Beneficial effect of a diet containing heat-killed Lactobacillus paracasei K71 on adult type atopic dermatitis

The use of essential oils in atopic dermatitis: a review

Atopic dermatitis (AD) has become a common childhood disease that affects a large number of children worldwide and has become a chronic skin disease that causes huge economical and psychological damage to the whole family. Despite the use of steroids, immunosuppressants, and various topical preparation, the prognosis is still poor. Hence, this review aimed to explore the potential of using essential oils (EO) as an active ingredient in managing AD. The review was completed by using Pubmed, Scopus, and Medline to search for relevant articles that study the pathophysiology of AD, the properties of EO, the use of EO in managing AD, and the suitable advanced formulation to incorporate EO. From the review conducted, it was concluded that EO have huge potential in managing AD and can be used as complimentary therapeutic agents in AD treatment. Scientists and industries should venture into commercializing more topical products with EO to help manage AD more effectively.

Tropical postbiotics alleviate the disorders in the gut microbiota and kidney damage induced by ochratoxin A exposure

Ochratoxin A (OTA), commonly found in various foods, significantly impacts the health of humans and animals, especially their kidneys. Our study explores OTA's effects on the gut microbiota and kidney damage while examining how postbiotics offer protection. Using metagenomic sequencing, we observed that OTA increased the potential gut pathogens such as Alistipes, elevating detrimental metabolites and inflammation. Also, OTA inhibited the Nrf2/HO-1 pathway, reducing kidney ROS elimination and leading to cellular ferroptosis and subsequent kidney damage. Postbiotics mitigate OTA's effects by downregulating the abundance of the assimilatory sulfate reduction IV pathway and virulence factors associated with iron uptake and relieving the inhibition of OTA on Nrf2/HO-1, restoring ROS-clearing capabilities and thereby alleviating chronic OTA-induced kidney damage. Understanding the OTA-gut-kidney link provides new approaches for preventing kidney damage, with postbiotics showing promise as a preventive treatment.

Dietary Interventions in Atopic Dermatitis: A Comprehensive Scoping Review and Analysis

BACKGROUND

This scoping review aims to critically assess gaps in the current literature on atopic dermatitis (AD) by evaluating the overall effectiveness of dietary interventions. Through a comprehensive analysis that follows the Preferred Reporting Item for Systematic Review and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines, we conducted a thorough search on the Web of Science database in May 2023 using specific search strategies to identify all relevant studies on the research topic.

SUMMARY

A total of 104 full-text articles were included for review. Our synthesis identified seven notable categories of dietary interventions for AD, showcasing the diversity of interventions utilized. This includes vitamin supplementation, probiotic and prebiotic supplementation, dietary fat, biological compounds, foods from natural sources, major nutrients, and diet-related approaches. Further analyses stratified by targeted populations revealed a predominant focus on pediatrics, particularly in probiotic supplementation, and on adults, with an emphasis on vitamin D and E supplementation.

KEY MESSAGES

Despite most dietary interventions demonstrating overall effectiveness in improving AD severity and its subjective symptoms, several significant gaps were identified. There was a scarcity of studies on adults and whole-diet interventions, a prevalence of short-term interventions, heterogeneity in study outcomes, designs, and population, occasional disparity between statistical significance and clinical relevance, and a lack of a comprehensive multidisciplinary approach. Nonetheless, these findings offer valuable insights for future AD research, guiding additional evidence-driven dietary interventions and informing healthcare professionals, researchers, and individuals, advancing both understanding and management of AD.

Oral Postbiotics as a Therapeutic Strategy for Atopic Dermatitis: A Systematic Review of Randomized Controlled Trials

Atopic dermatitis (AD) is a prevalent chronic skin disease affecting all age groups. The connection with the gut microbiome led to oral probiotics as a therapeutic strategy. However, being viable microorganisms, probiotics might present risks. Thus, non-viable postbiotics have been considered as an alternative. We aimed to evaluate the efficacy of oral Lactobacillus postbiotics for managing symptoms of AD in pediatric and adult patients. A systematic review was conducted following PRISMA guidelines. Nine randomized controlled trials assessing the effects of non-viable Lactobacillus spp. administered orally to patients diagnosed with AD were included in the review, in which 512 subjects were evaluated after the intervention. Most studies allowed the concomitant usage of corticosteroids. Three studies focused on adults and indicated symptom improvement. In contrast, three out of six trials evaluating pediatric patients did not report postbiotics-favoring results. The dosage seems to be relevant for outcome determination. Two trials compared postbiotics with their viable analogs, and only one reported positive results in both groups. Postbiotics-associated shifts in gut microbial communities were reported in one trial. Mild adverse effects were detected by a single study. The overall results suggested that Lactobacillus postbiotics might be successfully used as adjuvant AD therapy in adults. Thus far, data do not indicate efficacy in pediatric patients. Standardizing nomenclatures and experimental procedures, as well as expanding the studies to more geographic locations and assessing comprehensively the effects on the gut microbiome would provide better perspectives of postbiotics as a therapeutic option for AD.

Postbiotic production: harnessing the power of microbial metabolites for health applications

Postbiotics, which are bioactive substances derived from the metabolic processes of beneficial microbes, have received considerable attention in the field of microbiome science in recent years, presenting a promising path for exploration and innovation. This comprehensive analysis looks into the multidimensional terrain of postbiotic production, including an extensive examination of diverse postbiotic classes, revealing their sophisticated mechanisms of action and highlighting future applications that might significantly affect human health. The authors thoroughly investigate the various mechanisms that support postbiotic production, ranging from conventional fermentation procedures to cutting-edge enzyme conversion and synthetic biology approaches. The review, as an acknowledgment of the field's developing nature, not only highlights current achievements but also navigates through the problems inherent in postbiotic production. In order to successfully include postbiotics in therapeutic interventions and the production of functional food ingredients, emphasis is given to critical elements, including improving yields, bolstering stability, and assuring safety. The knowledge presented herein sheds light on the expanding field of postbiotics and their potential to revolutionize the development of novel therapeutics and functional food ingredients.

Effects of probiotic supplementation in adult with atopic dermatitis: a systematic review with meta-analysis

BACKGROUND

Atopic dermatitis (AD) is one of the most common chronic inflammatory skin diseases. The effect of probiotic administration on the severity of AD in adults has shown inconsistent results.

OBJECTIVES

To determine the effectiveness of probiotic supplementation as a therapeutic tool for adult AD.

METHODS

PubMed, Scopus and Embase were systematically searched to collect data from studies in which probiotics were administered to treat adult AD.

RESULTS

Out of 413 publications, 9 papers were included in the meta-analysis. Significant differences in the ScORing Atopic Dermatitis tool favouring probiotics were observed [relative risk (RR) -5.93, 95% confidence interval (CI) -8.43 to -3.43]. Lactobacillus salivarius presented with largest effect size (RR -9.79, 95% CI -13.04 to -6.54), followed by L. acidophilus (RR -5.77, 95% CI -10.82 to -0.72) and L. plantarum (RR -3.76, 95% CI -6.36 to -1.16). No benefit was observed with L. fermentum. Based on the severity of AD, probiotics showed better results in people with moderate-to-severe AD (RR -9.12, 95% CI -12.17 to -6.08) than in individuals with mild disease (RR -2.67, 95% CI -4.67 to -0.66). Serum levels of IgE and eosinophil count remained significantly unchanged after the probiotic intervention (RR 0.25, 95% CI -0.10 to 0.60; RR -0.27, 95% CI -0.68 to 0.13, respectively).

CONCLUSIONS

Current evidence supports a role for some probiotics as a therapeutic tool for the treatment of adult AD, particularly in patients with severe AD. The efficacy of probiotics is strain specific, with L. salivarius and L. acidophilus having the largest clinical benefit. Such benefit is apparently independent of IgE levels and eosinophil count. Despite these encouraging results, the decrease in AD severity did not translate into a clinically meaningful better quality of life as assessed by the Dermatology Life Quality Index. There currently is not enough reliable data to reach conclusions about the optimal dose and duration for probiotic treatment.

Paraprobiotics: definition, manufacturing methods, and functionality

Probiotics are living microorganisms that are beneficial to the host, enhancing the immune response by promoting antibody production, regulating cytokine secretion, and stimulating T cells. However, probiotics have limitations in that they require viability control and have a short shelf life. Recently, the use of paraprobiotics has gained attention. These include dead bacterial cells, bacterial fractions, and cell lysate that have health benefits and are stable and safe for use. Paraprobiotics comprise molecules of bacterial cell wall compounds, such as peptidoglycans, teichoic acids, polysaccharides, and cell surface proteins. Paraprobiotics are manufactured by a diverse range of techniques, including thermal treatments, high pressure, ultraviolet rays, sonication, ionizing radiation, and pH modification. Their beneficial health effects include immunomodulatory, intestinal balancing, anticancer, and antimicrobial activities. Therefore, this review summarizes and discusses the manufacturing methods and bioavailability of paraprobiotics and suggests their potential health advantages.

Clinical Efficacy of Nutritional Supplements in Atopic Dermatitis: Systematic Review

BACKGROUND

Atopic dermatitis (AD), also known as eczema, is a chronic inflammatory skin condition that presents with symptoms of intense pruritus, dryness, and erythema. Dissatisfaction with first-line therapies for AD, the desire to avoid steroids, and the extreme cost of effective biologics have created a demand for alternative treatment options such as oral vitamins and nutritional supplements.

OBJECTIVE

The purpose of this review was to assess the effectiveness of oral nutritional supplements, pre- and probiotics, and vitamin deficiencies and supplements on AD symptomology and clinical course.

METHODS

We searched Scopus, PubMed, and MEDLINE (Ovid interface) for English-language articles published between 1993 and 2023. The final search was conducted on June 22, 2023. The search terms comprised the following: "(Atopic Dermatitis or Atopic Eczema) AND (supplement OR vitamin OR mineral OR micronutrients OR Fish Oil OR Omega Fatty Acid OR Probiotics OR Prebiotics OR apple cider vinegar OR collagen OR herbal OR fiber)."

RESULTS

A total of 18 studies-3 (17%) evaluating vitamins, 4 (22%) evaluating herbal medicine compounds, 2 (11%) evaluating single-ingredient nutritional supplements, and 9 (50%) evaluating pre- and probiotics-involving 881 patients were included in this review.

CONCLUSIONS

Overall, there is weak evidence to support any one nutritional supplement intervention for the alleviation of AD symptoms. Multiple trials (4/18, 22%) showed promise for supplements such as Zemaphyte, kefir, and freeze-dried whey with Cuscuta campestris Yuncker extract. The most evidence was found on the effectiveness of probiotics on the clinical course of AD. Lactiplantibacillus plantarum, Ligilactobacillus salivarius, and Lactobacillus acidophilus specifically showed evidence of efficacy and safety across multiple studies (6/18, 33%). However, larger, more extensive randomized controlled trials are needed to determine the true effectiveness of these supplements on the broader population.

TRIAL REGISTRATION

PROSPERO CRD42023470596; https://tinyurl.com/4a9477u7.

Efficacy of an adjuvant Lactobacillus rhamnosus formula in improving skin lesions as assessed by PASI in patients with plaque psoriasis from a university-affiliated, tertiary-referral hospital in São Paulo (Brazil): a parallel, double-blind, randomized clinical trial

Psoriasis is an inflammatory disease of the skin, characterized by erythematous plaques. It is rather common, affecting 2-4% of the population in western countries. Psoriasis' etiology encompasses both genetic and environmental factors. Evidence suggests that the latter reflect the importance of changes in the microbiome for developing the disease. Thus, it is hypothesized that gut microbiome manipulation may arise as a way of treating psoriasis. However, few trials assessed the use of probiotics in psoriasis, although promising results were detected in small studies. Our objective was to assess the efficacy of adjuvant probiotics (Lactobacillus rhamnosus) in treating plaque psoriasis patients. This was a randomized, parallel, placebo-controlled, double-blind trial with two arms: experimental (n = 50) and control (n = 53). Inclusion of subjects and data gathering lasted from November 2020 to August 2021. Subjects were consecutive plaque psoriasis patients under regular follow-up in the Dermatology unit of a university-affiliated, tertiary-referral hospital in São Paulo (Brazil). Eligibility criteria included being over 18 years old, having plaque psoriasis and not having other skin diseases, neoplasms nor systemic inflammatory diseases. Subjects received standard-of-care plus probiotics (Lactobacillus rhamnosus formula). Controls received standard-of-care plus placebo. Primary outcome was skin lesion improvement as assessed by psoriasis area of severity index (PASI) at six months. Secondary outcome was quality-of-life as assessed by dermatology life quality index (DLQI) at six months. Regarding within-group analyses, changes in both PASI and DLQI were non-significant for the experimental group (mean PASI decreased by 1.58, p = 0.105, and mean DLQI increased by 0.05, p = 0.873) and significant for controls (mean PASI decreased by 1.90, p = 0.019, and mean DLQI decreased by 3.33, p = 0.031). Between-group analyses returned non-significant results (p = 0.620). Our findings do not support the hypothesis that gut microbiome modulation via ingestion of Lactobacillus rhamnosus produces clinical improvement in psoriasis patients. Further research is encouraged.Trial registration: Retrospectively registered at the Brazilian Clinical Trials Registry (RBR-8js7t83) on 08/02/2022.

Lacticaseibacillus paracasei K71 Alleviates UVB-Induced Skin Barrier Dysfunction by Attenuating Inflammation via Increased IL-10 Production in Mice

SCOPE

Ultraviolet B (UVB) radiation causes skin barrier dysfunction, leading to decreased water-holding capacity, impaired epidermal barrier function, and increased skin thickness. This study investigates the protective effects of oral administration of Lacticaseibacillus paracasei K71 against skin barrier dysfunction in UVB-irradiated mice.

METHODS AND RESULTS

Mice are fed diets with or without K71 and irradiated with UVB three times a week for 12 weeks. Oral administration of K71 suppresses UVB-induced decrease in stratum corneum water content, mitigates the increase of transepidermal water loss, and decreases epidermal thickness of the dorsal skin. Treatment with K71 reverses the upregulation of inflammatory cytokines and the activation of nuclear factor-κB induced by UVB irradiation and upregulates the expression of anti-inflammatory IL-10 in the dorsal skin. Notable upregulation of IL-10 is observed in the spleens of K71-treated mice. K71 treatment enhances IL-10 production in J774.1 macrophages; however, this enhancement is diminished by inhibiting K71 phagocytosis and TLR3. Furthermore, transfection using K71 RNAs significantly increases IL-10 production.

CONCLUSION

These results indicate that K71 may alleviate UVB-induced skin barrier dysfunction by attenuating inflammation via increasing IL-10 production and that K71 RNAs may induce IL-10 production in macrophages. Therefore, K71 may be beneficial for preventing skin barrier dysfunction.

Combination of Lactobacillus plantarum improves the effects of tacrolimus on colitis in a mouse model

The gut microbiome has been considered to play an important role in inflammatory bowel disease (IBD). Our previous study reported that tacrolimus-altered gut microbiota elicited immunoregulatory effects in both colonic mucosa and circulation, contributing to an increased allograft survival rate in mice. Here, we aimed to observe the changes in the tacrolimus-induced microbiome in a dextran sulfate sodium (DSS)-induced colitis mouse model and explore the possibility and efficacy of combination therapy with tacrolimus and the microbiome on colitis. Mice were divided into the control, DSS, tacrolimus monotherapy and tacrolimus plus Lactobacillus plantarum 550 (Lacto)-treated groups. The body weight, stool consistency, hematochezia and survival of mice were observed daily. Total RNA from colonic mucosa was extracted and subjected to transcriptome sequencing. Cecal contents were collected and the 16S rRNA sequencing was performed to characterize the gut microbiome and the ultrahigh- performance liquid chromatography-MS/MS (UHPLC-MS/MS) was used for targeted quantification of bile acids. The results confirmed that tacrolimus significantly ameliorated DSS-induced colitis in mice. Beneficial alterations of the gut microbiome characterized by a remarkable expansion of the genus Lactobacillus were induced by tacrolimus treatment. Oral supplementation with Lacto further improved the tacrolimus-mediated suppression of body weight loss in colitis, while the survival time of mice was further prolonged and the inflammation of colonic mucosa was obviously relieved. The immune and inflammation-related signaling pathways, including IFN-γ and IFN-α response, allograft rejection, IL2 STAT5 signaling and the inflammatory response pathways, were further downregulated in the tacrolimus plus Lacto cotreatment group. Cotreatment also improved the diversity of the gut microbiome and rescued the concentration of taurochenodeoxycholic acid (TCDCA) in colitis. The latter was positively correlated with the abundance of Lactobacillus but negatively related to the disease activity index score. Overall, our results indicated that Lactobacillus plantarum promoted the therapeutic effect of tacrolimus in experimental colitis, offering a promising strategy to combine tacrolimus and Lactobacillus in the treatment of colitis patients.

Lactobacillus for the treatment and prevention of atopic dermatitis: Clinical and experimental evidence

Atopic dermatitis (AD) is a chronic inflammatory skin disease, accompanied by itching and swelling. The main pathological mechanism of AD is related to the imbalance between Type 2 helper cells (Th2 cells) and Type 1 helper cells (Th1 cells). Currently, no safe and effective means to treat and prevent AD are available; moreover, some treatments have side effects. Probiotics, such as some strains of Lactobacillus, can address these concerns via various pathways: i) facilitating high patient compliance; ii) regulating Th1/Th2 balance, increasing IL-10 secretion, and reducing inflammatory cytokines; iii) accelerating the maturation of the immune system, maintaining intestinal homeostasis, and improving gut microbiota; and iv) improving the symptoms of AD. This review describes the treatment and prevention of AD using 13 species of Lactobacillus. AD is commonly observed in children. Therefore, the review includes a higher proportion of studies on AD in children and fewer in adolescents and adults. However, there are also some strains that do not improve the symptoms of AD and even worsen allergies in children. In addition, a subset of the genus Lactobacillus that can prevent and relieve AD has been identified in vitro. Therefore, future studies should include more in vivo studies and randomized controlled clinical trials. Given the advantages and disadvantages mentioned above, further research in this area is urgently required.

An Altered Skin and Gut Microbiota Are Involved in the Modulation of Itch in Atopic Dermatitis

Skin and gut microbiota play an important role in the pathogenesis of atopic dermatitis (AD). An alteration of the microbiota diversity modulates the development and course of AD, e.g., decreased microbiome diversity correlates with disease severity, particularly in lesional skin of AD. Itch is a hallmark of AD with unsatisfying treatment until now. Recent evidence suggests a possible role of microbiota in altering itch in AD through gut-skin-brain interactions. The microbial metabolites, proinflammatory cytokines, and impaired immune response lead to a modulation of histamine-independent itch, disruption of epidermal barrier, and central sensitization of itch mechanisms. The positive impact of probiotics in alleviating itch in AD supports this hypothesis, which may lead to novel strategies for managing itchy skin in AD patients. This review summarizes the emerging findings on the correlation between an altered microbiota and gut-skin-brain axis in AD, especially in modulating itchy skin.

Immunomodulatory Effects of Bifidobacterium spp. and Use of Bifidobacterium breve and Bifidobacterium longum on Acute Diarrhea in Children

The intake of probiotic lactic acid bacteria not only promotes digestion through the microbiome regulated host intestinal metabolism but also improves diseases such as irritable bowel syndrome and inflammatory bowel disease, and suppresses pathogenic harmful bacteria. This investigation aimed to evaluate the immunomodulatory effects in intestinal epithelial cells and to study the clinical efficacy of the selected the Bifidobacterium breve and Bifidobacterium longum groups. The physiological and biochemical properties were characterized, and immunomodulatory activity was measured against pathogenic bacteria. In order to find out the mechanism of inflammatory action of the eight viable and sonicated Bifidobacterium spp., we tried to confirm the changes in the pro-inflammatory cytokines (TNF-α, interleukin (IL)-6, IL-12) and anti-inflammatory cytokine (IL-10), and chemokines, (monocyte chemoattractant protein-1, IL-8) and inflammatory enzymatic mediator (nitric oxide) against Enterococcus faecalis ATCC 29212 infection in Caco-2 cells and RAW 264.7 cells. The clinical efficacy of the selected B. breve and B. longum group was studied as a probiotic adjuvant for acute diarrhea in children by oral administration. The results showed significant immunomodulatory effects on the expression levels of TNF-α, IL-6, IL-12, MCP-1, IL-8 and NO, in sonicated Bifidobacterium extracts and viable bifidobacteria. Moreover, each of the Bifidobacterium strains was found to react more specifically to different cytokines. However, treatment with sonicated Bifidobacterium extracts showed a more significant effect compared to treatment with the viable bacteria. We suggest that probiotics functions should be subdivided according to individual characteristics, and that personalized probiotics should be designed to address individual applications.

Postbiotics: From emerging concept to application

The microbiome innovation has resulted in an umbrella term, postbiotics, which refers to non-viable microbial cells, metabolic byproducts and their microbial components released after lysis. Postbiotics, modulate immune response, gene expression, inhibit pathogen binding, maintain intestinal barriers, help in controlling carcinogenesis and pathogen infections. Postbiotics have antimicrobial, antioxidant, and immunomodulatory properties with favorable physiological, immunological, neuro-hormonal, regulatory and metabolic reactions. Consumption of postbiotics relieves symptoms of various diseases and viral infections such as SARS-CoV-2. Postbiotics can act as alternatives for pre-probiotic specially in immunosuppressed patients, children and premature neonates. Postbiotics are used to preserve and enhance nutritional properties of food, elimination of biofilms and skin conditioning in cosmetics. Postbiotics have numerous advantages over live bacteria with no risk of bacterial translocation from the gut to blood, acquisition of antibiotic resistance genes. The process of extraction, standardization, transport, and storage of postbiotic is more natural. Bioengineering techniques such as fermentation technology, high pressure etc., may be used for the synthesis of different postbiotics. Safety assessment and quality assurance of postbiotic is important as they may induce stomach discomfort, sepsis and/or toxic shock. Postbiotics are still in their infancy compared to pre- and pro- biotics but future research in this field may contribute to improved physiological functions and host health. The current review comprehensively summarizes new frontiers of research in postbiotics.

Heat-Killed Lacticaseibacillus paracasei Ameliorated UVB-Induced Oxidative Damage and Photoaging and Its Underlying Mechanisms

Ultraviolet B (UVB) radiation is a major environmental causative factor of skin oxidative damage and photoaging. Lacticaseibacillus paracasei is a well-known probiotic strain that can regulate skin health. The present study investigated the effects of heat-killed Lacticaseibacillus paracasei (PL) on UVB linked oxidative damage and photoaging in skin cells (Normal human dermal fibroblast (NHDF) cells and B16F10 murine melanoma cells). Results demonstrated that: (1) PL prevented UVB-induced cytotoxicity relating to decreased DNA damage in NHDF and B16F10 cells; (2) PL alleviated UVB-induced oxidative damage through increasing GSH content, as well as antioxidant enzyme activities and mRNA levels (except MnSOD activity and mRNA levels as well as CAT mRNA level) relating to the activation of Sirt1/PGC-1α/Nrf2 signaling in NHDF cells; (3) PL attenuated UVB-induced photoaging was noticed with a decrease in the percentage of SA-β-gal positive cells in NHDF cells model. Moreover, PL attenuated UVB-induced photoaging through exerting an anti-wrinkling effect by enhancing the type I collagen level relating to the inhibition (JNK, p38)/(c-Fos, c-Jun) of signaling in NHDF cells, and exerting an anti-melanogenic effect by suppressing tyrosinase and TYRP-1 activity and/or expressions relating to the inhibition of PKA/CREB/MITF signaling in B16F10 cells. In conclusion, PL could ameliorate UVB-induced oxidative damage and photoaging. Therefore, PL may be a potential antioxidant and anti-photoaging active ingredient for the cosmetic industry.

The role of probiotics in the treatment of adult atopic dermatitis: a meta-analysis of randomized controlled trials

Background

Atopic dermatitis (AD) is chronic inflammatory skin disease that is relapsing and a serious condition that disrupts the quality of life of affected individuals. Probiotics are an immunomodulator that can enhance the immune control of atopic dermatitis.

Methods

All randomized controlled trials of probiotics for the treatment of adult AD published before December 2020 were included in this study from the PubMed databases and manual searching.

Results

Six randomized controlled trials (n = 241) were selected for this meta-analysis study. Probiotics were effective in treating adult patients with AD, indicated by the decrease in Scoring Atopic Dermatitis/SCORAD (Mean Difference (MD)  − 7.90, 95% CI − 7.25 to − 6.92; p < 0.00001; I² = 96%) and improved quality of life (MD − 7.68, 95% CI − 14.08 to − 1.29; p = 0.02; I² = 47%) which were statistically significant. However, skin severity, itch severity, Dermatology Life Quality Index (DLQI), IL-4, TFN-γ, and IgE showed no significant difference in this meta-analysis study (p > 0.05).

Limitations

The study found no available data for side effects of probiotics.

Strength

This meta-analysis analyzed a total of 241 AD patients of Asian and European origin.

Conclusion

The use of probiotics decreased SCORAD significantly in adult patients with AD. Probiotics can improve the quality of life of patients with AD.

Capsule summary

The use of probiotics in atopic dermatitis has been widely studied, with controversial results. This meta-analysis suggests that the use of probiotics can improve SCORAD and the quality of life of patients with atopic dermatitis.

Beneficial Effect of Heat-Killed Lactiplantibacillus plantarum L-137 on Skin Functions in Healthy Participants: A Randomized, Placebo-Controlled, Double-Blind Study

To determine whether consuming heat-killed Lactiplantibacillus plantarum L-137 (HK L-137) influences skin functions, we performed a randomized, placebo-controlled, double-blind study in healthy participants who were conscious of dry skin. A total of 80 healthy participants (20 men, 60 women; mean age, 47.3 years) were assigned to receive a tablet containing HK L-137 or a placebo tablet daily for 12 weeks. Every 4 weeks, the skin water content and transepidermal water loss (TEWL) were measured at the forearm and face, and participants completed two skin-related questionnaires, the Dermatology Life Quality Index and a self-evaluation. The HK L-137 group tended to show greater increases from baseline of water content at the forearm and larger decreases of TEWL at the face. The total scores of both questionnaires improved significantly more in the HK L-137 group. Water content and TEWL improved significantly in participants in the HK L-137 group who were above the median age of study participants or had relatively dry skin. These findings suggest that daily HK L-137 intake can improve dry skin, thereby contributing to skin satisfaction.

The effect of probiotics on the clinical status of adult patients with atopic dermatitis: a systematic review

Objectives

To describe, through a literature review, the results and benefits of oral and topical probiotics for adult patients with atopic dermatitis.

Design

A systematic review of articles published over a 13-year period was conducted to answer the following questions: (1) what information is given in the scientific literature concerning the use of probiotics in adult patients with atopic dermatitis? (2) Was there an improvement in the clinical status of the patients? (3) Was there a change in the microbial profile in patients after using such approaches? (4) Among the probiotics used, which was the most used in adult AD patients? (5) What was the average time of these interventions? (6) What were the outcomes?

Results

Seven studies with different sample sizes, ranging from 16 to 109 patients, were included in this review. These studies were all clinical trials (7/7), and probiotics (7/7) was the model of intervention chosen. Probiotics showed a potential to relieve the symptoms of the study groups with a reduction of pruritus and SCORAD when compared to the placebo groups. However, their effectiveness varied according to the strain, period, and form of administration.

Conclusions

Many studies have demonstrated that probiotics improve the symptoms of atopic dermatitis and even its prevention. However, there is still much controversy and divergence concerning the real benefits. Despite this, probiotics have demonstrated a fair ability in improving AD adult patients’ symptoms in terms of decreasing pruritus and severity related to SCORAD.

The efficacy of probiotics supplementation for the treatment of atopic dermatitis in adults: a systematic review and meta-analysis

BACKGROUND

There is a lack of certain evidence for the therapeutic efficacy of probiotics for adult atopic dermatitis (AD).

METHODS

PubMed, EMBASE, and the Cochrane Database were searched for relevant studies, and randomized controlled trials of AD describing treatment with single/mixed probiotic therapy were included. Changes in outcomes were calculated by standard mean difference (SMD) and 95% confidence interval (CI). Relative efficacies of the probiotics were ranked by the surface under the cumulative ranking (SUCRA).

RESULTS

Nine studies with a total of 402 participants, including 208 AD patients who received probiotic treatments and 194 controls, were considered during the current analysis. A reduction in disease severity for probiotic supplementation compared to controls in both the short term (SMD: 0.63; 95% CI: 0.02-1.25) and the long term (SMD: 1.57; 95% CI: 0.66-2.49). There was a significant improvement in long-term quality of life after probiotic supplementation compared with controls (SMD: 0.74; 95% CI: 0.39-1.09). A mixture of L. salivarius (LS01) and Bifidobacterium (BR03) was found the highest probability of the best supplementation.

CONCLUSIONS

Probiotic supplementation decreases clinical severity and improves the quality of life among adult AD patients. The mixture of LS01 and BR03 appeared optimal.

Manipulating Microbiota to Treat Atopic Dermatitis: Functions and Therapies

Atopic dermatitis (AD) is a globally prevalent skin inflammation with a particular impact on children. Current therapies for AD are challenged by the limited armamentarium and the high heterogeneity of the disease. A novel promising therapeutic target for AD is the microbiota. Numerous studies have highlighted the involvement of the skin and gut microbiota in the pathogenesis of AD. The resident microbiota at these two epithelial tissues can modulate skin barrier functions and host immune responses, thus regulating AD progression. For example, the pathogenic roles of Staphylococcus aureus in the skin are well-established, making this bacterium an attractive target for AD treatment. Targeting the gut microbiota is another therapeutic strategy for AD. Multiple oral supplements with prebiotics, probiotics, postbiotics, and synbiotics have demonstrated promising efficacy in both AD prevention and treatment. In this review, we summarize the association of microbiota dysbiosis in both the skin and gut with AD, and the current knowledge of the functions of commensal microbiota in AD pathogenesis. Furthermore, we discuss the existing therapies in manipulating both the skin and gut commensal microbiota to prevent or treat AD. We also propose potential novel therapies based on the cutting-edge progress in this area.

Efficacy of Probiotics in Children and Adolescents With Atopic Dermatitis: A Randomized, Double-Blind, Placebo-Controlled Study

Objective

To evaluate the clinical efficacy of a mixture of probiotics (Lactobacillus and Bifidobacterium) in children and adolescents with atopic dermatitis (AD) and the effects on sensitization, inflammation, and immunological tolerance.

Methods

In this double-blind, randomized, placebo-controlled clinical trial, we enrolled 60 patients aged between 6 months and 19 years with mild, moderate, or severe AD, according to the criteria proposed by Hanifin and Rajka. Patients were stratified to receive one gram per day of probiotics or placebo for 6 months. The primary outcome was a decrease in SCORing Atopic Dermatitis (SCORAD). Secondary outcomes were to assess the role of probiotics on the use of topical and oral medicines (standard treatment), serum IgE levels, skin prick test (SPT), and tolerogenic and inflammatory cytokines. Background therapy was maintained.

Results

Forty patients completed the study (24 probiotics, 16 placebo). After treatment for six months, the clinical response was significantly better in the probiotics group; the SCORAD decreased [mean difference (MD) 27.69 percentage points; 95% confidence interval (CI), 2.44–52.94], even after adjustment for co-variables (MD 32.33 percentage points; 95%CI, 5.52–59.13), especially from the third month of treatment on. The reduction of the SCORAD in probiotic group persisted for three more months after the treatment had been discontinued, even after adjustment for co-variables (MD 14.24 percentage points; 95%CI, 0.78–27.70). Patients in the probiotics group required topical immunosuppressant less frequently at 6 and 9 months. No significant changes were found for IgE levels, SPT and cytokines.

Conclusions

Children and adolescents with AD presented a significant clinical response after 6 months with a mixture of probiotics (Lactobacillus rhamnosus, Lactobacillus acidophilus, Lactobacillus paracasei, and Bifidobacterium lactis. However, this clinical benefit is related to treatment duration. Probiotics should be considered as an adjuvant treatment for AD.

A Journey on the Skin Microbiome: Pitfalls and Opportunities

The human skin microbiota is essential for maintaining homeostasis and ensuring barrier functions. Over the years, the characterization of its composition and taxonomic diversity has reached outstanding goals, with more than 10 million bacterial genes collected and cataloged. Nevertheless, the study of the skin microbiota presents specific challenges that need to be addressed in study design. Benchmarking procedures and reproducible and robust analysis workflows for increasing comparability among studies are required. For various reasons and because of specific technical problems, these issues have been investigated in gut microbiota studies, but they have been largely overlooked for skin microbiota. After a short description of the skin microbiota, the review tackles methodological aspects and their pitfalls, covering NGS approaches and high throughput culture-based techniques. Recent insights into the "core" and "transient" types of skin microbiota and how the manipulation of these communities can prevent or combat skin diseases are also covered. Finally, this review includes an overview of the main dermatological diseases, the changes in the microbiota composition associated with them, and the recommended skin sampling procedures. The last section focuses on topical and oral probiotics to improve and maintain skin health, considering their possible applications for skin diseases.

Gut Microbiota, Probiotics, and Their Interactions in Prevention and Treatment of Atopic Dermatitis: A Review

Atopic dermatitis (AD) is a public health concern and is increasing in prevalence in urban areas. Recent advances in sequencing technology have demonstrated that the development of AD not only associate with the skin microbiome but gut microbiota. Gut microbiota plays an important role in allergic diseases including AD. The hypothesis of the “gut-skin” axis has been proposed and the cross-talk mechanism between them has been gradually demonstrated in the research. Probiotics contribute to the improvement of the intestinal environment, the balance of immune responses, regulation of metabolic activity. Most studies suggest that probiotic supplements may be an alternative for the prevention and treatment of AD. This study aimed to discuss the effects of probiotics on the clinical manifestation of AD based on gut microbial alterations. Here we reviewed the gut microbial alteration in patients with AD, the association between gut microbiota, epidermal barrier, and toll-like receptors, and the interaction of probiotics and gut microbiota. The potential mechanisms of probiotics on alleviating AD via upregulation of epidermal barrier and regulation of immune signaling had been discussed, and their possible effective substances on AD had been explored. This provides the supports for targeting gut microbiota to attenuate AD.

Clinical efficacy of spray-based heat-treated lactobacilli in canine atopic dermatitis: a preliminary, open-label, uncontrolled study

BACKGROUND

Canine atopic dermatitis (cAD) is a common inflammatory and pruritic skin disease, with various treatment options. The use of topical products containing natural ingredients has proven increasingly popular.

OBJECTIVE

To evaluate the effects of a spray solution containing heat-killed Lactobacillus rhamnosus and L. reuteri, on the clinical signs and cutaneous microbiota of atopic dogs.

ANIMALS

Ten privately owned, mildly affected, nonseasonally atopic dogs.

METHODS AND MATERIALS

The spray was applied to the ventrum every 24 h for 28 days. Clinical scores, skin barrier function and owner assessment were evaluated on day (D)0, D14, D28 and D42. The cutaneous microbiota was analysed on D0 and D28.

RESULTS

A reduction in the total clinical score was seen at each time point (D14, P = 0.03; D28, P = 0.04; D42, P = 0.001). A reduction in the regional clinical scores was seen after D28 (P = 0.01) and D42 (P = 0.003). A significant reduction in the pruritus score was seen on D42 (P = 0.01). A lower hydration value was seen on D28 (P = 0.02) and D42 (P = 0.02) on the pinnae. A good-to-excellent response and an easy-to-use administration was reported by owners. There were no significant changes in the cutaneous microbiota after 28 days.

CONCLUSIONS AND CLINICAL IMPORTANCE

There was a significant and rapid decrease in the clinical signs associated with cAD after use of the spray. Future larger, randomized, controlled studies are needed to confirm these results and to assess the effects on the cutaneous immunity and microflora of atopic dogs.

Rice flour fermented with Lactobacillus paracasei CBA L74 in the treatment of atopic dermatitis in infants: A randomized, double- blind, placebo- controlled trial

To assess the effect of a fermented rice-flour obtained from Lactobacillus paracasei CBA L74 in managing infants with moderate to severe atopic dermatitis. Infants with moderate to severe atopic dermatitis, aged 6-36 months, were randomly assigned to receive once-daily consumption of rice flour containing heat-killed probiotic Lactobacillus paracasei CBA L74 or placebo for 12 weeks as supplementary approach to topical treatment. Primary outcome was SCORAD index change from baseline to 12 weeks; secondary outcomes were gut microbiota composition, as evaluated by the analysis of fecal samples, and serum cytokines at baseline and at the end of the intervention period in both groups, and steroid usage over the treatment period and one month after stopping it. V3-V4 region of the 16S ribosomal RNA gene was sequenced to evaluate changes in the gut microbiota. SCORAD index decreased over the treatment period in both groups. The difference in the SCORAD change was -2.1 (-5.5 to 1.3; p = 0.223) for the experimental vs. the placebo group, not reaching the minimal clinical difference of 8.7 units. The use of topical steroids, measured as finger tips units, decreased from 4 to 16 weeks, in both groups; the reduction was significantly higher in experimental than in placebo group (p value from Wilcoxon rank sum test = 0.031). No significant differences were observed for cytokines levels between groups. The composition of gut microbiota at the phylum and class taxonomic levels resulted very similar, at baseline and after intervention, in both groups. Similarly, no significant differences were observed in the relative abundance of bacterial genera between groups. In conclusion, though the heat-killed Lactobacillus paracaseiwas not proved to be effective in reducing the severity of atopic dermatitis, it showed a steroid sparing effect the value of which needs to be further investigated.

A randomized trial of Lactobacillus rhamnosus IDCC 3201 tyndallizate (RHT3201) for treating atopic dermatitis

BACKGROUND

Probiotic therapies, mainly live bacteria, have been proven to be effective in treating atopic dermatitis (AD) with some controversies. Killed probiotics or postbiotics would have immunomodulatory effect in allergic diseases including AD. This study was performed to evaluate the therapeutic effect and safety of tyndallized Lactobacillus rhamnosus (IDCC 3201, isolated from the feces of a Korean breastfed infant, repeated heat-treated and incubated, RHT3201) in children with AD.

METHODS

In a randomized, double-blind, placebo-controlled study, RHT3201 at a dose of 1.0 × 10¹⁰  CPU/d or placebo was given in children (aged 1-12 years) with moderate AD for 12 weeks. SCORing of AD (SCORAD) scores, allergic inflammatory markers, and safety parameters were evaluated.

RESULTS

For evaluating the therapeutic effects of RHT3201, 33 subjects in each group were analyzed. The change of SCORAD total score at 12 weeks (primary outcome) from baseline was significantly greater in the RHT3201 group (-13.89 ± 10.05) compared to the control group (-8.37 ± 9.95). Levels of eosinophil cationic protein (ECP) and interleukin (IL)-31 showed tendency to decrease in the RHT3201 group and significant decreases in subgroup analysis in AD for ≥50 months. For safety analysis, a total of 100 subjects (50 in the treated group and 50 in the control group) were evaluated, and there were no significant differences in safety parameters between two groups.

CONCLUSION

In children with moderate AD, oral administration of RHT3201 showed the therapeutic effect on AD, the effects in part correlated with decrement of ECP and IL-31, and the effect was more remarkable in subgroup analysis.

Postbiotics and paraprobiotics: From concepts to applications

In recent years, new probiotic-related concepts such as postbiotics and paraprobiotics have been used to describe non-viable microorganisms or bacterial-free extracts that may provide benefits to the host by offering bioactivities additional to probiotics. However, several aspects related to these postbiotics and paraprobiotics bioactivities remain unexplored or are poorly understood. Therefore, the aim of this work is to provide an overview of the general aspects and emerging trends of postbiotics and paraprobiotics, such as conceptualization of terms, production, characterization, bioactivities, health-promoting effects, bioengineering approaches, and applications. In vitro and in vivo studies have demonstrated that some postbiotics and paraprobiotics exhibit bioactivities such as anti-inflammatory, immunomodulatory, anti-proliferative, antioxidant, and antimicrobial. These bioactivities could be involved in health-promoting effects observed in human and clinical trials, but despite the scientific evidence available, the mechanisms of action and the signaling pathways involved have not been fully elucidated. Nevertheless, paraprobiotics and postbiotics possess valuable potential for the development of biotechnological products with functional ingredients for the nutraceutical industry.

Probiotics with ameliorating effects on the severity of skin inflammation in psoriasis: Evidence from experimental and clinical studies

Experimental and clinical studies have confirmed safety and the medical benefits of probiotics as immunomodulatory medications. Recent advances have emphasized the critical effect of gastrointestinal bacteria in the pathology of inflammatory disorders, even, outside the gut. Probiotics have shown promising results for curing skin-influencing inflammatory disorders through modulating the immune response by manipulating the gut microbiome. Psoriasis is a complex inflammatory skin disease, which exhibits a microbiome distinct from the normal skin. In the present review, we considered the impact of gastrointestinal microbiota on the psoriasis pathogenesis, and through literature survey, attempted to explore probiotic species utilized for psoriasis treatment.

Impact of Nutritional Supplementation on Canine Dermatological Disorders

Nutritional supplements, also known as complementary feeds, are products administered with the aim of furnishing health benefits, regardless of nutritional needs. They have been used since ancient times in veterinary dermatology, and a number of studies have focused on investigating the health benefits of some ingredients found in commercially available complementary feed for dogs. The aim of this paper is to review the literature available on the use of nutritional supplementation for the management of canine skin diseases, critically appraising the clinical efficacy of such interventions and summarizing the current state of knowledge. This review highlights how these feeds can be considered useful in the management of dermatological disorders and outlines their beneficial effects in the prevention of dietary deficiencies and treatment of diseases, alone, or in addition to conventional pharmacological therapy. In recent years, nutritional supplements have found increasing potential application in veterinary medicine, and the scientific proofs of their beneficial effects are described in this review.

Postbiotics and Their Potential Applications in Early Life Nutrition and Beyond

Postbiotics are functional bioactive compounds, generated in a matrix during fermentation, which may be used to promote health. The term postbiotics can be regarded as an umbrella term for all synonyms and related terms of these microbial fermentation components. Therefore, postbiotics can include many different constituents including metabolites, short-chain fatty acids (SCFAs), microbial cell fractions, functional proteins, extracellular polysaccharides (EPS), cell lysates, teichoic acid, peptidoglycan-derived muropeptides and pili-type structures. Postbiotics is also a rather new term in the '-biotics' field. Where consensus exists for the definitions of pre- and probiotics, this is not yet the case for postbiotics. Here we propose a working definition and review currently known postbiotic compounds, their proposed mechanisms, clinical evidence and potential applications. Research to date indicates that postbiotics can have direct immunomodulatory and clinically relevant effects and evidence can be found for the use of postbiotics in healthy individuals to improve overall health and to relief symptoms in a range of diseases such as infant colic and in adults atopic dermatitis and different causes of diarrhea.

Pretreatment with a Heat-Killed Probiotic Modulates the NLRP3 Inflammasome and Attenuates Colitis-Associated Colorectal Cancer in Mice

Colorectal cancer (CRC) is one of the most common malignancies worldwide. Inflammation contributes to cancer development and inflammatory bowel disease is an important risk factor for CRC. The aim of this study is to assess whether a widely used probiotic Enterococcus faecalis can modulate the NLRP3 inflammasome and protect against colitis and colitis-associated CRC. We studied the effect of heat-killed cells of E. faecalis on NLRP3 inflammasome activation in THP-1-derived macrophages. Pretreatment of E. faecalis or NLRP3 siRNA can inhibit NLRP3 inflammasome activation in macrophages in response to fecal content or commensal microbes, P. mirabilis or E. coli, according to the reduction of caspase-1 activation and IL-1β maturation. Mechanistically, E. faecalis attenuates the phagocytosis that is required for the full activation of the NLRP3 inflammasome. In in vivo mouse experiments, E. faecalis can ameliorate the severity of intestinal inflammation and thereby protect mice from dextran sodium sulfate (DSS)-induced colitis and the formation of CRC in wild type mice. On the other hand, E. faecalis cannot prevent DSS-induced colitis in NLRP3 knockout mice. Our findings indicate that application of the inactivated probiotic, E. faecalis, may be a useful and safe strategy for attenuation of NLRP3-mediated colitis and inflammation-associated colon carcinogenesis.

Probiotics for treating eczema

BACKGROUND

Eczema is a common chronic skin condition. Probiotics have been proposed as an effective treatment for eczema; their use is increasing, as numerous clinical trials are under way. This is an update of a Cochrane Review first published in 2008, which suggested that probiotics may not be an effective treatment for eczema but identified areas in which evidence was lacking.

OBJECTIVES

To assess the effects of probiotics for treating patients of all ages with eczema.

SEARCH METHODS

We updated our searches of the following databases to January 2017: the Cochrane Skin Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), in the Cochrane Library, the Global Resource of Eczema Trials (GREAT) database, MEDLINE, Embase, PsycINFO, the Allied and Complementary Medicine Database (AMED), and Latin American Caribbean Health Sciences Literature (LILACS). We searched five trials registers and checked the reference lists of included studies and relevant reviews for further references to relevant randomised controlled trials (RCTs). We also handsearched a number of conference proceedings. We updated the searches of the main databases in January 2018 and of trials registries in March 2018, but we have not yet incorporated these results into the review.

SELECTION CRITERIA

Randomised controlled trials of probiotics (live orally ingested micro-organisms) compared with no treatment, placebo, or other active intervention with no probiotics for the treatment of eczema diagnosed by a doctor.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by Cochrane. We recorded adverse events from the included studies and from a separate adverse events search conducted for the first review. We formally assessed reporting bias by preparing funnel plots, and we performed trial sequential analysis for the first primary outcome - eczema symptoms at the end of active treatment.We used GRADE to assess the quality of the evidence for each outcome (in italic font).

MAIN RESULTS

We included 39 randomised controlled trials involving 2599 randomised participants. We included participants of either gender, aged from the first year of life through to 55 years (only six studies assessed adults), who had mild to severe eczema. Trials were undertaken in primary and secondary healthcare settings, mainly in Europe or Asia. Duration of treatment ranged from four weeks to six months, and duration of follow-up after end of treatment ranged from zero to 36 months. We selected no standard dose: researchers used a variety of doses and concentrations of probiotics. The probiotics used were bacteria of the Lactobacillus and Bifidobacteria species, which were taken alone or combined with other probiotics, and were given with or without prebiotics. Comparators were no treatment, placebo, and other treatments with no probiotics.For all results described in this abstract, the comparator was no probiotics. Active treatment ranged from six weeks to three months for all of the following results, apart from the investigator-rated eczema severity outcome, for which the upper limit of active treatment was 16 weeks. With regard to score, the higher the score, the more severe were the symptoms. All key results reported in this abstract were measured at the end of active treatment, except for adverse events, which were measured during the active treatment period.Probiotics probably make little or no difference in participant- or parent-rated symptoms of eczema (13 trials; 754 participants): symptom severity on a scale from 0 to 20 was 0.44 points lower after probiotic treatment (95% confidence interval (CI) -1.22 to 0.33; moderate-quality evidence). Trial sequential analysis shows that target sample sizes of 258 and 456, which are necessary to demonstrate a minimum mean difference of -2 and -1.5, respectively, with 90% power, have been exceeded, suggesting that further trials with similar probiotic strains for this outcome at the end of active treatment may be futile.We found no evidence suggesting that probiotics make a difference in QoL for patients with eczema (six studies; 552 participants; standardised mean difference (SMD) 0.03, 95% CI -0.36 to 0.42; low-quality evidence) when measured by the participant or the parent using validated disease-specific QoL instruments.Probiotics may slightly reduce investigator-rated eczema severity scores (24 trials; 1596 participants). On a scale of 0 to 103 for total Severity Scoring of Atopic Dermatitis (SCORAD), a score combining investigator-rated eczema severity score and participant scoring for eczema symptoms of itch and sleep loss was 3.91 points lower after probiotic treatment than after no probiotic treatment (95% CI -5.86 to -1.96; low-quality evidence). The minimum clinically important difference for SCORAD has been estimated to be 8.7 points.We noted significant to extreme levels of unexplainable heterogeneity between the results of individual studies. We judged most studies to be at unclear risk of bias; six studies had high attrition bias, and nine were at low risk of bias overall.We found no evidence to show that probiotics make a difference in the risk of adverse events during active treatment (risk ratio (RR) 1.54, 95% CI 0.90 to 2.63; seven trials; 402 participants; low-quality evidence). Studies in our review that reported adverse effects described gastrointestinal symptoms.

AUTHORS' CONCLUSIONS

Evidence suggests that, compared with no probiotic, currently available probiotic strains probably make little or no difference in improving patient-rated eczema symptoms. Probiotics may make little or no difference in QoL for people with eczema nor in investigator-rated eczema severity score (combined with participant scoring for eczema symptoms of itch and sleep loss); for the latter, the observed effect was small and of uncertain clinical significance. Therefore, use of probiotics for the treatment of eczema is currently not evidence-based. This update found no evidence of increased adverse effects with probiotic use during studies, but a separate adverse events search from the first review revealed that probiotic treatment carries a small risk of adverse events.Results show significant, unexplainable heterogeneity between individual trial results. Only a small number of studies measured some outcomes.Future studies should better measure QoL scores and adverse events, and should report on new probiotics. Researchers should also consider studying subgroups of patients (e.g. patients with atopy or food allergies, adults) and standardising doses/concentrations of probiotics given.

Human Microbiome: Composition and Role in Inflammatory Skin Diseases

This review focuses on recent evidences about human microbiome composition and functions, exploring the potential implication of its impairment in some diffuse and invalidating inflammatory skin diseases, such as atopic dermatitis, psoriasis, hidradenitis suppurativa and acne. We analysed current scientific literature, focusing on the current evidences about gut and skin microbiome composition and the complex dialogue between microbes and the host. Finally, we examined the consequences of this dialogue for health and skin diseases. This review highlights how human microbes interact with different anatomic niches modifying the state of immune activation, skin barrier status, microbe-host and microbe-microbe interactions. It also shows as most of the factors affecting gut and skin microorganisms' activity have demonstrated to be effective also in modulating chronic inflammatory skin diseases. More and more evidences demonstrate that human microbiome plays a key role in human health and diseases. It is to be expected that these new insights will translate into diagnostic, therapeutic and preventive measures in the context of personalized/precision medicine.

New lactic acid bacteria for skin health via oral intake of heat-killed or live cells

Lactic acid bacteria play an essential role in the food industry in the manufacture of many fermented products (cheese, yogurt, fermented vegetables, etc.). Application of these organisms is now being extended to the area of health improvement, as their probiotic activities become known. Probiotics are defined as viable microorganisms that exert a beneficial effect on the health of the host when they are ingested in sufficient quantity. Lactic acid bacteria and bifidobacteria isolated from the human intestine are the most common probiotics used for human consumption. The development of new probiotics with new beneficial effects is eagerly awaited in the food industry. This review introduces Lactococcus, which are one of the genera of lactic acid bacteria and are mainly isolated from dairy products and fermented vegetables, as new probiotics, focusing especially on Lactococcus lactis H61, which improves skin status in Japanese women with oral intake of heat‐killed or live cells. The deduced mechanisms associated with the beneficial effects of strain H61 are also discussed.

Whether viable and dead probiotic are equally efficacious?

Purpose

Consumer inclination towards probiotic foods has been stimulated due to well-documented evidence of health benefits of probiotic-containing products and consumer demand for natural products. It is assumed that the viability and metabolic activities of probiotics are essential for extending health benefits and for successful marketing of probiotics as a functional food. The purpose of this paper is to demonstrate that even dead or inactivated probiotic cells could extend health benefits, indicating that probiotic viability is not always necessary for exhibiting health benefits.

Design/methodology/approach

Attempt has been made to review the literature on the status of probiotic foods available in the world market, their impact on the gut flora and the various factors affecting their viability. Both review and research papers related to efficacy of inactivated, killed or dead probiotic cells towards health benefits have been considered. Keywords used for data search included efficacy of viable or killed, inactivated probiotic cells.

Findings

The reviewed literature indicated that inactivated, killed or dead probiotic cells also possess functional properties but live cells are more efficacious. All live probiotic cultures are not equally efficacious, and accordingly, dead or inactivated cells did not demonstrate functional properties to extend health benefits to all diseases.

Originality/value

Capability of non-viable microorganisms to confer health benefits may attract food manufacturers owing to certain advantages over live probiotics such as longer shelf-life, handling and transportation and reduced requirements for refrigerated storage and inclusion of non-bacterial, biologically active metabolites present in fermented milks’ fraction as dried powders to food matrixes may result in the development of new functional foods.

Effects of heat-killed <i>Lactobacillus casei</i> subsp. <i>casei</i> 327 intake on defecation in healthy volunteers: a randomized, double-blind, placebo-controlled, parallel-group study

Lactobacillus casei subsp. casei 327 (L. casei 327) was isolated from brown rice. A preliminary study showed that intake of 50 mg of heat-killed L. casei 327 is effective in improving defecation. In this study, we conducted a randomized, double-blind, placebo-controlled, parallel-group trial to investigate the effect of intake of heat-killed L. casei 327 (25 mg: approximately 5 × 10¹⁰ bacteria) on defecation in healthy volunteers with relatively low defecation frequencies. We selected 104 healthy Japanese adults with relatively low defecation frequencies (approximately 3–5 times a week) by screening and pretrial tests. Subjects (n=52 in each group) were randomly given a tablet containing L. casei 327 (group A) or a placebo tablet (group P) daily for 2 weeks. After eliminating data for 9 subjects who met the exclusion criteria for efficacy analysis, data for 95 subjects were analyzed. The defecation frequency and number of defecation days during the intake period and their changes from the pretrial period were significantly higher in group A than in group P. The fecal volume during the intake period was higher in group A than group P, but the difference was not statistically significant. However, the change from the pretrial period was significantly higher in group A than in group P. There were no significant differences between groups in the values of fecal shape, color, odor, and feeling after defecation. These results suggested that intake of L. casei 327 improves defecation in healthy adults who have relatively low defecation frequencies.

Probiotics, Prebiotics, and Synbiotics for the Treatment and Prevention of Adult Dermatological Diseases

BACKGROUND

Probiotic, prebiotic, and synbiotic supplementation is becoming more prevalent nowadays. Clinical studies have demonstrated some of the medical benefits of probiotics, prebiotics, and synbiotics within dermatology but an evidence-based review of their effects in adults is needed.

OBJECTIVE

The aim of this study was to identify evidence for the use of supplementation with probiotics, prebiotics, or synbiotics for the prevention and treatment of dermatological diseases in adults.

DATA SOURCES

We conducted a search of the Ovid MEDLINE, Cochrane Central Register of Controlled trials and EMBASE electronic databases from 1 January 1946 to 11 January 2017.

STUDY SELECTION

Trials examining supplementation in the treatment of dermatological diseases using oral or topical probiotics, synbiotics, and prebiotics in adults over the age of 18 years were selected.

DATA EXTRACTION

Of 315 articles, 12 met the inclusion criteria.

DATA SYNTHESIS

Nutritional supplementation with probiotics and prebiotics was shown to improve atopic dermatitis (AD) symptomatology, quality of life, or clinical severity in six of nine studies. One study in psoriasis was shown to improve inflammatory markers, and one study suggested that probiotics could be used as adjunctive therapy in the treatment of acne.

CONCLUSION

Preliminary studies are optimistic for the use of some strains of probiotics for symptomatic and clinical improvement in AD, and as adjunctive treatment with antibiotics for acne. Further research is necessary to better assess how probiotics and prebiotics may be used within dermatology.

Skin-gut axis: The relationship between intestinal bacteria and skin health

The gut microbiome is an emerging area of interest in medicine. Imbalances in the gut microbiome have been linked to a number of disease states such as obesity and type 2 diabetes. The relationship between normally residing intestinal bacteria (the gut microbiota) and their potential role in the pathogenesis of skin diseases is an area of research for which we are only beginning to understand. Small studies have demonstrated underlying changes in the gut microbiome of patients with certain dermatological diseases. Interestingly, studies suggest that probiotics may have a role in the treatment of atopic dermatitis. However, the concept of the “skin-gut axis” is a newly emerging and important avenue of investigation, still lacking in pathobiological explanations. This review will introduce and describe the intestinal microbiome as it relates to skin health in a complex communication network between the immune system, endocrine system, metabolic system, and nervous system.

Is there a role for modified probiotics as beneficial microbes: a systematic review of the literature

Our objective was to conduct a systematic review and meta-analysis for the use of modified (heat-killed or sonicated) probiotics for the efficacy and safety to prevent and treat various diseases. Recent clinical research has focused on living strains of probiotics, but use in high-risk patients and potential adverse reactions including bacteremia has focused interest on alternatives to the use of live probiotics. We searched MEDLINE/PubMed, Embase, Cochrane Central Register of Controlled Trials, CINAHL, Alt Health Watch, Web of Science, Scopus, PubMed, from inception to February 14, 2017 for randomised controlled trials involving modified probiotic strains. The primary outcome was efficacy to prevent or treat disease and the secondary outcome was incidence of adverse events. A total of 40 trials were included (n=3,913): 14 trials (15 arms with modified probiotics and 20 control arms) for the prevention of diseases and 26 trials (29 arms with modified probiotics and 32 control arms) for treatment of various diseases. Modified microbes were compared to either placebo (44%), or the same living probiotic strain (39%) or to only standard therapies (17%). Modified microbes were not significantly more or less effective than the living probiotic in 86% of the preventive trials and 69% of the treatment trials. Modified probiotic strains were significantly more effective in 15% of the treatment trials. Incidence rates of adverse events were similar for modified and living probiotics and other control groups, but many trials did not collect adequate safety data. Although several types of modified probiotics showed significant efficacy over living strains of probiotics, firm conclusions could not be reached due to the limited number of trials using the same type of modified microbe (strain, daily dose and duration) for a specific disease indication. Further research may illuminate other strains of modified probiotics that may have potential as clinical biotherapeutics.

Anti-inflammatory potential of a heat-killed Lactobacillus strain isolated from Kimchi on house dust mite-induced atopic dermatitis in NC/Nga mice

AIMS

Atopic dermatitis (AD) is an allergic skin disease driven by the Th2-prone immune response. Therefore, a fundamental approach to restoring the Th1/Th2 balance is needed to treat AD.

METHODS AND RESULTS

Eighteen different Lactobacillus strains isolated from Kimchi were screened to identify those that stimulated immune cells to secret Th1-type or Th2-type cytokines. Lactobacillus brevis NS1401 induced the greatest IFN-γ and IL-12 secretion and the least IL-4 production among the tested Lactobacillus strains. Furthermore, oral administration of heat-killed NS1401 ameliorated the symptoms of dust mite-induced AD in NC/Nga mice by decreasing the serum IgE level and reducing the number of mast cells and eosinophils in lesions. Also, the size and number of cells in the draining lymph nodes of NS1401-administered mice were significantly reduced. In agreement with these results, secretion of a Th1-type cytokine (IFN-γ) and allergen-specific IgG2a were increased, whereas secretion of Th2-type cytokines (IL-4, IL-5, and IL-10) and allergen-specific IgG1 were decreased upon administration of NS1401 in mice.

CONCLUSIONS

Lactobacillus brevis NS1401 alleviates the symptoms of AD by restoring the Th1/Th2 balance through enhancing Th1-prone immunity.

SIGNIFICANCE AND IMPACT OF THE STUDY

The immunomodulatory function of L. brevis NS1401 may provide effective new therapeutics against AD.

Effects of intake of Lactobacillus casei subsp. casei 327 on skin conditions: a randomized, double-blind, placebo-controlled, parallel-group study in women

Lactic acid bacteria are gut flora that play key roles in intestinal homeostasis, which may affect a variety of physiological functions. Our preliminary double-blind, placebo-controlled, parallel-group trials have suggested that intake of heat-killed Lactobacillus casei subsp. casei 327 (designated L. K-1) is effective for improving skin conditions. The aim of this study was to confirm the effect of L. K-1 intake in a randomized, double-blind, placebo-controlled, parallel-group study in healthy female volunteers. Sixty-four subjects were allocated to either the placebo food group (group P, n=32) or active food group (group A, n=32), in which subjects consumed lactobacillus K-1 50 mg (approximately 1 × 10¹¹ bacteria) daily for 8 weeks. After excluding subjects who declined to participate (n=1), violated restrictions (n=4), or were judged ineligible by the principal investigators (n=1), data obtained with 58 subjects (30 in group A and 28 in group P) were analyzed for efficacy by comparing differences from pretrial levels between the two groups. When the level of transepidermal water loss (TEWL) was measured at the arm, the level of TEWL at week 4 of the intake period was significantly lower in group A than group P (p=0.021), suggesting an improvement of skin barrier function. Analysis of skin condition questionnaire data revealed a significant reduction in skin flakiness on the face (week 4). No adverse events were associated with intake of the test foods. The safety of L. K-1 was also confirmed in an independent open-label trial in 11 healthy subjects who consumed excessive amounts of L. K-1 250 mg (approximately 5 × 10¹¹ bacteria). Intake of L. K-1 may therefore be beneficial to skin condition improvement.

Pretreatment with a heat-killed probiotic modulates monocyte chemoattractant protein-1 and reduces the pathogenicity of influenza and enterovirus 71 infections

It has been proposed that inactivated probiotics may modulate the host immune system and contribute to mitigation of viral infections. This study demonstrated that administration of heat-killed Enterococcus faecalis, a widely used probiotic, can protect host animals against viral infections. The influenza-mediated morbidity and lung inflammation in E. faecalis-treated mice decreased significantly compared with those of the control mice. Furthermore, we found that the protection is associated with production of monocyte chemoattractant protein-1 (MCP-1). The intratracheal injection of a recombinant mouse MCP-1 protein abrogated the antiviral effects elicited by pretreatment with E. faecalis. CC chemokine receptor 2 (CCR2) is a receptor for MCP-1, and the intraperitoneal administration of a CCR2 antagonist effectively inhibited viral pathogenicity. The reduced pathogenicity was also observed in CCR2-deficient mice. Finally, E. faecalis significantly attenuated neuropathogenicity induced by another RNA virus, enterovirus 71. This study demonstrates that killed probiotics can reduce viral disease severity and identify that the MCP-1 pathway might act as a key mediator in the improved antiviral immune response. Our findings suggest that MCP-1 and its related signaling pathway can serve as critical therapeutic targets for development of new antiviral strategies.

Randomized, double-blind, placebo-controlled, parallel-group study of the effect of Lactobacillus paracasei K71 intake on salivary release of secretory immunoglobulin A

Lactobacillus paracasei K71 was shown to be effective in alleviating the severity of atopic dermatitis in a randomized controlled trial, and a preliminary open-label trial suggested that strain K71 intake enhanced secretory immunoglobulin A (sIgA) release in the saliva. This study investigated the effect of K71 on sIgA release in a randomized, double-blind, placebo-controlled, parallel-group trial. The trial included 62 Japanese subjects aged 20–64 years with relatively low rates of salivary sIgA release. Subjects (n=31 in each group) were randomly given a tablet containing 100 mg (approximately 2 × 10¹¹ bacteria) of K71 or a placebo tablet daily for 12 weeks. After eliminating data for eight subjects (four in each group) who met the exclusion criteria for efficacy analysis, data for 54 subjects were analyzed. The change in the rate of salivary sIgA release 8 weeks after initiation of the study compared with baseline was significantly higher in the K71 tablet group (105.5 ± 119.0 µg/min) than in the placebo group (52.7 ± 62.6 µg/min; p=0.047). There were no adverse events associated with intake of tablets containing K71. The safety of intake of L. paracasei K71 was also confirmed in an independent open-label trial with 20 healthy subjects who consumed excessive amounts of K71-containing food. L. paracasei K71 intake may therefore have some benefits in promoting mucosal immune function.

Anti-inflammatory effects of Lactobacillus brevis K65 on RAW 264.7 cells and in mice with dextran sulphate sodium-induced ulcerative colitis

Lactic acid bacteria (LAB) with anti-inflammatory effects may be beneficial to the prevention or treatment for inflammation-related diseases, such as inflammatory bowel diseases. In an in vitro assay, heat-killed Lactobacillus brevis K65 (K65) reduced lipopolysaccharide-induced production of nitric oxide, tumour necrosis factor (TNF)-α and prostaglandin E2 in RAW 264.7 cells. In RAW 264.7 cells stably expressing an ind=ucible nitric oxide synthase (iNOS) reporter, viable K65 showed greater inhibition of iNOS production than its heat-killed form. In order to further examine the in vivo anti-inflammatory effect of K65, viable K65 was orally administered to BALB/c mice before and during the period of dextran sulphate sodium (DSS)-induced ulcerative colitis (UC). K65 improved UC symptoms, including reduced the levels of the pro-inflammatory cytokines, TNF-α, interleukin (IL)-6 and IL-1β, and lowered the activity of myeloperoxidase. Furthermore, K65 inhibited TNF-α, cyclo-oxygenase 2, forkhead box P3, and Toll-like receptor 4 mRNA expression in the colonic tissue of DSS-induced UC mice. Taken together, K65, a LAB with in vitro anti-inflammatory activity showed preventive effects on mice with DSS-induced UC by lowering the expression of inflammatory molecules.