Neutrophil Interaction with Emerging Oral Pathogens: A Novel View of the Disease Paradigm.

Periodontitis is a multifactorial chronic inflammatory infectious disease that compromises the integrity of tooth-supporting tissues. The disease progression depends on the disruption of host-microbe homeostasis in the periodontal tissue. This disruption is marked by a shift in the composition of the polymicrobial oral community from a symbiotic to a dysbiotic, more complex community that is capable of evading killing while promoting inflammation. Neutrophils are the main phagocytic cell in the periodontal pocket, and the outcome of the interaction with the oral microbiota is an important determinant of oral health. Novel culture-independent techniques have facilitated the identification of new bacterial species at periodontal lesions and induced a reappraisal of the microbial etiology of periodontitis. In this chapter, we discuss how neutrophils interact with two emerging oral pathogens, Filifactor alocis and Peptoanaerobacter stomatis, and the different strategies deploy by these organisms to modulate neutrophil effector functions, with the goal to outline a new paradigm in our knowledge about neutrophil responses to putative periodontal pathogens and their contribution to disease progression.

Development of an aerosolized Mannheimia haemolytica experimental pneumonia model in clean-catch colostrum-deprived calves.

Mannheimia haemolytica is an important cause of bovine respiratory disease (BRD). BRD is usually a multifactorial disease with host factors and viral infections influencing pathogenesis. Previous studies that have attempted to experimentally induce pneumonia using aerosolized M. haemolytica alone have produced inconsistent results, yet an aerosol model would be useful to study the details of early infection and to investigate the role of innate defences in pathogenesis. The objective of these studies was to develop and characterize an aerosolized M. haemolytica disease model. In an initial study, conventionally raised calves with higher levels of antibody against M. haemolytica leukotoxin developed acute respiratory distress and diffuse alveolar damage, but did not develop bronchopneumonia, following challenge with M. haemolytica serotype 1. Clean-catch colostrum-deprived calves challenged with 1 × 1010 colony forming units of M. haemolytica serotype 1 consistently developed bronchopneumonia, with elevations in rectal temperature, serum haptoglobin, plasma fibrinogen, and blood neutrophils. Mannheimia haemolytica serotype 1 was consistently isolated from the nasal cavities and lungs of challenged calves. Despite distribution of aerosol and isolation of M. haemolytica in all lung lobes, gross lesions were mainly observed in the cranioventral area of lung. Gross and histologic lesions included neutrophilic bronchopneumonia and fibrinous pleuritis, with oat cells (necrotic neutrophils with streaming nuclei), and areas of coagulative necrosis, which are similar to lesions in naturally occurring BRD. Thus, challenge with M. haemolytica serotype 1 and use of clean-catch colostrum-deprived calves with low or absent antibody titres allowed development of an effective aerosol challenge model that induced typical clinical disease and lesions.

Livestock abundance predicts vampire bat demography, immune profiles and bacterial infection risk.

Human activities create novel food resources that can alter wildlife-pathogen interactions. If resources amplify or dampen, pathogen transmission probably depends on both host ecology and pathogen biology, but studies that measure responses to provisioning across both scales are rare. We tested these relationships with a 4-year study of 369 common vampire bats across 10 sites in Peru and Belize that differ in the abundance of livestock, an important anthropogenic food source. We quantified innate and adaptive immunity from bats and assessed infection with two common bacteria. We predicted that abundant livestock could reduce starvation and foraging effort, allowing for greater investments in immunity. Bats from high-livestock sites had higher microbicidal activity and proportions of neutrophils but lower immunoglobulin G and proportions of lymphocytes, suggesting more investment in innate relative to adaptive immunity and either greater chronic stress or pathogen exposure. This relationship was most pronounced in reproductive bats, which were also more common in high-livestock sites, suggesting feedbacks between demographic correlates of provisioning and immunity. Infection with both Bartonella and haemoplasmas were correlated with similar immune profiles, and both pathogens tended to be less prevalent in high-livestock sites, although effects were weaker for haemoplasmas. These differing responses to provisioning might therefore reflect distinct transmission processes. Predicting how provisioning alters host-pathogen interactions requires considering how both within-host processes and transmission modes respond to resource shifts.This article is part of the theme issue 'Anthropogenic resource subsidies and host-parasite dynamics in wildlife'.

Extremely high-frequency electromagnetic radiation enhances neutrophil response to particulate agonists.

The growing use of extremely high-frequency electromagnetic radiation (EHF EMR) in information and communication technology and in biomedical applications has raised concerns regarding the potential biological impact of millimeter waves (MMWs). Here, we elucidated the effects of MMW radiation on neutrophil activation induced by opsonized zymosan or E. coli in whole blood ex vivo. After agonist addition to blood, two samples were prepared. A control sample was incubated at ambient conditions without any treatment, and a test sample was exposed to EHF EMR (32.9-39.6 GHz, 100 W/m2 ). We used methods that allowed us to assess the functional status of neutrophils immediately after exposure: oxidant production levels were measured by luminol-dependent chemiluminescence, and morphofunctional changes to neutrophils were observed in blood smears. Results revealed that the response of neutrophils to both agonists was intensified if blood was exposed to MMW radiation for 15 min. Neutrophils were intact in both the control and irradiated samples if no agonist was added to blood before incubation. Similarly, exposing suspensions of isolated neutrophils in plasma to MMW radiation enhanced cell response to both zymosan and E. coli. Heating blood samples was shown to be the primary mechanism underlying enhanced EHF EMR-induced oxidant production by neutrophils in response to particulate agonists. Bioelectromagnetics. 39:144-155, 2018. © 2017 Wiley Periodicals, Inc.

Cytosolic Phospholipase A2α Promotes Pulmonary Inflammation and Systemic Disease during Streptococcus pneumoniae Infection.

Pulmonary infection by Streptococcus pneumoniae is characterized by a robust alveolar infiltration of neutrophils (polymorphonuclear cells [PMNs]) that can promote systemic spread of the infection if not resolved. We previously showed that 12-lipoxygenase (12-LOX), which is required to generate the PMN chemoattractant hepoxilin A3 (HXA3) from arachidonic acid (AA), promotes acute pulmonary inflammation and systemic infection after lung challenge with S. pneumoniae As phospholipase A2 (PLA2) promotes the release of AA, we investigated the role of PLA2 in local and systemic disease during S. pneumoniae infection. The group IVA cytosolic isoform of PLA2 (cPLA2α) was activated upon S. pneumoniae infection of cultured lung epithelial cells and was critical for AA release from membrane phospholipids. Pharmacological inhibition of this enzyme blocked S. pneumoniae-induced PMN transepithelial migration in vitro Genetic ablation of the cPLA2 isoform cPLA2α dramatically reduced lung inflammation in mice upon high-dose pulmonary challenge with S. pneumoniae The cPLA2α-deficient mice also suffered no bacteremia and survived a pulmonary challenge that was lethal to wild-type mice. Our data suggest that cPLA2α plays a crucial role in eliciting pulmonary inflammation during pneumococcal infection and is required for lethal systemic infection following S. pneumoniae lung challenge.

Bispecific antibody targets multiple Pseudomonas aeruginosa evasion mechanisms in the lung vasculature.

Pseudomonas aeruginosa is a major cause of severe infections that lead to bacteremia and high patient mortality. P. aeruginosa has evolved numerous evasion and subversion mechanisms that work in concert to overcome immune recognition and effector functions in hospitalized and immunosuppressed individuals. Here, we have used multilaser spinning-disk intravital microscopy to monitor the blood-borne stage in a murine bacteremic model of P. aeruginosa infection. P. aeruginosa adhered avidly to lung vasculature, where patrolling neutrophils and other immune cells were virtually blind to the pathogen's presence. This cloaking phenomenon was attributed to expression of Psl exopolysaccharide. Although an anti-Psl mAb activated complement and enhanced neutrophil recognition of P. aeruginosa, neutrophil-mediated clearance of the pathogen was suboptimal owing to a second subversion mechanism, namely the type 3 secretion (T3S) injectisome. Indeed, T3S prevented phagosome acidification and resisted killing inside these compartments. Antibody-mediated inhibition of the T3S protein PcrV did not enhance bacterial phagocytosis but did enhance killing of the few bacteria ingested by neutrophils. A bispecific mAb targeting both Psl and PcrV enhanced neutrophil uptake of P. aeruginosa and also greatly increased inhibition of T3S function, allowing for phagosome acidification and bacterial killing. These data highlight the need to block multiple evasion and subversion mechanisms in tandem to kill P. aeruginosa.

Nano-layered magnesium fluoride reservoirs on biomaterial surfaces strengthen polymorphonuclear leukocyte resistance to bacterial pathogens.

Biomaterial-related bacterial infections cause patient suffering, mortality and extended periods of hospitalization, imposing a substantial burden on medical systems. In this context, understanding of nanomaterials-bacteria-cells interactions is of both fundamental and clinical significance. Herein, nano-MgF2 films were deposited on titanium substrate via magnetron sputtering. Using this platform, the antibacterial behavior and mechanism of the nano-MgF2 films were investigated in vitro and in vivo. It was found that, for S. aureus (CA-MRSA, USA300) and S. epidermidis (RP62A), the nano-MgF2 films possessed excellent anti-biofilm activity, but poor anti-planktonic bacteria activity in vitro. Nevertheless, both the traditional SD rat osteomyelitis model and the novel stably luminescent mouse infection model demonstrated that nano-MgF2 films exerted superior anti-infection effect in vivo, which cannot be completely explained by the antibacterial activity of the nanomaterial itself. Further, using polymorphonuclear leukocytes (PMNs), the critical immune cells of innate immunity, a complementary investigation of MgF2-bacteria-PMNs co-culturing revealed that the nano-MgF2 films improved the antibacterial effect of PMNs through enhancing their phagocytosis and stability. To our knowledge, this is the first time of exploring the antimicrobial mechanism of nano-MgF2 from the perspective of innate immunity both in vitro and in vivo. Based on the research results, a plausible mechanism is put forward for the predominant antibacterial effect of nano-MgF2in vivo, which may originate from the indirect immune enhancement effect of nano-MgF2 films. In summary, this study of surface antibacterial design using MgF2 nanolayer is a meaningful attempt, which can promote the host innate immune response to bacterial pathogens. This may give us a new understanding towards the antibacterial behavior and mechanism of nano-MgF2 films and pave the way towards their clinical applications.

Guarea kunthiana Bark Extract Enhances the Antimicrobial Activities of Human and Bovine Neutrophils.

Guarea kunthiana is used in folk remedies for the treatment of several diseases including microbial infections. The mechanism behind this phenomenon still needs to be elucidated. Here, we investigated the effect of G. kunthiana bark extract on antimicrobial functions of human and bovine neutrophils as the first line of defense against infections. For this aim, neutrophils were isolated from either human or bovine blood and treated with G. kunthiana bark extract. The antimicrobial activity of the neutrophils against Staphylococcus (S.) aureus and Escherichia (E.) coli was tested in a bacterial survival assay and a fluorescence-based phagocytosis assay. Furthermore, the formation of neutrophil extracellular traps (NETs) was visualized by immunofluorescence microscopy. We show that neutrophils treated with G. kunthiana extract distinctly increased phagocytosis of S. aureus or E. coli. Interestingly, we demonstrate that G. kunthiana bark extract induces the formation of NETs in both cell types. This effect was abolished when treating the cells with diphenyleniodonium chloride (DPI) pointing to a direct implication of the NADPH oxidase-dependent formation of reactive oxygen species in this process. In summary, our data strongly suggest that G. kunthiana bark extract boosts the antimicrobial activities of neutrophils as the first line of defense against invading pathogens.

Effects of Rhodomyrtus tomentosa Extract on Killing Activity of Human Neutrophils and Membrane Integrity of Enterohaemorrhagic Escherichia coli O157:H7.

Enterohaemorrhagic Escherichia coli (E. coli) O157:H7 is one of the most virulent causative agents of foodborne disease. Use of antibiotics for the treatment against E. coli O157:H7 infection leads to hemolytic uremic syndrome. The present study evaluated the potential of ethanolic leaf extract of a medicinal plant, Rhodomyrtus tomentosa in enhancing the killing activity of human neutrophils against E. coli O157:H7. In addition, the effects of the extract on membrane permeability of the organisms were studied. In the killing assay, percentage survival of the bacterial cells after being exposed to human neutrophils in the presence of various concentrations of the extract were determined. At 45 min, percentage survival of E. coli O157:H7 and E. coli ATCC 25922 after treated with neutrophils in the presence of the extract at 125-250 µg/mL was 58.48%-50.28% and 69.13%-35.35%, respectively. Furthermore, upon treatment with R. tomentosa at 250 µg/mL uptake of crystal violet by E. coli O157:H7 and E. coli ATCC 25922 was increased to 40.07% and 36.16%, respectively. Therefore, it is suggested that the extract exhibited dual effects as immunostimulant and membrane permeabilizing agent perhaps resulted in enhancing the killing activity of neutrophils against the organisms.

Immunosuppressive effects of the standardized extract of Phyllanthus amarus on cellular immune responses in Wistar-Kyoto rats.

Phyllanthus amarus (family: Euphorbiaceae) is of immense interest due to its wide spectrum of biological activities. In the present study, the standardized 80% ethanol extract of P. amarus was investigated for its modulatory activity on various cellular immune parameters, including chemotaxis of neutrophils, engulfment of Escherichia coli by neutrophils, and Mac-1 expression, in leukocytes isolated from treated/nontreated Wistar-Kyoto rats. The detailed cell-mediated activity of P. amarus was also investigated, including analysis of the effects on T- and B-cell proliferation and CD4(+) and CD8(+) T-cell subsets in splenic mononuclear cells, and estimation of serum cytokine production by activated T-cells. The main components of the extract, phyllanthin, hypophyllanthin, corilagin, geraniin, ellagic acid, and gallic acid were identified and quantitatively analyzed in the extracts, using validated reversed-phase high-performance liquid chromatography (HPLC) methods. N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced neutrophils isolated from rats administered with the extract of P. amarus, at doses ranging from 100 to 400 mg/kg for 14 days, revealed a significant dose-dependent reduction in neutrophil migration (P<0.05). Similar patterns of inhibition were also observed in phagocytic activity and in fMLP-induced changes in expression of ß2 integrin polymorphonuclear neutrophils. The results in P. amarus-treated rats also demonstrated a dose-dependent inhibition of both lipopolysaccharide-stimulated B-cell proliferation and concanavalin A-stimulated T-cell proliferation as compared with sensitized control. At a dose of 400 mg/kg (P<0.01), there was a significant decrease in the (%) expression of CD4(+) and CD8(+) in splenocytes and in serum cytokines of T helper (Th1) (IL-2 and IFN-γ) and Th2 (IL-4). In conclusion, P. amarus showed effective immunosuppressive activities in cellular immune response, by various immune regulatory mechanisms, and may be useful for improvement of immune-related disorders.

Photoimmunological properties of borage in bovine neutrophil in vitro model.

Borage (Echium amoenum fisch) is one of the most commonly used medicinal plants, and has long been used as a traditional herbal medicine for many (non)infectious diseases in Iran. Study on photoredox and photoimmunology of borage is little. Natural immunomodulatory plants with minimal adverse/toxic effects could help boost animal health and, ultimately, public health. To determine the effect of borage on the functions of key circulating innate immune cells, effects of borage extract (BE) on bovine neutrophils (PMN) photoredox and phagocytosis events were evaluated using an in vitro model system. Blood PMN isolated from healthy high yielding dairy cows (n = 8/treatment) were pre-incubated with BE and the impact on phagocytosis-dependent-and-independent cellular chemiluminescence (CL), phagocytosis, killing of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), fluorescence-based PMN H2O2 production and necrosis were assessed. Relative to control (no BE) PMN, treatment with BE significantly increased phagocytosis-dependent-and-independent PMN CL (>10-15% increase). While BE also led to increased PMN H2O2 production, necrosis was also surprisingly higher in these cells. Phagocytosis and killing of both E. coli and S. aureus by PMN treated with BE was substantially higher than that by control PMN. The increased photoimmunobiological events especially intracellular CL, intracellular H2O2 formation, and phagocytic capacity of BE-treated PMN support the potential immunotherapeutic implications of borage and its components for particularly immunocompromised animals and humans.

The Effect of Bacteriophage Preparations on Intracellular Killing of Bacteria by Phagocytes.

Intracellular killing of bacteria is one of the fundamental mechanisms against invading pathogens. Impaired intracellular killing of bacteria by phagocytes may be the reason of chronic infections and may be caused by antibiotics or substances that can be produced by some bacteria. Therefore, it was of great practical importance to examine whether phage preparations may influence the process of phagocyte intracellular killing of bacteria. It may be important especially in the case of patients qualified for experimental phage therapy (approximately half of the patients with chronic bacterial infections have their immunity impaired). Our analysis included 51 patients with chronic Gram-negative and Gram-positive bacterial infections treated with phage preparations at the Phage Therapy Unit in Wroclaw. The aim of the study was to investigate the effect of experimental phage therapy on intracellular killing of bacteria by patients' peripheral blood monocytes and polymorphonuclear neutrophils. We observed that phage therapy does not reduce patients' phagocytes' ability to kill bacteria, and it does not affect the activity of phagocytes in patients with initially reduced ability to kill bacteria intracellularly. Our results suggest that experimental phage therapy has no significant adverse effects on the bactericidal properties of phagocytes, which confirms the safety of the therapy.

Eicosapentaenoic (EPA) and docosahexaenoic (DHA) acid differentially modulate rat neutrophil function in vitro.

Fish oils are used as therapeutic agents in chronic inflammatory diseases. The omega-3 fatty acids (FA) found in these oils are mainly eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. The anti-inflammatory properties of fish oils are attributed to both omega-3 fatty acids. However, it is unknown whether such effects are due to either EPA or DHA. In this study, the effects of EPA and DHA on rat neutrophil function in vitro were compared. Both EPA and DHA increased the production of H2O2 when cells were stimulated or not with lipopolysaccharides (LPS). However, EPA was more potent than DHA in triggering an increase in superoxide release by cells in the basal condition or when stimulated with phorbol myristate acetate (PMA) or zymosan. Only DHA increased the phagocytic capacity and fungicidal activity of neutrophils. Both FA increased the release of tumor necrosis factor-α (TNF-α) in nonstimulated cells, but only EPA increased the production of cytokine-inducing neutrophil chemoattractant-2 (CINC-2) in the absence or presence of LPS, whereas production of interleukin-1 beta (IL-1ß) was only increased by DHA in the presence of LPS. In addition, there was no alteration in the production of nitric oxide. In conclusion, we show herein that EPA and DHA can differently modulate aspects of the neutrophil response, which may be relevant for the development of therapies rich in one or other FA depending on the effect required.

Study of streptococcal hemoprotein receptor (Shr) in iron acquisition and virulence of M1T1 group A streptococcus.

Streptococcus pyogenes (group A streptococcus, GAS) is a human bacterial pathogen of global significance, causing severe invasive diseases associated with serious morbidity and mortality. To survive within the host and establish an infection, GAS requires essential nutrients, including iron. The streptococcal hemoprotein receptor (Shr) is a surface-localized GAS protein that binds heme-containing proteins and extracellular matrix components. In this study, we employ targeted allelic exchange mutagenesis to investigate the role of Shr in the pathogenesis of the globally disseminated serotype M1T1 GAS. The shr mutant exhibited a growth defect in iron-restricted medium supplemented with ferric chloride, but no significant differences were observed in neutrophil survival, antimicrobial peptide resistance, cell surface charge, fibronectin-binding or adherence to human epithelial cells and keratinocytes, compared with wild-type. However, the shr mutant displayed a reduction in human blood proliferation, laminin-binding capacity and was attenuated for virulence in in vivo models of skin and systemic infection. We conclude that Shr augments GAS adherence to laminin, an important extracellular matrix attachment component. Furthermore, Shr-mediated iron uptake contributes to GAS growth in human blood, and is required for full virulence of serotype M1T1 GAS in mouse models of invasive disease.

In vitro and in vivo immunomodulatory activities of iridoids fraction from Barleria prionitis Linn.

ETHNOPHARMACOLOGICAL RELEVANCE: Barleria prionitis Linn. (Family: Acanthaceae), one of the important Ayurvedic medicinal plant in India, has long been used to treat variety of ailments including swellings, gout, arthritic and rheumatic disorders, nervine and skin diseases, and also acts as immunorestorative. AIM OF THE STUDY: The present study was aimed to explore in vitro and in vivo immunomodulatory activities of the iridoids fraction i.e. n-butanol fraction of methanol extract from Barleria prionitis aerial parts (IFBp). MATERIALS AND METHODS: IFBp was studied for in vitro [nitroblue tetrazolium (NBT) test and neutrophils candidacidal assay] and in vivo immunomodulatory activity on cellular and humoral immune responses to the antigenic challenge by sheep red blood cells (SRBCs) and by neutrophil adhesion test, phagocytic activity and cyclophosphamide-induced myelosuppression. The study comprised the preliminary phytochemical screening, HPTLC standardization and maximum tolerable dose determination of IFBp. RESULTS: IFBp (50, 100 and 200µg/ml) significantly (P≤0.01) increased the intracellular killing activity of stimulated neutrophils assayed by in vitro NBT reduction test and neutrophils candidacidal assay. Pretreatment of IFBp (100 and 200mg/kg; p.o.) evoked a significant increase in percent neutrophils and neutrophils adhesion to nylon fibres. Oral administration of IFBp augmented the humoral immune response to SRBCs, evidenced by increase in antibody titres and dose dependently potentiated the delayed-type hypersensitivity reaction induced by SRBCs in mice. IFBp potentiated significantly (P≤0.01) the macrophage phagocytic activity and ameliorated the red blood cells, total white blood cells and platelets count and haemoglobin concentration, and also restored the myelosuppressive effects induced by cyclophosphamide. The content (% w/w; mean±SD, n=3) of main iridoids i.e. shanzhiside methyl ester and barlerin was found to be 21.55±2.40 and 10.03±1.69 in IFBp of BP, respectively. CONCLUSION: The present investigation reveals that IFBp is a potent immunostimulant, stimulating both the specific and non-specific immune mechanisms.

Effect of Byrsonima crassa and phenolic constituents on Helicobacter pylori-induced neutrophils oxidative burst.

Byrsonima crassa Niedenzu (Malpighiaceae) is used in Brazilian folk medicine for the treatment of diseases related mainly to gastric ulcers. In a previous study, our group described the gastric protective effect of the methanolic extract from the leaves of B. crassa. The present study was carried out to investigate the effects of methanolic extract and its phenolic compounds on the respiratory burst of neutrophils stimulated by H. pylori using a luminol-based chemiluminescence assay as well as their anti-H. pylori activity. The suppressive activity on oxidative burst of H. pylori-stimulated neutrophils was in the order of methyl gallate > (+)-catechin > methanol extract > quercetin 3-O-α-l-arabinopyranoside > quercetin 3-O-ß-d-galactopyranoside > amentoflavone. Methyl gallate, compound that induced the highest suppressive activity with IC(50) value of 3.4 µg/mL, did not show anti-H. pylori activity. B. crassa could be considered as a potential source of natural antioxidant in gastric ulcers by attenuating the effects on the damage to gastric mucosa caused by neutrophil generated reactive oxygen species, even when H. pylori displays its evasion mechanisms.

Immunostimulation of sugar cane extract on neutrophils to Salmonella typhimurium infection in mice.

The aim of this study was to evaluate the immunomodulatory effects of sugar cane extract (SCE) on the biological activities of neutrophils in mice. Six-week-old BALB/c mice were fed 1250 mg/kg of SCE once. The generation, migration and biological functions of neutrophils and the survival rates of the mice in response to Salmonella typhimurium infection were evaluated. The results show that the numbers of both bone marrow cells and neutrophils were significantly increased in response to SCE administration (p < 0.05) compared with controls. The migration, phagocytosis and H2O2 generation of neutrophils were all significantly enhanced in SCE-treated mice (p < 0.05). After challenge with S. typhimurium (lethal dose, 50% (LD50), SCE-treated mice had a 19.2% higher survival rate and milder hepatic lesions than the controls. Additionally, fewer invasive bacteria were recovered from the spleens of SCE-treated mice. In conclusion, our results suggest that SCE has a positive regulatory effect on the biological function of mouse neutrophils that may increase host resistance against bacterial infections.

Effect of daily mixed nutritional supplementation on immune indices in soldiers undertaking an 8-week arduous training programme.

The aim was to investigate the influence of a daily mixed nutritional supplement during an 8-week arduous training programme on immune indices and mediators including circulating leucocyte counts; bacterially stimulated neutrophil degranulation; interleukin-6 (IL-6), cortisol and saliva secretory immunoglobulin-A (SIgA). Thirty men (mean (SD): age 25 (3) years; body mass, 80.9 (7.7) kg) received a habitual diet (CON, n = 15) or received a habitual diet plus an additional food supplement (SUP, n = 15). From weeks 0-6, CON received 14.0 MJ day(-1) and SUP received 19.7 MJ day(-1), and during a final 2-week field exercise in weeks 7 and 8, CON received 17.7 MJ day(-1) and SUP received 21.3 MJ day(-1). Blood and saliva were taken at rest after an overnight fast at weeks 0, 6 and 8. Body mass loss over the 8 weeks was greater in CON (CON, 5.0 (2.3); SUP, 1.6 (1.5) kg: P < 0.001). Training-induced decreases in circulating total leucocytes (CON: weeks 0, 8.0 (2.1); weeks 8, 6.5 (1.6) 10(9) l(-1), P < 0.01), lymphocytes (21%, P < 0.01) and monocytes (20%, P < 0.01) were prevented by the nutritional supplement. Saliva SIgA secretion rate increased approximately twofold by week 8 in SUP (P < 0.01) and was greater at week 8 compared with CON (P < 0.01). Circulating neutrophils, bacterially stimulated neutrophil degranulation, IL-6 and cortisol were similar in CON and SUP at week 8. In conclusion, a daily mixed nutritional supplement prevented the decrease in circulating total leucocytes, lymphocytes and monocytes and increased saliva SIgA output during an 8-week arduous training programme. The increase in saliva SIgA with nutritional supplementation during training may reduce susceptibility to upper respiratory infection.

Probiotic supplementation affects pulmonary exacerbations in patients with cystic fibrosis: a pilot study.

OBJECTIVE: Probiotics reduce intestinal inflammation in, and Lactobacillus GG (LGG) reduces pulmonary exacerbation rate cystic fibrosis (CF) patients. We intended to determine the effect of a mixed probiotic preparation on pulmonary exacerbations and inflammatory characteristics of the sputum in CF patients. STUDY DESIGN: A prospective pilot study of 10 CF patients with mild-moderate lung disease and Pseudomonas aeruginosa colonization, treated with probiotics for 6 months. Pulmonary function tests (PFT's), sputum cultures with semi-quantitative bacterial analysis, and sputum neutrophil count and interleukin-8 (IL-8) levels were compared to pre-treatment and post-treatment values. The rate of pulmonary exacerbations was compared to 2 years prior to the study. RESULTS: The exacerbation rate was significantly reduced in comparison to the previous 2 years and to 6 months post-treatment (P = 0.002). PFT's have not changed at the end of treatment and during 6 months post-treatment. No change in sputum bacteria, neutrophil count, and IL-8 levels was observed. CONCLUSION: Probiotics reduce pulmonary exacerbations rate in patients with CF. Probiotics may have a preventive potential for pulmonary deterioration in CF patients.