Marco Toscano

Probiotics reduce gut microbial translocation and improve adult atopic dermatitis.

Background: It has been suggested that probiotics modulate atopic dermatitis (AD) progression, but no data are actually available on their mechanisms of action and on their ability to act as immunomodulators in this pathology. Objective: The aim of this randomized double-blinded active treatment versus placebo study was to evaluate clinical efficacy of an intake of a combination of 2 probiotics (Lactobacillus salivarius LS01 and Bifidobacterium breve BR03) for the treatment of adult AD patients. Methods: Forty-eight patients were enrolled in the study (randomization ratio 2:1) and treated with a combination (LS01 and BR03) or placebo (maltodextrin) for 12 weeks. Clinical efficacy was assessed from baseline by changes in the SCORAD index and DLQ index improvement. Analysis on the gut permeability barrier, immunologic parameters, and changes in fecal microbiota and recovery of probiotics were performed at baseline, at the end of therapy, and 2 months later. Results: Patients receiving probiotics showed a significant improvement in clinical parameters (SCORAD, P<0.0001 and DLQ index, P=0.021) from baseline. The probiotics reduced microbial translocation (P=0.050), immune activation (P<0.001), improved T-helper cell (Th)17/regulatory T cell (Treg) (P=0.029) and Th1/Th2 (P=0.028) ratios. None of these changes were observed in the placebo group. Conclusions: Our results suggest that this specific mixture of probiotics (LS01 and BR03 strains) may induce beneficial effects for clinical and immunologic alterations in adult AD. This combination could be considered as adjuvant therapy for the treatment of AD in adult patients.

Antibiofilm agents and implant-related infections in orthopaedics: where are we?

Abstract Orthopaedics is currently the largest market of biomaterials worldwide and implant-related infections, although relatively rare, remain among the first reasons for joint arthroplasty and osteosynthesis failure. Bacteria start implant infection by adhering to biomaterials and producing biofilms, which represent a major reason for bacterial persistence, in spite of antibiotic treatment and host’s defence. In the last two decades, a number of different antibiofilm agents have been studied and both in vitro and in vivo results appear now promising, even if their effective role in orthopaedics remains to be assessed. In this review, we introduce an original classification of antibiofilm agents, based on their mechanism of action and examine the available data concerning their possible application to orthopaedic implant-related infections. Molecules that interfere with biofilm production (biofilm prevention agents) include anti-adhesion compounds, quorum sensing inhibitors, non-steroideal anti-inflammatory drugs, and antimicrobial peptides; N-acetylcysteine and specific enzymes promise the greatest therapeutic possibilities by disrupting established biofilms (biofilm disrupting agents). The identification of antimicrobials able to bypass the biofilm barrier (biofilm bypassing agents), and antibiofilm vaccines are further strategies aimed to reduce the impact of biofilm-related infections, opening new pathways in controlling implant-related infections. However, this review shows that still insufficient knowledge is currently available as to regard the efficacy and safety of the investigated antibiofilm strategies to treat infection that involve bone tissue and biomaterials commonly implanted in orthopaedics, pointing out the need for further research in this promising field.

Cultivable and pyrosequenced fecal microflora in centenarians and young subjects

Goal: The aim of this study was to characterize the composition of the intestinal microbiota in healthy centenarians in comparison with younger adults, considering both quantitative and qualitative aspects of gut community structure. Background: The gut microbiota plays an essential role in human health. Toward seniority, its balance is affected by deep physiological changes. Long-lived people (age >90 y) have unusual features that differ from the younger elderly, so they should be considered separately when analyzing age-related features. However, they have been included in few studies and they have usually been grouped together with the younger elderly. Study: The gut microbiota of 14 centenarians and 10 younger adults was analyzed. Cultivable bacteria belonging to the following groups were enumerated: enterobacteriaceae, Enterococcus, Staphylococcus, Lactobacillus, Bifidobacterium, Clostridium, Bacteroides, and yeast. Lactobacilli and Bifidobacteria were further characterized at the species level by pyrosequencing. Results: In centenarians, we observed a reduction in the quantity of enterobacteriaceae, bifidobacteria, and bacteroides and an increase in clostridia sensu stricto (P<0.05). The number of Lactobacillus and Bifidobacterium species isolated in centenarians and younger adults was similar. The composition of the Lactobacillus subpopulation was quite different between the groups. The presence of Bifidobacterium longum in the gut seems to be a particular feature in centenarians. It is interesting to note that only 1 strain of B. longum was isolated from each centenarian subject. Conclusions: The gut microbiota of centenarians has particular features that differ from both younger adults and the younger elderly. Further studies would help to understand whether the intestinal microbiota can influence life expectancy and whether the administration of probiotic bacteria could help to extend the longevity of human life.

Changing of fecal flora and clinical effect of L. salivarius LS01 in adults with atopic dermatitis.

Goal: To evaluate cytokine stimulation with 3 strains of Lactobacillus salivarius in vitro and to assess changes in intestinal microflora and clinical improvements in adults with atopic dermatitis (AD) induced by the strain showing the best immunomodulatory features. Background: AD is a common skin disease in children and adults. It is characterized by chronic inflammation, eczema, and increasing intestinal permeability. Various studies have shown that patients with AD presented some modifications in the intestinal microbiota composition; as a result, intestinal microflora is thought to have a pivotal role in this disease. Methods: Thirty-eight patients aged from 18 to 46 years with moderate/severe AD were recruited. Subjects were randomized in a double-blind placebo-controlled study to receive active treatment with L. salivarius LS01: probiotic (n=19) or placebo (n=19). Cytokine production was determined by means of specific quantitative enzyme-linked immunosorbent assays. Intestinal bacterial groups were quantified using conventional culture techniques, whereas L. salivarius LS01 was identified using polymerase chain reaction and pulse field gel electrophoresis. Results: L. salivarius LS01 showed the best immunomodulatory features and it was chosen for the second phase of the study. AD subjects showed a reduction in their SCORAD score after probiotic treatment and a significant decrease in the staphylococci load compared with the placebo group. Moreover, L. salivarius LS01 showed the ability to reduce the production of Th2 cytokines, maintaining the production of Th1 cytokines stable. Conclusions: Treatment with the L. salivarius LS01 strain seems to positively modify clinical and immunologic status and dermatology life quality in a group of adults affected by moderate/severe AD, leading to a rebalancing of altered intestinal microbiota.

TPD-TPR-MS mechanistic study of the ammoxidation of 2-methylpyrazine over Sb-V-Mn-O catalyst

The setting up of a TPD-TPR-MS apparatus particularly suited to the study of the mechanisms of heterogeneous catalytic reactions is described. The system has been employed for the study of the ammoxidation of 2-methylpyrazine. The information collected showed that all the reactants and products except oxygen adsorb competitively on at least two types of site on the catalyst surface. From sites of the first type (the lower-energy sites) they desorb unaltered, while sites of the second type are higher-energy sites on which the reactants are activated both for the desired reaction to 2-cyanopyrazine and for the decomposition to by-products. Ammonia adsorbs also on a third type of site (very high-energy sites), which are able to activate the molecule for the oxidation to N2 and NOx Oxygen does not compete in adsorption with any of the other species. Very likely it dissolves in the solid, rapidly diffusing through the bulk and is involved in the reaction through a Mars-van Krevelen mechanism. A Rideal-Eley type of mechanism, with either oxygen or ammonia coming from the gas phase, seems not to be supported by the present results.

Preliminary results on clinical effects of probiotic Lactobacillus salivarius LS01 in children affected by atopic dermatitis.

Goals: The goal of this study was to evaluate the clinical efficacy of an intake of Lactobacillus salivarius LS01 (DSM 22775) for the treatment of atopic dermatitis (AD) in children. Background: AD is an inflammatory and pruritic chronic relapsing skin disorder with multifactorial etiopathology. Some evidence suggests that probiotics may improve AD by modulating the immune system and the composition of intestinal microbiota. Study: A total of 43 patients aged from 0 to 11 years were enrolled in the study (M/F ratio=1:1) and treated with the probiotic strain L. salivarius LS01. Clinical efficacy of probiotic treatment was assessed from baseline by changes in itch index and in the objective SCORAD/SCORAD index. Results: Patients being given probiotic treatment showed a significant improvement in clinical parameters (SCORAD and itch values) from baseline. The reduction in SCORAD and itch index observed after 4 weeks of treatment also persisted after the cessation of probiotic supplementation. Conclusions: L. salivarius LS01 seems to be able to improve the quality of life of children affected by AD and, as a consequence, it may have promising clinical and research implications.

Antimicrobial activity and resistance selection of different bioglass S53P4 formulations against multidrug resistant strains

AIMS This study aimed to evaluate the antimicrobial activity of two different formulations of bioglass BAG-S53P4 against multiresistant microorganisms involved in bone infections, and the capability of bioglass to select for resistance. METHODS Antibacterial activity was evaluated by means of killing curves. The ability to select for resistant bacteria was evaluated by subculturing microorganisms in serial dilutions of bioglass. Scanning electron microscope acquisitions were conducted to evaluate bioglass-induced morphology changes. RESULTS BAG-S53P4 formulations display a high antimicrobial activity and do not seem to select for resistance. Scanning electron microscopy analysis showed cell shrinkage and membrane damage after exposure to bioglass. CONCLUSIONS BAG-S53P4 has a significant potential as bone substitute for the treatment of infections caused by multiresistant microorganisms.

Immunomodulatory Effects of Lactobacillus salivarius LS01 and Bifidobacterium breve BR03, Alone and in Combination, on Peripheral Blood Mononuclear Cells of Allergic Asthmatics

The aim of this study was to evaluate probiotic characteristics of Lactobacillus salivarius LS01 and Bifidobacterium breve BR03 alone and in combination and their immunomodulatory activity in asthmatic subjects. Subjects affected by allergic asthma were recruited. Initially, LS01 and BR03 were analyzed for their growth compatibility by a broth compatibility assay. To study the antimicrobial activity of probiotic strains, an agar diffusion assay was performed. Finally, cytokine production by peripheral blood mononuclear cells (PBMCs) stimulated with LS01 and BR03 was determined by means of specific quantitative enzyme-linked immunosorbent assay (ELISA). The growth of some clinical pathogens were slightly inhibited by LS01 and LS01-BR03 co-culture supernatant not neutralized to pH 6.5, while only the growth of E. coli and S. aureus was inhibited by the supernatant of LS01 and LS01-BR03 neutralized to pH 6.5. Furthermore, LS01 and BR03 combination was able to decrease the secretion of proinflammatory cytokines by PBMCs, leading to an intense increase in IL-10 production. L. salivarius LS01 and B. breve BR03 showed promising probiotic properties and beneficial immunomodulatory activity that are increased when the 2 strains are used in combination in the same formulation.

Treatment of atopic dermatitis eczema with a high concentration of Lactobacillus salivarius LS01 associated with an innovative gelling complex: a pilot study on adults.

Goals: To evaluate the efficacy of a highly concentrated Lactobacillus salivarius preparation containing a gelling complex formed by Streptococcus thermophilus ST10 and tara gum in the treatment of atopic dermatitis (AD). Background: Previous studies have demonstrated an improvement in AD symptoms after administration of the probiotic strain L. salivarius LS01. S. thermophilus ST10 and tara gum create a gelling complex that adheres to intestinal mucus and improves barrier function. Study: A prospective, controlled pilot trial was carried out to evaluate how the association of S. thermophilus ST10 and tara gum could improve the activity of L. salivarius LS01 administered at high doses to adults with AD. Twenty-five patients were included into the study: 13 were treated for 1 month with the active formulation, whereas 12 represented the placebo group. Scoring Atopic Dermatitis index was determined before and at the end of probiotic administration. Fecal samples were also collected to evaluate changes in bacterial counts of Staphylococcus aureus and clostridia. Results: A significant improvement in SCORAD index was observed in the probiotic group after 1 month of treatment, whereas no significant changes occurred in placebo patients. A slight decrease in fecal S. aureus count was observed in probiotic-treated patients. Conclusions: Data obtained in this study suggest a potential role for L. salivarius LS01 in the treatment of AD. The addition of tara gum and S. thermophilus ST10 seems to improve the overall efficacy of the probiotic strain, in particular shortening the time required for the onset of the positive effects. Further studies to investigate the activity of this preparation are advisable.

Microbiota network and mathematic microbe mutualism in colostrum and mature milk collected in two different geographic areas: Italy versus Burundi

Human milk is essential for the initial development of newborns, as it provides all nutrients and vitamins, such as vitamin D, and represents a great source of commensal bacteria. Here we explore the microbiota network of colostrum and mature milk of Italian and Burundian mothers using the auto contractive map (AutoCM), a new methodology based on artificial neural network (ANN) architecture. We were able to demonstrate the microbiota of human milk to be a dynamic, and complex, ecosystem with different bacterial networks among different populations containing diverse microbial hubs and central nodes, which change during the transition from colostrum to mature milk. Furthermore, a greater abundance of anaerobic intestinal bacteria in mature milk compared with colostrum samples has been observed. The association of complex mathematic systems such as ANN and AutoCM adopted to metagenomics analysis represents an innovative approach to investigate in detail specific bacterial interactions in biological samples.