Lactobacillus GG has in vitro effects on enhanced interleukin-10 and interferon-gamma release of mononuclear cells but no in vivo effects in supplemented mothers and their neonates

Impact of Bifidobacterium longum1714® on maternal cytokine response in peripheral blood mononuclear cells

PURPOSE

The maternal immune system is implicated in adverse pregnancy outcomes. Manipulation of maternal immune response by probiotics holds potential to reduce pregnancy complications. The MicrobeMom2 study investigates the impact of probiotic supplementation on maternal immune responses to pathogen associated molecular patterns (PAMPs) in peripheral blood mononuclear cells (PBMCs) during pregnancy.

METHODS

This double-blinded randomised-controlled trial involved oral supplementation of Bifidobacterium longum subsp. longum 1714® (B. longum 1714; daily ingestion of a minimum of 1x109 colony forming units) or placebo from 16 to 20-weeks' gestation until delivery in healthy pregnant women. The primary outcome was a change in IL-10 production, after stimulation with Lipopolysaccharide (LPS) or anti-CD3/28/2, in PBMCs isolated from blood samples taken at baseline (11-15 weeks' gestation) and late pregnancy (28-32 weeks' gestation) after 48 h incubation. 68 subjects were needed (34ineachgroup) for 80 % power at an alpha significance of 0.05 to detect differences in IL10.

RESULTS

72 women (mean ± SD age 33.17 ± 4.53 years and median (25th, 75th centile) body mass index 24.93 (21.93, 27.57 kg/m2)) were recruited with primary outcome data. Using LPS, late pregnancy fold change in IL-10 in PBMCs after 48 h incubation was median (25th, 75th centile) 88.45 (4.88, 488.78) in the intervention, 24.18 (6.36, 141.17) in the control group, p = 0.183. Using anti-CD3/28/2, values were 189.69 (425.96, 866.57),148.74 (31.67, 887.03) in intervention and control groups, respectively, p = 0.506. No significant differences were observed between the two groups.

CONCLUSION

Maternal antenatal supplementation with B. longum 1714 did not alter cytokine production by maternal PBMCs in response to PAMPs or anti-CD3/28/2.

TRIAL REGISTRATION NUMBER

ISRCTN registry ISRCTN43013285.

Dietary methionine sources and levels modulate the intestinal health status of broiler chickens

Given the key role of methionine in biological processes, adequate methionine should be provided to meet the nutritional requirements. DL-2-hydroxy-4-(methylthio)-butanoic acid (DL-HMTBA) has been considered as an important source of methionine. However, the effects of different sources and levels of methionine on the intestinal health status have not been clarified yet. An experiment was carried out to investigate the effects of different dietary sources and levels of methionine on the intestinal epithelial barrier, inflammatory cytokines expression, ileal morphology, microbiota composition, and cecal short chain fatty acids (SCFA) profiles. For this purpose, 720 male Arbor Acre broiler chicks at 1 d old were randomly assigned to a 2 × 3 factorial arrangement with 2 methionine sources (DL-methionine and DL-HMTBA) and 3 total sulfur amino acids (TSAA) levels (80%, 100%, and 120% of Arbor Acre recommendation). The results showed that DL-HMTBA supplementation promoted intestinal physical barrier at both gene expression level of claudin-1 and serum diamine oxidase level (P < 0.05), and the inflammatory cytokine IL-6 mRNA expression was down-regulated by dietary DL-HMTBA supplementation compared with the DL-methionine group (P < 0.05). Meanwhile, an upregulated gene expression of claudin-1 and zonula occluden-1 (ZO-1) were observed in the low-TSAA treatment on d 14 (P < 0.05), whereas this treatment increased the expression of IL-1β and IL-6 (P < 0.05). Villus height to crypt depth ratio was high (P < 0.05) in the middle-level TSAA group. Furthermore, DL-HMTBA supplementation optimized the microbiota of the ileum especially the relative abundance of Lactobacillus, where the digestion and absorption were completed, and elevated the concentrations of SCFA (acetate, propionate, and butyrate) in the cecal content on d 21 (P < 0.01). In conclusion, dietary DL-HMTBA supplementation improved the intestinal barrier function, immune homeostasis and optimized the microbiota to promote intestinal health status in broiler chickens.

Effect and safety of probiotics for treating urticaria: A systematic review and meta-analysis

BACKGROUND

To assess the effect and safety of probiotics for treating urticaria.

METHODS

Randomized controlled trial (RCT) papers on the probiotics treatment published before May 2019 were retrieved from various databases like PubMed, EMbase, MEDLINE (Ovid), SCI-Hub, Springer, ClinicalKey, VIP, and CNKI. The treatment plan that we include are oral administration of single probiotic, multiple probiotics, and the combination of probiotics and antihistamines. Meta-analysis of the data was performed by RevMan 5.3 software.

RESULTS

A total of nine RCT papers were included: four papers for oral administration of single probiotic, three papers for oral administration of multiple probiotics, and two papers for oral administration of a probiotic combined with antihistamines. The results of meta-analysis showed that the therapeutic effect of the probiotic group was significantly higher than the control group (placebo or antihistamines) (RR = 1.09, 95% CI: 1.03-1.16, p = 0.006). And compared with the placebo group, the therapeutic effect of single probiotic group was significantly improved (RR = 1.11, 95% CI: 1.01-1.21, p = 0.03). Regarding therapeutic effect, there was no statistically significant difference between the multiple probiotics group and placebo group (RR = 1.00, 95% CI: 0.94 ~ 1.07, p = 0.91); the therapeutic effect of single probiotic combined antihistamine group was significantly higher than the antihistamine group (RR = 1.13, 95% CI: 1.07-1.19, p < 0.0001). Regarding the incidence of adverse reactions, there was no significant difference between the probiotic group and the control group (p = 0.46).

CONCLUSION

The treatment plan of oral administration of probiotics has significant therapeutic effects on urticaria, but the therapeutic effects of the administration of multiple probiotics and the safety of probiotic therapy are still not yet obvious. Some large-scale, multi-centered RCT studies are needed in the future for clarification.

Different probiotic strains alter human cord blood monocyte responses

BACKGROUND

Probiotics have a protective effect on various diseases. In neonatology, they are predominantly used to prevent necrotising enterocolitis (NEC), a severe inflammatory disease of the neonatal intestine. The mechanisms by which probiotics act are diverse; little is known about their direct effect on neonatal immune cells.

METHODS

In this study, we investigated the effect of probiotics on the functions of neonatal monocytes in an in vitro model using three different strains (Lactobacillus rhamnosus (LR), Lactobacillus acidophilus (LA) and Bifidobacterium bifidum (BB)) and mononuclear cells isolated from cord blood.

RESULTS

We show that stimulation with LR induces proinflammatory effects in neonatal monocytes, such as increased expression of surface molecules involved in monocyte activation, increased production of pro-inflammatory and regulatory cytokines and increased production of reactive oxygen species (ROS). Similar effects were observed when monocytes were stimulated simultaneously with LPS. Stimulation with LA and BB alone or in combination also induced cytokine production in monocytes, with BB showing the least effects.

CONCLUSIONS

Our results suggest that probiotics increase the defence functions of neonatal monocytes and thus possibly favourably influence the newborn's ability to fight infections.

IMPACT

Probiotics induce a proinflammatory response in neonatal monocytes in vitro. This is a previously unknown mechanism of how probiotics modulate the immune response of newborns. Probiotic application to neonates may increase their ability to fight off infections.

Vaginal and oral probiotics effect in the prevention of preterm delivery in patients visiting Kamali Hospital, Karaj, Iran in 2020

INTRODUCTION

The prevalence of preterm labor (PTL) is growing, and annually one in ten babies is born prematurely. Various studies have examined the effect of oral or vaginal probiotics on the prevention of preterm labor, which has yielded contrasting results. This study aimed to compare the impact of vaginal and oral probiotics on the prevention of preterm delivery.

METHODS

This clinical trial was performed among 185 pregnant women with a gestational age greater than or equal to 25 weeks visiting Kamali Hospital, Karaj, Iran in 2020. The participants were divided into three groups; intervention group 1 receiving Oral probiotic pill once a day until 37 weeks of pregnancy, intervention group 2 receiving probiotic vaginal suppository once a day until 37 weeks of pregnancy, and control group not receiving any intervention. Patients were then followed up until the end of pregnancy.

RESULTS

Demographic characteristics and gestational age at the time of intervention were not significantly different among the three groups. Overall, 26.7 % in the control group, 30 % in intervention group 1 %, and 22.5 % in intervention group 2 had deliveries less than 37 weeks. There was no significant difference in the frequency of preterm labor and the duration of pregnancy among the groups (all p > 0.05).

CONCLUSION

Probiotics use does not increase the rate of preterm delivery or reduce the duration of pregnancy, but the rate of preterm delivery was lower in the oral probiotic group. Further clinical studies on the impact of probiotics on PTL can yield valuable results.

Modulatory Impacts of Multi-Strain Probiotics on Rabbits’ Growth, Nutrient Transporters, Tight Junctions and Immune System to Fight against Listeria monocytogenes Infection

Simple Summary

Weaning is a crucial period associated with great stress and susceptibility to infection, implying adverse impacts on farmed rabbits’ production. Recently, probiotics have been provided as direct microbial feed supplements, which are considered the ideal antibiotic substitutes during pathogenic infections with an emphasis on promoting rabbits’ growth and modulating their immune functions. Therefore, our experiment was carried out to explore the efficacy of multi-strain probiotics (MSP) on rabbits’ growth, molecular aspects, such as nutrients transporters, cytokines, and intestinal integrity, and effectiveness against Listeria monocytogenes (L. monocytogenes) infection. Altogether, our findings proposed the beneficial consequences of MSP on rabbits’ growth, gut health, and immunity. After post-experimental infection of rabbits with L. monocytogenes, administration of MSP during the whole rearing period greatly reduced the detrimental impact of infection and consequently renovated efficient rabbits’ production.

Abstract

Multi-strain probiotics (MSP) are considered innovative antibiotics’ substitutes supporting superior gut health and immunity of farmed rabbits. The promising roles of MSP on performance, intestinal immunity, integrity and transporters, and resistance against Listeria monocytogenes (L. monocytogenes) were evaluated. In the feeding trial, 220 rabbits were fed a control diet or diet supplemented with three MSP graded levels. At 60 days of age, rabbits were experimentally infected with L. monocytogenes and the positive control, enrofloxacin, prophylactic MSP (MSPP), and prophylactic and therapeutic MSP (MSPTT) groups were included. During the growing period, MSP at the level of 1 × 10⁸ CFU/kg diet (MSPIII) promoted the rabbits’ growth, upregulated the nutrient transporters and tight-junction-related genes, and modified cytokines expression. Supplementing MSPTT for L. monocytogenes experimentally-infected rabbits restored the impaired growth and intestinal barriers, reduced clinical signs of severity and mortalities, and attenuated the excessive inflammatory reactions. Notably, enrofloxacin decreased L. monocytogenes and beneficial microbial loads; unlike MSPTT, which decreased pathogenic bacterial loads and sustained the beneficial ones. Histopathological changes were greatly reduced in MSPTT, confirming its promising role in restricting L. monocytogenes translocation to different organs. Therefore, our results suggest the use of MSPTT as an alternative to antibiotics, thereby conferring protection for rabbits against L. monocytogenes infection.

The neuroprotective effects of polyphenols, their role in innate immunity and the interplay with the microbiota

Neurodegenerative disorders, particularly in the elderly population, represent one of the most pressing social and health-care problems in the world. Besides the well-established role of both oxidative stress and inflammation, alterations of the immune response have been found to be closely linked to the development of neurodegenerative diseases. Interestingly, various scientific evidence reported that an altered gut microbiota composition may contribute to the development of neuroinflammatory disorders. This leads to the proposal of the concept of the gut-brain-immune axis. In this scenario, polyphenols play a pivotal role due to their ability to exert neuroprotective, immunomodulatory and microbiota-remodeling activities. In the present review, we summarized the available literature to provide a scientific evidence regarding this neuroprotective and immunomodulatory effects and the interaction with gut microbiota of polyphenols and, the main signaling pathways involved that can explain their potential therapeutic application in neurodegenerative diseases.

Examining Associations Between Dietary Inflammatory Index in Pregnancy, Pro-inflammatory Cytokine and Chemokine Levels at Birth, and Offspring Asthma and/or Wheeze by Age 4 Years

BACKGROUND

Few studies have demonstrated associations between maternal dietary inflammatory index (DII) during pregnancy and offspring asthma and/or wheeze.

OBJECTIVE

The study aimed to assess associations between maternal DII during pregnancy and 1) offspring cord sera pro-inflammatory cytokines (interleukin [IL]-1β, IL-4, IL-6, IL-10, tumor necrosis factor-α) and chemokines (IL-8, monocyte chemoattractant protein-1) at birth and 2) offspring asthma and/or wheeze at age 4 years.

DESIGN

The Healthy Start study is a prospective prebirth longitudinal study that recruited pregnant women in Denver, Colorado and tracked their offspring.

PARTICIPANTS AND SETTING

This study used data from 1228 mother-child dyads enrolled in the Healthy Start study. Pregnant women were recruited in Denver, Colorado, between 2009 and 2014, and offspring tracked until age 4 years.

MAIN OUTCOME MEASURES

Cord sera cytokines and chemokines were analyzed with multiplex panel immunoassays. Offspring diagnosis of asthma and/or wheeze by age 4 years was extracted from electronic medical records.

STATISTICAL ANALYSES PERFORMED

Unadjusted and adjusted linear and logistic regression models were used to assess associations. Covariates included factors such as nulliparity, race/ethnicity, gestational smoking, and maternal history of asthma.

RESULTS

Unadjusted analysis showed that increasing maternal DII scores were associated with increased odds of child asthma and/or wheeze by 4 years (odds ratio = 1.17; 95% CI: 1.07-1.27), but the association was attenuated and no longer statistically significant in the adjusted model (odds ratio = 1.15; 95% CI: 0.99-1.33). There were no significant associations between DII scores and cord sera cytokine or chemokine levels.

CONCLUSIONS

The study showed that the inflammatory profile of the maternal diet was not associated with cytokines and chemokine levels at birth. The results suggested that a more inflammatory maternal diet was associated with increased odds of offspring asthma and/or wheeze by age 4 years, which could be considered of clinical relevance but the finding was not statistically significant at the .05 level.

Effects of chronic treatment with new strains of Lactobacillus plantarum on cognitive, anxiety- and depressive-like behaviors in male mice

Psychobiotics correspond to a class of probiotics, mainly of the genus Lactobacillus and Bifidobacterium, capable of producing neuroactive substances, such as γ-aminobutyric acid (GABA) and serotonin, which exert effects on the brain-gut axis. Evidence suggests that psychobiotics can have a beneficial effect on mood, anxiety and cognition. The present study evaluated the effects of chronic administration of two new strains of Lactobacillus plantarum, L. plantarum 286 (Lp 286) and L. plantarum 81 (Lp 81) isolated from the fermentation of cocoa (Theobroma cacao L.) and cupuaçu (Theobroma grandiflorum), respectively, on cognitive, anxiety- and depressive-like behaviors in male Swiss mice. Different groups of animals were administered (oral gavage) solutions of vehicle (0.85% saline plus 15% skim milk), Lp 286 (10⁹/0.1 ml CFU) or Lp 81 (10⁹/0.1 ml CFU) for 30 days, and animals were tested for general locomotor activity, depressive-like behavior in the forced swim test, and learning/memory and anxiety-like behavior in the plus-maze discriminative avoidance task. Treatment with the strains Lp 286 and Lp 81 did not interfere with locomotor activity or learning and memory. The Lp 286 strain exerted anti-depressant- and anxiolytic-like effects under our experimental conditions. Our findings add to the current body of evidence suggesting that probiotics from the genus Lactobacillus may exert psychobiotic potential and introduce a new strain, Lp 286, as a potential candidate in the prevention or as therapeutic adjuvant in the treatment of mental disorders.

Efficacy of a multispecies probiotic as adjunctive therapy in generalized anxiety disorder: a double blind, randomized, placebo-controlled trial

ABSTRACT Objectives: Studies have shown that probiotics may decrease anxiety symptoms, but to our knowledge so far no trial has investigated the effects of probiotics in generalized anxiety disorder (GAD). The aim of the present study was to determine the effects of probiotics as adjunctive therapy on anxiety severity and quality of life (QOL) in patients with GAD. Methods: Forty-eight drug-free patients with a diagnosis of GAD based on DSM-V criteria were randomly assigned to two groups to receive daily either one capsule of probiotics or placebo in addition to 25 mg sertraline for 8 weeks. Probiotic capsules contained 18*10⁹ CFU Bifidobacterium longom, Bifidobacterium bifidum, Bifidobacterium lactis and Lactobacillus acidophilus bacteria. Results: Intention to treat analysis was performed in 39 Patients who completed at least 4 weeks of the intervention. After 8 weeks, the score of Hamilton Rating Scale for anxiety (HAM-A) decreased more in the probiotics + sertraline (PS) group (p = 0.003). Although the reduction of Beck Anxiety Inventory (BAI) was also more in the PS group, it was not significantly different from that of the sertraline alone(S) group. Moreover, despite the greater reduction of State-Anxiety Inventory score in the PS group, the score of Trait-Anxiety Inventory was not statistically different between the two groups at week 8. With regard to QOL, there was no significant difference between the two groups in the change of the score of QOL domains. Conclusions: Probiotics + sertraline combination was superior to sertraline alone in decreasing anxiety symptoms after 8 weeks in patients with GAD, although it did not affect QOL.

Will every child have allergic rhinitis soon?

OBJECTIVES

Given the increasing prevalence of AR amongst children, we aimed to review the literature regarding the future of AR in this population.

METHODS

We searched the PubMed, Google and Proquest Central databases at Kırıkkale University Library. Search terms used were: "allergic rhinitis", "children", "paediatric", "allergy", "future", "risk factors", "treatment", "pharmacotherapy" and/or "allergen - specific immunotherapy". With regard to risk factors for allergic rhinitis, the terms "Environmental factors", "Improved hygiene", "Increased indoor allergen exposure", "Farms, villages, worms, and other parasites", "Environmental toxicants", "Diet", "Lifestyle changes", "Air pollution" and "Climate factors" were searched for. "Prevention of allergic diseases" and "Allergen-specific immunotherapy in the future" were also included in the search.

RESULTS

AR has a high prevalence and causes considerable morbidity, has associated comorbidity and features specific complications. The principal treatments rely on avoiding the allergens responsible, and administering drug treatment or immunotherapy, which targets specific antigens. Genetic drift does not explain the rising prevalence of allergic disorders, but multifactorial environmental factors are likely culprits. Amongst such environmental factors to consider are the rise in caesarean births, decreases in breast feeding, dietary changes resulting in less fresh produce being consumed, the eradication of intestinal worm infestations, alterations in the way homes are aired and heated, children taking less exercise and being outdoors for shorter periods, whilst also having more contact with pollution.

CONCLUSION

Barring substantial lifestyle alterations, more and more children are likely to develop AR. It may prove feasible to stop allergy developing in the first place through manipulation of the microbiome, but the exact format such a modification should involve remains to be discovered. Molecular allergological techniques do offer the prospect of more precisely targeted immunotherapy, the sole disease modifier at present. However, at present the complexity and cost of such interventions prevents their widespread use and research in this area is still needed. The majority of children with AR are going to be managed using nasal saline sprays, since they are the most straightforward and least risky alternative for first line treatment.

Maternal probiotic supplementation for prevention of morbidity and mortality in preterm infants

BACKGROUND

Inflammation may contribute to preterm birth and to morbidity of preterm infants. Preterm infants are at risk for alterations in the normal protective microbiome. Oral probiotics administered directly to preterm infants have been shown to decrease the risk for severe necrotizing enterocolitis (NEC) as well as the risk of death, but there are safety concerns about administration of probiotics directly to preterm infants. Through decreasing maternal inflammation, probiotics may play a role in preventing preterm birth and/or decreasing the inflammatory milieu surrounding delivery of preterm infants, and may alter the microbiome of the preterm infant when given to mothers during pregnancy. Probiotics given to mothers after birth of preterm infants may effect infant bacterial colonization, which could potentially reduce the incidence of NEC.

OBJECTIVES

1. To compare the efficacy of maternal probiotic administration versus placebo or no intervention in mothers during pregnancy for the prevention of preterm birth and the prevention of morbidity and mortality of infants born preterm.2. To compare the efficacy of maternal probiotic administration versus placebo, no intervention, or neonatal probiotic administration in mothers of preterm infants after birth on the prevention of mortality and preterm infant morbidities such as NEC.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2017, Issue 2), MEDLINE via PubMed (1966 to 21 March 2017), Embase (1980 to 21 March 2017), and CINAHL (1982 to 21 March 2017). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomized controlled trials and quasi-randomized trials.

SELECTION CRITERIA

We included randomized controlled trials in the review if they administered oral probiotics to pregnant mothers at risk for preterm birth, or to mothers of preterm infants after birth. Quasi-randomized trials were eligible for inclusion, but none were identified. Studies enrolling pregnant women needed to administer probiotics at < 36 weeks' gestation until the trimester of birth. Probiotics considered were of the genera Lactobacillus, Bifidobacterium or Saccharomyces.

DATA COLLECTION AND ANALYSIS

We used the standard methods of the Cochrane Collaboration and Cochrane Neonatal to determine the methodologic quality of studies, and for data collection and analysis.

MAIN RESULTS

We included 12 eligible trials with a total of 1450 mothers and 1204 known infants. Eleven trials administered probiotics to mothers during pregnancy and one trial administered probiotics to mothers after birth of their preterm infants. No studies compared maternal probiotic administration directly with neonatal administration. Included prenatal trials were highly variable in the indication for the trial, the gestational age and duration of administration of probiotics, as well as the dose and formulation of the probiotics. The pregnant women included in these trials were overall at low risk for preterm birth. In a meta-analysis of trial data, oral probiotic administration to pregnant women did not reduce the incidence of preterm birth < 37 weeks (typical risk ratio (RR) 0.92, 95% confidence interval (CI) 0.32 to 2.67; 4 studies, 518 mothers and 506 infants), < 34 weeks (typical risk difference (RD) 0.00, 95% CI -0.02 to 0.02; 2 studies, 287 mothers and infants), the incidence of infant mortality (typical RD 0.00, 95% CI -0.02 to 0.02; 2 studies, 309 mothers and 298 infants), or the gestational age at birth (mean difference (MD) 0.15, 95% CI -0.33 to 0.63; 2 studies, 209 mothers with 207 infants).One trial studied administration of probiotics to mothers after preterm birth and included 49 mothers and 58 infants. There were no significant differences in the risk of any NEC (RR 0.44, 95% CI 0.13 to 1.46; 1 study, 58 infants), surgery for NEC (RR 0.15, 95% CI 0.01 to 2.58; 1 study, 58 infants), death (RR 0.66, 95% CI 0.06 to 6.88; 1 study, 58 infants), and death or NEC (RR 0.53, 95% CI 0.19 to 1.49; 1 study, 58 infants). There was an improvement in time to reach 50% enteral feeds in infants whose mothers received probiotics, but the estimate is imprecise (MD -9.60 days, 95% CI -19.04 to -0.16 days; 58 infants). No other improvement in any neonatal outcomes were reported. The estimates were imprecise and do not exclude the possibility of meaningful harms or benefits from maternal probiotic administration. There were no cases of culture-proven sepsis with the probiotic organism. The GRADE quality of evidence was judged to be low to very low due to inconsistency and imprecision.

AUTHORS' CONCLUSIONS

There is insufficient evidence to conclude whether there is appreciable benefit or harm to neonates of either oral supplementation of probiotics administered to pregnant women at low risk for preterm birth or oral supplementation of probiotics to mothers of preterm infants after birth. Oral supplementation of probiotics to mothers of preterm infants after birth may decrease time to 50% enteral feeds, however, this estimate is extremely imprecise. More research is needed for post-natal administration of probiotics to mothers of preterm infants, as well as to pregnant mothers at high risk for preterm birth.

Probiotic Lactobacillus plantarum Promotes Intestinal Barrier Function by Strengthening the Epithelium and Modulating Gut Microbiota

Weaning disturbs the intestinal barrier function and increases the risk of infection in piglets. Probiotics exert beneficial health effects, mainly by reinforcing the intestinal epithelium and modulating the gut microbiota. However, the mechanisms of action, and especially, the specific regulatory effects of modulated microbiota by probiotics on the intestinal epithelium have not yet been elucidated. The present study aimed to decipher the protective effects of the probiotic Lactobacillus plantarum strain ZLP001 on the intestinal epithelium and microbiota as well as the effects of modulated microbiota on epithelial function. Paracellular permeability was measured with fluorescein isothiocyanate-dextran (FD-4). Gene and protein expression levels of tight junction (TJ) proteins, proinflammatory cytokines, and host defense peptides were determined by RT-qPCR, ELISA, and western blot analysis. Short-chain fatty acid (SCFA) concentrations were measured by ion chromatography. Fecal microbiota composition was assessed by high-throughput sequencing. The results showed that pretreatment with 10⁸ colony forming units (CFU) mL⁻¹ of L. plantarum ZLP001 significantly counteracted the increase in gut permeability to FD-4 induced by 10⁶ CFU mL⁻¹ enterotoxigenic Escherichia coli (ETEC). In addition, L. plantarum ZLP001 pretreatment alleviated the reduction in TJ proteins (claudin-1, occludin, and ZO-1) and downregulated proinflammatory cytokines IL-6 and IL-8, and TNFα expression and secretion caused by ETEC. L. plantarum ZLP001 also significantly increased the expression of the host defense peptides pBD2 and PG1-5 and pBD2 secretion relative to the control. Furthermore, L. plantarum ZLP001 treatment affected piglet fecal microbiota. The abundance of butyrate-producing bacteria Anaerotruncus and Faecalibacterium was significantly increased in L. plantarum ZLP001-treated piglets, and showed a positive correlation with fecal butyric and acetic acid concentrations. In addition, the cell density of Clostridium sensu stricto 1, which may cause epithelial inflammation, was decreased after L. plantarum ZLP001 administration, while the beneficial Lactobacillus was significantly increased. Our findings suggest that L. plantarum ZLP001 fortifies the intestinal barrier by strengthening epithelial defense functions and modulating gut microbiota.

Effects of Lactobacillus rhamnosus GG and Escherichia coli Nissle 1917 Cell-Free Supernatants on Modulation of Mucin and Cytokine Secretion on Human Intestinal Epithelial HT29-MTX Cells

This study examined modulation effects of cell-free supernatants of two commonly studied probiotic bacteria Lactobacillus rhamnosus GG (LGG) and Escherichia coli Nissle 1917 (EcN) on mucin and cytokine profiles of human intestinal epithelial HT29-MTX cells. It was found that LGG and EcN supernatants differentially modulated MUC5AC and MUC5B mRNA and protein, and total mucin-like glycoprotein secretion. Regarding modulation of cytokine profiles, LGG supernatants moderately influenced the secretion of anti-inflammatory cytokines such as interleukin (IL)-4, IL-5, and IL-10, while those of EcN exerted a broad proinflammatory effect to intestinal epithelial cells by inducing the secretion of proinflammatory cytokines such as IL-8, monocyte chemotactic protein-1, transforming growth factor α, tumor necrosis factor α, granulocyte macrophage colony-stimulating factor, and interferon γ. These results suggested that LGG and EcN might produce different bioactive products that display differential modulation of mucin and cytokines, which may contribute to intestinal health and/or defense against bacteria/pathogens.

PRACTICAL APPLICATION

The results suggested that LGG and EcN might produce different bioactive products that display differential modulation of mucin and cytokines, which may contribute to intestinal health and/or defense against bacteria/pathogens.

Pre- and probiotics for allergy prevention: time to revisit recommendations?

Reduced intensity and diversity of microbial exposure is considered a major factor driving abnormal postnatal immune maturation and increasing allergy prevalence, particularly in more affluent regions. Quantitatively, the largest important source of early immune-microbial interaction, the gut microbiota, is of particular interest in this context, with variations in composition and diversity in the first months of life associated with subsequent allergy development. Attempting to restore the health consequences of the 'dysbiotic drift' in modern society, interventions modulating gut microbiota for allergy prevention have been evaluated in several randomized placebo-controlled trials. In this review, we provide an overview of these trials and discuss recommendations from international expert bodies regarding prebiotic, probiotic and synbiotic interventions. Recent guidelines from the World Allergy Organization recommend the use of probiotics for the primary prevention of eczema in pregnant and breastfeeding mothers of infants at high risk for developing allergy and in high-risk infants. It is however stressed that these recommendations are conditional, based on very low-quality evidence and great heterogeneity between studies, which also impedes specific and practical advice to consumers on the most effective regimens. We discuss how the choice of probiotic strains, timing and duration of administration can critically influence the outcome due to different effects on immune modulation and gut microbiota composition. Furthermore, we propose strategies to potentially improve allergy-preventive effects and enable future evidence-based implementation.

Bugging allergy; role of pre-, pro- and synbiotics in allergy prevention

Large-scale biodiversity loss and complex changes in social behaviors are altering human microbial ecology. This is increasingly implicated in the global rise in inflammatory diseases, most notably the "allergy epidemic" in very early life. Colonization of human ecological niches, particularly the gastrointestinal tract, is critical for normal local and systemic immune development and regulation. Disturbances in composition, diversity and timing of microbial colonization have been associated with increased allergy risk, indicating the importance of strategies to restore a dysbiotic gut microbiota in the primary prevention of allergic diseases, including the administration of probiotics, prebiotics and synbiotics. Here, we summarize and discuss findings of randomized clinical trials that have examined the effects of these microbiome-related strategies on short and long-term allergy preventative effects - including new guidelines from the World Allergy Organization which now recommend probiotics and prebiotics for allergy prevention under certain conditions. The relatively low quality evidence, limited comparative studies and large heterogeneity between studies, have collectively hampered recommendations on specific probiotic strains, specific timing and specific conditions for the most effective preventive management. At the same time the risk of using available products is low. While further research is needed before specific practice guidelines on supplement probiotics and prebiotics, it is equally important that the underlying dietary and lifestyle factors of dysbiosis are addressed at both the individual and societal levels.

Gut Microbiota-brain Axis

Objective:

To systematically review the updated information about the gut microbiota-brain axis.

Data Sources:

All articles about gut microbiota-brain axis published up to July 18, 2016, were identified through a literature search on PubMed, ScienceDirect, and Web of Science, with the keywords of “gut microbiota”, “gut-brain axis”, and “neuroscience”.

Study Selection:

All relevant articles on gut microbiota and gut-brain axis were included and carefully reviewed, with no limitation of study design.

Results:

It is well-recognized that gut microbiota affects the brain's physiological, behavioral, and cognitive functions although its precise mechanism has not yet been fully understood. Gut microbiota-brain axis may include gut microbiota and their metabolic products, enteric nervous system, sympathetic and parasympathetic branches within the autonomic nervous system, neural-immune system, neuroendocrine system, and central nervous system. Moreover, there may be five communication routes between gut microbiota and brain, including the gut-brain's neural network, neuroendocrine-hypothalamic-pituitary-adrenal axis, gut immune system, some neurotransmitters and neural regulators synthesized by gut bacteria, and barrier paths including intestinal mucosal barrier and blood-brain barrier. The microbiome is used to define the composition and functional characteristics of gut microbiota, and metagenomics is an appropriate technique to characterize gut microbiota.

Conclusions:

Gut microbiota-brain axis refers to a bidirectional information network between the gut microbiota and the brain, which may provide a new way to protect the brain in the near future.

Fecal Microbiota Transplantation and Its Usage in Neuropsychiatric Disorders

Fecal microbiota transplantation has a 1700-year history. This forgotten treatment method has been put into use again during the last 50 years. The interest in microbiota-gut-brain axis and fecal microbiota transplantation is rapidly increasing. New evidence is obtained in the etiopathogenesis of neuropsychiatric disorders. There is a large number of experimental and clinical researches in the field of gut-brain axis. There is limited information on fecal microbiota transplantation. Despite this, initial results are promising. It is commonly used in the treatment of gastrointestinal diseases such as Clostridium difficile infection, Crohn’s disease, ulcerative colitis. It is also experimentally used in the treatment of metabolic and autoimmune diseases. There are case reports that it is effective in the treatment of autism, Parkinson’s disease, multiple sclerosis, chronic fatigue syndrome and irritable bowel syndrome. Its implementation is easy, and it is a cheap and reliable treatment method. However, the long-term risks are unknown. Additionally, standard application protocols have not yet been established. There are a lot of questions to be answered. A university in Turkey has got official permission this year, and started to apply fecal microbiota transplantation. In this review, neuropsychiatric areas of use of fecal microbiota transplantation have been discussed in the light of the current information.

Chlamydia pneumoniae enhances the Th2 profile of stimulated peripheral blood mononuclear cells from asthmatic patients

Chlamydia pneumoniae is a cause of respiratory infection in adults and children. There is evidence for an association between atypical bacterial respiratory pathogens and the pathogenesis of asthma. We compared T helper (Th) responses in C. pneumoniae - infected peripheral blood mononuclear cells (PBMC) in patients with or without asthma. PBMC (1×10(6)/mL) from asthmatic patients (N=11) and non-asthmatic controls (N=12) were infected or mock-infected for 1h +/- C. pneumoniae TW-183 at a multiplicity of infection (MOI)=1 and MOI=0.1, or cultured for 24h +/- Lactobacillus rhamnosus GG (LGG). Interleukin (IL)-4, IL-10, IL-12, Interferon (IFN)-gamma and total IgE levels were measured in supernatants (ELISA). C. pneumoniae infection led to an increase (>50%) of IgE levels in PBMC from asthmatics, compared with mock-infected on day 10; IgE wasn't detected in non-asthmatics. C. pneumoniae - infected PBMC from asthmatics increased levels of IL-4 and IFN-gamma after 24h, compared with PBMC alone; levels of IL-10 and IL-12 were low. When uninfected-PBMC from asthmatics were LGG-stimulated, after 24h, IL-4 was undetectable, but IL-10, IL-12, and IFN-gamma increased, compared with PBMC alone. Thus, C. pneumoniae infection has the ability to induce allergic responses in PBMC of asthmatics, as evidenced by production of Th2 responses and IgE.

The Gut-Brain Axis: The Missing Link in Depression

The gut microbiota is essential to human health and the immune system and plays a major role in the bidirectional communication between the gut and the brain. Based on evidence, the gut microbiota is associated with metabolic disorders such as obesity, diabetes mellitus and neuropsychiatric disorders such as schizophrenia, autistic disorders, anxiety disorders and major depressive disorders. In the past few years, neuroscientific research has shown the importance of the microbiota in the development of brain systems. Recent studies showed that the microbiota could activate the immune and central nervous systems, including commensal and pathogenic microorganisms in the gastrointestinal tract. Gut microorganisms are capable of producing and delivering neuroactive substances such as serotonin and gamma-aminobutyric acid, which act on the gut-brain axis. Preclinical research in rodents suggested that certain probiotics have antidepressant and anxiolytic activities. Effects may be mediated via the immune system or neuroendocrine systems. Herein, we present the latest literature examining the effects of the gut microbiota on depression.

Immune system stimulation by probiotic microorganisms

Probiotic organisms are claimed to offer several functional properties including stimulation of immune system. This review is presented to provide detailed informations about how probiotics stimulate our immune system. Lactobacillus rhamnosus GG, Lactobacillus casei Shirota, Bifidobacterium animalis Bb-12, Lactobacillus johnsonii La1, Bifidobacterium lactis DR10, and Saccharomyces cerevisiae boulardii are the most investigated probiotic cultures for their immunomodulation properties. Probiotics can enhance nonspecific cellular immune response characterized by activation of macrophages, natural killer (NK) cells, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in strain-specific and dose-dependent manner. Mixture and type (gram-positive and gram-negative) of probiotic organisms may induce different cytokine responses. Supplementation of probiotic organisms in infancy could help prevent immune-mediated diseases in childhood, whereas their intervention in pregnancy could affect fetal immune parameters, such as cord blood interferon (IFN)-γ levels, transforming growth factor (TGF)-β1 levels, and breast milk immunoglobulin (Ig)A. Probiotics that can be delivered via fermented milk or yogurt could improve the gut mucosal immune system by increasing the number of IgA(+) cells and cytokine-producing cells in the effector site of the intestine.

Psychobiotics: a novel class of psychotropic

Here, we define a psychobiotic as a live organism that, when ingested in adequate amounts, produces a health benefit in patients suffering from psychiatric illness. As a class of probiotic, these bacteria are capable of producing and delivering neuroactive substances such as gamma-aminobutyric acid and serotonin, which act on the brain-gut axis. Preclinical evaluation in rodents suggests that certain psychobiotics possess antidepressant or anxiolytic activity. Effects may be mediated via the vagus nerve, spinal cord, or neuroendocrine systems. So far, psychobiotics have been most extensively studied in a liaison psychiatric setting in patients with irritable bowel syndrome, where positive benefits have been reported for a number of organisms including Bifidobacterium infantis. Evidence is emerging of benefits in alleviating symptoms of depression and in chronic fatigue syndrome. Such benefits may be related to the anti-inflammatory actions of certain psychobiotics and a capacity to reduce hypothalamic-pituitary-adrenal axis activity. Results from large scale placebo-controlled studies are awaited.

Perinatal outcomes of prenatal probiotic and prebiotic administration: an integrative review

The purpose of this integrative review was to identify, critique, and synthesize the maternal and neonatal evidence on the prenatal use of probiotics and prebiotics to inform perinatal health professionals. A comprehensive literature search resulted in 37 studies of prenatal probiotics and 1 on antepartal prebiotics published from 1990 through 2011 that reported maternal, fetal, and/or neonatal outcomes. The methodologic quality of the studies reviewed was high, although investigators used different probiotic combinations and inconsistently reported perinatal clinical outcomes. The extraction of perinatal outcome variables resulted in identification of 9 maternal and 5 neonatal categories. Prenatal probiotics significantly reduced the incidence of bacterial vaginosis, increased colonization with vaginal Lactobacillus and intestinal Lactobacillus rhamnosus, altered immune markers in serum and breast milk, improved maternal glucose metabolism, and reduced the incidence of gestational diabetes and preeclampsia. Antepartally, probiotics were associated with significantly higher counts of Bifidobacterium and Lactococcus lactis (healthy intestinal flora) in neonatal stool. Prenatal prebiotics significantly increased maternal intestinal Bifidobacterium. No adverse events were reported and there was evidence of safety and tolerance of prenatal probiotics and prebiotics in the scientific investigations reviewed. It is recommended that in future investigations of prenatal probiotics researchers explicitly report maternal and neonatal outcomes.

Probiotics in the treatment and prevention of allergy in children

Several fold increase in allergic diseases in developed, high-income countries during recent decades is attributed to environmental changes such as urbanization with improved hygiene. This, together with conquering severe bacterial infections during childhood, has reduced the microbial stimulation of the developing immune system of infants. Studies on the pathogenesis of allergy both in man and experimental animal have shown the importance of commensal bacteria in the gastrointestinal tract in stimulating and directing the immune system. The interest in modulating commensal bacterial flora with probiotics to prevent and treat allergy has multiplied in recent years.

In the present review we report results on randomized, controlled studies in which childhood atopic eczema was treated or which aimed to prevent development of allergy during childhood.

Nine studies with 639 patients have looked at the effect of probiotics in treatment of eczema. While 3 studied showed no effect, other studies suggested a moderate benefit of the use of probiotics on the severity of eczema. Studies suggested that the effect may be seen particularly in patients with food allergy and/or sensitization.

Nine studies have reported on the prevention of allergy on 6 study population with altogether 1989 high risk infants. While the early study reporting the development of allergy at ages 2, 4 and 7 years showed a marked reduction of eczema in 77 treated infants, later studies have failed to show similar success. Two studies showed no effect. In the largest study with more than 900 children at age 2 atopic eczema was reduced by 20%, but at age 5 positive effect was present in only the subgroup of children who had born by cesarean section. None of studies has reported adverse effects of probiotics in infants.

Result in both treatment and prevention studies are quite variable, the major reason being the use of different strains of probiotic bacteria and varying types of intervention. Even if the results are encouraging, we need a stronger effect. This may be reached by finding new strains of probiotics affecting stronger stimulation of immune system, together with longer lasting and varying treatment schedules. However, safety issues have to be observed.

The impact of probiotics and prebiotics on the immune system

Probiotics and prebiotics are increasingly being added to foodstuffs with claims of health benefits. Probiotics are live microorganisms that are thought to have beneficial effects on the host, whereas prebiotics are ingredients that stimulate the growth and/or function of beneficial intestinal microorganisms. But can these products directly modulate immune function and influence inflammatory diseases? Here, Nature Reviews Immunology asks four experts to discuss these issues and provide their thoughts on the future application of probiotics as a disease therapy.

Probiotics: a potential role in the prevention of gestational diabetes?

The gut microbiome has a complex relationship with host metabolism and immune function. Host health and diet influence the composition of the gut microbiome, and conversely, different microbiome compositions influence host metabolism. Gestational diabetes mellitus is increasingly common and has serious implications for maternal and foetal health both during pregnancy and later in life. To date, clinical trials of exercise and dietary interventions to prevent the onset of gestational diabetes have had heterogeneous results and have proven disappointingly difficult. Alternative prevention strategies of gestational diabetes mellitus need to be considered and trialled in a placebo-controlled manner in combination with dietary and behavioural measures. One such potential preventative therapy is probiotic supplementation, that is, ingestion of specific bacterial strains with beneficial effects on the host. Probiotic supplements have been shown to improve metabolism by increasing host insulin sensitivity, cholesterol metabolism and also have a beneficial effect on the immune system. This discussion paper examines the evidence for the influence of the gut microbiome on host metabolism and the potential metabolic impact of probiotic supplementation, with particular regard for the evidence surrounding a possible use of probiotic supplements for the prevention of gestational diabetes. Probiotics offer the tantalising possibility of a feasible intervention for the prevention of gestational diabetes and improvement of metabolic syndromes, but there is a pressing need for further studies of the mechanisms underlying the apparent metabolic benefits and for the use of randomised controlled trials to allow examination of the effectiveness of probiotic supplementation in this setting.

Is a multispecies probiotic mixture effective in constipation during pregnancy? 'A pilot study'

BACKGROUND

Constipation during pregnancy is a common problem. Nowadays only few effective interventions are published preventing or treating constipation during pregnancy. However, their use is limited due to side-effects. This uncontrolled intervention study was performed to determine if a mixture of probiotics in the treatment of constipation during pregnancy is effective.

METHODS

Women aged ≥ 18 years with functional constipation were included at the Obstetrical outpatient clinic and midwife practices. Patients received during four weeks a daily dose of Ecologic®Relief (Bifidobacterium bifidum W23, Bifidobacterium lactis W52, Bifidobacterium longum W108, Lactobacillus casei W79, Lactobacillus plantarum W62 and Lactobacillus rhamnosus W71 (total 4*10⁹ CFU)). For all analyses, the non-parametric paired Wilcoxon test was used. Primary outcome measure was change in defecation frequency. Secondary outcome measures were stool consistency, sensation of incomplete evacuation, sensation of anorectal obstruction, manual manoeuvres to facilitate defecation, abdominal pain, adverse effects, presence of reflux episodes and intake of Bisacodyl.

RESULTS

20 women were included. Defecation frequency significantly increased from 3.1 at baseline to 6.7 in week four (p < 0.01). Compared to baseline, a significant decrease in 1) sensation of anorectal obstruction from 90.0% to 45.0% (p < 0.01), 2) sensation of incomplete evacuation from 90.0% to 40.0% (p < 0.01), 3) straining during defecation from 100% to 65% (p = 0.01), 4) episodes of abdominal pain from 60% to 20% (p = 0.01) and 5) the presence of reflux episodes from 60% to 20% in week four (p = 0.01) was found. Other secondary outcomes did not decrease significantly. No side effects were reported.

CONCLUSIONS

Ecologic®Relief is effective in the treatment of constipation during pregnancy. A randomised placebo controlled trial is required to confirm these data.

[The revised guideline on Primary Allergy Prevention]

The recommendations of the revised guideline Primary Allergy Prevention published in 2009 are summarized and discussed. The updated guidelines do not further recommend reducing house dust mite allergen exposure as a measure of primary prevention. New suggestions include the avoidance of overweight, and reduction of the exposure to indoor and/or outdoor air pollutants. In line with the current guidelines, there is no scientific evidence that prolonged introduction of solid food is an allergy-preventive measure. Consequently, even children with a family history of atopy can introduce solid foods at the beginning of the 5th month. The recommendations on avoiding environmental tobacco smoke, breast feeding over 4 months, avoiding a mold-promoting indoor climate, vaccination according to current recommendations, and avoidance of furry pets (especially cats) in risk babies have remained unchanged.

Gut microbiota and probiotics in maternal and infant health

The interplay between both heredity and environmental factors seems to affect every stage of development from conception to the early postnatal period with potential long-term effects on child and adult health. During pregnancy, immune and metabolic functions of the fetus are dependent on the mother; moreover, the refinement of these functions seems to commence inside the uterus and to be diet sensitive. The microbiota inhabiting the intestinal tract develop an array of physiologic roles within the human body, which influences both metabolic and immune functions, particularly during early neonatal life and possibly even in utero. Transmission of bacteria from the mother to the neonate through direct contact with maternal microbiota during birth and through breast milk during lactation also seems to influence the infant's gut colonization, with potential health consequences. In this context, intentional modulation of microbiota composition through the use of probiotics during the perinatal and early postnatal period has been proposed as a possible dietary strategy to reduce risk of disease. Herein, studies are reviewed on the composition of the intestinal microbiota during pregnancy and clinical trials evaluating the effects of perinatal administration of probiotics on different clinical outcomes.

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 in the treatment and prevention of allergies in children

Several studies on the pathogenesis of allergy both in man and experimental animals continue to show the importance of commensal bacteria in the gastrointestinal tract in stimulating and directing the immune system. The interest in modulating commensal bacteria flora with pre- and probiotics to prevent and treat food allergy has multiplied in recent years. We recently studied 230 infants with atopic dermatitis and suspected cow’s milk allergy. The infants were randomly allocated to groups which received Lactobacillus GG (LGG), a mixture of four probiotic strains (MIX) or placebo for 4 weeks. We inferred that probiotics induce systemically detectable low-grade inflammation, which may explain the clinical effects and the secretion pattern of cytokines induced by PBMC. To study the ability of probiotics to prevent allergy in children, we recruited 1223 pregnant women carrying fetuses at increased risk of allergy for a double-blind placebo-controlled trial. Mothers used a mixture of four probiotic bacteria or a placebo from the 36th week of gestation. Their infants received the same probiotics plus prebiotic galacto-oligosaccharides for 6 months. At the 2-year follow-up, a total of 925 infants participated. The cumulative incidence of allergic disease did not differ significantly between the synbiotic and the placebo group. However, synbiotics significantly reduced eczema. The preventive effect of synbiotics was more pronounced against IgE-associated diseases. At the 5 year follow-up, 891(88%) of the 1018 intention-to-treat infants attended. In the probiotic and placebo groups, frequencies of allergic symptoms and IgE-associated allergic disease and sensitization were similar, and the frequencies of eczema did not differ between the groups. Atopic eczema, allergic rhinitis and asthma appeared equal frequency in the groups. However, less IgE-associated allergic disease occurred in the cesarean-delivered infants given probiotics. In cesarean-delivered childen, we noticed a delayed rise in bifidobacteria recovery in placebo-treated children which was corrected by pro- and prebiotic supplementation. Indications from studies of feces and blood at the age 6 months suggest that probiotics may enhance both inflammation and immune defence of the gut. The probiotic treatment further stimulated maturation of the immune system since the infants given probiotics showed increased resistance to respiratory infections and improved vaccine antibody responses.

The potential role of probiotics in the management of childhood autism spectrum disorders

Gastrointestinal (GI) dysfunction has been reported in a substantial number of children with autism spectrum disorders (ASD). Activation of the mucosal immune response and the presence of abnormal gut microbiota are repeatedly observed in these children. In children with ASD, the presence of GI dysfunction is often associated with increased irritability, tantrums, aggressive behaviour, and sleep disturbances. Moreover, modulating gut bacteria with short-term antibiotic treatment can lead to temporary improvement in behavioral symptoms in some individuals with ASD. Probiotics can influence microbiota composition and intestinal barrier function and alter mucosal immune responses. The administration of probiotic bacteria to address changes in the microbiota might, therefore, be a useful novel therapeutic tool with which to restore normal gut microbiota, reduce inflammation, restore epithelial barrier function, and potentially ameliorate behavioural symptoms associated with some children with ASD. In this review of the literature, support emerges for the clinical testing of probiotics in ASD, especially in the context of addressing GI symptoms.

No detectable beneficial systemic immunomodulatory effects of a specific synbiotic mixture in infants with atopic dermatitis

BACKGROUND

In a murine model of allergic inflammation, Bifidobacterium breve M-16V has been shown to reduce IL-4 and IgE by inducing IL-10 and IFN-γ. However, it remains unknown whether this strain has the same effect in humans with allergic disease.

OBJECTIVE

To determine the effects of Bifidobacterium breve M-16V combined with a prebiotic oligosaccharide mixture (synbiotic) on atopic markers, ex vivo cytokine production by peripheral blood mononuclear cells (PBMCs) and circulating regulatory T cell percentage in infants with atopic dermatitis.

METHODS

In a double-blind, placebo-controlled multi-centre trial, 90 infants with atopic dermatitis, age <7 months, were randomized to receive an infant formula with Bifidobacterium breve M-16V and a mixture of short chain galactooligosaccharides and long chain fructooligosaccharides (Immunofortis(®) ), or the same formula without synbiotics during 12 weeks. At week 0 and 12, plasma levels of IL-5, IgG1, IgG4, CTACK and TARC, ex vivo cytokine responses by PBMCs and percentage of regulatory T cells, were determined.

RESULTS

There were no significant differences between the synbiotic and the placebo group in IL-5, IgG1, IgG4, CTACK and TARC levels and ex vivo cytokine production by anti-CD3/anti-CD28-stimulated PBMCs. With allergen-specific stimuli, we found a decreased IL-12p40/70 and IL-12p70 production in response to egg allergen (P = 0.04 and P = 0.01, respectively) and decreased IL-12p70 production in response to peanut allergen (P = 0.003) in the synbiotic compared with the placebo group. Circulating regulatory T cell percentage did not significantly differ between the groups.

CONCLUSIONS AND CLINICAL RELEVANCE

This synbiotic mixture has no detectable effect on plasma levels of the analysed atopic disease markers, ex vivo cytokine production and circulating regulatory T cell percentage in infants with atopic dermatitis, besides down-regulation of IL-12 production in egg- and peanut-stimulated PBMCs. These results do not support the use of this synbiotic in clinical practice.

Gut derived lactic acid bacteria induce strain specific CD4(+) T cell responses in human PBMC

BACKGROUND & AIMS

Probiotic bacteria are used as food supplement in many different disease settings. The immune modulating capacity of different strains is not always properly tested which might result in a suboptimal choice of strains for clinical use.

METHODS

The CD4 T cell responses to 19 different gut derived lactic acid bacteria were tested with different methods to show their diversity in immune modulation and to make a well-founded choice on which strains to use in future clinical trials. After co-culture of PBMC with bacteria, the induction of CD4(+) T cell subsets (regulatory T cells, T helper type (TH)1, TH2 and TH17) was analysed by rtPCR of transcription factor mRNA, intracellular FACS staining of transcription factors and cytokine production.

RESULTS

Bacterial strains all have diverse, unique immune modulatory properties. Strains can induce Treg, TH1, TH2 and TH17 cells which can be shown at different levels of T cell activation, and is consistent for most strains tested. For TH1, TH17 and Treg, a positive correlation between the different methods was found. For TH2 cells the correlation was less consistent.

CONCLUSIONS

Probiotic bacteria have very different immune modulating capacities. Analysis of transcription factor mRNA is a suitable method for in vitro characterization of strains prior to clinical application.

Lactobacillus rhamnosus HN001 attenuates allergy development in a pig model

Background

Probiotics have been studied as immunomodulatory agents of allergy. Several human probiotic trials tracking the development of eczema and other forms of allergy have yielded inconsistent results. A recent infant study demonstrated that pre and postnatal Lactobacillus rhamnosus HN001 (HN001) supplementation decreased the prevalence of eczema and IgE associated eczema. However, the influence of HN001 on the incidence of wheeze, asthma, and/or other allergic manifestations has yet to be reported.

Objective

This study was conducted to determine the effects of the probiotic HN001 on the development of allergic lung disease in a pig model.

Methods

Allergy was induced by a series of subcutaneous and intratracheal sensitizations with Ascaris suum allergen (ASA) during a six week time frame in post-weanling pigs supplemented daily with HN001, or without supplementation. One week following final sensitization intradermal skin tests and respiratory challenges were conducted.

Results

In response to intradermal and respiratory challenges, ASA-sensitized pigs fed HN001 had less severe skin flare reactions, smaller increases in pleural pressure, and trends towards lower changes in arterial oxygen and carbon dioxide partial pressure levels compared to control pigs. The frequency of ASA-specific IFN-γ-secreting peripheral blood mononuclear cells, as well as the amount of IL-10 produced by ASA-specific cells, was of greater magnitude in probiotic-fed pigs compared to control animals. These observations suggest that differences in clinical responses to the allergen challenges may be related to probiotic-induced modulation of Th1 (IFN-γ) and regulatory (IL-10) cytokine expression.

Conclusions

Probiotic supplementation decreased the severity of allergic skin and lung responses in allergen-sensitized pigs with a corresponding increase in IFN-γ expression. A similar correlation between certain allergic responses and increased IFN-γ expression has been reported in human clinical studies of allergy; this pig model of allergy may be indicative of potential probiotic modulation of allergic lung disease in humans.

Lactobacillus-mediated priming of the respiratory mucosa protects against lethal pneumovirus infection

The inflammatory response to respiratory virus infection can be complex and refractory to standard therapy. Lactobacilli, when targeted to the respiratory epithelium, are highly effective at suppressing virus-induced inflammation and protecting against lethal disease. Specifically, wild-type mice primed via intranasal inoculation with live or heat-inactivated Lactobacillus plantarum or Lactobacillus reuteri were completely protected against lethal infection with the virulent rodent pathogen, pneumonia virus of mice; significant protection (60% survival) persisted for at least 13 wk. Protection was not unique to Lactobacillus species, and it was also observed in response to priming with nonpathogenic Gram-positive Listeria innocua. Priming with live lactobacilli resulted in diminished granulocyte recruitment, diminished expression of multiple proinflammatory cytokines (CXCL10, CXCL1, CCL2, and TNF), and reduced virus recovery, although we have demonstrated clearly that absolute virus titer does not predict clinical outcome. Lactobacillus priming also resulted in prolonged survival and protection against the lethal sequelae of pneumonia virus of mice infection in MyD88 gene-deleted (MyD88(-/-)) mice, suggesting that the protective mechanisms may be TLR-independent. Most intriguing, virus recovery and cytokine expression patterns in Lactobacillus-primed MyD88(-/-) mice were indistinguishable from those observed in control-primed MyD88(-/-) counterparts. In summary, we have identified and characterized an effective Lactobacillus-mediated innate immune shield, which may ultimately serve as critical and long-term protection against infection in the absence of specific antiviral vaccines.

Probiotic modulation of dendritic cells and T cell responses in the intestine

Over the past decade it has become clear that probiotic and commensal interactions with mucosal dendritic cells in the lamina propria or epithelial cells lining the mucosa can modulate specific functions of the mucosal immune system. Innate pattern-recognition receptors such as TLRs, NLRs and CLRs play a crucial role in the host recognition of probiotics and other microorganism. Signalling via these receptors directly influences the chemokine and cytokine response of dendritic cells as well as the crosstalk between the epithelium and the immune cells in the lamina propria. This can influence the population of effector and regulatory T cell subsets in the mucosa. Immune assays with probiotics have shown that the in vitro immune response is both species and strain-specific. Such assays may be useful for the selection of probiotic strains that have beneficial effects on the regulation of intestinal inflammation but more comparative studies are needed to confirm recent findings. A better understanding of the molecular mechanisms of probiotics, the effect of dose, and frequency of administration on microbial sampling by mucosal APC will also help to clarify the value of immune assays as selection criteria for probiotics.

Lactic acid bacteria enhance autophagic ability of mononuclear phagocytes by increasing Th1 autophagy-promoting cytokine (IFN-gamma) and nitric oxide (NO) levels and reducing Th2 autophagy-restraining cytokines (IL-4 and IL-13) in response to Mycobacterium tuberculosis antigen

BACKGROUND AND OBJECTIVES

Control of the intracellular Mycobacterium tuberculosis (Mtb), mainly requires an appropriate ratio of Th1/Th2 cytokines to induce autophagy, a physiologically, and immunologically regulated process that has recently been highlighted as an innate defense mechanism against intracellular pathogens. Current vaccines/adjuvants induce both protective Th1 autophagy-promoting cytokines, such as IFN-gamma, and immunosuppressive Th2 autophagy-restraining cytokines, such as IL-4 and IL-13. TB infection itself is also characterized by relatively high levels of Th2 cytokines, which down-regulate Th1 responses and subsequently subvert adequate protective immunity, and a low ratio of IFN-gamma/IL-4. Therefore, there is a need for a safe and non-toxic vaccine/adjuvant that will induce Th1 autophagy-promoting cytokine (IFN-gamma) secretion and suppress the pre-existing subversive Th2 autophagy-restraining cytokines (IL-4 and IL-13). As lactic acid bacteria (LAB) belonging to the natural intestinal microflora and their components have been shown to shift immune responses against other antigens from Th2-type cytokines toward Th1-type cytokines like IFN-gamma, we investigated whether LAB can improve the polarization of Th1/Th2 cytokines and autophagic ability of mononuclear phagocytes in response to Mtb antigen.

METHODS

Peripheral blood mononuclear cells (PBMCs), which are a part of the mononuclear phagocyte system and source of crucial macrophage activators in the in vivo situation, and human monocyte-derived macrophages (HMDMs) were treated with Mtb antigen in the presence or absence of two strains of LAB, L. rhammosus GG (LGG) and Bifidobacterium bifidum MF 20/5 (B.b). PBMCs cell culture supernatants were analyzed for the production of the autophagy-promoting factors IFN-gamma, and nitric oxide (NO) and the autophagy-restraining cytokines IL-4 and IL-13, using ELISA and Griess assays to detect the production of cytokines and NO, respectively. In HMDMs, expression of microtubule-associated protein 1 light chain 3 (LC3-I), membrane-associated (LC3-II) forms of LC3 protein and Beclin-1, as hallmarks of autophagy, were assessed using Western blot to detect the autophagy markers. The secreted interleukin 6 (IL-6), interleukin 10 (IL-10), interleukin (IL)-12 and transformig growth factor-beta (TGF-beta), and chemokine (C-C motif) ligand 18 (CCL18) from HMDMs were determined by ELISA. Also, reverse transcription polymerase chain reaction (RT-PCR) analysis was used to assess the mRNA expressions of CCL18 in HMDMs.

RESULTS

Treatment of PBMCs with either Mtb antigen or with LAB significantly increased the IFN-gamma and NO production. Combination of Mtb antigen and LAB led to synergistic increase in IFN-gamma, and an additive increase in NO. Treatment with Mtb antigen alone significantly increased the IL-4 and IL-13 production. LAB significantly decreased IL-4 and IL-13 secretion in both unstimulated and Mtb antigen-stimulated PBMCs. The IFN-gamma/IL-4+IL-13 ratio was enhanced, indicating Th1/Th2 polarization. Treatment of macrophages with combined use of Mtb antigen and LAB led to an additive increase in Beclin-1, LC3-II expression, as well as in synergistic increase in IL-12 production. Treatment of macrophages with combined use of Mtb antigen and LAB led to a decrease in IL-6, IL-10, and CCL18 secretion. LAB inhibited the secretion of TGF-beta by Mtb-stimulated macrophages, however not significantly. Treatment of macrophages with combined use of Mtb antigen and LAB led to a decrease in CCL18 mRNA expression.

CONCLUSION

Our study implies that LAB may reinforce the response of the mononuclear phagocytes to Mtb antigen by inducing production of the autophagy-promoting factors IFN-gamma and NO, while decreasing the Th2 autophagy-restraining cytokines IL-4 and IL-13. Hence, combination of Mtb antigen and LAB may perhaps be safer in more efficacious TB vaccine formulation.

Probiotics and prebiotics in atopic dermatitis: review of the theoretical background and clinical evidence

The prevalence of atopic dermatitis (AD) has risen over the past decades, especially in western societies. According to the revised hygiene hypothesis this increase is caused by a changed intestinal colonization pattern during infancy, which has an impact on the immune system. Manipulating the intestinal microflora with pro-, pre- or synbiotics is an innovative way to prevent or treat AD. This review provides an overview of the theoretical basis for using probiotics and prebiotics in AD and presents the current evidence from randomized controlled trials (RCTs) regarding prevention and treatment of AD and food allergy in children with pro-, pre- and synbiotics. Seven RCTs on prevention and 12 RCTs on treatment were found by searching the Pubmed, Embase and Cochrane databases. Results of these trials are conflicting. In conclusion, at this moment there is not enough evidence to support the use of pro-, pre- or synbiotics for prevention or treatment of AD in children in clinical practice.

Developments in the field of allergy in 2008 through the eyes of Clinical & Experimental Allergy

In 2008, many thousands of articles were published on the subject of allergic disease with over 200 reviews, editorials and original papers in Clinical & Experimental Allergy alone. These represent a considerable amount of data and even the most avid reader could only hope to assimilate a small fraction of this knowledge. There is therefore a pressing need for the key messages that emerge from a journal such as Clinical & Experimental Allergy to be summarized by experts in the field in a form that highlights the significance of the developments and sets them in the context of important findings in the field published in other journals. This also has the advantage of making connections between new data in conditions such as asthma, where articles often appear in different sections of the journal. As can be seen from this review, the body of work is diverse both in terms of the disease of interest and the discipline that has been used to investigate it. However, taken as a whole, we hope that the reader will gain a flavour of where the field is mature, where there remain controversies and where the cutting edge is leading.

Probiotics have clinical, microbiologic, and immunologic efficacy in acute infectious diarrhea

BACKGROUND

Acute infectious diarrhea is a major cause of childhood morbidity and economic burden for families. We evaluate the clinical, microbiologic, and immunologic effects of probiotics in acute infectious diarrhea.

METHODS

Children (n = 304) aged 3 months to 6 years hospitalized for acute diarrhea were randomized to receive Bio-three (a mixture of Bacillus mesentericus, Enterococcus faecalis, and Clostridium butyricum) or placebo orally 3 times daily for 7 days. Fecal samples were homogenized for bacterial culture and blood cells were isolated for cell culture and cytokine analysis. This study is registered (NCT00463190).

RESULTS

The mean duration of diarrhea after start of therapy was 60.1 hours in the probiotics group versus 86.3 hours in the placebo group (P = 0.003). Hospital stay was shorter in the probiotics group than in the placebo group (P = 0.009). Counts of Bifidobacteria and Lactobacillus species were elevated in stool culture of the probiotics (Bio-three) group. IL-10 was increased in the serum and supernatants of cell culture in the probiotics group, and tumor necrosis factor-alpha values were down-regulated. Interferon- gamma and IL-12 were mildly elevated in the probiotics group, compared with the placebo group.

CONCLUSIONS

This probiotics mixture reduced the severity of diarrhea and length of hospital stay in children with acute diarrhea. In addition to restoring beneficial intestinal flora, probiotics may enhance host protective immunity such as down-regulation of pro-inflammatory cytokines and up-regulation of anti-inflammatory cytokines.

The effects of selected probiotic strains on the development of eczema (the PandA study)

BACKGROUND

Modification of the intestinal microbiota by administration of probiotic bacteria may be a potential approach to prevent allergic disease. We aimed to study primary prevention of allergic disease in high-risk children by pre- and postnatal supplementation of selected probiotic bacteria.

METHODS

In a double-blind, randomized, placebo-controlled trial, a mixture of probiotic bacteria selected by in-vitro experiments (Bifidobacterium bifidum, Bifidobacterium lactis, and Lactococcus lactis; Ecologic Panda) was prenatally administered to mothers of high-risk children (i.e. positive family history of allergic disease) and to their offspring for the first 12 months of life.

RESULTS

Parental-reported eczema during the first 3 months of life was significantly lower in the intervention group compared with placebo, 6/50 vs 15/52 (P = 0.035). After 3 months, the incidence of eczema was similar in both groups. Cumulative incidence of parental-reported eczema at 1 and 2 years was 23/50 (intervention) vs 31/48 (placebo) and 27 (intervention) vs 34 (placebo), respectively. The number needed to treat was 5.9 at age 3 and 12 months and 6.7 at age 2 years. The intervention group was significantly more frequently colonized with higher numbers of Lc. lactis. Furthermore, at age 3 months, in vitro production of IL-5 (146 pg/ml vs 72 pg/ml; P = 0.04) was decreased in the probiotic-group compared with the placebo-group.

CONCLUSIONS

This particular combination of probiotic bacteria shows a preventive effect on the incidence of eczema in high-risk children, which seems to be sustained during the first 2 years of life. In addition to previous studies, the preventive effect appears to be established within the first 3 months of life.