS

After 56 days of product's use, an increase in alpha and beta diversity was found (p < 0.01), with a decrease in the relative abundance of C. acnes (48.99% vs. 38.83%, p < 0.001). Regarding clinical results, a decrease in acne severity on the IGA scale (27.33%, p < 0.001), number of non-inflammatory and inflammatory lesions (respectively: 31.12%, p = 0.05; 42.27%, p < 0.001), amount of sebum (89.00%, p < 0.01) and erythema (15.35%, p < 0.01), was found. Responder analysis of the IGA score showed that 61.36% of patients improved by at least one point at day 56. The product was well tolerated throughout the study.

CONCLUSIONS

The use of the facial cream gel on skin was effective in rebalancing the microbiota, inhibiting biofilm formation and other virulence factors, reducing the number of mild-moderate acne lesions and sebum secretion, and consequently improving acne's severity.

Characterization of the forehead skin microbiome in the early phase of acne

BACKGROUND

The skin microbiota is known to be imbalanced in acne vulgaris, but the changes occurring during the early stages of acne onset remain poorly described.

OBJECTIVES

To characterize the skin microbiome of subclinical stages of acne in adults and adolescents.

METHODS

The composition and diversity of the microbiota from non-lesional skin on the forehead of subjects with mild-to-moderate acne were compared to the ones from non-acne subjects. Analyses of skin swab samples were performed using high-throughput sequencing of the V1-V3 regions of the bacterial 16S ribosomal RNA gene, the tuf gene fragment of Staphylococcus species and the internal transcribed spacer (ITS1) region of the fungal rRNA gene to determine the relative abundance, alpha-diversity and beta-diversity of bacteria and fungi.

RESULTS

Compared with non-acne subjects, acne subjects had a higher abundance of Cutibacterium (72.4% vs. 57.8%) and lower abundances of Corynebacterium (2.8% vs. 4.8%) and Streptococcus (1.4% vs. 3.2%). Bacterial alpha- and beta-diversity indices also differed significantly between the two groups, reflecting differences in richness, evenness, abundance and phylogenetic distance between bacterial populations. Differences were also observed at the level of Staphylococcus species: S. capitis was predominant in skin samples from non-acne subjects (46.7%), whereas S. epidermidis was the most abundant Staphylococcus species in non-lesional forehead skin areas of acne subjects (44.2%). Conversely, no significant between-group differences were found for fungi, with Malasseziales being the predominant order in both subject groups.

CONCLUSION

Dysbiosis was observed very early in subclinical acne stages of the forehead skin, with the overall abundance, richness and evenness of the bacterial population being lower in acne than in non-acne skin samples. Dysbiosis was also found at the level of Staphylococcus species. The development of acne lesions could therefore be prevented by using a skin care product that rebalances facial skin microbiota at very early stages.

A new topical biotechnological phytocomplex for truncal mild-moderate acne restores skin microbiota balance

BACKGROUND

The disruption of the microbial community or dysbiosis alters the functional composition, metabolic activity, and local distribution of the microbiota leading the development of acne. The aim of this study is to evaluate the effect of a lotion containing a biotechnological phytocomplex, niacinamide, and succinic acid in the bacterial diversity of subjects with truncal mild-moderate acne and its clinical benefits due to microbiota changes.

MATERIALS AND METHODS

Open, clinical study in 43 subjects with truncal mild-moderate acne treated with a lotion for 8 weeks. Bacterial diversity was analyzed by 16S rRNA gene sequencing of skin samples. Clinical effects were evaluated through IGA acne severity scale, biometric measurements, and safety.

RESULTS

After 56 days of product's use, an increase in richness alpha diversity was found (p = 0.005), with a decrease in Cutibacterium acnes relative abundance (66.43% vs. 58.11%, p = 0.009). The clinical results showed a decrease in IGA score (27.59% decrease; p = 0.001), the inflammatory lesions (52.12% decrease, p = 0.006) and erythema (18.33% decrease, p = 0.007), and desquamation index (63.83% decrease, p = 0.02). The responder analysis of the IGA score showed that 60.47% of patients improved by at least one point at day 56. The product was well tolerated along the study.

CONCLUSION

The use of the lotion on acneic skin was effective on rebalancing the microbiota, inhibiting biofilm formation and other virulence factors, reducing erythema and desquamation, and improving acne's severity.

The Microbiome and Acne: Perspectives for Treatment

The skin microbiome consists of the microorganisms populating the human skin. Cutibacterium acnes (C. acnes, formerly named Propionibacterium acnes) is recognized as a key factor in acne development, regulating inflammatory and immune pathways. Dysbiosis has been described as the imbalance in skin microbiome homeostasis and may play a role in acne pathogenesis. Microbial interference has been shown to be a contributor to healthy skin homeostasis and staphylococcal strains may exclude acne-associated C. acnes phylotypes. In this review we present an update on the skin microbiome in acne and discuss how current acne treatments such as benzoyl peroxide, orally administered isotretinoin, and antibiotics may affect the skin microbiome homeostasis. We highlight the collateral damage of acne antibiotics on the skin microbiome, including the risk of antimicrobial resistance and the dysregulation of the microbiome equilibrium that may occur even with short-term antibiotic courses. Consequently, the interest is shifting towards new non-antibiotic pharmacological acne treatments. Orally administered spironolactone is an emerging off-label treatment for adult female patients and topical peroxisome proliferator-activated receptor gamma (PPARγ) modulation is being studied for patients with acne. The potential application of topical or oral probiotics, bacteriotherapy, and phage therapy for acne are further promising areas of future research.