The 3-D configuration of excisional skin wound healing after topical probiotic application

Global Trends and Scientific Impact of Topical Probiotics in Dermatological Treatment and Skincare

The skin plays a crucial role in maintaining homeostasis and protecting against external aggressors. Recent research has highlighted the potential of probiotics and postbiotics in dermatological treatments and skincare. These beneficial microorganisms interact with the skin microbiota, modulate the immune response, and enhance the skin barrier, offering a promising therapeutic avenue for various skin conditions, such as acne, dermatitis, eczema, and psoriasis. This bibliometric study aims to analyze the global trends and scientific impact of topical probiotics in dermatology. By reviewing 106 articles published between 2013 and 2023, the study categorizes the applications of probiotics in wound healing, inflammatory skin diseases, and general skincare. The findings indicate a significant increase in publications from 2021 onwards, attributed to the heightened focus on medical research during the COVID-19 pandemic. This study also identifies the most productive countries, institutions, and authors in this field, highlighting the importance of international collaborations. The results underscore the efficacy of probiotic-based topical formulations in improving skin health, reducing inflammation, and enhancing wound healing. This comprehensive analysis supports the development of new therapeutic strategies based on topical probiotics and encourages high-quality research in this promising area.

Protective effect of Bifidobacterium animalis CGMCC25262 on HaCaT keratinocytes

Bifidobacteria are the most prevalent members of the intestinal microbiota in mammals and other animals, and they play a significant role in promoting gut health through their probiotic effects. Recently, the potential applications of Bifidobacteria have been extended to skin health. However, the beneficial mechanism of Bifidobacteria on the skin barrier remains unclear. In this study, keratinocyte HaCaT cells were used as models to evaluate the protective effects of the cell-free supernatant (CFS), heat-inactivated bacteria, and bacterial lysate of Bifidobacterium animalis CGMCC25262 on the skin barrier and inflammatory cytokines. The results showed that all the tested samples were able to upregulate the transcription levels of biomarker genes associated with the skin barrier, such as hyaluronic acid synthetase (HAS) and aquaporins (AQPs). Notably, the transcription of the hyaluronic acid synthetase gene-2 (HAS-2) is upregulated by 3~4 times, and AQP3 increased by 2.5 times when the keratinocyte HaCaT cells were co-incubated with 0.8 to 1% CFS. In particular, the expression level of Filaggrin (FLG) in HaCaT cells increased by 1.7 to 2.7 times when incubated with Bifidobacterial samples, reaching its peak at a concentration of 0.8% CFS. Moreover, B. animalis CGMCC25262 also decreased the expression of the proinflammatory cytokine RANTES to one-tenth compared to the levels observed in HaCaT cells induced with tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ). These results demonstrate the potential of B. animalis CGMCC25262 in protecting the skin barrier and reducing inflammatory response.

Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis BB-12 promote infected wound healing via regulation of the wound microenvironment

Infected wounds can result in complex clinical complications and delayed healing, presenting a significant global public health challenge. This study explored the effects of topical application of two probiotics, Lactobacillus rhamnosus GG (LGG) and Bifidobacterium animalis subsp. lactis BB-12, on the microenvironment of infected wounds and their impact on wound healing. LGG and BB-12 were applied separately and topically on the Staphylococcus aureus (S. aureus)-infected skin wounds of the rat model on a daily basis. Both probiotics significantly accelerated wound healing, demonstrated by enhanced granulation tissue formation and increased collagen deposition, with BB-12 showing superior efficacy. LGG and BB-12 both effectively inhibited neutrophil infiltration and decreased the expression of pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Notably, BB-12 markedly reduced IL-6 levels, while LGG significantly lowered TNF-α, transforming growth factor-β (TGF-β) and vascular endothelial growth factor (VEGF). Additionally, both probiotics promoted macrophage polarization towards the anti-inflammatory M2 phenotype. Microbiota analysis revealed that LGG and BB-12 significantly decreased the abundance of pathogenic bacteria (e.g. Staphylococcus and Proteus) and increased the proportion of beneficial bacteria (e.g. Corynebacterium). Particularly, BB-12 was more effective in reducing Staphylococcus abundance, whereas LGG excelled in promoting Corynebacterium growth. These findings suggest the ability of LGG and BB-12 to modulate the wound microenvironment, enhance wound healing and provide valuable insights for the management of infected wounds.

Advancements in employing two-dimensional nanomaterials for enhancing skin wound healing: a review of current practice

The two-dimensional nanomaterials are characterized by their ultra-thin structure, diverse chemical functional groups, and remarkable anisotropic properties. Since its discovery in 2004, graphene has attracted significant scientific interest due to its potential applications in various fields, including electronics, energy systems, and biomedicine. In medicine, graphene is used for designing smart drug delivery systems, especially for antibiotics, and biosensing. Skin trauma is a prevalent dermatological condition that increasingly contributes to morbidities and mortalities, thus representing a significant health burden. During tissue damage, rapid skin repair is crucial to prevent blood loss and infection. Therefore, drugs used for skin trauma must possess antimicrobial and anti-inflammatory properties. Two-dimensional (2D) nanomaterials possess remarkable physical, chemical, optical, and biological characteristics due to their uniform shape, increased surface area, and surface charge. Graphene and its derivatives, transition-metal dichalcogenides (TMDs), black phosphorous (BP), hexagonal boron nitride (h-BN), MXene, and metal-organic frameworks (MOFs) are among the commonly used 2D nanomaterials. Moreover, they exhibit antibacterial and anti-inflammatory properties. This review presents a comprehensive discussion of the clinical approaches employed for wound healing treatment and explores the applications of commonly used 2D nanomaterials to enhance wound healing outcomes.

Direct metagenomics investigation of non-surgical hard-to-heal wounds: a review

BACKGROUND

Non-surgical chronic wounds, including diabetes-related foot diseases (DRFD), pressure injuries (PIs) and venous leg ulcers (VLU), are common hard-to-heal wounds. Wound evolution partly depends on microbial colonisation or infection, which is often confused by clinicians, thereby hampering proper management. Current routine microbiology investigation of these wounds is based on in vitro culture, focusing only on a limited panel of the most frequently isolated bacteria, leaving a large part of the wound microbiome undocumented.

METHODS

A literature search was conducted on original studies published through October 2022 reporting metagenomic next generation sequencing (mNGS) of chronic wound samples. Studies were eligible for inclusion if they applied 16 S rRNA metagenomics or shotgun metagenomics for microbiome analysis or diagnosis. Case reports, prospective, or retrospective studies were included. However, review articles, animal studies, in vitro model optimisation, benchmarking, treatment optimisation studies, and non-clinical studies were excluded. Articles were identified in PubMed, Google Scholar, Web of Science, Microsoft Academic, Crossref and Semantic Scholar databases.

RESULTS

Of the 3,202 articles found in the initial search, 2,336 articles were removed after deduplication and 834 articles following title and abstract screening. A further 14 were removed after full text reading, with 18 articles finally included. Data were provided for 3,628 patients, including 1,535 DRFDs, 956 VLUs, and 791 PIs, with 164 microbial genera and 116 species identified using mNGS approaches. A high microbial diversity was observed depending on the geographical location and wound evolution. Clinically infected wounds were the most diverse, possibly due to a widespread colonisation by pathogenic bacteria from body and environmental microbiota. mNGS data identified the presence of virus (EBV) and fungi (Candida and Aspergillus species), as well as Staphylococcus and Pseudomonas bacteriophages.

CONCLUSION

This study highlighted the benefit of mNGS for time-effective pathogen genome detection. Despite the majority of the included studies investigating only 16 S rDNA, ignoring a part of viral, fungal and parasite colonisation, mNGS detected a large number of bacteria through the included studies. Such technology could be implemented in routine microbiology for hard-to-heal wound microbiota investigation and post-treatment wound colonisation surveillance.

Bacterial Biofilm in Chronic Wounds and Possible Therapeutic Approaches

Wound repair and skin regeneration is a very complex orchestrated process that is generally composed of four phases: hemostasis, inflammation, proliferation, and remodeling. Each phase involves the activation of different cells and the production of various cytokines, chemokines, and other inflammatory mediators affecting the immune response. The microbial skin composition plays an important role in wound healing. Indeed, skin commensals are essential in the maintenance of the epidermal barrier function, regulation of the host immune response, and protection from invading pathogenic microorganisms. Chronic wounds are common and are considered a major public health problem due to their difficult-to-treat features and their frequent association with challenging chronic infections. These infections can be very tough to manage due to the ability of some bacteria to produce multicellular structures encapsulated into a matrix called biofilms. The bacterial species contained in the biofilm are often different, as is their capability to influence the healing of chronic wounds. Biofilms are, in fact, often tolerant and resistant to antibiotics and antiseptics, leading to the failure of treatment. For these reasons, biofilms impede appropriate treatment and, consequently, prolong the wound healing period. Hence, there is an urgent necessity to deepen the knowledge of the pathophysiology of delayed wound healing and to develop more effective therapeutic approaches able to restore tissue damage. This work covers the wound-healing process and the pathogenesis of chronic wounds infected by biofilm-forming pathogens. An overview of the strategies to counteract biofilm formation or to destroy existing biofilms is also provided.

Evolution of the urinary microbiota in spinal cord injury patients with decubitus ulcer: A snapshot study

Current microbiome investigations of patients with pressure ulcers (PU) are mainly based on wound swabs and/or biopsy sequencing, leaving the colonization scenario unclear. Urinary microbiota has been never studied. As a part of the prospective ESCAFLOR study, we studied urinary microbiota of spinal cord injury (SCI) patients with PU without any urinary tract infection at the inclusion, collected at two times (at admission [D0] and after 28 days [D28]) during the patient's care, investigated by 16S rDNA metagenomics next generation sequencing. Subgroup analyses were carried out between patients with wounds showing improved evolution versus stagnated/worsened wounds at D28. Analysis was done using EPISEQ® 16S and R software. Among the 12 studied patients, the urinary microbiota of patients with improved wound evolution at D28 (n = 6) presented a significant decrease of microbial diversity. This modification was associated with the presence of Proteobacteria phylum and an increase of Escherichia-Shigella (p = 0.005), as well as the presence of probiotic anaerobic bacteria Lactobacillus and Bifidobacterium. In contrast, Proteus abundance was significantly increased in urine of patients with stagnated/worsened wound evolution (n = 6) (p = 0.003). This study proposes urinary microbiota as a complementary factor indirectly associated with the wound evolution and patient cure. It opens new perspectives for further investigations based on multiple body microbiome comparison to describe the complete scenario of the transmission dynamics of wound-colonizing microorganisms.

Looking for the Ideal Probiotic Healing Regime

Wound healing is a multi-factorial response to tissue injury, aiming to restore tissue continuity. Numerous recent experimental and clinical studies clearly indicate that probiotics are applied topically to promote the wound-healing process. However, the precise mechanism by which they contribute to healing is not yet clear. Each strain appears to exert a distinctive, even multi-factorial action on different phases of the healing process. Given that a multi-probiotic formula exerts better results than a single strain, the pharmaceutical industry has embarked on a race for the production of a formulation containing a combination of probiotics capable of playing a role in all the phases of the healing process. Hence, the object of this review is to describe what is known to date of the distinctive mechanisms of each of the most studied probiotic strains in order to further facilitate research toward the development of combinations of strains and doses, covering the whole spectrum of healing. Eleven probiotic species have been analyzed, the only criterion of inclusion being a minimum of two published research articles.

The role of probiotics as wound healers: an overall view

A wound is an injury to the skin or damage to the body tissue. The healing process differs between various kinds of wounds. Treatment of hard-to-heal (chronic) wounds becomes challenging for healthcare practitioners, especially if patients have underlying health complications such as diabetes. Infection of wounds is another factor that interferes with the healing process and extends its duration. Active research is being conducted into the development of advanced wound dressing technologies. These wound dressings are intended to manage the exudate, reduce bacterial infection and speed up the healing process. Probiotics have been receiving much attention because of their potential application in the clinical field, especially in diagnostics and treatment strategies of various infectious and non-infectious diseases. The host immune-modulatory response and antimicrobial activity of probiotics are expanding their role in the development of improved wound dressing technology.

Role of Lactiplantibacillus plantarum UBLP-40, Lactobacillus rhamnosus UBLR-58 and Bifidobacterium longum UBBL-64 in the Wound Healing Process of the Excisional Skin

The probiotics Lactiplantibacillus plantarum UBLP-40, Lactobacillus rhamnosus UBLR-58 and Bifidobacterium longum UBBL-64 seem to promote wound healing when applied topically. Our aim was to investigate their effect on the mRNA expression of pro-inflammatory, healing and angiogenetic factors during the healing process of a standardized excisional wound model in rats. Rats subjected to six dorsal skin wounds were allocated to Control; L. plantarum; combined formula of L. rhamnosus plus B. longum; L. rhamnosus; and B. longum treatments, applied every two days, along with tissue collection. The pro-inflammatory, wound-healing, and angiogenetic factors of mRNA expression were assessed by qRT-PCR. We found that L. plantarum exerts a strong anti-inflammatory effect in relation to L. rhamnosus-B. longum, given alone or in combination; the combined regime of L. rhamnosus-B. longum, works better, greatly promoting the expression of healing and angiogenic factors than L. plantarum. When separately tested, L. rhamnosus was found to work better than B. longum in promoting the expression of healing factors, while B. longum seems stronger than L. rhamnosus in the expression of angiogenic factors. We, therefore, suggest that an ideal probiotic treatment should definitively contain more than one probiotic strain to speed up all three healing phases.

Anti-inflammatory and wound healing properties of lactic acid bacteria and its peptides

Recent studies manifest an increase of inflammatory diseases at an alarming rate due to gut microbiota dysbiosis, genetic and other environmental factors. Lactic acid bacteria (LAB) are known for their antimicrobial properties and their extensive applications in food and pharmaceutical industries. Cyclic peptides are receiving increased attention due to their remarkable stability to withstand variations in temperature and pH. LAB produces anti-inflammatory that can inhibit lipopolysaccharide-induced production of proinflammatory cytokines in macrophages. The structural backbones of cyclic peptides offer a promising approach for the treatment of chronic inflammatory conditions. The current review aims to present the overview of anti-inflammatory and wound healing properties of LAB-derived cyclic peptides.

The Probiotic Strains Bifidοbacterium lactis, Lactobacillus acidophilus, Lactiplantibacillus plantarum and Saccharomyces boulardii Regulate Wound Healing and Chemokine Responses in Human Intestinal Subepithelial Myofibroblasts

Bifidobacterium lactis, Lactobacillus acidophilus, Lactiplantibacillus plantarum and Saccharomyces boulardii are common probiotic supplements. Colonic subepithelial myofibroblasts (cSEMFs) are actively involved in mucosal wound healing and inflammation. cSEMFs, isolated from healthy individuals, were stimulated with 102 or 104 cfu/mL of these probiotic strains alone and in combination, and their effect on chemokine and wound healing factor expression was assessed by qRT-PCR, ELISA and Sircol Assay, and on cSEMFs migration, by Wound Healing Assay. These strains remained viable and altered cSEMFs’ inflammatory and wound healing behavior, depending on the strain and concentration. cSEMFs treated with a combination of the four probiotics had a moderate, but statistically significant, increase in the mRNA and/or protein expression of chemokines CXCL1, CXCL2, CXCL4, CXCL8, CXCL10, CCL2 and CCL5, and healing factors, collagen type I and III, fibronectin and tissue factor. In contrast, when each strain was administered alone, different effects were observed, with greater increase or decrease in chemokine and healing factor expression, which was balanced by the mixture. Overall, this study highlights that the use of multiple probiotic strains can potentially alert the gut mucosal immune system and promote wound healing, having a better effect on mucosal immunity than the use of single probiotics.

White pitahaya as a natural additive: potential usage in cosmetic industry

The awareness of some harmful side effects of the chemicals contained in synthetic cosmetics has increased the demand for herbal-based cosmetic products today. White pitahaya fruit and peel methanol extracts were prepared to determine their usage potential in the cosmetic industry. Firstly, we investigated their antimicrobial activity against some test microorganisms using the disc diffusion assay. We also determined their minimal inhibition and minimal bactericidal or fungicidal concentrations. Then, we assayed the antimicrobial activity of a commercial cream containing white pitahaya extracts and the probiotic Lactobacillus fermentum MA-7 strain against the test microorganisms. Finally, we measured the sun protection factors of the white pitahaya fruit and peel extracts and the cream with the extracts. The white pitahaya fruit and peel extracts exhibited antimicrobial activity against the test microorganisms. The cream formulation containing a pitahaya fruit extract had the highest inhibition zone diameter of 11.25 mm against Escherichia coli O157:H7. The highest sun protection value among the extracts and cream with extracts was determined for peel extract as 6.66 and 23.34, respectively. The results indicate that pitahaya fruit and peel extracts have effective antibacterial and antifungal properties, as well as high sun protection factors, and therefore they could be used as natural preservatives in the cosmetic industry.

A Four-Probiotic Regime to Reduce Surgical Site Infections in Multi-Trauma Patients

Investigations that focused on the protective role of probiotics against Surgical Site Infections (SSI) in multiple-trauma (MT) patients are generally few, probably due to the complexity of the concept of trauma. We aimed to assess the efficacy of a four-probiotic regime to reduce the incidence of SSI in MT patients, with a brain injury included. MT patients, being intubated and expected to require mechanical ventilation for >10 days, were randomly allocated into placebo (n = 50) or probiotic treatment (n = 53) comprising Lactobacillus acidophilus LA-5 (1.75 × 109 cfu), Lactiplantibacillus plantarum UBLP-40 (0.5 × 109 cfu), Bifidobacterium animalis subsp. lactis BB-12 (1.75 × 109 cfu), and Saccharomycesboulardii Unique-28 (1.5 × 109 cfu) in sachets. All patients received two sachets of placebo or probiotics twice/day for 15 days and were followed-up for 30 days. The operations were classified as neurosurgical, thoracostomies, laparotomies, orthopedics, and others; then, the SSI and the isolated pathogen were registered. A total of 23 (46.0%) and 13 (24.5%) infectious insults in 89 (50 placebo patients) and 88 (53 probiotics-treated) operations (p = 0.022) were recorded, the majority of them relating to osteosynthesis—17 and 8, respectively. The most commonly identified pathogens were Staphylococcus aureus and Acinetobacter baumannii. Our results support published evidence that the prophylactic administration of probiotics in MT patients exerts a positive effect on the incidence of SSI.