Effects of dietary yoghurt on immunological and clinical parameters of rhinopathic patients

Kefir: A protective dietary supplementation against viral infection

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by a recently discovered coronavirus termed 'severe acute respiratory syndrome coronavirus 2' (SARS-CoV-2). Several scholars have tested antiviral drugs and compounds to overcome COVID-19. 'Kefir' is a fermented milk drink similar to a thin yogurt that is made from kefir grains. Kefir and its probiotic contents can modulate the immune system to suppress infections from viruses (e.g., Zika, hepatitis C, influenza, rotaviruses). The antiviral mechanisms of kefir involve enhancement of macrophage production, increasing phagocytosis, boosting production of cluster of differentiation-positive (CD4+), CD8+, immunoglobulin (Ig)G+ and IgA+ B cells, T cells, neutrophils, as well as cytokines (e.g., interleukin (IL)-2, IL-12, interferon gamma-γ). Kefir can act as an anti-inflammatory agent by reducing expression of IL-6, IL-1, TNF-α, and interferon-γ. Hence, kefir might be a significant inhibitor of the 'cytokine storm' that contributes to COVID-19. Here, we review several studies with a particular emphasis on the effect of kefir consumption and their microbial composition against viral infection, as well as discussing the further development of kefir as a protective supplementary dietary against SARS-CoV-2 infection via modulating the immune response.

Lipid mediators and asthma: Scope of therapeutics

Lipids and their mediators are known to play a pro-inflammatory role in several human diseases including asthma. The influence of leukotrienes and prostaglandins through arachidonate metabolism in asthma pathophysiology is well established and hence, prompted the way for therapeutic strategies targeting lipid metabolites. In addition, various types of fatty acids have been reported to play a diverse role in asthma. For instance, CD4⁺ T-lymphocytes differentiation towards T-effector (T_eff) or T-regulatory (Tregs) cells seems to be controlled reciprocally by fatty acid metabolic pathways. Further, the dysregulated lipid status in obesity complicates the asthma manifestations suggesting the role of lipid metabolites particularly ω-6 fatty acids in the process. On the other hand, clinical and pre-clinical studies suggests the role of short chain fatty acids in curbing asthma through upregulation of T-regulatory cells or clearance of inflammatory cells through promoting apoptosis. Accordingly, the present review compiles various studies for comprehensive analysis of different types of lipid based metabolites in asthma manifestation. Finally, we have proposed certain strategies which may enhance the usefulness of lipid mediators for balanced immune response during asthma.

Food consumption and the risk of childhood allergy

Background

The prevalence of allergic conditions is increasing in most countries. One possible explanation may be childhood nutrition.

Objective

The aim of the study was to investigate the relationship between consumption of pre-specified types of food in school-aged children and presence of respiratory and allergic symptoms.

Methods

A total of 191 students aged 9-11 years were recruited from 5 schools to geographically cover all of Malta. Data was collected between October 2011 and February 2012. This was part of a bigger study which included clinical and environmental tests besides standardized health questionnaires. For the purposes of this part of the study only the health questionnaires were used. These standardized health questionnaires based on the International Study of Asthma and Allergies in Childhood (ISAAC) were used to identify the presence of respiratory and allergic symptoms and to identify the types of foods and the frequency of consumption of various types of foods.

Results

We found that milk, meat, butter, olive oil, and yoghurt consumption had a negative association with allergic symptoms in children, whilst fish consumption had a detrimental effect. These relationships remained significant after correction for paternal level of education.

Conclusion

The study highlights the fact that nutrition in early childhood may have a significant effect on the risk of allergic conditions. Our results, taken together with data in the literature, suggest that different types of fish might have had different effects. This is probably related to their different fatty acid constitution thus warranting further studies.

International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis

BACKGROUND

Critical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).

METHODS

Using previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.

CONCLUSION

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

Oral administration of Lactobacillus paracasei L9 attenuates PM2.5-induced enhancement of airway hyperresponsiveness and allergic airway response in murine model of asthma

This study investigated allergy immunotherapy potential of Lactobacillus paracasei L9 to prevent or mitigate the particulate matter 2.5 (PM2.5) enhanced pre-existing asthma in mice. Firstly, we used a mouse model of asthma (a 21-day ovalbumin (OVA) sensitization and challenge model) followed by PM2.5 exposure twice on the same day of the last challenge. PM2.5 was collected from the urban area of Beijing and underwent analysis for metals and polycyclic aromatic hydrocarbon contents. The results showed that PM2.5 exposure enhanced airway hyper-responsiveness (AHR) and lead to a mixed Th2/ IL-17 response in asthmatic mice. Secondly, the PM2.5 exposed asthmatic mice were orally administered with L9 (4×107, 4×109 CFU/mouse, day) from the day of first sensitization to the endpoint, for 20 days, to investigate the potential mitigative effect of L9 on asthma. The results showed that L9 ameliorated PM2.5 exposure enhanced AHR with an approximate 50% decrease in total airway resistance response to methacholine (48 mg/ml). L9 also prevented the exacerbated eosinophil and neutrophil infiltration in bronchoalveolar lavage fluid (BALF), and decreased the serum level of total IgE and OVA-specific IgG1 by 0.44-fold and 0.3-fold, respectively. Additionally, cytokine production showed that L9 significantly decreased T-helper cell type 2 (Th2)-related cytokines (IL-4, -5, -13) and elevated levels of Th1 related IFN-γ in BALF. L9 also reduced the level of IL-17A and increased the level of TGF-β. Taken together, these results indicate that L9 may exert the anti-allergic benefit, possibly through rebalancing Th1/Th2 immune response and modulating IL-17 pro-inflammatory immune response. Thus, L9 is a promising candidate for preventing PM exposure enhanced pre-existing asthma.

Oral administration of Lactobacillus paracasei L9 attenuates PM2.5-induced enhancement of airway hyperresponsiveness and allergic airway response in murine model of asthma

This study investigated allergy immunotherapy potential of Lactobacillus paracasei L9 to prevent or mitigate the particulate matter 2.5 (PM2.5) enhanced pre-existing asthma in mice. Firstly, we used a mouse model of asthma (a 21-day ovalbumin (OVA) sensitization and challenge model) followed by PM2.5 exposure twice on the same day of the last challenge. PM2.5 was collected from the urban area of Beijing and underwent analysis for metals and polycyclic aromatic hydrocarbon contents. The results showed that PM2.5 exposure enhanced airway hyper-responsiveness (AHR) and lead to a mixed Th2/ IL-17 response in asthmatic mice. Secondly, the PM2.5 exposed asthmatic mice were orally administered with L9 (4×107, 4×109 CFU/mouse, day) from the day of first sensitization to the endpoint, for 20 days, to investigate the potential mitigative effect of L9 on asthma. The results showed that L9 ameliorated PM2.5 exposure enhanced AHR with an approximate 50% decrease in total airway resistance response to methacholine (48 mg/ml). L9 also prevented the exacerbated eosinophil and neutrophil infiltration in bronchoalveolar lavage fluid (BALF), and decreased the serum level of total IgE and OVA-specific IgG1 by 0.44-fold and 0.3-fold, respectively. Additionally, cytokine production showed that L9 significantly decreased T-helper cell type 2 (Th2)-related cytokines (IL-4, -5, -13) and elevated levels of Th1 related IFN-γ in BALF. L9 also reduced the level of IL-17A and increased the level of TGF-β. Taken together, these results indicate that L9 may exert the anti-allergic benefit, possibly through rebalancing Th1/Th2 immune response and modulating IL-17 pro-inflammatory immune response. Thus, L9 is a promising candidate for preventing PM exposure enhanced pre-existing asthma.

Do probiotics have a role in the treatment of allergic rhinitis? A comprehensive systematic review and meta-analysis

OBJECTIVE

To investigate clinical evidence for the efficacy of probiotics in the treatment of allergic rhinitis (AR).

METHODS

A systematic search was conducted to review the results of all randomized, double-blind, placebo-controlled trials by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement. Primary outcome measurements were total nasal and ocular symptom scores (SS) and quality of life (QoL) questionnaires. Secondary outcome measurements were individual nasal SS and immunologic parameters.

RESULTS

Twenty-two randomized, double-blind, placebo-controlled studies were included. Seventeen trials showed significant benefit of probiotics clinically, whereas eight trials showed significant improvement in immunologic parameters compared with placebo. All five studies with Lactobacillus paracasei (LP) strains demonstrated clinically significant improvements compared with placebo. Probiotics showed significant reduction in nasal and ocular SS (standardized mean difference [SMD], -1.23, p < 0.001; and SMD, -1.84, p < 0.001; respectively), total, nasal, and ocular QoL scores compared with placebo (SMD, -1.84, p < 0.001; SMD, -2.30, p = 0.006; and SMD, -3.11, p = 0.005; respectively). Although heterogeneity was high, in subgroup analysis, SMD for total nasal and ocular symptoms with patients with seasonal AR and for nasal QoL scores for studies with LP-33 strain were significant and homogenous. Scores of nasal blockage, rhinorrhea, and nasal itching were significantly lower in the probiotic group compared with placebo. The meta-analysis studies SS the Japanese guidelines revealed a significant, homogenous SMD score of -0.34 for individual nasal SS, above the minimal important clinical difference value of 0.3. The T-helper 1 to T-helper 2 ratio was significantly lower in the probiotic group compared with placebo (SMD, -0.78; p = 0.045).

CONCLUSION

Despite high variability among the studies, synthesis of available data provided significant evidence of beneficial clinical and immunologic effects of probiotics in the treatment of AR, especially with seasonal AR and LP-33 strains. With the rising pool of studies, the most promising strains in specific allergies can be revealed and adjuvant therapy with probiotics can be recommended for the treatment of AR.

Distal Mucosal Site Stimulation by Kefir and Duration of the Immune Response

Kefir is a fermented milk (drink) produced by the action of lactic acid bacteria, yeasts and acetic acid bacteria. We recently reported a comparative study on the effect of kefir containing viable or non-viable bacteria by studying their modulatory activity on the intestinal immune response. A functional dose was established in a murine model and the pattern of regulatory and pro-inflammatory cytokines induced was also studied. The existence of a common mucosal immune system implies that the immune cells stimulated in one mucosal tissue can spread and relocate through various mucosal sites. The aim of this work was to determine the effect of an oral administration of kefir on the duration of the intestinal mucosa immune response and the modulatory activity in distal mucosal sites, specifically in the peritoneal and pulmonary macrophages and in the bronchial tissue. BALB/c mice were fed with kefir or pasteurized kefir at doses previously determined as functional for intestinal mucosa immunomodulation. Kefir feeding was stopped and the number of IgA, IgG, IL-4, IL-6, IL-10, IIFNγ and TNFα producing cells was determined in the lamina propria of small intestine immediately, and after 2 and 7 days of kefir withdrawal. IgA producing cells were also measured in the bronchial tissue of lungs immediately and 2 and 7 days after kefir withdrawal. Phagocytic activity of peritoneal and pulmonary macrophages was also determined. The oral administration of kefir or pasteurized kefir increased the number of IgA+ cells not only in the gut lamina propria, but also in the bronchial tissue, supporting the concept of local antibody secretion after remote-site stimulation in the intestinal tract. Both peritoneal and pulmonary macrophages were activated by kefir or pasteurized kefir feeding. Peritoneal macrophages were stimulated faster than pulmonary macrophages (for kefir). The enhanced phagocytic activity achieved by kefir or pasteurized kefir lasted longer for the peritoneal than for the pulmonary macrophages. Due to the increased bronchial IgA and phagocytic activity of pulmonary macrophages after kefir feeding observed in this study, the oral administration of kefir could act as a natural adjuvant for enhancing the specific immune response against respiratory pathogens. The parameters studied returned to control values within a week of cessation of kefir administration. This would suggest that there is a low risk of overstimulating the gut mucosal immune system during periodic consumption of kefir.

Mechanism of Action of Probiotic Bacteria on Intestinal and Systemic Immunities and Antigen-Presenting Cells

Immunomodulation has been shown to be one of the major functions of probiotic bacteria. This review is presented to provide detailed information on the immunomodulatory properties of probiotics in various animal models and clinical practices. Probiotics can regulate helper T (Th) responses and release of cytokines in a strain-specific manner. For example, Lactobacillus rhamnosus GG can induce beneficial Th1 immunomodulatory effect in infants with cow's milk allergy and relieve intestinal inflammation in atopic children by promoting IL-10 generation. Mechanism of action of probiotics on antigen-presenting cells at gastrointestinal tract is also postulated in this review. Probiotic bacterial cells and their soluble factors may activate dendritic cells, macrophages, and to certain extent monocytes via toll-like-receptor recognition and may further provoke specific Th responses. They are speculated to elicit immunomodulatory effects on intestinal and systemic immunities.

A systematic review and meta-analysis of probiotics for the treatment of allergic rhinitis

BACKGROUND

Probiotics have proven beneficial in a number of immune-mediated and allergic diseases. Several human studies have evaluated the efficacy of probiotics in allergic rhinitis; however, evidence for their use has yet to be firmly established. The current systematic review seeks to synthesize the results of available randomized trials.

METHODS

In a systematic review and meta-analysis, the Medline, EMBASE, and Cochrane Library databases were reviewed and randomized controlled trials (RCTs) were extracted based on defined inclusion criteria. The effect of probiotics on Rhinitis Quality of Life (RQLQ) scores, Rhinitis Total Symptom Scores (RTSS), as well as total and antigen-specific serum immunoglobulin E (IgE) levels were evaluated by meta-analysis.

RESULTS

A total of 23 studies with 1919 patients were identified, including 21 double-blind RCTs and 2 randomized crossover studies. Multiple probiotic strains, study populations, and outcome measures were used in individual trials. Seventeen studies showed a significant clinical benefit from the use of probiotics in at least 1 outcome measure when compared to placebo, whereas 6 trials showed no benefit. Among the trials eligible for meta-analysis, the use of probiotics resulted in a significant improvement in RQLQ scores compared to placebo (standard mean difference [SMD] -2.23; p = 0.02). Probiotics had no effect on RTSS (SMD -0.36; p = 0.13) or total IgE levels (SMD 0.01; p = 0.94), although there was a trend toward a reduction in antigen-specific IgE (SMD 0.20; p = 0.06) in the placebo group compared to probiotic.

CONCLUSION

Probiotics may be beneficial in improving symptoms and quality of life in patients with allergic rhinitis; however, current evidence remains limited due to study heterogeneity and variable outcome measures. Additional high-quality studies are needed to establish appropriate recommendations.

Effects of immunomodulatory supplementation with Lactobacillus rhamnosus on airway inflammation in a mouse asthma model

BACKGROUND

Asthma is a common allergic disease. In previous studies, probiotics improved the balance of intestinal microbes, reduced inflammation, and promoted mucosal tolerance. This study investigated whether oral administrations of Lactobacillus rhamnosus GG (LGG) inhibited allergen (ovalbumin or OVA)-induced airway inflammation in a mouse asthma model.

METHODS

The allergy/asthma animal model in this study was sensitization with OVA. After intranasal challenge with OVA, the airway inflammation and hyper-responsiveness were determined by a Buxco system, bronchoalveolar lavage fluid analysis with Liu stain, and enzyme-linked immunosorbent assay. Histopathologic changes in the lung were detected by hematoxylin and eosin staining and immunohistochemistry staining.

RESULTS

Both pre- and post-treatment with LGG suppressed the airway hyper-responsiveness to methacholine and significantly decreased the number of infiltrating inflammatory cells and Th2 cytokines in bronchoalveolar lavage fluid and serum compared with the OVA-sensitized mice. In addition, LGG reduced OVA-specific IgE levels in serum. Oral LGG decreased matrix metalloproteinase 9 expression in lung tissue and inhibited inflammatory cell infiltration.

CONCLUSION

LGG had an anti-inflammatory effect on OVA-induced airway inflammation and might be an additional or supplementary therapy for allergic airway diseases.

Oral delivery of a probiotic induced changes at the nasal mucosa of seasonal allergic rhinitis subjects after local allergen challenge: a randomised clinical trial

Objective

To determine effects of probiotic consumption on clinical and immunological parameters of seasonal allergic rhinitis (SAR) in an out-of-season single nasal allergen challenge.

Methods

In a study registered at ClinicalTrials.Gov (NCT01123252), a 16-week dietary intervention was undertaken in 60 patients with allergic rhinitis (>16 years old). Using a double-blinded, placebo-controlled anonymised design, the patients were divided equally into two groups. One group was given a dairy drink containing Lactobacillus casei Shirota to ingest daily while the other consumed a similar drink without bacteria. Participants attended the clinic on two consecutive days before the intervention and then again at the end of the study period. On the first day of each 2-day visit, following clinical examination, assessments were made of total nasal symptoms scores and peak nasal inspiratory flow. Nasal scrapings, nasal lavage and blood were collected for laboratory analyses of cellular phenotypes, soluble mediator release and in vitro responses to pollen allergen. These procedures were repeated 24 hours following nasal allergen challenge.

Results

Prior to and following intervention there were no detectable differences between study groups in measured clinical outcome. After intervention, there were differences between groups in their percentages of CD86+ epithelial cells (p = 0.0148), CD86+CD252+ non-epithelial cells (p = 0.0347), sIL-1RII release (p = 0.0289) and IL-1β (p = 0.0224) levels at the nasal mucosa. Delivery of probiotic also suppressed production of sCD23 (p = 0.0081), TGF-β (p = 0.0283) and induced increased production of IFN-γ (p = 0.0351) in supernatants of cultured peripheral blood.

Conclusions & Clinical Relevance

This study did not show significant probiotic-associated changes with respect to the primary clinical endpoint. An absence of overt clinical benefit may be due to an inability of single nasal challenges to accurately represent natural allergen exposure. Nevertheless, oral delivery of probiotics produced changes of the immunological microenvironment at the nasal mucosa in individuals affected by SAR.

Trial Registration

ClinicalTrials.Gov NCT01123252

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.

Probiotics in treatment of allergic rhinitis

Many randomized controlled trials (RCTs) have been done on role of probiotics as a treatment modality in allergic rhinitis. We conducted a review on the same. A systematic search of published literature was done. RCTs comparing effect of probiotics with placebo were included. A predefined set of outcome measures were assessed. Continuous data were expressed as pooled standardized mean difference (SMD) with 95% confidence interval (CI). Dichotomous data were expressed as odds ratio with 95% CI. P value < 0.05 was considered significant. RevMan version 5 was used for all the analyses. Seven RCTs were eligible for inclusion. Probiotic intake improved quality of life score in patients with allergic rhinitis [SMD -1.17 (95% CI -1.47, -0.86; P < 0.00001)]. Other parameter that improved with probiotic intake was decrease in the number of episodes of rhinitis per year. There was no significant change in blood or immunologic parameters in the probiotic group, SMD -0.10 (95% CI -0.26, 0.06; P = 0.22). Adverse events were not significant. Probiotic therapy might be useful in rhinitis, but the present data do not allow any treatment recommendations.

Effect of oral feeding with Clostridium leptum on regulatory T-cell responses and allergic airway inflammation in mice

BACKGROUND

Allergic lung inflammation is mediated by allergen-specific T responses, which are negatively regulated by regulatory T cells (Tregs). Previous studies have reported that inoculation of indigenous Clostridium species in the early lives of mice can induce Tregs that colonize the colon. However, whether inoculation of C leptum alone in adult mice could induce systemic Treg responses and inhibit allergic airway inflammation remains unclear.

OBJECTIVE

To investigate the effect of oral administration of C leptum on systemic Treg responses and allergic airway inflammation in a mouse model of asthma.

METHODS

Adult BABL/c mice were injected with ovalbumin to induce asthma and treated orally with C leptum or vehicle daily for 2 weeks. The numbers of Foxp3(+)CD4(+)CD25(+) Tregs in both the spleen and mediastinal lymph nodes were examined by flow cytometry. After allergen challenge, the airway hyperresponsiveness of individual mice was measured, and the numbers of inflammatory infiltrates and the levels of cytokines in bronchoalveolar lavage fluids ere determined.

RESULTS

Oral feeding with C leptum increased the percentage and total number of Tregs in the spleens and mediastinal lymph nodes at 14 days after inoculation and attenuated allergen-induced airway hyperresponsiveness and inflammation by inhibiting inflammatory cytokine production but enhancing interleukin 10 and transforming growth factor β1 production in the lungs.

CONCLUSION

Oral treatment with C leptum can attenuate induced allergic airway inflammation in adult mice.

Effect of probiotics on allergic rhinitis in Df, Dp or dust-sensitive children: a randomized double blind controlled trial

OBJECTIVE

To study, we examined the effect of Lactobacillus salivarius on the clinical symptoms and medication use among children with established allergic rhinitis (AR).

DESIGN

Double blind, randomized, controlled trial.

SETTING

Hualien Tzu-Chi General Hospital.

METHODS

Atopic children with current allergic rhinitis received 4x10(9) colony forming units/g of Lactobacillus salivarius (n=99) or placebo (n=100) daily as a powder mixed with food or water for 12 weeks. The SCORing Allergic rhinitis index (specific symptoms scores [SSS] and symptom medication scores [SMS]), which measures the extent and severity of AR, was assessed in each subject at each of the visits--2 weeks prior to treatment initiation (visit 0), at the beginning of the treatment (visit 1), then at 4 (visit 2), 8 (visit 3) and 12 weeks (visit 4) after starting treatment. The WBC, RBC, platelet and, eosinophil counts as well as the IgE antibody levels of the individuals were evaluated before and after 3 months of treatment.

RESULTS

The major outcome, indicating the efficacy of Lactobacillus salivarius treatment, was the reduction in rhinitis symptoms and drug scores. No significant statistical differences were found between baseline or 12 weeks in the probiotic and placebo groups for any immunological or blood cell variables.

CONCLUSIONS

Our study demonstrates that Lactobacillus salivarius treatment reduces rhinitis symptoms and drug usage in children with allergic rhinitis.

Consumption of Galactooligosaccharides together with Probiotics Stimulates the In Vitro Peripheral Blood Mononuclear Cell Proliferation and IFNγ Production in Healthy Men

Probiotics and prebiotics modify the intestinal environment and could have immunomodulatory effects. The proliferation of spontaneous and phytohemagglutinin-stimulated peripheral blood mononuclear cells (PBMCs) and their production of interleukin-4, interleukin-5, transforming growth factor-β1, and interferon-γ (IFNγ) were determined in eighteen men at the baseline and during a 2-week period of probiotics (mixture of Lactobacillus rhamnosus GG, Lactobacillus rhamnosus LC705, Propionibacterium freudenreichii ssp. shermanii JS, and Bifidobacterium breve Bb99) and galactooligosaccharides (GOSs) (3.8 g/day). The spontaneous and stimulated proliferation of PBMC increased from the baseline during probiotics+GOS (P<0.001). The secretion of IFNγ, but not other cytokines, by stimulated PBMC increased during the same period (P<0.05). In conclusion, the consumption of this probiotic mixture including GOS appears to increase the capacity of PBMC to proliferate and release IFNγ selectively in healthy men.

Probiotics for allergic diseases: realities and myths

The prevalence of allergic diseases such as asthma, allergic rhinitis, and atopic dermatitis has increased sharply over the past two to three decades in many countries, and allergies are now the most common chronic disease among children throughout the world. In the past few years, probiotics have been advocated for the management of allergic diseases in many parts of the world. Physicians have a responsibility to ensure the efficacy and safety of any products they prescribe or recommend. This article provides a comprehensive overview and a critical interpretation of currently available evidence regarding the role of probiotics in the prevention and treatment of allergic diseases in humans and also discusses several major myths and potential risks associated with the use of probiotics. In the current era of evidence-based medicine, there is still insufficient evidence to recommend probiotics for the prevention of allergic diseases or as part of standard management for any allergic conditions in children.

Probiotics for allergic respiratory diseases--putting it into perspective

Respiratory allergies include allergic rhinitis, sinusitis and asthma. Increasing attention on pathogenesis of allergic airway diseases has given rise to "atopic march" hypothesis i.e. clinical features of atopic eczema occur first and precede the development of asthma and allergic rhinitis. The "hygiene hypothesis" proposes that the increase in allergic diseases reflects a decrease in infections during childhood. Clinical trials also suggest that the exposure to microbes through the gastrointestinal tract powerfully shapes immune function. Probiotics are live organisms which exert a beneficial effect in the prevention as well as treatment of allergic diseases through modification of immune system of host via gut ecosystem. Intestinal microbiota differs in infants who later develop allergic diseases, and feeding probiotics to infants at risk has been shown to reduce their rate of developing eczema. This has prompted studies of feeding probiotics in prevention as well as treatment of respiratory allergy. We hereby discuss the status of probiotics in respiratory allergy.

Probiotics for the treatment of allergic rhinitis and asthma: systematic review of randomized controlled trials

OBJECTIVE

To evaluate the clinical evidence for the use of probiotics as a therapeutic modality for allergic rhinitis (AR) and asthma.

DATA SOURCES

PubMed was searched to identify randomized controlled trials (RCTs) that studied the effects of probiotics on AR (n = 12) and asthma (n = 4).

STUDY SELECTION

RCTs that studied the effects of probiotics administration on the treatment but not the prevention of AR and asthma were selected for inclusion in this review.

RESULTS

Nine of the 12 RCTs that evaluated clinical outcomes in AR showed an improvement due to the use of probiotics. All the RCTs that studied perennial AR showed lower symptom scoring and medication use with the use of probiotics compared with placebo. Also, 5 of the 8 RCTs that referred to seasonal AR suggested an improvement in clinical outcomes. Nine RCTs that reported various immunologic measurements of allergy found no significant probiotic effects. The RCTs that studied the effect of probiotic administration on the treatment of asthma showed no positive effects.

CONCLUSIONS

Probiotics may have a beneficial effect in AR by reducing symptom severity and medication use. Many more good-quality studies are needed to resolve this issue.

Probiotics in clinical practice: an overview

The observation that intestinal bacterial microflora might be able to influence immune system surveillance through changed nutritional habits has raised awareness of the role of probiotics. These are live microorganisms that are able to reach the gastrointestinal tract and alter its microfloral composition, producing beneficial health effects when consumed in adequate amounts. Recent clinical trials have evaluated the clinical effectiveness of probiotics in the treatment and prevention of a wide range of acute and chronic gastrointestinal diseases, and also non-gastrointestinal diseases, such as atopy, respiratory infections, vaginitis and hypercholesterolaemia. Probiotic supplements are generally regarded as safe because the microorganisms they contain are identical to those found in human gastrointestinal and vaginal microflora. Guidelines on the use of probiotics in the clinical setting require periodical updates for the latest data to be included in clinical applications. The purpose of this clinical report is to review current evidence on the use of probiotics in a variety of gastrointestinal and non-gastrointestinal conditions.

Probiotic-induced suppression of allergic sensitization and airway inflammation is associated with an increase of T regulatory-dependent mechanisms in a murine model of asthma

BACKGROUND

Microbial intestinal colonization in early in life is regarded to play a major role for the maturation of the immune system. Application of non-pathogenic probiotic bacteria during early infancy might protect from allergic disorders but underlying mechanisms have not been analysed so far.

OBJECTIVE

The aim of the current study was to investigate the immune effects of oral application of probiotic bacteria on allergen-induced sensitization and development of airway inflammation and airway hyper-reactivity, cardinal features of bronchial asthma.

METHODS

Newborn Balb/c mice received orally 10(9) CFU every second day either Lactobacillus rhamnosus GG or Bifidobacterium lactis (Bb-12) starting from birth for consecutive 8 weeks, during systemic sensitization (six intraperitoneal injections, days 29-40) and airway challenge (days 54-56) with ovalbumin.

RESULTS

The administration of either Bb-12 or LGG suppressed all aspects of the asthmatic phenotype: airway reactivity, antigen-specific immunoglobulin E production and pulmonary eosinophilia (mean: 137 vs. 17 and 13 cellsx10(3)/mL, respectively). Antigen-specific recall proliferation by spleen cells and T-helper type 2 cytokine production (IL-4, IL-5 and IL-10) by mesenteric lymph node cells also showed significant reduction, while TGF production remained unchanged. Oral LGG administration particularly suppressed allergen-induced proliferative responses and was associated with an increase in numbers of TGF-beta-secreting CD4+/CD3+ T cells in mesenteric lymph nodes (6.5, 16.7%) as well as nearly 2-fold up-regulation of Foxp3-expressing cells in peribronchial lymph nodes.

CONCLUSIONS

Neonatal application of probiotic bacteria inhibits subsequent allergic sensitization and airway disease in a murine model of asthma by induction of T regulatory cells associated with increased TGF-beta production.

LKM512 yogurt consumption improves the intestinal environment and induces the T-helper type 1 cytokine in adult patients with intractable atopic dermatitis

BACKGROUND

In atopic dermatitis (AD) patients, the intestinal mucosal barrier function is weakened, permiting frequent invasion by antigens. Polyamines and short-chain fatty acids (SCFA) produced by intestinal bacteria are involved in the promotion of intestinal mucosal barrier functions.

AIM

Our aim was to investigate the effect of pro-biotic yogurt containing Bifidobacterium animalis subsp. lactis LKM512 (LKM512 yogurt) on subjective symptoms, intestinal microbiota, intestinal bacterial metabolites (polyamines and SCFA), and T-helper type 1 (Th1)/Th2 balance in intractable AD patients.

METHODS

In a double-blind, placebo-controlled, crossover study, LKM512 yogurt was given for 4 weeks to 10 adult AD patients who were diagnosed with moderate AD (four males and six females; average age, 22.1 years). The subjective symptoms were recorded after each intervention. The dynamics of fecal microbiota were analysed by the terminal-restriction fragment length polymorphism method. The effects of LKM512 yogurt on fecal polyamines, SCFA, and serum cytokines were evaluated.

RESULTS

Scores of itch and burning tended to improve to a greater extent by LKM512 yogurt consumption than by placebo consumption. LKM512 yogurt (P<0.005) and placebo consumption (P<0.05) significantly increased the serum IFN-gamma concentration by six- and threefold, respectively. Fecal microbiota was altered dynamically by LKM512 yogurt consumption, in particular, the bacterial species and phylotypes of Bifidobacterium, Clostridium cluster IV and subcluster XIVa were increased in number. In addition, fecal spermidine concentration was significantly (P<0.05) increased, while fecal butyrate also tended to be increased by LKM512 yogurt consumption.

CONCLUSION

We conclude that LKM512 yogurt consumption may be effective against intractable adult-type AD and this effect depends on the recovery of the intestinal mucosal barrier function and the induction of the Th1-type cytokine by polyamines and SCFA, particularly, butyrate, produced by the altered intestinal microbiota.

A randomized prospective double blind controlled trial on effects of long-term consumption of fermented milk containing Lactobacillus casei in pre-school children with allergic asthma and/or rhinitis

To examine whether long-term consumption of fermented milk containing a specific Lactobacillus casei may improve the health status of preschool children suffering from allergic asthma and/or rhinitis a randomized, prospective, double blind, controlled trial was conducted in 187 children 2-5 y of age. The children received for 12 mo either fermented milk (100 mL) containing Lactobacillus casei (10(8) cfu/mL) or placebo. The time free from and the number of episodes of asthma/rhinitis after starting intervention were the outcome measures. The number of fever or diarrhea episodes and the change in serum immunoglobulin were further assessed. No statistical difference between intervention and control group occurred in asthmatic children. In children with rhinitis, the annual number of rhinitis episodes was lower in the intervention group, mean difference (95% CI), -1.6 (-3.15 to -0.05); the mean duration of an episode of diarrhea was lower in the intervention group, mean difference -0.81 (-1.52 to -0.10) days. While long-term consumption of fermented milk containing Lactobacillus casei may improve the health status of children with allergic rhinitis no effect was found in asthmatic children.

Use of probiotics in pediatrics: rationale, mechanisms of action, and practical aspects

The use of probiotics (ingested microbes that can modify intestinal microbial populations in a way that benefit the host) has moved from concept to actual demonstration of specific benefits by specific microorganisms for specific populations. It is increasingly clear that these benefits to the host are mostly mediated by the profound effect that intestinal microflora (microbiota) have on gut barrier function and host immune response. Intestinal bacteria are more numerous than the human cells of the host that harbors them. Despite having many potential pathogens in this microflora, humans do not routinely get infected. It is no coincidence that gut-associated immune tissue constitutes approximately 80% of all immunologically active cells in the human host. The gut interacts with intestinal bacteria, both resident and ingested, to develop protective mechanisms (via improving gut barrier function and immune stimulation for defense) and appropriate, nonexaggerated responses (via immune modulation and immune tolerance) to support host health. The mechanisms of this interaction between host and bacteria are increasingly being unraveled and in great part explain the clinical benefits that have been reported with specific probiotic bacteria by enhancing host defense mechanisms (such as for treatment and prevention of viral diarrhea and reducing risk of necrotizing enterocolitis), mitigating antibiotic-associated diarrhea, and modulating host immune response (such as in allergic disease).

Prospective, randomized controlled trial on Lactobacillus rhamnosus in infants with moderate to severe atopic dermatitis

BACKGROUND

A reduction of symptoms of atopic dermatitis (AD) in small infants by the administration of Lactobacillus rhamnosus has been reported in a few studies. One study with older children and adolescents failed to show any effect.

OBJECTIVES

We conducted a prospective study to reassess the efficacy of orally administered L. rhamnosus strain GG (LGG) in infants with AD.

METHODS

In a randomized, double-blind, placebo-controlled study, 54 infants aged 1-55 months with moderate to severe AD were randomized to daily 10 x 10(9) colony-forming units of LGG or to placebo during an 8-week intervention phase. Emollients, class I-II topical corticosteroids and antihistamines were permitted.

RESULTS

The treatment with LGG was well tolerated. At the end of treatment there were no significant differences between the groups with respect to clinical symptoms (SCORAD, pruritus, sleep loss), the use of topical corticosteroids and antihistamines, immunological parameters, or health-related quality of life of the parents.

CONCLUSIONS

Our results could not confirm LGG as an effective treatment of AD in infancy.

Effects of Probiotics on Allergic Rhinitis Induced by Japanese Cedar Pollen: Randomized Double-Blind, Placebo-Controlled Clinical Trial

BACKGROUND

Lactobacillus casei strain Shirota (LcS) has been found to exert antiallergic effects in animal experiments, but there is little information about its clinical effects in human patients with allergy.

METHODS

We performed a randomized double-blind, placebo-controlled study to investigate the effects of LcS in patients with allergic rhinitis triggered by Japanese cedar pollen (JCP). Participants were asked to drink fermented milk containing LcS (LcS group) or placebo (control group) for 8 weeks. Clinical symptoms and immunological parameters were compared between the two groups.

RESULTS

Symptom-medication scores (SMS) worsened in accordance with the increase in the amount of scattered JCP. In terms of the nasal and ocular SMS, there was no significant difference between the LcS group and the placebo group during the ingestion period. In the subgroup of patients with moderate-to-severe nasal symptom scores before starting the ingestion of test samples, supplementation with LcS tended to reduce nasal SMS.

CONCLUSION

These results indicate that fermented milk containing LcS does not prevent allergic symptoms in patients sensitive to JCP, but may delay the occurrence of allergic symptoms in patients with moderate-to-severe nasal symptom scores.

Survival of yogurt bacteria in the human gut

Whether Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus can be recovered after passage through the human gut was tested by feeding 20 healthy volunteers commercial yogurt. Yogurt bacteria were found in human feces, suggesting that they can survive transit in the gastrointestinal tract.

Probiotics: immunomodulation and evaluation of safety and efficacy

The intake of probiotics has been associated with beneficial effects on the immune system, such as improved disease resistance and diminished risk of allergies. This review gives an overview of the immunomodulatory effects of probiotics investigated with in vitro assays, experimental animal models, and clinical trials, and explores possible mechanisms underlying the immunomodulatory effects. Immunomodulation, however, is not always beneficial and might induce detrimental effects; therefore, a scheme is proposed for benefit-risk assessment of immunomodulation by probiotics. Within this scheme, expert judgment based on data derived from a panel of in vitro assays, animal models, and clinical trials should lead to conclusions on efficacy and safety aspects of probiotics.