Human microflora, probiotics and wound healing

A potential therapeutic strategy of an innovative probiotic formulation toward topical treatment of diabetic ulcer: an in vivo study

BACKGROUND

The probiotic potential of Lacticacid bacteria has been studied in various medical complications, from gastrointestinal diseases to antibiotic resistance infections recently. Moreover, diabetic ulcer (DU) is known as one of the most significant global healthcare concerns, which comprehensively impacts the quality of life for these patients. Given that the conventional treatments of DUs have failed to prevent later complications completely, developing alternative therapies seems to be crucial.

METHODS

We designed the stable oleogel-based formulation of viable probiotic cells, including Lactobacillus rhamnosus (L. rhamnosus), Lactobacillus casei (L. casei), Lactobacillus fermentum (L. fermentum), and Lactobacillus acidophilus (L. acidophilus) individually to investigate their effect on wound healing process as an in vivo study. The wound repair process was closely monitored regarding morphology, biochemical, and histopathological changes over two weeks and compared it with the effects of topical tetracycline as an antibiotic approach. Furthermore, the antibiofilm activity of probiotic bacteria was assessed against some common pathogens.

RESULTS

The findings indicated that all tested lactobacillus groups (excluded L. casei) included in the oleogel-based formulation revealed a high potential for repairing damaged skin due to the considerably more levels of hydroxyproline content of tissue samples along with the higher numerical density of mature fibroblasts cell and volume density of hair follicles, collagen fibrils, and neovascularization in comparison with antibiotic and control groups. L. acidophilus and L. rhamnosus showed the best potential of wound healing among all lactobacillus species, groups treated by tetracycline and control groups. Besides, L. rhamnosus showed a significant biofilm inhibition activity against tested pathogens.

CONCLUSIONS

This experiment demonstrated that the designed formulations containing probiotics, particularly L. acidophilus and L. rhamnosus, play a central role in manipulating diabetic wound healing. It could be suggested as an encouraging nominee for diabetic wound-healing alternative approaches, though further studies in detailed clinical trials are needed.

Intestinal Delivery of Probiotics: Materials, Strategies, and Applications

Probiotics with diverse and crucial properties and functions have attracted broad interest from many researchers, who adopt intestinal delivery of probiotics to modulate the gut microbiota. However, the major problems faced for the therapeutic applications of probiotics are the viability and colonization of probiotics during their processing, oral intake, and subsequent delivery to the gut. The challenges of simple oral delivery (stability, controllability, targeting, etc.) have greatly limited the use of probiotics in clinical therapies. Nanotechnology can endow the probiotics to be delivered to the intestine with improved survival rate and increased resistance to the adverse environment. Additionally, the progress in synthetic biology has created new opportunities for efficiently and purposefully designing and manipulating the probiotics. In this article, a brief overview of the types of probiotics for intestinal delivery, the current progress of different probiotic encapsulation strategies, including the chemical, physical, and genetic strategies and their combinations, and the emerging single-cell encapsulation strategies using nanocoating methods, is presented. The action mechanisms of probiotics that are responsible for eliciting beneficial effects are also briefly discussed. Finally, the therapeutic applications of engineered probiotics are discussed, and the future trends toward developing engineered probiotics with advanced features and improved health benefits are proposed.

Immunological aspects of probiotics for improving skin diseases: Influence on the Gut-Brain-Skin Axis

The interplay between gut microbiota and human health, both mental and physical, is well-documented. This connection extends to the gut-brain-skin axis, linking gut microbiota to skin health. Recent studies have underscored the potential of probiotics and prebiotics to modulate gut microbiota, supported by in vivo and clinical investigations. In this comprehensive review, we explore the immunological implications of probiotics in influencing the gut-skin axis for the treatment and prevention of skin conditions, including psoriasis, acne, diabetic ulcers, atopic dermatitis, and skin cancer. Our analysis reveals that probiotics exert their effects by modulating cytokine production, whether administered orally or topically. Probiotics bolster skin defenses through the production of antimicrobial peptides and the induction of keratinocyte differentiation and regeneration. Yet, many questions surrounding probiotics remain unanswered, necessitating further exploration of their mechanisms of action in the context of skin diseases.

Unraveling the Puzzle: Health Benefits of Probiotics-A Comprehensive Review

A growing number of probiotic-containing products are on the market, and their use is increasing. Probiotics are thought to support the health of the gut microbiota, which in turn might prevent or delay the onset of gastrointestinal tract disorders. Obesity, type 2 diabetes, autism, osteoporosis, and some immunological illnesses are among the conditions that have been shown to possibly benefit from probiotics. In addition to their ability to favorably affect diseases, probiotics represent a defense system enhancing intestinal, nutritional, and oral health. Depending on the type of microbial strain utilized, probiotics can have variable beneficial properties. Although many microbial species are available, the most widely employed ones are lactic acid bacteria and bifidobacteria. The usefulness of these bacteria is dependent on both their origin and their capacity to promote health. Probiotics represent a valuable clinical tool supporting gastrointestinal health, immune system function, and metabolic balance. When used appropriately, probiotics may provide benefits such as a reduced risk of gastrointestinal disorders, enhanced immunity, and improved metabolic health. Most popular probiotics, their health advantages, and their mode of action are the topic of this narrative review article, aimed to provide the reader with a comprehensive reappraisal of this topic matter.

Effect of the Combination of Probiotics and Korean Red Ginseng on Diabetic Wound Healing Exposed to Diesel Exhaust Particles(DEPs)

Background and Objectives: Diesel exhaust particles (DEPs) are a major component of air pollution and adversely affect respiratory and cardiovascular disease and diabetic foot ulcers if diabetic patients are exposed to them. There are currently no studies on treating diabetic wounds exposed to DEPs. So, the effect of a combination of probiotics and Korean red ginseng on a diabetic wound model exposed to DEPs was confirmed. Materials and Methods: Rats were randomly divided into three groups according to DEP inhalation concentration and whether they underwent applications of probiotics (PB) and Korean red ginseng (KRG). Wound tissue was collected from all rats, and wound healing was evaluated using molecular biology and histology methods. Results: The wound size of all groups decreased over time, but there was no significant difference. As a result of the molecular biology experiment, the expression of NF-κB p65 on day 7 was significantly higher in group 2 than in the normal control group. As a result of histological analysis, unlike the primary control group, it was confirmed that granule tissue was formed on the 14th day in the normal control group and group 2. Conclusions: The findings in this study suggest that combined treatment with PB and KRG can promote the healing of DEP-exposed diabetic wounds.

The effect of probiotic supplementation on episiotomy wound healing among primiparous women: a triple-blind randomized clinical trial

BACKGROUND

Probiotics increase the defense power of immune system and accelerate the wound healing process by anti-inflammatory mechanisms at the wound site. The present study aimed at evaluating the effect of Lactobacillus casei oral supplementation on episiotomy wound healing among primiparous women.

METHODS

This triple-blind randomized clinical trial was performed on 74 primiparous women delivered in Alzahra Hospital, Tabriz, Iran. Participants with mediolateral episiotomy (incision length equal to and less than 5 cm) were randomly assigned to the probiotic and placebo groups. The probiotic group received Lactobacillus casei 431 with 1.5 * 109 colony-forming unit /capsule once a day from the day after birth to 14 days. Wound healing as a primary outcome was measured by Redness, Edema, Ecchymosis, Discharge, Approximation and pain as a secondary outcome by the Visual Analogue Scale before discharge, 5 ± 1 and 15 ± 1 days after birth. The data were analyzed using independent t-test and repeated measures one way analysis of variance.

RESULTS

The mean (standard deviation: SD) score of wound healing in the probiotic group altered from 4.91(1.86) before discharge to 1.55 (0.99) during 5 ± 1 days after birth and reached to 0.95 (0.27) during 15 ± 1 days after birth. Further, the mean (SD) score of wound healing in the placebo group altered from 4.62 (1.99) before discharge to 2.80 (1.20) during 5 ± 1 days after birth and reached to 1.45(0.71) during 15 ± 1 days after birth (adjusted mean difference: -0.50, confidence interval 95%: -0.96 to -0.05, P = 0.03).

CONCLUSION

Lactobacillus casei oral supplementation is effective in healing episiotomy wounds. It is suggested to evaluate the effect of topical use of Lactobacillus casei on episiotomy repair and pain in further studies.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials (IRCT): IRCT20170506033834N7. Date of registration: 11/08/2021.

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.

Multifunctional effects of wound dressing based on chitosan-coordinated argentum with resistant bacterial penetration

Third-degree scald, causing serious tissue destruction with continuous pain, easily leads to microbial infections and delayed wound healing. Therefore, a multifunctional treatment is attractive for seriously damaged tissue. Herein, carboxymethyl chitosan-coordinated argentum (Ag-CMC) was synthesized via a complexation method, and then the Ag⁺ release, antibacterial activity, biocompatibility, pain relief and wound healing properties of Ag-CMC were investigated in vitro and in vivo. The results revealed that Ag⁺ had interacted with carboxymethyl chitosan, containing approximately 1.2% of silver. The Ag-CMC (50-200 μg/mL) with Ag⁺ sustained release exhibited significant antibacterial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, drug-resistant E. coli, PA, MRSA and good biocompatibility with L929 cells. Furthermore, antibacterial and wound healing experiments demonstrated that Ag-CMC achieved an effective contraction rate of 90% after 28 days by accelerating re-epithelialization, regulating inflammation response, relieving pain and infections. Therefore, Ag-CMC is a safe multifunctional treatment for wound healing and infections.

Overview of the angiogenic effect of probiotics (Lactobacillus acidophilus and Lactobacillus rhamnosus) at human umbilical vein endothelial cells

Introduction: Angiogenesis (neovascularization), which means new vessel construction, is normal and physiologically, wound healing, embryogenesis, a necessary menstrual cycle it's a mechanism. When taken in appropriate amounts together with or separately with nutrients, mucosal and by regulating systemic immunity, ensuring nutritional and microbial balance in the intestines living nonpatogenic microorganisms that positively affect the health of the host it is called "probiotics". Lactic acid bacteria, the most probiotic microorganisms it constitutes its important group. Where probiotics have an effect on angiogenesis, and it is thought to help heal wounds through the road. With this research indicated that roles of Lactobacillus acidophilus and Lactobacillus rhamnosus on angiogenesis if present to demonstrate in vitro methods and the gene expression responsible for the formation of these effects it is intended to reveal. Material and Method: This study is an experimental study conducted in vitro human umbilical cord vein endothelial cell (HUVEC) MTT test in cell culture with (3-[4,5-Dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide; Thiazolyl blue) evaluation of viability and proliferation wound healing model, tube formation method and gene expression with real rime-polymer chain reaction (RT-PCR) methods of appointment were used. Results: HUVEC cells L. acidophilus 10⁹ CFU\ml after extract application statistical of mRNA expression of VEGF and FGF genes by control group 24 per hour it was found to increase significantly. L. rhamnosus 10 6 CFU\ml and 109 CFU\ml after application of extracts VEGF gene mRNA by control group 24 per hour its expression was found to be statistically significantly increased. Also L. rhamnosus extracts cell proliferation and migration of in vitro wound model it was found to increase statistically significantly. Conclusion: In this study, in vitro L. acidophilus 10⁹ CFU\ml extract and 10⁶ CFU\ml and 10⁹ CFU\ml extract of L. rhamnosus, VEGF gene mRNA revealed to be effective on angiogenesis in HUVEC cells by increasing expression it is.

The Gut-Skin Microbiota Axis and Its Role in Diabetic Wound Healing-A Review Based on Current Literature

Diabetic foot ulcers (DFU) are a growing concern worldwide as they pose complications in routine clinical practices such as diagnosis and management. Bacterial interactions on the skin surface are vital to the pathophysiology of DFU and may control delayed wound healing. The microbiota from our skin directly regulates cutaneous health and disease by interacting with the numerous cells involved in the wound healing mechanism. Commensal microbiota, in particular, interact with wound-repairing skin cells to enhance barrier regeneration. The observed microbes in DFU include Staphylococcus, Streptococcus, Corynebacterium, Pseudomonas, and several anaerobes. Skin commensal microbes, namely S. epidermidis, can regulate the gamma delta T cells and induce Perforin-2 expression. The increased expression of Perforin-2 by skin cells destroyed S. aureus within the cells, facilitating wound healing. Possible crosstalk between the human commensal microbiome and different cell types involved in cutaneous wound healing promotes the immune response and helps to maintain the barrier function in humans. Wound healing is a highly well-coordinated, complex mechanism; it can be devastating if interrupted. Skin microbiomes are being studied in relation to the gut-skin axis along with their effects on dermatologic conditions. The gut-skin axis illustrates the connection wherein the gut can impact skin health due to its immunological and metabolic properties. The precise mechanism underlying gut-skin microbial interactions is still unidentified, but the immune and endocrine systems are likely to be involved. Next-generation sequencing and the development of bioinformatics pipelines may considerably improve the understanding of the microbiome-skin axis involved in diabetic wound healing in a much more sophisticated way. We endeavor to shed light on the importance of these pathways in the pathomechanisms of the most prevalent inflammatory conditions including the diabetes wound healing, as well as how probiotics may intervene in the gut-skin axis.

ANTIMICROBIAL POTENTIAL OF LACTIC ACID BACTERIA LACTOBACILLUS RHAMNOSUS LYSATE

According to World Health Organization, antibiotic resistance is rising to dangerously high levels in all parts of the world. New resistance mechanisms are emerging and spreading globally, threatening our ability to treat common infectious diseases. Therefore, searching for new antimicrobial agents of natural origin is an extraordinary global problem. The work aimed to determine the antimicrobial activity of lyophilized enzymatic lysate of cells of the Lactobacillus rhamnosus V strain of lactic acid bacteria. The object of the study was the drug Del-Imun V®, which hasanti-allergican dimmuno stimulating activity. The researchers' efforts aimed to fully reveal the drug's potential, particularlyitsanti microbialaction. Antimicrobial activity was determined by the minimum inhibitory concentration (MIC). Determination of MIC was carried out by the method of twotime serial dilutions in meat-peptone broth (MPB) for bacteria and liquid wort for yeast. Gram-negative (Escherichia coli IEM-1, Proteus vulgaris PA-12, Pseudomonas sp. MI-2) and Gram-positive (Bacillus subtilis BТ-2, Staphylococcus aureus BМС-1) bacteria, as well as yeast (Candida albicans D-6, Candida tropicalis PE-2, Candida utilis BVS-65). It was shown that MIC valuesof the native preparation for the bacterial test cultures (EscherichiacoliIEM-1, Bacillussubtilis BT-2, Staphylococcusaureus BMS-1, Proteusvulgaris PA-12, Pseudomonassp. MI-2) were 8 time slower, than those of the thermally in activated preparation, forthe yeasts (Candidaalbicans D-6, Candidatropicalis PE-2, Candidautilis BVS-65) – 4-8 time slower. As a result of the conducted research, the antibacterial and antifungal activity of the drugDel-Imun V® was established. The spectrum of antimicrobial activity concerned gram-positiveand gram-negative bacteria and yeast-like fungi of the genus Candida. The minimum inhibitory concentrations were quite low: from 1.0 to 4.0 μg/ml for bacterial cultures and from 62.5 to 125 μg/ml for yeast. The culture of B. subtilis BT-2 was the least sensitive to the drug's action (MIC – 12.5 μg/ml). There fore, it can be concluded that the lysate of Lactobacillus rhamnosus V lacticacid bacteriahasanti bacteria landanti fungal properties.

Does Probiotic Consumption Enhance Wound Healing? A Systematic Review

The use of probiotics is one of the emerging lines of treatment for wound healing. This systematic review aimed to summarize currently available evidence on the effect of oral or enteral probiotic therapy on skin or oral mucosal wound healing in humans. To verify the developments in this field and the level of available scientific evidence, we applied a broad search strategy with no restrictions on wound type, target population, probiotic strain, or intervention protocol used. This review included seven studies involving 348 individuals. Four studies reported positive outcomes for healing improvement after probiotic therapy, and none of the studies reported adverse effects or a marked increase in wound healing time. The positive or neutral results observed do not generate strong evidence regarding the effectiveness of probiotics for wound healing. However, they suggest a promising field for future clinical research where the probiotic strains used, type of wounds, and target population are controlled for.

A Novel Effective Formulation of Bioactive Compounds for Wound Healing: Preparation, In Vivo Characterization, and Comparison of Various Postbiotics Cold Creams in a Rat Model

The wound is a break in the integrity of the skin produced by injury, illness, or operation. Wound healing is an essential dynamic biological/physiological process that occurs in response to tissue damage. The huge health, economic, and social effects of wounds on patients and societies necessitate the research to find novel potential therapeutic agents in order to promote wound healing. Postbiotics, the newest member of the biotics family, are valuable functional bioactive substances produced by probiotics through their metabolic activity, which have several beneficial properties, including immunomodulatory, anti-inflammatory, antimicrobial, and angiogenesis characteristics, resulting in acceleration of wound healing. In the current study, three topical cold cream formulations containing postbiotics obtained from Lactobacillus fermentum, Lactobacillus reuteri, or Bacillus subtilis sp. natto probiotic strains were prepared. The effectiveness and wound healing activity of the developed postbiotics cold cream formulations were investigated compared to cold cream without postbiotics and no treatment via wound closure investigation, hydroxyproline content assay, and histological assessment in 25 Sprague Dawley rats divided into five groups. Interestingly, analysis of the results revealed that all three formulations containing postbiotics significantly accelerated the wound healing process. However, in general, the Bacillus subtilis natto cold cream manifested a better wound healing property. The pleasing wound healing characteristics of the topical postbiotics cold creams through the in vivo experiment suggest that formulations containing postbiotics can be considered as a promising nominee for wound healing approaches.

Nutritional and Health Potential of Probiotics: A Review

Several products consist of probiotics that are available in markets, and their potential uses are growing day by day, mainly because some strains of probiotics promote the health of gut microbiota, especially Furmicutes and Bacteroidetes, and may prevent certain gastrointestinal tract (GIT) problems. Some common diseases are inversely linked with the consumption of probiotics, i.e., obesity, type 2 diabetes, autism, osteoporosis, and some immunological disorders, for which the disease progression gets delayed. In addition to disease mitigating properties, these microbes also improve oral, nutritional, and intestinal health, followed by a robust defensive mechanism against particular gut pathogens, specifically by antimicrobial substances and peptides producing probiotics (AMPs). All these positive attributes of probiotics depend upon the type of microbial strains dispensed. Lactic acid bacteria (LAB) and Bifidobacteria are the most common microbes used, but many other microbes are available, and their use depends upon origin and health-promoting properties. This review article focuses on the most common probiotics, their health benefits, and the alleviating mechanisms against chronic kidney diseases (CKD), type 1 diabetes (T1D), type 2 diabetes (T2D), gestational diabetes mellitus (GDM), and obesity.

Insight Into the Beneficial Role of Lactiplantibacillus plantarum Supernatant Against Bacterial Infections, Oxidative Stress, and Wound Healing in A549 Cells and BALB/c Mice

Lactiplantibacillus plantarum MTCC 2621 is a well-characterized probiotic strain and is reported to possess many health benefits. However, the wound healing potential of this probiotic is yet to be explored. Here, we have assessed the antibacterial, antioxidant, and wound healing activities of cell-free supernatant of Lactiplantibacillus plantarum MTCC 2621 (Lp2621). Lp2621 exhibited excellent antibacterial activity against the indicator bacteria in the agar well diffusion assay. Lp2621 did not show any hemolytic activity. The safety of Lp2621 gel was established using the skin irritation assay in BALB/c mice, and no dermal reactions were observed. The supernatant showed 60–100% protection of A549 cells against H₂O₂-induced stress. In the scratch assay, Lp2621 accelerated wound healing after 24 h of treatment. The percent wound healing was significantly higher in cells treated with Lp2621 at 18–24 h posttreatment. In an excision wound healing in mice, topical application of Lp2621 gel showed faster healing than the vehicle- and betadine-treated groups. Similar wound healing activity was observed in wounds infected with Staphylococcus aureus. Histological examination revealed better wound healing in Lp2621-treated mice. Topical treatment of the wounds with Lp2621 gel resulted in the upregulation of pro-inflammatory cytokine IL-6 in the early phase of wound healing and enhanced IL-10 expression in the later phase. These findings unveil a protective role of Lp2621 against bacterial infection, oxidative stress, and wound healing.

Alginate-chitosan oligosaccharide-ZnO composite hydrogel for accelerating wound healing

Moist, breathable and antibacterial microenvironment can promote cell proliferation and migration, which is beneficial to wound healing. Here, we fabricated a novel sodium alginate-chitosan oligosaccharide‑zinc oxide (SA-COS-ZnO) composite hydrogel by spontaneous Schiff base reaction, using aldehydated sodium alginate (SA), chitosan oligosaccharide (COS), and zinc oxide (ZnO) nanoparticles, which can provide a moist and antibacterial environment for wound healing. The porosity and swelling degree of SA-COS-ZnO hydrogel are 80% and 150%, respectively, and its water vapor permeability is 682 g/m2/24h. The composite hydrogel showed good biocompatibility to blood cells, 3T3 cells, and 293T cells, and significant antibacterial activity against Escherichia coli, Staphylococcus aureus, Candida albicans, and Bacillus subtilis. Moreover, the hydrogel showed a promoting effect on wound healing in a rat scald model. The present study suggests that marine carbohydrates composite hydrogels are promising in wound care management.

Procoagulant and Antimicrobial Effects of Chitosan in Wound Healing

Chitosan, a polysaccharide derived from chitin, has excellent wound healing properties, including intrinsic antimicrobial and hemostatic activities. This study investigated the effectiveness of chitosan dressing and compared it with that of regular gauze dressing in controlling clinically surgical bleeding wounds and profiled the community structure of the microbiota affected by these treatments. The dressings were evaluated based on biocompatibility, blood coagulation factors in rat, as well as antimicrobial and procoagulant activities, and the microbial phylogenetic profile in patients with abdominal surgical wounds. The chitosan dressing exhibited a uniformly fibrous morphology with a large surface area and good biocompatibility. Compared to regular gauze dressing, the chitosan dressing accelerated platelet aggregation, indicated by the lower ratio of prothrombin time and activated partial thromboplastin time, and had outstanding blood absorption ability. Adenosine triphosphate assay results revealed that the chitosan dressing inhibited bacterial growth up to 8 d post-surgery. Moreover, 16S rRNA-based sequencing revealed that the chitosan dressing effectively protected the wound from microbial infection and promoted the growth of probiotic microbes, thereby improving skin immunity and promoting wound healing. Our findings suggest that chitosan dressing is an effective antimicrobial and procoagulant and promotes wound repair by providing a suitable environment for beneficial microbiota.

The Insights of Microbes' Roles in Wound Healing: A Comprehensive Review

A diverse range of normal flora populates the human skin and numbers are relatively different between individuals and parts of the skin. Humans and normal flora have formed a symbiotic relationship over a period of time. With numerous disease processes, the interaction between the host and normal flora can be interrupted. Unlike normal wound healing, which is complex and crucial to sustaining the skin’s physical barrier, chronic wounds, especially in diabetes, are wounds that fail to heal in a timely manner. The conditions become favorable for microbes to colonize and establish infections within the skin. These include secretions of various kinds of molecules, substances or even trigger the immune system to attack other cells required for wound healing. Additionally, the healing process can be slowed down by prolonging the inflammatory phase and delaying the wound repair process, which causes further destruction to the tissue. Antibiotics and wound dressings become the targeted therapy to treat chronic wounds. Though healing rates are improved, prolonged usage of these treatments could become ineffective or microbes may become resistant to the treatments. Considering all these factors, more studies are needed to comprehensively elucidate the role of human skin normal flora at the cellular and molecular level in a chronic injury. This article will review wound healing physiology and discuss the role of normal flora in the skin and chronic wounds.

Stress and the Gut-Brain Axis: Implications for Cancer, Inflammation and Sepsis

BACKGROUND

The gut-brain axis has been discussed, directly or indirectly, for centuries, with the ideas of the gut affecting anything from moods to overall physiology being discussed across the centuries. With a recent explosion in research that looks to the microbiota as a mechanistic link between the gut and the brain, one sees that the gut-brain axis has various means of communication, such as through the vagus nerve and the enteric nervous system and can use the metabolites in the gut to communicate to the brain.

METHODS

The purpose of this review is to view the gut-brain axis through the lens of stress and how stress, from the prenatal period all the way through adulthood can impact the physiology of a human being. Studies have shown multiple mechanisms of measurable change with disruption in the microbiota that lead to behavioral changes. There are also effects of gut inflammation on the brain and the corresponding systemic response observed.

CONCLUSION

The overall literature is encouraging that the more understanding of the gut-brain axis, the greater ability to wield that understanding for therapeutic benefits.

Two-Sided Antibacterial Cellulose Combining Probiotics and Silver Nanoparticles

The constant increase of antibiotic-resistant bacteria demands the design of novel antibiotic-free materials. The combination of antibacterials in a biocompatible biomaterial is a very promising strategy to treat infections caused by a broader spectrum of resistant pathogens. Here, we combined two antibacterials, silver nanoparticles (AgNPs) and living probiotics (Lactobacillus fermentum, Lf), using bacterial cellulose (BC) as scaffold. By controlling the loading of each antibacterial at opposite BC sides, we obtained a two-sided biomaterial (AgNP-BC-Lf) with a high density of alive and metabolically active probiotics on one surface and AgNPs on the opposite one, being probiotics well preserved from the killer effect of AgNPs. The resulting two-sided biomaterial was characterized by Field-Emission Scanning Electron Microscopy (FESEM) and Confocal Laser Scanning Microscopy (CLSM). The antibacterial capacity against Pseudomonas aeruginosa (PA), an opportunistic pathogen responsible for a broad range of skin infections, was also assessed by agar diffusion tests in pathogen-favorable media. Results showed an enhanced activity against PA when both antibacterials were combined into BC (AgNP-BC-Lf) with respect to BC containing only one of the antibacterials, BC-Lf or AgNP-BC. Therefore, AgNP-BC-Lf is an antibiotic-free biomaterial that can be useful for the therapy of topical bacterial infections.

Microbiological effects in patients with leg ulcers and diabetic foot treated with Lucilia sericata larvae

Lucilia sericata bottle fly worms can be used to heal infected, chronic, or necrotic wounds, including those associated with ulceration and diabetic foot. The study aimed to evaluate changes in the microflora in patients treated with L sericata larvae due to leg ulcers and diabetic foot. One hundred twenty-nine patients diagnosed with lower limb ulceration and diabetic foot were enrolled in the study, of which 80 of them met the eligibility criteria for maggot debridement therapy (MDT). On the contrary, 49 unqualified patients were offered ozone therapy (22 with leg ulcers; 27 with diabetic foot). In each of these patients, a microbiological swab was performed before and after the start of therapy. The group of 80 patients was further divided into four equal groups in terms of the treated area (lower leg vs foot) and the number of larvae/cm² (5 vs 10). Twenty-three particular species of bacteria in the infected wound were studied microbiologically in terms of presence/absence within the wound environment before and after treatment of patients with diabetic foot and lower limb ulceration. It was noted that there was a more intensive bacterial accumulation in the feet of patients compared to legs; furthermore, this applies to almost all analysed species. Diabetes status is also a clinical factor that generates a lower chance of bacterial appearance in the wound environment. Densification of MDT larvae per wound area unit also reduced the chance of the presence of Corynebacterium species, Enterobacteriaceae, Pseudomonas aeruginosa, Staphylococcus aureus MSSA, and Streptococcus coagulase negativa; however, it increased the likelihood of occurrence for Proteus mirabilis and the Proteus species. A microbiological analysis in this non-reference study shows the efficacy of larval therapy for leg and foot ulcers. Rearrangement of the microflora within the wound has been reported as a result of the therapy.

Probiotic cellulose: Antibiotic-free biomaterials with enhanced antibacterial activity

The alarming increase of antibiotic-resistant bacteria, causing conventional treatments of bacterial infections to become increasingly inefficient, is one of the biggest threats to global health. Here, we have developed probiotic cellulose, an antibiotic-free biomaterial for the treatment of severe skin infections and chronic wounds. This composite biomaterial was in-depth characterized by Gram stain, scanning electron microscopy (SEM) and confocal fluorescence microscopy. Results demonstrated that probiotic cellulose consists of dense films of cellulose nanofibers, free of cellulose-producing bacteria, completely invaded by live probiotics (Lactobacillus fermentum or Lactobacillus gasseri). Viability assays, including time evolution of pH and reducing capacity against electrochromic polyoxometalate, confirmed that probiotics within the cellulose matrix are not only alive but also metabolically active, a key point for the use of probiotic cellulose as an antibiotic-free antibacterial biomaterial. Antibacterial assays in pathogen-favorable media, a real-life infection scenario, demonstrated that probiotic cellulose strongly reduces the viability of Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA), the most active pathogens in severe skin infections and chronic wounds. Likewise, probiotic cellulose was also found to be effective to inhibit the proliferation of methicillin-resistant SA (MRSA). The combination of the properties of bacterial cellulose as wound dressing biomaterial and the antibacterial activity of probiotics makes probiotic cellulose an alternative to antibiotics for the treatment of topical infections, including severe and hard-to-heal chronic wounds. In addition, probiotic cellulose was obtained by a one-pot synthetic approach under mild conditions, not requiring the long and expensive chemical treatments to purify the genuine bacterial cellulose.

The Role of Probiotics and Synbiotics on Hirsutism

Probiotics and synbiotics are known to have beneficial effects on human health and disease. Hirsutism, a disorder that is characterised by the presence of coarse terminal hairs in a male-like pattern, is usually caused by elevated androgen levels in blood plasma. This disorder is usually observed in PCOS women and it is linked to insulin resistance (IR). Although idiopathic hirsutism (IH) is not shown to have excess androgen production from the ovarian and adrenal glands, increased 5α-reductase in peripheral tissues and insulin resistance are common observations. The effect of probiotics and synbiotics have been recently studied on PCOS women; androgens were also included in the hormonal groups that were investigated. Only a few studies focus on hirsutism and the potential effect of the beneficial microbes mentioned, whereas the increasing interest on insulin resistance and synbiotics indicate a potential beneficial effect on hirsutism through the management of insulin resistance.

Development and In Vivo Characterization of Probiotic Lysate-Treated Chitosan Nanogel as a Novel Biocompatible Formulation for Wound Healing

Wound healing is a physiological reaction to tissue injuries which plays a crucial role in replacing the destroyed tissues. Probiotics produce valuable compounds that possess antibacterial and anti-inflammatory activities, immunomodulatory effects, and angiogenesis traits leading to the promotion of wound healing. Chitosan nanostructures have versatile properties making them quickly produced into gels, scaffolds, nanoparticles, beads, and sponge structures that can be incorporated into wound healing processes. In the current study, three formulations from nanogel consisting of probiotic supernatant (Lactobacillus reuteri, Lactobacillus fermentum, and Bacillus subtilis sp. natto)-loaded chitosan nanogels were prepared from the culture of corresponding cultures. The chitosan nanogels were previously characterized by Zetasizer, FTIR, and TEM. The prepared formulations' effectiveness and dressing activity were assessed by evaluating wound closure and histological trials in Sprague-Dawley rats. The results indicated that all probiotic lysate formulations have advantages over the wound healing process. However, Bacillus subtilis natto has a better wound healing quality, which is well known in pathology examination. The favorable effects of probiotic lysate nanogels, including the reasonable wound closing rate, good wound appearance, and satisfactory histological observation via in vivo examination, suggest it as a promising nominee for wound healing purposes.

Highly Sensitive Bacteria-Responsive Membranes Consisting of Core-Shell Polyurethane Polyvinylpyrrolidone Electrospun Nanofibers for In Situ Detection of Bacterial Infections

Bacteria responsive color-changing wound dressings offer a valuable platform for continuous monitoring of the wound bed facilitating early detection of bacterial infections. In this study, we present a highly sensitive electrospun nanofibrous polyurethane wound dressing incorporating a hemicyanine-based chromogenic probe with a labile ester linkage that can be enzymatically cleaved by bacterial lipase released from clinically relevant strains, such as Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA). A rapid chromogenic response was achieved by localizing the dye at the surface of core-shell fibers, resulting in a 5x faster response relative to conventional nanofibers. By incorporating polyvinylpyrrolidone (PVP) dopant in the shell, the sensitivity was boosted to enable detection of bacteria at clinically relevant concentrations after 2 h exposure: 2.5 × 10⁵ CFU/cm² P. aeruginosa and 1.0 × 10⁶ CFU/cm² MRSA. Introduction of PVP in the shell also boosted the degree of hydrolysis of the chromogenic probe by a factor of 1.2× after a 3 h exposure to a low concentration of P. aeruginosa (10⁵ CFU/cm²). PVP was also found to improve the discernibility of the color change at high bacterial concentrations. The co-operativity between the chromogenic probe, fiber structure, and polymer composition is well-suited for timely in situ detection of wound infection.

Evaluation of Probiotics for Warfighter Health and Performance

The probiotic industry continues to grow in both usage and the diversity of products available. Scientific evidence supports clinical use of some probiotic strains for certain gastrointestinal indications. Although much less is known about the impact of probiotics in healthy populations, there is increasing consumer and scientific interest in using probiotics to promote physical and psychological health and performance. Military men and women are a unique healthy population that must maintain physical and psychological health in order to ensure mission success. In this narrative review, we examine the evidence regarding probiotics and candidate probiotics for physical and/or cognitive benefits in healthy adults within the context of potential applications for military personnel. The reviewed evidence suggests potential for certain strains to induce biophysiological changes that may offer physical and/or cognitive health and performance benefits in military populations. However, many knowledge gaps exist, effects on health and performance are generally not widespread among the strains examined, and beneficial findings are generally limited to single studies with small sample sizes. Multiple studies with the same strains and using similar endpoints are needed before definitive recommendations for use can be made. We conclude that, at present, there is not compelling scientific evidence to support the use of any particular probiotic(s) to promote physical or psychological performance in healthy military personnel. However, plausibility for physical and psychological health and performance benefits remains, and additional research is warranted. In particular, research in military cohorts would aid in assessing the value of probiotics for supporting physical and psychological health and performance under the unique demands required of these populations.

Nanocoatings for Chronic Wound Repair-Modulation of Microbial Colonization and Biofilm Formation

Wound healing involves a complex interaction between immunity and other natural host processes, and to succeed it requires a well-defined cascade of events. Chronic wound infections can be mono- or polymicrobial but their major characteristic is their ability to develop a biofilm. A biofilm reduces the effectiveness of treatment and increases resistance. A biofilm is an ecosystem on its own, enabling the bacteria and the host to establish different social interactions, such as competition or cooperation. With an increasing incidence of chronic wounds and, implicitly, of chronic biofilm infections, there is a need for alternative therapeutic agents. Nanotechnology shows promising openings, either by the intrinsic antimicrobial properties of nanoparticles or their function as drug carriers. Nanoparticles and nanostructured coatings can be active at low concentrations toward a large variety of infectious agents; thus, they are unlikely to elicit emergence of resistance. Nanoparticles might contribute to the modulation of microbial colonization and biofilm formation in wounds. This comprehensive review comprises the pathogenesis of chronic wounds, the role of chronic wound colonization and infection in the healing process, the conventional and alternative topical therapeutic approaches designed to combat infection and stimulate healing, as well as revolutionizing therapies such as nanotechnology-based wound healing approaches.