Randomized placebo-controlled trial of lactobacillus on asthmatic children with allergic rhinitis

Probiotics as additives on therapy in allergic airway diseases: a systematic review of benefits and risks

BACKGROUND

We conducted a systematic review to find out the role of probiotics in treatment of allergic airway diseases.  

METHODS

A comprehensive search of the major electronic databases was done till March 2013. Trials comparing the effect of probiotics versus placebo were included. A predefined set of outcome measures were assessed. Continuous data were expressed as standardized mean difference with 95% CI. Dichotomous data were expressed as odds ratio with 95% CI. P value < 0.05 was considered as significant.

RESULTS

A total of 12 studies were included. Probiotic intake was associated with a significantly improved quality of life score in patients with allergic rhinitis (SMD -1.9 (95% CI -3.62, -0.19); P = 0.03), though there was a high degree of heterogeneity. No improvement in quality of life score was noted in asthmatics. Probiotic intake also improved the following parameters: longer time free from episodes of asthma and rhinitis and decrease in the number of episodes of rhinitis per year. Adverse events were not significant.

CONCLUSION

As the current evidence was generated from few trials with high degree of heterogeneity, routine use of probiotics as an additive on therapy in subjects with allergic airway diseases cannot be recommended.

Psychosocial factors and behavioral medicine interventions in asthma

OBJECTIVE

This review examines the evidence for psychosocial influences in asthma and behavioral medicine approaches to its treatment.

METHOD

We conducted a systematic review of the literature on psychosocial influences and the evidence for behavioral interventions in asthma with a focus on research in the past 10 years and clinical trials. Additional attention was directed at promising new developments in the field.

RESULTS

Psychosocial factors can influence the pathogenesis and pathophysiology of asthma, either directly through autonomic, endocrine, immunological, and central nervous system mechanisms or indirectly through lifestyle factors, health behaviors, illness cognitions, and disease management, including medication adherence and trigger avoidance. The recent decade has witnessed surging interest in behavioral interventions that target the various pathways of influence. Among these, self-management training, breathing training, and exercise or physical activation programs have proved particularly useful, whereas other essential or promising interventions, such as smoking cessation, dietary programs, perception and biofeedback training, and suggestive or expressive psychotherapy, require further, more rigorous evaluation. Given the high comorbidity with anxiety and mood disorders, further evaluation of illness-specific cognitive behavior therapy is of particular importance. Progress has also been made in devising community-based and culturally tailored intervention programs.

CONCLUSION

In concert with an essential medication treatment, behavioral medicine treatment of asthma is moving closer toward an integrated biopsychosocial approach to disease management.

Characterization of candidate anti-allergic probiotic strains in a model of th2-skewed human peripheral blood mononuclear cells

BACKGROUND

Pre-clinical and clinical studies have evaluated the efficacy of probiotics in allergy. However, predictive in vitro systems for rational strain selection are still missing.

METHODS

We developed a novel in vitro screening system for the characterization of probiotics with anti-allergic potential. In this model, human peripheral blood mononuclear cells (PBMC) from healthy donors (n = 68) were skewed towards a Th2 cytokine phenotype by culture with IL-4 and anti-CD40, to resemble cells from allergic donors. Th2-skewed cells were then co-cultured with probiotics; a total of 35 strains were tested. Levels of IFN-γ, IL-10, IL-5 and 7 additional cytokines in culture supernatants were determined by ELISA or multiplex assay. Gene expression was assessed by real-time PCR. For validation, splenocytes from ovalbumin-primed mice and PBMC from grass-allergic donors were restimulated with respective antigen and co-cultured with probiotics, and cytokine profiles were correlated.

RESULTS

Culture with IL-4 and anti-CD40 antibody induced secretion of IL-5 from PBMC, indicative of induction of a Th2 phenotype. Cytokine profiles induced by probiotics were strain specific even though species- and genus-specific clustering was observed for many strains by principal component analysis. This was paralleled by mRNA levels of the corresponding genes such as increased Tbet and reduced GATA-3 gene expression. Cytokine profiles induced by probiotics in PBMC stimulated with IL-4 and anti-CD40 correlated with those obtained from allergen-stimulated murine splenocytes or human PBMC from grass-allergic donors.

CONCLUSIONS

Cytokine profiling of probiotic strains with IL-4-/anti-CD40-stimulated PBMC allowed to determine the effect of probiotics on Th2-skewed cells and thus to classify probiotic strains with anti-allergic potential.

Reduced medication use and improved pulmonary function with supplements containing vegetable and fruit concentrate, fish oil and probiotics in asthmatic school children: a randomised controlled trial

Dietary pattern changes may be one of the key factors associated with increasing asthma prevalence. Observational studies have found negative associations between fruit, vegetable and fish consumption and risk of asthma. Experimental studies have also shown that probiotics can modulate the immune system. However, each dietary component exhibits a modest effect. The objective of the present study was to investigate the joint effect of multiple beneficial dietary components on asthma. We designed a 16-week school-based double-blind placebo-controlled randomised trial. The supplement group received fruit plus vegetable concentrate, fish oil and probiotics (FVFP supplement), while the control group received placebos. A total of 192 asthmatic children aged 10-12 years were recruited from elementary schools in metropolitan Taipei. Pulmonary function, medication usage, Paediatric Asthma Quality of Life Questionnaire (PAQLQ) score and the Childhood Asthma Control Test score were evaluated at baseline, and at weeks 8 and 16. Compared with the placebo group, the supplement group showed significant improvement in pulmonary function parameters (91 v. 178 ml for forced vital capacity (FVC), 40 v. 107 ml for forced expiratory volume in 1 s (FEV1) and 1·6 v. 4·8 % for FEV1:FVC ratio; all P values < 0·01) and had a significantly reduced proportion of those using short-acting inhaled bronchodilators and inhaled corticosteroids. However, the PAQLQ score and the Childhood Asthma Control Test score were not significantly different between the two groups, possibly because the majority of the children were treated routinely. FVFP supplements reduced medication use and improved pulmonary function in asthmatic children. The present study supports an adjuvant intervention with a combination of fruit, vegetable, fish and probiotic foods.

Early-life gut bacteria associate with IL-4-, IL-10- and IFN-γ production at two years of age

Microbial exposure early in life influences immune maturation and potentially also the development of immune-mediated disease. Here we studied early-life gut colonization in relation to cytokine responses at two years of age. Fecal samples were collected from infants during the first two months of life. DNA was extracted from the fecal samples and Bifidobacterium (B.) adolescentis, B. breve, B. bifidum, a group of lactobacilli (L. casei, L. paracasei and L. rhamnosus) as well as Staphylococcus (S.) aureus were detected with real time PCR. Peripheral mononuclear cells were stimulated with phytohaemagglutinin (PHA) and numbers of IL-4−, IL-10− and IFN-γ secreting cells were evaluated using ELISpot. We further stimulated peripheral blood mononuclear cells with bacterial supernatants in vitro and assessed the IL-4−, IL-10− and IFN-γ inducing capacity by flow cytometry and ELISA. Early S. aureus colonization associated with higher numbers of IL-4− (p = 0.022) and IL-10 (p = 0.016) producing cells at two years of age. In contrast to colonization with S. aureus alone, co-colonization with lactobacilli associated with suppression of IL-4− (p = 0.004), IL-10− (p = 0.004) and IFN-γ (p = 0.034) secreting cells. In vitro stimulations of mononuclear cells with bacterial supernatants supported a suppressive role of L. rhamnosus GG on S. aureus-induced cytokine responses. We demonstrate that the early gut colonization pattern associates with the PHA-induced cytokine profile at two years of age and our in vitro findings support that specific bacterial species influence the T helper cell subsets. This suggests that dysbiosis in the early microbiota may modulate the risk of developing inflammatory conditions like allergy.

Clinical Use of Probiotics in Pediatric Allergy (CUPPA): A World Allergy Organization Position Paper

BACKGROUND

: Probiotic administration has been proposed for the prevention and treatment of specific allergic manifestations such as eczema, rhinitis, gastrointestinal allergy, food allergy, and asthma. However, published statements and scientific opinions disagree about the clinical usefulness.

OBJECTIVE

: A World Allergy Organization Special Committee on Food Allergy and Nutrition review of the evidence regarding the use of probiotics for the prevention and treatment of allergy.

METHODS

: A qualitative and narrative review of the literature on probiotic treatment of allergic disease was carried out to address the diversity and variable quality of relevant studies. This variability precluded systematization, and an expert panel group discussion method was used to evaluate the literature. In the absence of systematic reviews of treatment, meta-analyses of prevention studies were used to provide data in support of probiotic applications.

RESULTS

: Despite the plethora of literature, probiotic research is still in its infancy. There is a need for basic microbiology research on the resident human microbiota. Mechanistic studies from biology, immunology, and genetics are needed before we can claim to harness the potential of immune modulatory effects of microbiota. Meanwhile, clinicians must take a step back and try to link disease state with alterations of the microbiota through well-controlled long-term studies to identify clinical indications.

CONCLUSIONS

: Probiotics do not have an established role in the prevention or treatment of allergy. No single probiotic supplement or class of supplements has been demonstrated to efficiently influence the course of any allergic manifestation or long-term disease or to be sufficient to do so. Further epidemiologic, immunologic, microbiologic, genetic, and clinical studies are necessary to determine whether probiotic supplements will be useful in preventing allergy. Until then, supplementation with probiotics remains empirical in allergy medicine. In the future, basic research should focus on homoeostatic studies, and clinical research should focus on preventive medicine applications, not only in allergy. Collaborations between allergo-immunologists and microbiologists in basic research and a multidisciplinary approach in clinical research are likely to be the most fruitful.

Lactobacillus gasseri suppresses Th17 pro-inflammatory response and attenuates allergen-induced airway inflammation in a mouse model of allergic asthma

Probiotics are normal inhabitants of the gastrointestinal tract of man and are widely considered to exert a number of beneficial effects in many diseases. But the mechanism by which they modulate the immune system is poorly understood. The present study was planned to explore the anti-allergic effect of Lactobacillus gasseri on a mouse model of allergic asthma. Dermatophoides pteronyssinus (Der p) sensitised and challenged BALB/c mice were orally administered via oral administration with three different doses of L. gasseri (low, 1 × 10(6) colony-forming units (CFU); medium, 2 × 10(6) CFU; high, 4 × 10(6) CFU), in 700 μl of PBS daily, starting from 2 weeks before Der p sensitisation for 4 weeks. After the allergen challenge, airway responsiveness to methacholine, influx of inflammatory cells to the lung, and cytokine levels in bronchoalveolar lavage (BAL) fluids and splenocytes culture were assessed. Our results showed that oral administration of a high dose of L. gasseri (4 × 10(6) CFU) decreased airway responsiveness to methacholine, attenuated the influx of inflammatory cells to the airways and reduced the levels of TNF-α, thymus and activation-regulated chemokine (TARC) and IL-17A in BAL fluids of Der p-sensitised and -challenged mice. Moreover, L. gasseri decreased IL-17A production in transforming growth factor-α and IL-6 stimulated splenocytes and cell numbers of IL-17 producing alveolar macrophages in L. gasseri-treated mice as compared to non-treated, Der p-sensitised and -challenged mice. In conclusion, oral administration with L. gasseri can attenuate major characteristics of allergen-induced airway inflammation and IL-17 pro-inflammatory immune response in a mouse model of allergic asthma, which may have clinical implication in the preventive or therapeutic potential in allergic asthma.

Probiotics in childhood: allergic illness and respiratory infections

Over the last decade, there has been a growing interest in the use of probiotics for allergic diseases. In the last years, some studies showed a significant improvement for atopic eczema by the administration of probiotics during pregnancy and postnatally. About food allergy, probiotics administration seems to be effective in the management of food allergy symptoms but has no effect on the prevention of sensitization. In the international literature, there are few studies that evaluated the probiotic effect on allergic rhinitis, and authors reported that probiotics might have a beneficial effect in AR by reducing symptom severity and medication use. Another major potential benefit of probiotics has been suggested in patients with asthma. On this topic, several studies have been carried out using different probiotics and the results have not been univocal. Indeed, probiotics seems to be able to offer protection about common cold and respiratory infections in healthy and hospitalized children.

Probiotic therapy as a novel approach for allergic disease

The prevalence of allergic disease has increased dramatically in Western countries over the past few decades. The hygiene hypothesis, whereby reduced exposure to microbial stimuli in early life programs the immune system toward a Th2-type allergic response, is suggested to be a major mechanism to explain this phenomenon in developed populations. Such microbial exposures are recognized to be critical regulators of intestinal microbiota development. Furthermore, intestinal microbiota has an important role in signaling to the developing mucosal immune system. Intestinal dysbiosis has been shown to precede the onset of clinical allergy, possibly through altered immune regulation. Existing treatments for allergic diseases such as eczema, asthma, and food allergy are limited and so the focus has been to identify alternative treatment or preventive strategies. Over the past 10 years, a number of clinical studies have investigated the potential of probiotic bacteria to ameliorate the pathological features of allergic disease. This novel approach has stemmed from numerous data reporting the pleiotropic effects of probiotics that include immunomodulation, restoration of intestinal dysbiosis as well as maintaining epithelial barrier integrity. In this mini-review, the emerging role of probiotics in the prevention and/or treatment of allergic disease are discussed with a focus on the evidence from animal and human studies.

Immune disorders and its correlation with gut microbiome

Allergic disorders such as atopic dermatitis and asthma are common hyper-immune disorders in industrialized countries. Along with genetic association, environmental factors and gut microbiota have been suggested as major triggering factors for the development of atopic dermatitis. Numerous studies support the association of hygiene hypothesis in allergic immune disorders that a lack of early childhood exposure to diverse microorganism increases susceptibility to allergic diseases. Among the symbiotic microorganisms (e.g. gut flora or probiotics), probiotics confer health benefits through multiple action mechanisms including modification of immune response in gut associated lymphoid tissue (GALT). Although many human clinical trials and mouse studies demonstrated the beneficial effects of probiotics in diverse immune disorders, this effect is strain specific and needs to apply specific probiotics for specific allergic diseases. Herein, we briefly review the diverse functions and regulation mechanisms of probiotics in diverse disorders.

A trial of adding Lactobacillus johnsonii EM1 to levocetirizine for treatment of perennial allergic rhinitis in children aged 7-12 years

BACKGROUND

Supplementary consumption of probiotics may temporarily alter the intestinal microflora of infants and children, thereby preventing and treating allergic disorders.

OBJECTIVE

To compare the clinical efficacy of levocetirizine with that of levocetirizine plus Lactobacillus johnsonii EM1 (Lj EM1) for treating perennial allergic rhinitis (PAR) in children.

METHODS

Sixty-three children aged 7-12 years fulfilled the entry criteria for the study and had moderate to severe PAR of at least 1 year's duration. The treatment followed a randomized, open-label crossover design: all subjects were randomized to 2 crossover treatment regimens of levocetirizine with Lj EM1 (group 1) or levocetirizine alone (group 2) for 12 weeks; subsequently, treatments were reversed for a further 12 weeks. The effects of the 2 regimens were compared using the Pediatric Rhinoconjunctivitis Quality of Life Questionnaire (PRQLQ) and the total symptom score (TSS) from diary cards. The parameters evaluated were nasal peak expiratory flow rate (nPEFR), FVC, FEV1, serum immunoglobulin E (IgE), mite-specific IgE, eosinophilic cationic protein (ECP), resistin, blood eosinophils, eosinophil percentage in nasal smears, IL-4, IL-10, interferon-γ (IFN-γ), and transforming growth factor-β (TGF-β).

RESULTS

After the first 12 weeks of treatment, TSS in both groups had improved progressively compared with that in the run-in period. Both groups had improved TSS at weeks 4, 8, and 12 (P<0.05), and group 1 was more efficacious than group 2 at week 4 (P=0.014), week 8 (P=0.011), and week 12 (P<0.009). During the second 12-week period, group 2 showed continual and progressive improvement, while group 1 did not. The PRQLQ scores were significantly decreased in both groups (P<0.05), but there was no statistically significant difference between the 2 groups (P=0.446). The eosinophil percentage in nasal smears decreased in both groups compared with that in the run-in period, and significant differences were detected in groups 2 and 1at 16 and 24 weeks of treatment, respectively (P<0.05). Both groups showed significant improvement in nPEFR at weeks 4, 8, 12, 16, and 24 (P<0.01), and the treatment for group 1 appeared to be more efficacious than that for group 2 at weeks 12, 16, and 20 (P<0.05). FVC and FEV1 were improved in both groups at weeks 8 through 24 (P<0.05), but there was no significant difference between the 2 groups. In cytokine measurements, IFN-γ and IL-10 increased significantly and IL-4 decreased significantly in both groups, while elevation of TGF-β was seen only in group 1 at 12 weeks (P<0.001). However, the difference in TGF-β disappeared after 24 weeks treatment. There was no difference in serum resistin levels. No serious adverse events were recorded in either treatment group.

CONCLUSION

The 24-week, 2-phase, crossover treatment program showed that levocetirizine plus Lj EM1 was more effective for PAR than levocetirizine and that this difference persisted for at least 3 months after discontinuation of Lj EM1.

Effects of probiotics on the prevention of atopic dermatitis

Atopic dermatitis (AD) is an immune disorder that is becoming increasingly prevalent throughout the world. The exact etiology of AD remains unknown, and a cure for AD is not currently available. The hypothesis that appropriate early microbial stimulation contributes to the establishment of a balanced immune system in terms of T helper type Th1, Th2, and regulatory T cell (Treg) responses has led to the use of probiotics for the prevention and treatment of AD in light of various human clinical studies and animal experiments. Meta-analysis data suggests that probiotics can alleviate the symptoms of AD in infants. The effects of balancing Th1/Th2 immunity and enhancing Treg activity via the interaction of probiotics with dendritic cells have been described in vitro and in animal models, although such an effect has not been demonstrated in human studies. In this review, we present some highlights of the immunomodulatory effects of probiotics in humans and animal studies with regard to their effects on the prevention of AD.

Immunomodulatory effects of feeding with Bifidobacterium longum on allergen-induced lung inflammation in the mouse

BACKGROUND

The intestinal microbiota has important effects on host immune responses and feeding with certain commensal organisms has anti-inflammatory effects in a variety of diseases, including experimental asthma. The aim of the current study was to examine how robust the effects of feeding with the commensal strain, Bifidobacterium longum (Bif) were on the pulmonary responses to allergen sensitization and challenge.

METHODS

BALB/c mice were given two intraperitoneal injections of ovalbumin (10 μg in alum) on days 0 and 7 and were fed daily with Bif or vehicle from days 0-14. Challenges with ovalbumin (10 μg) were administered intra-nasally once on day 14 or three times on days 14, 15 and 16 and the lung inflammatory response was assessed one day later.

RESULTS

Bif feeding attenuated airway inflammation following a single ovalbumin challenge, reducing bronchoalveolar lavage (BAL) eosinophilia, BAL fluid IL-4 protein and BAL cell IL-4 and IFN-γ mRNA levels. However, BAL fluid IL-5 protein was increased. There was an accompanying increase in lung regulatory T cells assessed by flow cytometry. Responses to triple challenge with ovalbumin were much less affected by Bif feeding, including unchanged cytokine levels, ovalbumin-specific IgE and airway hyperresponsiveness to methacholine.

CONCLUSION

These results show modest immunoregulatory effects of oral feeding with Bif with inhibition of certain components of allergen-induced airway inflammation that is associated with the expansion of regulatory T cells in the lungs but that is overcome by repeated allergen exposure.

The microbiology of asthma

Asthma remains an important human disease that is responsible for substantial worldwide morbidity and mortality. The causes of asthma are multifactorial and include a complex mix of environmental, immunological and host genetic factors. In addition, epidemiological studies show strong associations between asthma and infection with respiratory pathogens, including common respiratory viruses such as rhinoviruses, human respiratory syncytial virus, adenoviruses, coronaviruses and influenza viruses, as well as bacteria (including atypical bacteria) and fungi. In this Review, we describe the many roles of microorganisms in the risk of developing asthma and in the pathogenesis of and protection against the disease, and we discuss the mechanisms by which infections affect the severity and prevalence of asthma.

The effects of commensal microbiota on immune cell subsets and inflammatory responses

Billions of years of coevolution shaped the mutually beneficial relationships between metazoans and symbiotic commensal microorganisms. Commensal microorganisms profoundly affect the physiology of the host and provide the host with survival advantages in several ways, while they could also trigger pathogenic immune responses and threaten the well-being of the host. Recent advances in DNA sequencing technology enabled the analysis of commensal microbiota, and improvements in the techniques of culturing gut-resident microorganisms and of rearing gnotobiotic rodents have made it possible to assess the effect of individual component of microbial communities on host physiology. In this review, we discuss the current understanding of the interactions of commensal microbiota with the host immune system.