Effects of Bifidobacterium breve on inflammatory gene expression in neonatal and weaning rat intestine

Microbial and immune faecal determinants in infants hospitalized with COVID-19 reflect bifidobacterial dysbiosis and immature intestinal immunity

The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread rapidly worldwide, seriously endangering human health. Although SARS-CoV-2 had a lower impact on paediatric population, children with COVID-19 have been reported as suffering from gastrointestinal (GI) symptoms at a higher rate than adults. The aim of this work was to evaluate faeces as a source of potential biomarkers of severity in the paediatric population, with an emphasis on intestinal microbiota and faecal immune mediators, trying to identify possible dysbiosis and immune intestinal dysfunction associated with the risk of hospitalization. This study involved 19 patients with COVID-19 under 24 months of age hospitalized during the pandemic at 6 different hospitals in Spain, and it included a comparable age-matched healthy control group (n = 18). Patients and controls were stratified according to their age in two groups: newborns or young infants (from 0 to 3 months old) and toddlers (infants from 6 to 24 months old). To characterize microbial intestinal communities, sequencing with Illumina technology of total 16S rDNA amplicons and internal transcribed spacer (ITS) amplicons of bifidobacteria were used. Faecal calprotectin (FC) and a range of human cytokines, chemokines, and growth factors were measured in faecal samples using ELISA and a multiplex system. Significant reduction in the abundance of sequences belonging to the phylum Actinobacteria was found in those infants with COVID-19, as well as in the Bifidobacteriaceae family. A different pattern of bifidobacteria was observed in patients, mainly represented by lower percentages of Bifidobacterium breve, as compared with controls. In the group of hospitalized young infants, FC was almost absent compared to age-matched healthy controls. A lower prevalence in faecal excretion of immune factors in these infected patients was also observed.

CONCLUSION

 Hospitalized infants with COVID-19 were depleted in some gut bacteria, such as bifidobacteria, in particular Bifidobacterium breve, which is crucial for the proper establishment of a functional intestinal microbiota, and important for the development of a competent immune system. Our results point to a possible immature immune system at intestine level in young infants infected by SARS-CoV2 requiring hospitalization.

WHAT IS KNOWN

• Although SARS-CoV-2 had a lower impact on paediatric population, children with COVID-19 have been reported as suffering from gastrointestinal symptoms at a higher rate than adults. • Changes in microbial composition have been described in COVID-19 adult patients, although studies in children are limited.

WHAT IS NEW

• The first evidence that hospitalized infants with COVID-19 during the pandemic had a depletion in bifidobacteria, particularly in Bifidobacterium breve, beneficial gut bacteria in infancy that are crucial for the proper establishment of a competent immune system. • In young infants (under 3 months of age) hospitalized with SARS-CoV2 infection, the aberrant bifidobacterial profile appears to overlap with a poor intestinal immune development as seen by calprotectin and the trend of immunological factors excreted in faeces.

Investigation of therapeutic effects of rhubarb decoction retention enema on minimal hepatic encephalopathy in rats based on 16S rDNA gene sequencing and bile acid metabolomics

Minimal hepatic encephalopathy (MHE) is an early stage of hepatic encephalopathy (HE), with high incidence and a high rate of clinically missed diagnosis. Early diagnosis of MHE and effective clinical intervention are of great importance. Rhubarb decoction (RD)-induced retention enema can effectively improve the cognitive function of patients with MHE, whereas disturbances in the enterohepatic circulation of bile acid (BAs) can induce MHE. However, the molecular mechanisms underlying the therapeutic effects of RD have not been examined from the perspective of intestinal microbiota and bile metabolomics. In this study, we investigated the effects of RD-induced retention enema on intestinal microbiota and bile metabolites in rats with CCl₄- and TAA-induced MHE. RD-induced retention enema significantly improved liver function, reduced blood ammonia levels, alleviated cerebral oedema and restored cognitive function in rats with MHE. In addition, it increased the abundance of intestinal microbes; partially reversed the disorder in the composition of intestinal microbiota, including the Bifidobacterium and Bacteroides genera; and regulated BA metabolism, such as taurine combined with increased BA synthesis. In conclusion, this study highlights the potential importance of BA enterohepatic circulation for RD to improve cognitive function in MHE rats, providing a new perspective on the mechanism of this herb. The findings of this study will facilitate experimental research on RD and help to develop RD-based strategies for clinical application.

Bamboo shavings derived O-acetylated xylan alleviates loperamide-induced constipation in mice

BSH-1 is an O-acetylated xylan obtained from bamboo shavings. This study determined the protective effects of BSH-1 against loperamide (Lop)-induced constipation in mice. Mice received BSH-1 by gavage daily for 14 days. In constipated mice, BSH-1 significantly shortened the defecation time and raised the gastrointestinal (GI) transit rate, stool production, and cecal concentration of short-chain fatty acids (SCFAs). BSH-1 regulated the serum levels of gut hormones and neurotransmitters. BSH-1 also significantly altered the cecal microbiota of the constipated mice by increasing the abundance of potentially beneficial bacteria (e.g., Lactobacillus, Roseburia, and Bacteroidales_S24-7) and decreasing potentially pathogenic bacteria (e.g., Alloprevotella and Staphylococcus). Furthermore, colonic transcriptome analysis revealed that BSH-1 significantly reversed the expression changes of genes related to intestinal motility, water and ion transport, inflammation and cancer in constipated mice. Our findings indicated that BSH-1 effectively relieved Lop-induced constipation in mice and could be potentially used for constipation treatment.

Role of Bifidobacteria on Infant Health

Bifidobacteria are among the predominant microorganisms during infancy, being a dominant microbial group in the healthy breastfed infant and playing a crucial role in newborns and infant development. Not only the levels of the Bifidobacterium genus but also the profile and quantity of the different bifidobacterial species have been demonstrated to be of relevance to infant health. Although no definitive proof is available on the causal association, reduced levels of bifidobacteria are perhaps the most frequently observed alteration of the intestinal microbiota in infant diseases. Moreover, Bifidobacterium strains have been extensively studied by their probiotic attributes. This review compiles the available information about bifidobacterial composition and function since the beginning of life, describing different perinatal factors affecting them, and their implications on different health alterations in infancy. In addition, this review gathers exhaustive information about pre-clinical and clinical studies with Bifidobacterium strains as probiotics in neonates.

Difficulties in developmental follow-up of preterm neonates in a randomised-controlled trial of Bifidobacterium breve M16-V - Experience from Western Australia

BACKGROUND

Probiotics may be neuroprotective for preterm neonates due to their anti-inflammatory effects and ability to facilitate nutrition.

AIM

To assess long-term effects of early probiotic supplementation on neuropsychological development in preterm infants.

STUDY DESIGN

Follow up study.

SUBJECTS

Children at age 3 to 5 years who had participated as preterm infants (<33 week) in the randomised controlled trial.

OUTCOMES

Primary: Continuous early learning composite measure derived from the Mullen's Scale of Early Learning (MSEL). Other outcomes were assessed by the Developmental, Dimensional and Diagnostic Interview, Developmental NEuroPSYchological assessment-2nd Edition, Parental questionnaires using children's communication checklist-2nd edition, social responsiveness scale, and Vineland Adaptive Behavioural Scales-2nd edition.

MEASURES

Continuous scores derived from all the measures.

RESULTS

67 children of the 159 participants (42%) (Probiotic: 36/79, Placebo: 31/80) were followed-up for at least one neuropsychological assessment. All six assessments were completed in 18/31 (58.1%) of the control vs. 11/36 (30.6%) probiotic group children. Multivariable analysis of MSEL composite score showed no evidence of probiotic effect univariately, or after adjustment for gestation, intrauterine growth restriction, Apgar <7 at 5 min and age at assessment (adjusted mean effect in probiotic group: -2.7, 95% CI -8.5-3.0, p = 0.349).

CONCLUSION

There was no significant effect on neurodevelopment of children assessed at the age of 3 to 5 years who participated as preterm neonates in the RCT of B. breve M-16V. The validity of these results is limited by the reduced sample size due to high rate of loss to follow up.

Evaluation of Porcine Intestinal Epitheliocytes as an In vitro Immunoassay System for the Selection of Probiotic Bifidobacteria to Alleviate Inflammatory Bowel Disease

The use of in vitro systems that allow efficient selection of probiotic candidates with immunomodulatory properties could significantly minimize the use of experimental animals. In this work, we generated an in vitro immunoassay system based on porcine intestinal epithelial (PIE) cells and dextran sodium sulfate (DSS) administration that could be useful for the selection and characterization of potential probiotic strains to be used in inflammatory bowel disease (IBD) patients. Our strategy was based on two fundamental pillars: on the one hand, the capacity of PIE cells to create a monolayer by attaching to neighboring cells and efficiently mount inflammatory responses and, on the other hand, the use of two probiotic bifidobacteria strains that have been characterized in terms of their immunomodulatory capacities, particularly in mouse IBD models and patients. Our results demonstrated that DSS administration can alter the epithelial barrier created in vitro by PIE cells and induce a potent inflammatory response, characterized by increases in the expression levels of several inflammatory factors including TNF-α, IL-1α, CCL4, CCL8, CCL11, CXCL5, CXCL9, CXCL10, SELL, SELE, EPCAM, VCAM, NCF2, and SAA2. In addition, we demonstrated that Bifidobacterium breve M-16V and B. longum BB536 are able to regulate the C-jun N-terminal kinase (JNK) intracellular signalling pathway, reducing the DSS-induced alterations of the in vitro epithelial barrier and differentially regulating the inflammatory response in a strain-dependent fashion. The good correlation between our in vitro findings in PIE cells and previous studies in animal models and IBD patients shows the potential value of our system to select new probiotic candidates in an efficient way.

Cytokine Expression by Human Macrophage-Like Cells Derived from the Monocytic Cell Line THP-1 Differs Between Treatment With Milk from Preterm- and Term-Delivering Mothers and Pasteurized Donor Milk

Immunomodulatory proteins from human milk may enhance the protection and development of the infant’s gut. This study compared the immunomodulatory effects of treatment with milk from preterm-(PM) and term-delivering (TM) mothers and pasteurized donor milk (DM) on cytokine gene expression in human macrophage-like cells derived from the monocytic cell line THP-1. The gene expression of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-12 (p40), IL-10 and GAPDH in macrophages treated with PM, TM and DM at steady and activated (inflammatory) states were measured using real-time reverse transcription-polymerase chain reaction. TNF-α and IL-6 in macrophages (both states) with DM were higher than PM or TM. IL-10 in steady state macrophages with DM was higher than PM whereas DM increased IL-10 in activated macrophages compared with TM. TM increased IL-6 and IL-12 (p40) in steady state macrophages compared with PM. IL-12 (p40) in activated macrophages with TM was higher than PM. IL-10 in steady state macrophages with TM was higher than PM. These results suggest that DM induces higher gene expression of pro-inflammatory and anti-inflammatory cytokines in macrophages compared with PM or TM. PM reduced gene expression of pro-inflammatory cytokines compared with TM, which may decrease the development of necrotizing enterocolitis and systematic inflammation.

The Relationship between the Infant Gut Microbiota and Allergy. The Role of Bifidobacterium breve and Prebiotic Oligosaccharides in the Activation of Anti-Allergic Mechanisms in Early Life

The increase in allergy prevalence observed in recent decades may be a consequence of early intestinal dysbiosis. The intestinal microbiota is formed in the first 1000 days of life, when it is particularly sensitive to various factors, such as the composition of the mother’s microbiota, type of delivery, infant’s diet, number of siblings, contact with animals, and antibiotic therapy. Breastfeeding and vaginal birth favorably affect the formation of an infant’s intestinal microbiota and protect against allergy development. The intestinal microbiota of these infants is characterized by an early dominance of Bifidobacterium, which may have a significant impact on the development of immune tolerance. Bifidobacterium breve is a species commonly isolated from the intestines of healthy breastfed infants and from human milk. This review outlines the most important environmental factors affecting microbiota formation and the importance of Bifidobacterium species (with a particular emphasis on Bifidobacterium breve) in microbiota modulation towards anti-allergic processes. In addition, we present the concept, which assumes that infant formulas containing specific probiotic Bifidobacterium breve strains and prebiotic oligosaccharides may be useful in allergy management in non-breastfed infants.

Influence of freezing temperature before freeze-drying on the viability of various Lactobacillus plantarum strains

Although freeze-drying is an excellent method for preserving microorganisms, it inevitably reduces cell activity and function. Moreover, probiotic strains differ in terms of their sensitivity to the freeze-drying process. Therefore, it is necessary to optimize the variables relevant to this process. The pre-freezing temperature is a critical parameter of the freeze-drying process, but it remains unclear whether the optimal pre-freezing temperature differs among strains and protectants. This study explored the effects of 4 different pre-freezing temperatures on the survival rates of different Lactobacillus plantarum strains after freeze-drying in the presence of different protectants. Using phosphate-buffered saline solution and sorbitol as protectants, pre-freezing at -196°C, -40°C, and -20°C ensured the highest survival rates after freeze-drying for AR113, AR307, and WCFS1, respectively. Using trehalose, pre-freezing at -20°C ensured the best survival rate for AR113, and -60°C was the best pre-freezing temperature for AR307 and WCFS1. These results indicate that the pre-freezing temperature can be changed to improve the survival rate of L. plantarum, and that this effect is strain-specific. Further studies have demonstrated that pre-freezing temperature affected viability via changes in cell membrane integrity, membrane permeability, and lactate dehydrogenase activity. In summary, pre-freezing temperature is a crucial factor in L. plantarum survival after freeze-drying, and the choice of pre-freezing temperature depends on the strain and the protectant.

Exploring the Science behind Bifidobacterium breve M-16V in Infant Health

Probiotics intervention has been proposed as a feasible preventative approach against adverse health-related complications in infants. Nevertheless, the umbrella concept of probiotics has led to a massive application of probiotics in a range of products for promoting infant health, for which the strain-specificity, safety and efficacy findings associated with a specific probiotics strain are not clearly defined. Bifidobacterium breve M-16V is a commonly used probiotic strain in infants. M-16V has been demonstrated to offer potential in protecting infants from developing the devastating necrotising enterocolitis (NEC) and allergic diseases. This review comprehends the potential beneficial effects of M-16V on infant health particularly in the prevention and treatment of premature birth complications and immune-mediated disorders in infants. Mechanistic studies supporting the use of M-16V implicated that M-16V is capable of promoting early gut microbial colonisation and may be involved in the regulation of immune balance and inflammatory response to protect high-risk infants from NEC and allergies. Summarised information on M-16V has provided conceptual proof of the use of M-16V as a potential probiotics candidate aimed at promoting infant health, particularly in the vulnerable preterm population.

Synbiotics Combined with Glutamine Stimulate Brain Development and the Immune System in Preterm Pigs

Background

Preterm infants are born with an immature gut, brain, and immune system, predisposing them to short- and long-term complications.

Objective

We hypothesized that a milk diet supplemented with pre- and probiotics (i.e. synbiotics) and glutamine would improve gut, brain, and immune maturation in preterm neonates, using preterm pigs as a model.

Methods

Preterm pigs (Landrace x Yorkshire x Duroc, n = 40, delivered by c-section at 90% of gestation) were reared individually until day 23 after birth under highly standardized conditions. Piglets in the intervention group (PPG, n = 20) were fed increasing volumes of bovine milk supplemented with prebiotics (short-chain galacto- and long chain fructo-oligosaccharides 9:1, 4-12 g/L), probiotics (Bifidobacterium breve M16-V, 3 × 109 CFU/d) and l-glutamine [0.15-0.30 g/(kg · d)], and compared with pigs fed bovine milk with added placebo compounds as control (CON, n = 20). Clinical, gastrointestinal, immunological, cognitive, and neurological endpoints were measured.

Results

The PPG pigs showed more diarrhea but weight gain, body composition, and gut parameters were similar between the groups. Cognitive performance, assessed in a T-maze, was significantly higher in PPG pigs (P < 0.01), whereas motor function and exploratory interest were similar between the groups. Using ex vivo diffusion imaging, the orientation dispersion index in brain cortical gray matter was 50% higher (P = 0.04), and fractional anisotropy value was 7% lower (P = 0.05) in PPG pigs compared with CON pigs, consistent with increased dendritic branching in PPG. In associative fibers, radial diffusivity was lower and fractional anisotropy was higher in PPG pigs compared with CON pigs (all P < 0.05), while measures in the internal capsule showed a tendency towards reduced radial diffusivity and mean diffusivity (both P = 0.09). On day 23 pigs in the PPG group showed higher blood leukocyte numbers (+43%), neutrophil counts (+100%), and phagocytic rates (+24%), relative to CON, all P < 0.05.

Conclusion

Preterm pigs supplemented with Bifidobacterium breve, galacto- and fructo-oligosaccharides, and l-glutamine showed enhanced neuronal and immunological development. The findings indicate the potential for targeted nutritional interventions after preterm birth, to support development of important systems such as immunity and brain.

Effect of probiotics on C-reactive protein levels in preterm infants: Secondary analysis of a randomized controlled trial

BACKGROUND

Excessive inflammation is associated with adverse outcomes in preterm infants. C- reactive protein (CRP) is a marker of inflammation/infection. Probiotics have anti-inflammatory properties. Randomized controlled trials (RCTs) in preterm infants have not reported effect of probiotics on CRP.

AIM

To evaluate effect of probiotics on CRP in preterm infants who had participated in a RCT of Bifidobacterium breve (B. breve) m-16v.

METHODS

Data on all infants (GA <33 weeks, n = 159) enrolled in the RCT was analyzed. For study purpose, CRP <15 mg/L and ≤10 mg/L was considered normal for the first week, and thereafter respectively. Mixed logistic regression modelling was used to assess probiotic effect on CRP levels.

RESULTS

There were 1579 CRP measurements (Probiotic: 851 vs. Placebo: 728). Baseline characteristics and number [Median (IQR)] of CRP estimations per infant [l0 (5, 20) vs. 10 (6, 17), p = 0.861] were comparable between probiotic vs. placebo group. There was no significant difference in the proportion of infants with high CRP over time (treatment by weekly time points interaction, p = 0.187), and across all time points between probiotic and placebo group (adjusted OR: 1.62, 95% CI: 0.91-2.88, p = 0.102)CONCLUSION:B. breve m-16v did not decrease CRP levels in preterm infants born <33 weeks.

Effect of probiotic Bifidobacterium bifidum G9-1 on the relationship between gut microbiota profile and stress sensitivity in maternally separated rats

Although gut microbiota and early life events are likely involved in the development of irritable bowel syndrome (IBS), it remains unclear how these factors interact in the pathophysiology of IBS. In the present study, using rats subjected to maternal separation (MS) as a model of IBS, we investigated interrelationships among gut microbiota, stress susceptibility and intestinal permeability, and examined the effect of the probiotic Bifidobacterium bifidum G9-1 (BBG9-1) on those interrelationships. When compared with the controls at postnatal day 20, MS rats showed hypercorticosteronemia, enhanced intestinal permeability and changes in gut microbiota structure. All of these changes in MS rats were prevented by treatment with BBG9-1. Although the gut microbiota profile and basal serum corticosterone level did not differ between MS and control rats at postnatal day 56, MS rats showed hypersensitivity to restraint stress in terms of serum corticosterone level and fecal frequency. However, such hypersensitivity was not observed in MS rats treated with BBG9-1. These findings suggest that MS initiates the link between gut microbiota alteration and hypersensitivity to stress and that the triggering of this process can be prevented by the treatment with the probiotic BBG9-1.

Bifidobacterium breve M-16V as a Probiotic for Preterm Infants: A Strain-Specific Systematic Review

INTRODUCTION

Bifidobacterium breve M-16V has been used as a probiotic in preterm infants. Probiotic strain-specific data are essential to guide clinical practice.

OBJECTIVE

To assess effects of B breve M-16V in preterm neonates.

DESIGN

A systematic review of randomized controlled trials (RCTs) and non-RCTs of B breve M-16V in preterm infants was conducted. Multiple databases, proceedings of Pediatric Academy Society, and other relevant conferences were searched in September 2016 and on January 5, 2017.

RESULTS

Five RCTs (n = 482) and 4 non-RCTs (n = 2496) were included. Of the 5 RCTs, 4 carried high/unclear risk of bias in many domains. Meta-analysis (fixed effects model) of RCTs showed no significant benefits on stage ≥2 necrotizing enterocolitis, late-onset sepsis, mortality, and postnatal age at full feeds. Meta-analysis of non-RCTs showed significant benefits on (1) late-onset sepsis-3 studies (n = 2452), odds ratio = 0.56 (95% CI, 0.45-0.71), P < .0001; (2) mortality-2 studies (n = 2319), odds ratio = 0.61 (95% CI, 0.44-0.84), P = .002; and (3) postnatal age at full feeds (days)-2 studies (n = 361), mean difference, -2.42 (95% CI, -2.55 to -2.3), P < .00001. There were no adverse effects from B breve M-16V. On Grading of Recommendations, Assessment, Development, and Evaluation analysis, the overall quality of evidence was deemed very low.

CONCLUSIONS

Current evidence is limited regarding the potential of B breve M-16V in preterm neonates. Adequately powered, preferably cluster RCTs are needed to confirm these findings.

Gene expression profiling in the intestinal mucosa of obese rats administered probiotic bacteria

We investigated whether the administration of Lactobacillus paracasei CNCM I-4034, Bifidobacterium breve CNCM I-4035 and Lactobacillus rhamnosus CNCM I-4036 modulate the expression of genes in the intestinal mucosa of obese Zucker rats. Forty-eight Zucker-Leprfa/fa and 16 Zucker lean Lepr+/fa rats were used. Eight Zucker lean Lepr+/fa and 8 Zucker-Leprfa/fa rats were euthanized as a reference. The remaining 40 Zucker-Leprfa/fa rats were then assigned to receive 1010 colony forming units (CFU) of one of the three probiotic strains, a mixture of L. paracasei CNCM I-4034 and B. breve CNCM I-4035, or a placebo by oral administration for 30 days. An additional group of 8 Zucker lean Lepr+/fa rats received the placebo for 30 days. Over 27,000 rat genes were studied using a DNA array. Four animals per group were used. Total RNA was extracted from intestinal mucosa and cDNA was synthesized, fragmented and labeled. Labeled cDNA was hybridized using GeneChip kits, and the latter were scanned. Intensity values of each probe were processed and normalized to obtain an individual value for each set of probes.

Ratio of Klebsiella/Bifidobacterium in early life correlates with later development of paediatric allergy

Several studies have reported that intestinal microbial colonisation patterns differ between non-allergic and allergic infants. However, the microbial signature underlying the pathogenesis of allergies remains unclear. We aim to gain insight into the development of the intestinal microbiota of healthy infants and infants who develop allergy in early life, and identify potential microbiota biomarkers of later allergic disease. Using a case-control design in a Chinese sub-cohort of a Singaporean birth cohort (GUSTO), we utilised 16S rRNA gene sequencing to assess intestinal microbial composition and diversity of 21 allergic and 18 healthy infants at 3 weeks, 3 months and 6 months of age, and correlated the microbiota with allergy at ages 18 and 36 months. Pronounced differences in intestinal microbiota composition between allergic and healthy infants were observed at 3 months of age. The intestine of healthy infants was colonised with higher abundance of commensal Bifidobacterium. Conversely, Klebsiella, an opportunistic pathogen, was significantly enriched in the allergic infants. Interestingly, infants with a high Klebsiella/Bifidobacterium (K/B) ratio (above the population median K/B ratio) at age 3 months had an odds ratio of developing allergy by 3 years of age of 9.00 (95% confidence interval 1.46-55.50) compared to those with low K/B ratio. This study demonstrated a relationship between the ratio of genera Klebsiella and Bifidobacterium during early infancy and development of paediatric allergy in childhood. Our study postulates that an elevated K/B ratio in early infancy could be a potential indicator of an increased risk of allergy development. This line of research might enable future intervention strategies in early life to prevent or treat allergy. Our study provides new insights into microbial signatures associated with childhood allergy, in particular, suggests that an elevated K/B ratio could be a potential early-life microbiota biomarker of allergic disease.

Adamdec1, Ednrb and Ptgs1/Cox1, inflammation genes upregulated in the intestinal mucosa of obese rats, are downregulated by three probiotic strains

We have previously reported that administration of Lactobacillus paracasei CNCM I-4034, Bifidobacterium breve CNCM I-4035 and Lactobacillus rhamnosus CNCM I-4036 to obese Zucker-Lepr fa/fa rats attenuates liver steatosis and exerts anti-inflammatory effects. The goal of the present work was to investigate the modulation of gene expression in intestinal mucosa samples of obese Zucker-Lepr fa/fa rats fed the probiotic strains using a DNA microarray and postgenomic techniques. We also measured secretory IgA content in the gut and lipopolysaccharide (LPS)-binding protein (LBP) in serum. Expression of three genes (Adamdec1, Ednrb and Ptgs1/Cox1) was up-regulated in the intestinal mucosa of the obese rats compared with that in the rats when they were still lean. Probiotic administration down-regulated expression of Adamdec1 and Ednrb at the mRNA and protein levels and that of Ptgs1/Cox1 at the mRNA level, and this effect was in part mediated by a decrease in both macrophage and dendritic cell populations. Probiotic treatment also increased secretory IgA content and diminished the LBP concentration. Based on results reported in this work and else where, we propose a possible mechanism of action for these bacterial strains.

Effect of Bifidobacterium breve on the Intestinal Microbiota of Coeliac Children on a Gluten Free Diet: A Pilot Study

Coeliac disease (CD) is associated with alterations of the intestinal microbiota. Although several Bifidobacterium strains showed anti-inflammatory activity and prevention of toxic gliadin peptides generation in vitro, few data are available on their efficacy when administered to CD subjects. This study evaluated the effect of administration for three months of a food supplement based on two Bifidobacterium breve strains (B632 and BR03) to restore the gut microbial balance in coeliac children on a gluten free diet (GFD). Microbial DNA was extracted from faeces of 40 coeliac children before and after probiotic or placebo administration and 16 healthy children (Control group). Sequencing of the amplified V3-V4 hypervariable region of 16S rRNA gene as well as qPCR of Bidobacterium spp., Lactobacillus spp., Bacteroides fragilis group Clostridiumsensu stricto and enterobacteria were performed. The comparison between CD subjects and Control group revealed an alteration in the intestinal microbial composition of coeliacs mainly characterized by a reduction of the Firmicutes/Bacteroidetes ratio, of Actinobacteria and Euryarchaeota. Regarding the effects of the probiotic, an increase of Actinobacteria was found as well as a re-establishment of the physiological Firmicutes/Bacteroidetes ratio. Therefore, a three-month administration of B. breve strains helps in restoring the healthy percentage of main microbial components.

Maximum-biomass concentration prediction for Bifidobacteria in the pH-controlled fed-batch culture

Our objective was to systematically study the relationship between maximum biomass concentration of different Bifidobacteria and total-acid anions accumulation, and develop a prediction equation for the maximum biomass concentration in the fed-batch culture at pH-controlled 7·0. The accumulation of acid anions and the consumption of nutrients of various strains were evaluated. In addition, minimum inhibitory concentrations (MICs) of acid anions on a range of strains were examined at pH 7·0. The inhibition of acid anions, which had the same MIC as sodium chloride, was due to the osmotic pressure under pH 7·0 conditions. Moreover, the concentration of total-acid anions completely inhibiting each strain in the fed-batch culture at pH-controlled 7·0 had no significant differences with the MIC of acid anions for the corresponding strains. The osmotic pressures under two conditions were not significantly different. Finally, the maximum biomass concentration of Bifidobacteria was found to be closely related to biomass yield per unit of acid anion produced (YX/P ) and MIC (C) which were needed for the prediction, and different strains exhibited marked correlation (P ˂ 0·01, R = 0·985). An equation for the prediction of the maximum biomass concentration was developed as follows: Xmax -X0  = (0·71 ± 0·03)·YX/P ·C.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides further insights into the inhibition of Bifidobacteria by dissociated acid anions (the dissociated form) at pH 7·0. The high correlation between different strains suggested that the equation established in this paper is appropriate for different strains of Bifidobacteria. The prediction equation could be used to guide practical production in the preparation of materials, the control of the end of fermentation and production plans for further products such as freeze-dried powder of Bifidobacteria or food fermentation.

Bifidobacterium breve alters immune function and ameliorates DSS-induced inflammation in weanling rats

BACKGROUND

Bifidobacterium breve M-16V (M16V) is a probiotic bacterial strain with a long tradition of use in neonatal intensive care units in some countries. Previous study showed that the effects of M16V administration on gene expression were greater during the weaning period than in the neonatal period and were greater in the colon than in the small intestine and spleen, suggesting that M16V has anti-inflammatory effects. In this study, we evaluated the effects of inflammation during the weaning period and the effects of M16V on normal and inflammatory conditions.

METHODS

From postnatal day (PD) 21 to 34, weanling rats were administered of 2.5 × 10(9) of M16V daily, and colitis was induced by administration of 2% dextran sulfate sodium from PD28 to 35. Colitis severity, immune function, and microbiota were investigated.

RESULTS

Colitis caused a reduction in body weight gain, colon shortening, poor nutritional status, anemia, changes in blood and spleen lymphocyte populations, spleen T-cell malfunctions, and alterations in colon microbiota. M16V administration improved some but not all of the changes induced by colitis.

CONCLUSION

M16V could suppress inflammation and, therefore, can be considered a safe strain to use not only during the neonatal period but also the weaning period.

Food intolerance and mucosal inflammation

Most infants are immunologically active and are able to develop a tolerance to oligoclonal antigens by producing IgA, along with activation of regulatory T cells, in early infancy. Cytokines and their signaling molecules are important mediators in the intestine, regulating both oral tolerance and mucosal inflammation. This system works efficiently in most individuals, but for an as yet undefined reason, some people react to food and other proteins as though they were pathogens, with induction of chronic inflammation in the mucosa. The adverse reaction caused by ingested foods is defined as food intolerance. The clinical features of food intolerance include vomiting, diarrhea, bloody stool, eczema, failure to thrive, and a protean range of other symptoms. Intolerance can be divided into two categories depending on whether or not they are immunologically mediated. Food intolerance and mucosal inflammation are deeply related because tolerance cannot be established when there is an inflammation in the intestinal mucosa. Mast cells, eosinophils, mucosal lymphocytes, and epithelial cells are deeply involved and related to each other in the development of mucosal inflammation. Meanwhile, rectal bleeding in infancy is related to lymphoid hyperplasia with eosinophil infiltration into the colonic mucosa facilitated by C-C motif ligand 11 (CCL11, known as eotaxin-1) and C-X-C motif chemokine ligand 13 (CXCL13). Rectal bleeding in infancy may not be simply caused by allergic reactions against specific antigens, but may be due to migrated lymphocytes developing immunological tolerance; including IgA synthesizing, in the intestinal mucosa.

Modulation of immunity and inflammatory gene expression in the gut, in inflammatory diseases of the gut and in the liver by probiotics

The potential for the positive manipulation of the gut microbiome through the introduction of beneficial microbes, as also known as probiotics, is currently an active area of investigation. The FAO/WHO define probiotics as live microorganisms that confer a health benefit to the host when administered in adequate amounts. However, dead bacteria and bacterial molecular components may also exhibit probiotic properties. The results of clinical studies have demonstrated the clinical potential of probiotics in many pathologies, such as allergic diseases, diarrhea, inflammatory bowel disease and viral infection. Several mechanisms have been proposed to explain the beneficial effects of probiotics, most of which involve gene expression regulation in specific tissues, particularly the intestine and liver. Therefore, the modulation of gene expression mediated by probiotics is an important issue that warrants further investigation. In the present paper, we performed a systematic review of the probiotic-mediated modulation of gene expression that is associated with the immune system and inflammation. Between January 1990 to February 2014, PubMed was searched for articles that were published in English using the MeSH terms “probiotics" and "gene expression" combined with “intestines", "liver", "enterocytes", "antigen-presenting cells", "dendritic cells", "immune system", and "inflammation". Two hundred and five original articles matching these criteria were initially selected, although only those articles that included specific gene expression results (77) were later considered for this review and separated into three major topics: the regulation of immunity and inflammatory gene expression in the gut, in inflammatory diseases of the gut and in the liver. Particular strains of Bifidobacteria, Lactobacilli, Escherichia coli, Propionibacterium, Bacillus and Saccharomyces influence the gene expression of mucins, Toll-like receptors, caspases, nuclear factor-κB, and interleukins and lead mainly to an anti-inflammatory response in cultured enterocytes. In addition, the interaction of commensal bacteria and probiotics with the surface of antigen-presenting cells in vitro results in the downregulation of pro-inflammatory genes that are linked to inflammatory signaling pathways, whereas other anti-inflammatory genes are upregulated. The effects of probiotics have been extensively investigated in animal models ranging from fish to mice, rats and piglets. These bacteria induce a tolerogenic and hyporesponsive immune response in which many genes that are related to the immune system, in particular those genes expressing anti-inflammatory cytokines, are upregulated. By contrast, information related to gene expression in human intestinal cells mediated by the action of probiotics is scarce. There is a need for further clinical studies that evaluate the mechanism of action of probiotics both in healthy humans and in patients with chronic diseases. These types of clinical studies are necessary for addressing the influence of these microorganisms in gene expression for different pathways, particularly those that are associated with the immune response, and to better understand the role that probiotics might have in the prevention and treatment of disease.

Wild-type and IL10-null mice have differential colonic epithelial gene expression responses to dietary supplementation with synbiotic Bifidobacterium animalis subspecies lactis and inulin

Prebiotic plus probiotic (synbiotic) supplementations promote fermentation and have shown anti-inflammatory activity in colonic epithelium. However, in many instances, patients with inflammatory bowel disease (IBD) have demonstrated adverse effects after prebiotic supplementation at a dose well tolerated by normal individuals. To test the hypothesis that the host inflammation affects the colonic epithelial response to increased fermentation, the gene expression of colonic epithelium was analyzed. In a 1-way experimental design to test the effect of supplements in wild-type mice using the standard diet formulated by the American Institute of Nutrition (AIN-93G) as the control diet, fermentable fiber inulin (5%) in the absence or presence of the probiotic Bifidobacterium animalis subspecies lactis (Bb12) (10(8) CFU/kg diet) showed limited effects on gene expression as determined by whole-genome microarray. Bb12 supplementation alone was known not to increase fermentation and here instead significantly upregulated genes in nucleic acid metabolic processes. The effects of the synbiotic diet were then determined in mice exposed to LPS-induced inflammation in a 2-way experimental design testing the effect of diet and LPS. The microarray and quantitative reverse transcription-polymerase chain reaction analyses on the wild-type mice revealed that LPS-induced changes in the colonic epithelium were 4- to 10-fold less in the synbiotic diet group compared with the control diet group. Unlike the wild-type mice, anti-inflammatory cytokine interleukin 10 (IL10)-null mice (susceptible to IBD) given the synbiotic diet, compared with those given the control diet, had 3- to 40-fold increased expression of inflammation-related genes such as Cxcl1 (chemokine C-X-C motif ligand 1) and S100a9 (S100 calcium binding protein A9) in the absence and presence of LPS exposure. These contrasting intestinal epithelial responses to increased fermentation in wild-type and IL10-null mice are similar to the difference between healthy human individuals and those with IBD, suggesting that the host disease/genetic background should be considered before prebiotic/probiotic supplementation.

Efficacy of Bifidobacterium breve NCC2950 against DSS-induced colitis is dependent on bacterial preparation and timing of administration

Probiotics have been proposed as a therapy for inflammatory bowel disease, but variations in strains, formulations, and protocols used in clinical trials have hindered the creation of guidelines for their use. Thus, preclinical insight into the mechanisms of specific probiotic strains and mode of administration would be useful to guide future clinical trial design. In this study, live, heat inactivated (HI), and spent culture medium preparations of the probiotic Bifidobacterium breve NCC2950 were administered to specific pathogen free C57BL/6 mice before or during colitis, as well as before colitis reactivation. Five days of 3.5% dextran sulphate sodium in drinking water was used to induce colitis. Pretreatment with live B. breve reduced disease severity, myeloperoxidase activity, microscopic damage, cytokine production, interleukin (IL)-12/IL-10 ratio, and lymphocyte infiltration in the colon. B. breve did not attenuate on-going colitis. After acute colitis, disease symptoms were normalised sooner with live and HI B. breve treatment; however, reactivation of colitis was not prevented. These findings indicate that the efficacy of a probiotic to modulate intestinal inflammation is dependent on the formulation as well as state of inflammation when administered. Overall, live B. breve was most efficacious in preventing acute colitis. Live and HI B. breve also promoted recovery from diarrhoea and colon bleeding after a bout of acute colitis.

Probiotics VSL#3 protect against development of visceral pain in murine model of irritable bowel syndrome

BACKGROUND AND AIMS

Irritable bowel syndrome (IBS) is linked to post-inflammatory and stress-correlated factors that cause changes in the perception of visceral events. Probiotic bacteria may be effective in treating IBS symptoms. Here, we have investigated whether early life administration of VSL#3, a mixture of 8 probiotic bacteria strains, protects against development of visceral hypersensitivity driven by neonatal maternal separation (NMS), a rat model of IBS.

METHODS

Male NMS pups were treated orally with placebo or VSL#3 from days 3 to 60, while normal, not separated rats were used as controls. After 60 days from birth, perception of painful sensation induced by colorectal distension (CRD) was measured by assessing the abdominal withdrawal reflex (score 0-4). The colonic gene expression was assessed by using the Agilent Whole Rat Genome Oligo Microarrays platform and confirmed by real time PCR.

RESULTS

NMS rats exhibited both hyperalgesia and allodynia when compared to control rats. VSL#3 had a potent analgesic effect on CRD-induced pain without changing the colorectal compliance. The microarray analysis demonstrated that NMS induces a robust change in the expression of subsets of genes (CCL2, NOS3, THP1, NTRK1, CCR2, BDRKRB1, IL-10, TNFRSF1B, TRPV4, CNR1 and OPRL1) involved in pain transmission and inflammation. TPH1, tryptophan hydroxylase 1, a validated target gene in IBS treatment, was markedly upregulated by NMS and this effect was reversed by VSL#3 intervention.

CONCLUSIONS

Early life administration of VSL#3 reduces visceral pain perception in a model of IBS and resets colonic expression of subsets of genes mediating pain and inflammation.

TRANSCRIPT PROFILING

Accession number of repository for expression microarray data is GSE38942 (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE38942).

Colonic mucosal microbiome differs from stool microbiome in cirrhosis and hepatic encephalopathy and is linked to cognition and inflammation

Although hepatic encephalopathy (HE) is linked to the gut microbiota, stool microbiome analysis has not found differences between HE and no-HE patients. This study aimed to compare sigmoid mucosal microbiome of cirrhotic patients to controls, between HE vs. no-HE patients, and to study their linkage with cognition and inflammation. Sixty cirrhotic patients (36 HE and 24 no-HE) underwent cognitive testing, stool collection, cytokine (Th1, Th2, Th17, and innate immunity), and endotoxin analysis. Thirty-six patients (19 HE and 17 no-HE) and 17 age-matched controls underwent sigmoid biopsies. Multitag pyrosequencing (including autochthonous genera, i.e., Blautia, Roseburia, Fecalibacterium, Dorea) was performed on stool and mucosa. Stool and mucosal microbiome differences within/between groups and correlation network analyses were performed. Controls had significantly higher autochthonous and lower pathogenic genera compared with cirrhotic patients, especially HE patients. HE patients had worse MELD (model for end-stage liver disease) score and cognition and higher IL-6 and endotoxin than no-HE. Mucosal microbiota was different from stool within both HE/no-HE groups. Between HE/no-HE patients, there was no difference in stool microbiota but mucosal microbiome was different with lower Roseburia and higher Enterococcus, Veillonella, Megasphaera, and Burkholderia abundance in HE. On network analysis, autochthonous genera (Blautia, Fecalibacterium, Roseburia, and Dorea) were associated with good cognition and decreased inflammation in both HE/no-HE, whereas genera overrepresented in HE (Enterococcus, Megasphaera, and Burkholderia) were linked to poor cognition and inflammation. Sigmoid mucosal microbiome differs significantly from stool microbiome in cirrhosis. Cirrhotic, especially HE, patients' mucosal microbiota is significantly different from controls with a lack of potentially beneficial autochthonous and overgrowth of potentially pathogenic genera, which are associated with poor cognition and inflammation.