The Effect of Lacticaseibacillus rhamnosus, Lacticaseibacillus paracasei, and Bifidobacterium animalis ssp. lactis on the Prevention of Asthma in an Animal Model

The increase in the prevalence of asthma, particularly in urban communities, has encouraged investigations into preventive strategies. The hygiene theory proposes that early exposure to infections and unhygienic conditions during childhood influences immune system development, potentially protecting against allergic diseases. The mechanisms involved are related to alterations in the intestinal microbiota, such as with probiotics. This study aimed to evaluate the preventive effect of Lacticaseibacillus rhamnosus, Lacticaseibacillus paracasei, and Bifidobacterium animalis ssp. lactis, administered isolated or in combination, at various concentrations, on asthma in an animal model. Mice received two concentrations (1 × 109 and 1 × 1010 CFU/ml) of three probiotics, isolated and in combination, over 26 consecutive days, initiating 10 days before sensitizing and challenging with ovalbumin. In vivo bronchial hyperresponsiveness and airway and lung inflammation were assessed. The administration of L. paracasei, L. rhamnosus, and B. animalis spp. lactis in different concentrations, isolated or in combination, did not reduce hyperresponsiveness and airway and lung inflammation. As probiotic effects are strain and dose-dependents, specific studies are necessary to assess the effect of different probiotic strains, doses, and regimes.

Dose-Response Effect of Saccharomyces cerevisiae UFMG A-905 on the Prevention of Asthma in an Animal Model

Probiotics should be administered in adequate amounts to confer health benefits. Probiotic dose-response studies are still missing. Saccharomyces cerevisiae UFMG A-905 prevented asthma development; however, the ideal dose has not been investigated. We evaluated the optimal dose and administration regimen of S. cerevisiae UFMG A-905 in the prevention of asthma. Male Balb/c mice were sensitized intraperitoneally with ovalbumin (OVA) and challenged with OVA intranasally. Mice received, via gavage, daily or alternate-day S. cerevisiae UFMG A-905. In daily regimen, different concentrations (107, 108, or 109 CFU/mL) were given 10 days before OVA sensitization and during challenges. In alternate-day regimen, a concentration of 109 CFU/mL was administered three times per week for 5 weeks, starting 2 weeks prior to the first sensitization. After the last challenge, in vivo bronchial hyperresponsiveness and airway and lung inflammation were assessed. OVA-challenged mice, when compared to saline-challenged mice, presented a significant increase in bronchial hyperresponsiveness and airway and lung inflammation. Daily and alternate-day administration of 109 CFU/mL of S. cerevisiae UFMG A-905 significantly reduced bronchial hyperresponsiveness; lower concentrations of S. cerevisiae UFMG A-905 did not significantly reduce bronchial hyperresponsiveness. Daily regimen with the highest concentration significantly reduced total cell number, eosinophil count in the BAL, and the levels of IL-4, IL-5, and IL-13. Daily administration of S. cerevisiae UFMG A-905 at 107 and 108 CFU/mL and alternate-day regimen did not significantly decrease airway and lung inflammation. S. cerevisiae UFMG A-905 led to a significant attenuation of bronchial hyperresponsiveness and lung inflammation in a dose-dependent manner.

Probiotics in Infancy and Childhood for Food Allergy Prevention and Treatment

Food allergy represents a failure of oral tolerance mechanisms to dietary antigens. Over the past few years, food allergies have become a growing public health problem worldwide. Gut microbiota is believed to have a significant impact on oral tolerance to food antigens and in initiation and maintenance of food allergies. Therefore, probiotics have also been proposed in this field as a possible strategy for modulating both the gut microbiota and the immune system. In recent years, results from preclinical and clinical studies suggest a promising role for probiotics in food allergy prevention and treatment. However, future studies are needed to better understand the mechanisms of action of probiotics in food allergies and to design comparable study protocols using specific probiotic strains, defined doses and exposure times, and longer follow-up periods.

A systematic scoping review of study methodology for randomized controlled trials investigating probiotics in athletic and physically active populations

BACKGROUND

The purported ergogenic and health effects of probiotics have been a topic of great intrigue among researchers, practitioners, and the lay public alike. There has also been an increased research focus within the realm of sports science and exercise medicine on the athletic gut microbiota. However, compared to other ergogenic aids and dietary supplements, probiotics present unique study challenges. The objectives of this systematic scoping review were to identify and characterize study methodologies of randomized controlled trials investigating supplementation with probiotics in athletes and physically active individuals.

METHODS

Four databases (MEDLINE, CINAHL, Cochrane CENTRAL, and Cochrane Database of Systematic Reviews) were searched for randomized controlled studies involving healthy athletes or physically active individuals. An intervention with probiotics and inclusion of a control and/or placebo group were essential. Only peer-reviewed articles in English were considered, and there were no date restrictions. Results were extracted and presented in tabular form to detail study protocols, characteristics, and outcomes. Bias in randomized controlled trials was determined with the RoB 2.0 tool.

RESULTS

A total of 45 studies were included in the review, with 35 using a parallel group design and 10 using a cross-over design. Approximately half the studies used a single probiotic and the other half a multi-strain preparation. The probiotic dose ranged from 2 × 108 to 1 × 1011 colony forming units daily, and the length of intervention was between 7 and 150 days. Fewer than half the studies directly assessed gastrointestinal symptoms, gut permeability, or the gut microbiota. The sex ratio of participants was heavily weighted toward males, and only 3 studies exclusively investigated females. Low-level adverse events were reported in only 2 studies, although the methodology of reporting varied widely. The risk of bias was generally low, although details on randomization were lacking in some studies.

CONCLUSION

There is a substantial body of research on the effects of probiotic supplementation in healthy athletes and physically active individuals. Considerable heterogeneity in probiotic selection and dosage as well as outcome measures has made clinical and mechanistic interpretation challenging for both health care practitioners and researchers. Attention to issues of randomization of participants, treatments and interventions, selection of outcomes, demographics, and reporting of adverse events will facilitate more trustworthy interpretation of probiotic study results and inform evidence-based guidelines.

Drying of probiotics to enhance the viability during preparation, storage, food application, and digestion: A review

Functional food products containing viable probiotics have become increasingly popular and demand for probiotic ingredients that maintain viability and stability during processing, storage, and gastrointestinal digestions. This has resulted in heightened research and development of powdered probiotic ingredients. The aim of this review is to overview the development of dried probiotics from upstream identification to downstream applications in food. Free probiotic bacteria are susceptible to various environmental stresses during food processing, storage, and after ingestion, necessitating additional materials and processes to preserve their activity for delivery to the colon. Various classic and emerging thermal and nonthermal drying technologies are discussed for their efficiency in preparing dehydrated probiotics, and strategies for enhancing probiotic survival after dehydration are highlighted. Both the formulation and drying technology can influence the microbiological and physical properties of powdered probiotics that are to be characterized comprehensively with various techniques. Furthermore, quality control during probiotic manufacturing and strategies of incorporating powdered probiotics into liquid and solid food products are discussed. As emerging technologies, structure-design principles to encapsulate probiotics in engineered structures and protective materials with improved survivability are highlighted. Overall, this review provides insights into formulations and drying technologies required to supplement viable and stable probiotics into functional foods, ensuring the retention of their health benefits upon consumption.

Brewer's Spent Grain Enhanced the Recovery of Potential Probiotic Strains in Fermented Milk After Exposure to In Vitro-Simulated Gastrointestinal Conditions

Brewer's spent grain (BSG) is a beer industry by-product with interesting functional properties by its high fiber content and bioactive compounds, which may be possibly employed as a prebiotic ingredient. The fermentability of BSG by ten probiotics and two starter cultures was evaluated, and the co-culture of Lacticaseibacillus paracasei subsp. paracasei F-19® (probiotic) and Streptococcus thermophilus TH-4® (starter) was selected to produce a potentially probiotic fermented milk (FM). Four formulations of FM were studied: FM1 (control), FM2 (probiotic - /BSG +), FM3 (probiotic + /BSG -), and FM4 (probiotic + /BSG +). The viability of the microorganisms in the FM was monitored throughout 28 days of storage. The resistance of the microorganisms in the FM to in vitro-simulated gastrointestinal tract (GIT) conditions was also evaluated. Even though the BSG did not influence the fermentation kinetics or increase the populations of both microorganisms in the FM, a significant improvement on the survival of TH-4® against in vitro-simulated GIT stress was observed in the formulations containing BSG alone or in combination with F-19®. All formulations showed potential as probiotic FM, since total probiotic populations were kept above 10¹⁰ CFU in a daily portion of 200 mL, and a minimum of 10¹⁰ and 10⁸ CFU equivalent of, respectively, TH-4® and F-19® was recovered after the GIT stress. Therefore, TH-4® has potential as a probiotic strain in addition to its starter feature, while BSG may be employed as a possible prebiotic ingredient in a synbiotic approach. Nonetheless, further studies to evaluate possible health benefits are needed.

Stress Response in Bifidobacteria

Bifidobacteria naturally inhabit diverse environments, including the gastrointestinal tracts of humans and animals. Members of the genus are of considerable scientific interest due to their beneficial effects on health and, hence, their potential to be used as probiotics. By definition, probiotic cells need to be viable despite being exposed to several stressors in the course of their production, storage, and administration. Examples of common stressors encountered by probiotic bifidobacteria include oxygen, acid, and bile salts. As bifidobacteria are highly heterogenous in terms of their tolerance to these stressors, poor stability and/or robustness can hamper the industrial-scale production and commercialization of many strains. Therefore, interest in the stress physiology of bifidobacteria has intensified in recent decades, and many studies have been established to obtain insights into the molecular mechanisms underlying their stability and robustness. By complementing traditional methodologies, omics technologies have opened new avenues for enhancing the understanding of the defense mechanisms of bifidobacteria against stress. In this review, we summarize and evaluate the current knowledge on the multilayered responses of bifidobacteria to stressors, including the most recent insights and hypotheses. We address the prevailing stressors that may affect the cell viability during production and use as probiotics. Besides phenotypic effects, molecular mechanisms that have been found to underlie the stress response are described. We further discuss strategies that can be applied to improve the stability of probiotic bifidobacteria and highlight knowledge gaps that should be addressed in future studies.

Biotics in pediatrics: a short overview

The aim of this review was to provide a general overview to the topic of this special issue. In this study the available categories of biotics were defined (i.e., probiotics, prebiotics, postobiotics and synbiotics) as first actors of therapies that target the gut flora, with the aim to modify it in a specific direction, generally with the goal of controlling inflammatory phenomena. The points that must be considered when evaluating the results of these interventions, and, specifically, the changes in gut microbiota following the assumption of biotics were analyzed. This context typically represented the one of clinical trials aimed at inducing or maintaining remission in pediatric autoimmune inflammatory diseases, that often yield conflicting results. We finally attempted to draft possible research developments for the next years.

Best Practices for Probiotic Research in Athletic and Physically Active Populations: Guidance for Future Randomized Controlled Trials

Probiotic supplementation, traditionally used for the prevention or treatment of a variety of disease indications, is now recognized in a variety of population groups including athletes and those physically active for improving general health and performance. However, experimental and clinical trials with probiotics commonly suffer from design flaws and different outcome measures, making comparison and synthesis of conclusions difficult. Here we review current randomized controlled trials (RCTs) using probiotics for performance improvement, prevention of common illnesses, or general health, in a specific target population (athletes and those physically active). Future RCTs should address the key elements of (1) properly defining and characterizing a probiotic intervention, (2) study design factors, (3) study population characteristics, and (4) outcome measures, that will allow valid conclusions to be drawn. Careful evaluation and implementation of these elements should yield improved trials, which will better facilitate the generation of evidence-based probiotic supplementation recommendations for athletes and physically active individuals.

Different Reactions in Each Enterotype Depending on the Intake of Probiotic Yogurt Powder

Probiotics can be used as a nutritional strategy to improve gut homeostasis. We aimed to evaluate the intestinal microbiota profile of 18 subjects after ingestion of probiotic yogurt powder (PYP) based on enterotype. The subjects were classified into three enterotypes according to their microbial community: Bacteroides (n = 9, type B), Prevotella (n = 3, type P), and Ruminococcus (n = 6, type R). We performed controlled termination in a transient series that included a control period of three weeks before probiotic intake, PYP intake for three weeks, and a three-week washout period. Fecal microbiota composition was analyzed by sequencing the V3-V4 super variable region of 16S rRNA. Based on the Bristol stool shape scale, abnormal stool shape improved with PYP intake, and bowel movements were activated. The abundance of Faecalibacterium, Eggerthella, and Leuconostoc, which ferment and metabolize glucose, showed a strong correlation with type B Bacteroides, and glucose metabolism improvement was observed in all type B subjects. Alkaline phosphatase was significantly improved only in type B. In addition, the abundance of type B Bacteroides showed a negative correlation with that of Lactobacillus. The abundance of Streptococcus, Agathobacter, and Christensenella, which are involved in lipid metabolism, showed a strong correlation with that of type P Prevotella, and triglyceride metabolism improvement was observed in all type P subjects. The gut microbiota showed only short-term changes after PYP intake and showed resilience by returning to its original state when PYP intake was interrupted. In summary, the different responses to PYP intake may result from the different enterotypes and associated strains; therefore, the probiotic composition should be adjusted based on the individual enterotype.

Probiotics in the Prevention and Treatment of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a disease with high morbidity and mortality that occurs mainly in premature born infants. The pathophysiologic mechanisms indicate that gastrointestinal dysbiosis is a major risk factor. We searched for relevant articles published in PubMed and Google Scholar in the English language up to October 2020. Articles were extracted using subject headings and keywords of interest to the topic. Interesting references in included articles were also considered. Network meta-analysis suggests the preventive efficacy of Bifidobacterium and Lactobacillus spp., but even more for mixtures of Bifidobacterium, Streptococcus, and Bifidobacterium, and Streptococcus spp. However, studies comparing face-to-face different strains are lacking. Moreover, differences in inclusion criteria, dosage strains, and primary outcomes in most trials are major obstacles to providing evidence-based conclusions. Although adverse effects have not been reported in clinical trials, case series of adverse outcomes, mainly septicemia, have been published. Consequently, systematic administration of probiotic bacteria to prevent NEC is still debated in literature. The risk-benefit ratio depends on the incidence of NEC in a neonatal intensive care unit, and evidence has shown that preventive measures excluding probiotic administration can result in a decrease in NEC.

Prebiotic and probiotic supplementation and the tryptophan-kynurenine pathway: A systematic review and meta analysis

This systematic review aimed to synthesise the results from studies investigating the effects of prebiotics and probiotics on kynurenine pathway metabolism. Thirteen studies were identified for inclusion, comprising 12 probiotic and two prebiotic arms. Participants included healthy individuals and individuals with various clinical conditions. Twelve metabolites were examined across the studies, using a range of biological samples. Across all interventions, 11 reported an effect on ≤ metabolite. Although limited by clinical and methodological heterogeneity, pooled analysis (n = 253) found probiotics to significantly affect serum kynurenine (g = 0.315, CI = 0.070 to 0.560, p = 0.012, 4 studies, I² = 0%) and the kynurenine:tryptophan ratio (g = 0.442, CI = 0.074 to 0.810, p = 0.018, 4 studies, I² = 42 %). Risk of bias across the studies was generally low. The results provide preliminary evidence that probiotics can modulate kynurenine pathway metabolism, with less evidence available regarding prebiotics. Future studies which further consider methodological confounds and sample characteristics are required, to establish intervention efficacy. PROSPERO registration #CRD42019154677.

Lemon Exosome-like Nanoparticles-Manipulated Probiotics Protect Mice from C. d iff Infection

Clostridioides difficile (C. diff) is the leading cause of antibiotic-associated colitis. Here, we report that lemon exosome-like nanoparticles (LELNs) manipulated probiotics to inhibit C. diff infection (CDI). LELN-manipulated Lactobacillus rhamnosus GG (LGG) and Streptococcus thermophilus ST-21 (STH) (LELN-LS) decrease CDI mortality via an LELN-mediated increase in bile resistance and gut survivability. LELN-LS treatment increases the AhR ligands indole-3-lactic acid (I3LA) and indole-3-carboxaldehyde (I3Ald), leading to induction of IL-22, and increases lactic acid leading to a decrease of C. diff fecal shedding by inhibiting C. diff growth and indole biosynthesis. A synergistic effect between STH and LGG was identified. The STH metabolites inhibit gluconeogenesis of LGG and allow fructose-1,6-bisphosphate (FBP) to accumulate in LGG; accumulated FBP then activates lactate dehydrogenase of LGG (LGG-LDH) and enhances production of lactic acid and the AhR ligand. Our findings provide a new strategy for CDI prevention and treatment with a new type of prebiotics.

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LELNs-manipulated probiotics protect mice from C. diff infection

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LELNs manipulation modulates gut metabolomics composition

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Cross talk between LGG and STH enhances production of lactic acid and AhR ligands

Physicochemical and microstructural properties and probiotic survivability of symbiotic almond yogurt alternative using polymerized whey protein as a gelation agent

A plain symbiotic almond yogurt-like product was formulated and developed using a plant-based starter YF-L02 (Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus supplemented with Lactobacillus acidophilus, Lactobacillus paracasei, and Bifidobacterium animalis) and inulin; 0.6% polymerized whey protein (PWP), 0.3% pectin, and 0.05% xanthan gum were optimized for the formula of the almond yogurt alternative. Two groups with/without calcium citrate and vitamin D₂ were prepared and analyzed for chemical composition, changes in pH, viscosity, and probiotic survivability during storage at 4 °C for 10 weeks. The results showed that (1) over 10 weeks storage, the differences in the pH, viscosity, and probiotic survivability between the control and the fortified samples were not significant (P > 0.05); (2) the pH of both yogurt samples decreased 0.2 units while their viscosity slightly increased during storage; (3) the populations of L. paracasei and B. animalis remained above 10⁶ cfu/g during the storage, whereas the population of L. acidophilus decreased dramatically during the first 4 weeks, especially the control group; (4) the microstructure was examined by scanning electron microscopy, revealing a compact and denser gel structure formed by 0.6% PWP with the presence of 0.3% pectin and 0.05% xanthan gum. In conclusion, PWP might be a proper gelation agent for the formulation of symbiotic almond yogurt alternative. PRACTICAL APPLICATION: In this study, polymerized whey protein was used as a gelation agent to formulate symbiotic almond yogurt alternatives with comparable physical texture and probiotic survivability to dairy yogurt during storage. This technology may be used for the development of plant-based fermented foods.

Probiotics' efficacy in paediatric diseases: which is the evidence? A critical review on behalf of the Italian Society of Pediatrics

During the last decade several paediatric studies have been published with different possible indications for probiotics, leading to a global increase of probiotics' market. Nevertheless, different study designs, multiple single/combined strains and small sample size still leave many uncertainties regarding their efficacy. In addition, different regulatory and quality control issues make still very difficult the interpretation of the clinical data. The objective of this review is to critically summarise the current evidence on probiotics' efficacy and safety on a different number of pathologies, including necrotizing enterocolitis, acute infectious diarrhoea, allergic diseases and functional gastrointestinal disorders in order to guide paediatric healthcare professionals on using evidence-based probiotics' strains. To identify relevant data, literature searches were performed including Medline-PubMed, the Cochrane Library and EMBASE databases. Considering probiotics strain-specific effects, the main focus was on individual probiotic strains and not on probiotics in general.

Influence of Lactobacillus kefiri on Intestinal Microbiota and Fecal IgA Content of Healthy Dogs

The increasing incidence of gastrointestinal tract pathologies in dogs and the worrisome topic of antibiotic resistance have raised the need to look for new therapeutic frontiers. Of these, the use of probiotics represents a potential therapeutic alternative. Lactobacillus kefiri (Lk) is a species of Lactobacillus isolated from kefir. Previous studies have demonstrated that its administration in mice downregulates the expression of proinflammatory mediators and increases anti-inflammatory molecules in the gut immune system. It also regulates intestinal homeostasis, incrementing immunoglobulin A (IgA) secretion. Since Lk has never been studied as a single probiotic in dogs, the aim of this study was to evaluate the safety of Lk in dogs, and its effect on IgA secretion and on intestinal microbiota composition. Ten healthy dogs without a history of gastrointestinal diseases were included. The dogs received Lk at a dose of 10⁷ live microorganisms orally, once daily for 30 days. The fecal samples were tested before administration, in the middle, at the end, and 30 days after discontinuation. The IgA secretion concentration and the microbiota composition were evaluated on the fecal samples. The results in this study suggested that Lk did not influence the concentration of IgA, nor significant changes of the intestinal microbiota were observed during and after the treatment. Therefore, additional studies are needed to investigate if a higher daily dosage of Lk can influence the intestinal homeostasis of dogs.

Probiotic powders prepared by mixing suspension of Lactobacillus salivarius NRRL B-30514 and spray-dried lactose: Physical and microbiological properties

Preparation of powdered probiotics is important for storage and application. In this work, a novel method to prepare powdered probiotic ingredients was studied by mixing a Lactobacillus salivarius NRRL B-30514 suspension with amorphous spray-dried lactose at suspension: lactose (v:w) ratios (SLR) of 1:5, 1:15, and 1:25. The simple procedure resulted in lactose-probiotics powders (LPPs) with greater probiotic viability initially and during subsequent 6-month storage at a smaller SLR. In LPPs with SLRs of 1:5 and 1:15, X-ray diffraction spectroscopy and scanning electron microscopy results indicated the formation of lactose crystals, and BacLight® assay suggested the significantly lowered membrane integrity of probiotics due to hypertonic pressure of lactose dissolved in excessive water. A viable but non-culturable state of L. salivarius in LPPs may exist based on the BacLight® and CTC reduction assays. The present study may provide a novel approach to prepare powdered probiotic ingredients.

Effects of Lactobacillus acidophilus D2/CSL (CECT 4529) supplementation on healthy cat performance

Background

The present study aimed to evaluate the effects of the probiotic strain Lactobacillus acidophilus D2/CSL (CECT 4529) on nutritional condition and faecal quality in cats.

Methods

Ten healthy adult cats from the same cattery were included (aged >9 months; male:female sex ratio=3:7). The animals were randomly assigned to a control group (CTR; n=5; male:female=1:4; room 1: 16 m²) and to a treated group (LACTO; n=5; male:female=2:3; room 2: 16 m²) receiving the same commercial dry diet. The LACTO group diet was supplemented with the probiotic (5 x 10⁹ cfu/kg feed at least). A five-week experimental period was applied, and nutritional status was monitored by bodyweight (BW) and body condition score (BCS). Faecal quality was evaluated using faecal score (FS) and faecal moisture (FM) parameters. Plate counts of some faecal bacteria species were carried out. The data obtained were analysed using MIXED, GLM and NPAR1WAY procedures (SAS V.9.4; P≤0.05).

Results

The two groups did not show differences in BW and BCS data. A clear effect of the probiotic supplementation on FM was recorded (LACTO 44 per cent v CTR group 46 per cent; P=0.04). FS in the LACTO group (3.35) was close to ideal values (2-3) in comparison with the CTR group (3.75). Positive effects of L acidophilus D2/CSL have been recorded in terms of increase in faecal lactobacilli counts and reduction in faecal coli counts.

Conclusions

This study's preliminary results describe how inclusion of L acidophilus D2/CSL (CECT 4529) probiotic strain in cats' diets could effectively improve faecal quality parameters and consequently gut health in adult healthy cats.

High-intensity-exercise-induced intestinal damage is protected by fermented milk supplemented with whey protein, probiotic and pomegranate (Punica granatum L.)

Here we evaluated the effect of fermented milk supplemented with whey protein (approximately 80 % protein), probiotic (Bifidobacterium animalis subsp. lactis BB12) and pomegranate juice (Punica granatum L.) on the physical performance, intestinal motility and villi structure, inflammatory markers and intestinal microbiota of rats under high-intensity acute exercise. In all, twenty-four Wistar rats were separated into groups: control (Ctrl), supplemented (Supp), exercised (Exe) and exercised and supplemented (Exe+Supp). Rats in the Supp groups received fermented milk during 6 weeks by oral administration. At the end of the supplementation period, the Exe groups were submitted to high-intensity acute exercise on a treadmill. We found that intense acute exercise caused changes in the intestinal villi interspace, changes in the proportion of Lactobacillus species and an increase in Clostridium species, as well as a decrease in intestinal motility. Supplementation increased intestinal motility, and maintained the intestinal villi interspace and the natural microbiota proportions of the exercised rats. Physical performance was not improved by fermented milk supplementation. We conclude that the fermented milk containing whey protein, B. animalis (BB12) and pomegranate juice can re-establish intestinal microbiota and protect the animals from the undesirable effects of intense acute exercise.

Thirty Years of Lactobacillus rhamnosus GG: A Review

Lactobacillus rhamnosus GG (LGG) was the first strain belonging to the genus Lactobacillus to be patented in 1989 thanks to its ability to survive and to proliferate at gastric acid pH and in medium containing bile, and to adhere to enterocytes. Furthermore LGG is able to produces both a biofilm that can mechanically protect the mucosa, and different soluble factors beneficial to the gut by enhancing intestinal crypt survival, diminishing apoptosis of the intestinal epithelium, and preserving cytoskeletal integrity. Moreover LGG thanks to its lectin-like protein 1 and 2 inhibits some pathogens such as Salmonella species. Finally LGG is able to promote type 1 immune-responsiveness by reducing the expression of several activation and inflammation markers on monocytes and by increasing the production of interleukin-10, interleukin-12 and tumor necrosis factor-α in macrophages. A large number of research data on Lactobacillus GG is the basis for the use of this probiotic for human health. In this review we have considered predominantly randomized controlled trials, meta-analysis, Cochrane Review, guide lines of Scientific Societies and anyway studies whose results were evaluated by means of relative risk, odds ratio, weighted mean difference 95% confidence interval. The effectiveness of LGG in gastrointestinal infections and diarrhea, antibiotic and Clostridium difficile associated diarrhea, irritable bowel syndrome, inflammatory bowel disease, respiratory tract infections, allergy, cardiovascular diseases, nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, cystic fibrosis, cancer, elderly end sport were analyzed.

Dose-interval study of a dual probiotic in preterm infants

OBJECTIVE

The objective of this study was to investigate the appropriate dosing interval of a probiotic (Infloran) given daily, biweekly and weekly in preterm infants <32 weeks' gestation.

METHODS

There were 8 infants in the daily group, 8 infants in the biweekly group and 10 infants in the weekly group, all born between 25 and 32 weeks' gestation. The control group consisted of 12 preterm infants who did not receive the probiotic. Infloran (250 mg/capsule), containing Bifidobacterium bifidum (1×10⁹ colony-forming unit (CFU)) and Lactobacillus acidophilus (1×10⁹ CFU), was administered in 2.5 mL of breast milk per kilogram weight of the infant (2×10⁹ CFU of bacteria in total), until 34 weeks postmenstrual age (PMA). Stool samples were collected at 31, 34, 41 and 44 weeks PMA and frozen at -20°C.

RESULTS

After administration of the probiotic at 31 weeks PMA, Bifidobacterium were significantly higher in the daily group (45%) in comparison with the biweekly (17%) and weekly (9%) groups. At 34 weeks PMA, Bifidobacterium were significantly higher again in the daily (60%) group in comparison with the biweekly (21%), weekly (23%) and control (15%) groups. At 41 weeks PMA a decrease in the relative abundances of Streptococcaceae and Enterococcaceae was found in all three probiotic groups, and by 44 weeks PMA significantly higher levels of Lactobacillus were found in the biweekly group (16.5%) in comparison with the weekly group (2.1%).

CONCLUSION

Our results indicate that a daily dose of Infloran is a suitable dosage for preterm infants in the neonatal intensive care unit, with significantly higher levels of Bifidobacterium found in the daily probiotic group up to 44 weeks PMA.

Effect of Cell Concentration on the Persistence in the Human Intestine of Four Probiotic Strains Administered through a Multispecies Formulation

Studies devoted to evaluating the outcome of different doses of probiotics are very limited, especially for multistrain formulations. In this context, we performed an intervention study that aimed to compare the effect of the administration of two doses (7 billion and 70 billion bacterial cells) of a multistrain probiotic formulation on the persistence of the four probiotic strains that were present in the product in the fecal samples collected from healthy subjects. The overall persistence of the probiotic strains was significantly higher for the 70 billion formulation than for the 7 billion formulation. Furthermore, probiotic strains were detected earlier and for longer for the 70 billion formulation compared to those for the 7 billion formulation. All probiotic strains were recovered alive from the 70 billion preparation, whereas recovery was not possible in a few fecal samples upon administration of the 7 billion preparation. In addition, the overall number of viable probiotic cells recovered on day 14 (i.e., the last day of consumption) was significantly higher for the 70 billion formulation than that for the 7 billion formulation. Finally, we found that the viability of the probiotic cells was stable over the course of the trial independent of volunteers' handling, demonstrating good manufacturing of the product. In conclusion, this study demonstrated that strains belonging to different taxa may coexist in the human gastrointestinal tract upon ingestion of a multispecies probiotic formulation. Moreover, this study suggests that higher doses of bacterial cells in probiotic formulations may permit a higher, earlier, and longer recovery of the probiotics in the feces of healthy adults.

Molecular and in vitro assessment of some probiotic characteristics of amylolytic Lactobacillus plantarum strains from Bulgarian fermented products

In the recent years, consumers' interest in healthy diet opened a new field for functional food development through combining the valuable composition of cereals and the health-promoting properties of lactic acid bacteria (LAB). LAB with amylolytic properties can assimilate starch in a single-step process and could be successfully applied as starter cultures offering an efficient nutritional conversion of cereal matrices. The probiotic potential of amylolytic LAB has not been investigated so far, therefore the present study focused on the molecular screening and in vitro tests of five amylolytic Lactobacillus plantarum strains to assess their tolerance to high acid and bile salts concentrations and antibiotic resistance as basic characteristics required for probiotic strains selection. Results showed excellent correspondence between the genetic screening and the phenotypic tests performed. Survivability at high acidity and bile salts presence was strain specific, with significant positive effect observed for cultures in stationary phase compared to those in exponential phase. Effect of starch in the medium proved most important to ensure viability of the amylolytic strains, which reveals the excellent potential of amylolytic LAB for commercially relevant probiotic applications. The strains proved to be generally safe in terms of antibiotic resistance. Among the five tested strains, L. plantarum Bom2 showed the best probiotic potential.

Effect of a probiotic beverage consumption (Enterococcus faecium CRL 183 and Bifidobacterium longum ATCC 15707) in rats with chemically induced colitis

Background

Some probiotic strains have the potential to assist in relieving the symptoms of inflammatory bowel disease. The impact of daily ingestion of a soy-based product fermented by Enterococcus faecium CRL 183 and Lactobacillus helveticus 416 with the addition of Bifidobacterium longum ATCC 15707 on chemically induced colitis has been investigated thereof within a period of 30 days.

Methods

Colitis was induced by dextran sulfate sodium. The animals were randomly assigned into five groups: Group C: negative control; Group CL: positive control; Group CLF: DSS with the fermented product; Group CLP: DSS with the non-fermented product (placebo); Group CLS: DSS with sulfasalazine. The following parameters were monitored: disease activity index, fecal microbial analyses, gastrointestinal survival of probiotic microorganisms and short-chain fatty acids concentration in the feces. At the end of the protocol the animals’ colons were removed so as to conduct a macroscopical and histopathological analysis, cytokines and nitrite quantification.

Results

Animals belonging to the CLF group showed fewer symptoms of colitis during the induction period and a lower degree of inflammation and ulceration in their colon compared to the CL, CLS and CLP groups (p<0.05). The colon of the animals in groups CL and CLS presented severe crypt damage, which was absent in CLF and CLP groups. A significant increase in the population of Lactobacillus spp. and Bifidobacterium spp. at the end of the protocol was verified only in the CLF animals (p<0.05). This group also showed an increase in short-chain fatty acids (propionate and acetate). Furthermore, the intestinal survival of E. faecium CRL 183 and B. longum ATCC 15707 in the CLF group has been confirmed by biochemical and molecular analyzes.

Conclusions

The obtained results suggest that a regular intake of the probiotic product, and placebo to a lesser extent, can reduce the severity of DSS-induced colitis on rats.

A Possible Role of Intestinal Microbiota in the Pathogenesis of Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory disease primarily affecting the sacroiliac joints and the spine, for which the pathogenesis is thought to be a result of the combination of host genetic factors and environmental triggers. However, the precise factors that determine one’s susceptibility to AS remain to be unraveled. With 100 trillion bacteria residing in the mammalian gut having established a symbiotic relation with their host influencing many aspects of host metabolism, physiology, and immunity, a growing body of evidence suggests that intestinal microbiota may play an important role in AS. Several mechanisms have been suggested to explain the potential role of the microbiome in the etiology of AS, such as alterations of intestinal permeability, stimulation of immune responses, and molecular mimicry. In this review, the existing evidence for the involvement of the microbiome in AS pathogenesis was discussed and the potential of intestinal microbiome-targeting strategies in the prevention and treatment of AS was evaluated.

Experimental support for the effects of a probiotic/digestive enzyme supplement on serum cholesterol concentrations and the intestinal microbiome

Background

Elevated levels of blood cholesterol are associated with cardiovascular disease, a leading cause of morbidity and mortality worldwide. Current therapies for addressing elevated blood cholesterol can be inadequate, ineffective or associated with side effects; therefore, the search for additional therapies is ongoing. This study evaluated Daily Body Restore (DBR), a proprietary blend of 9 probiotic organisms of the genera Lactobacillus and Bifidobacterium, and 10 digestive enzymes, for its effects on cholesterol metabolism using an in vitro system and a mouse model.

Methods

We used a murine model of hypercholesterolemia induced by a high fat diet to evaluate the effects of DBR on blood cholesterol concentrations. Hypercholesterolemic mice were supplemented with DBR in their drinking water for 8 weeks and compared to control mice given low fat diets or unsupplemented high fat diets. To evaluate the effects of DBR on the activity of gut microbiota in vitro, the Shime^® system consisting of sequential colon reactors was supplemented with DBR for analysis of short chain fatty acid production.

Results

Analysis of hypercholesterolemic mice after 4 and 8 weeks of DBR supplementation revealed significant decreases in blood concentrations of low-density lipoprotein (LDL) and increases in high-density lipoprotein (HDL) while triglyceride concentrations were unaltered. Specifically, after 4 weeks of DBR supplementation, there was a 47 % decrease in LDL and a 32 % increase in HDL in peripheral blood compared to unsupplemented, high fat diet-fed mice. After 8 weeks of DBR treatment, LDL concentrations were dramatically reduced by 78 % and HDL was increased by 52 % relative to control mice. Addition of DBR to the Shime^® system led to significantly increased production of propionate in colon reactors, indicative of microbial production of short chain fatty acids known to inhibit cholesterol synthesis.

Conclusions

DBR, a probiotic and digestive enzyme supplement, lowered harmful LDL and increased HDL levels in a mouse model and also exerted in vitro effects consistent with cholesterol-lowering activity. Given the magnitude of the effects of DBR, these findings are promising for clinical implementation of DBR for treating hypercholesterolemia.

Survival of Lactobacillus casei strain Shirota in the intestines of healthy Chinese adults

Lactobacillus casei strain Shirota (LcS) is a widely used probiotic strain with health benefits. In this study, the survival of LcS in the intestines of healthy Chinese adults was assessed and the effects of LcS on stool consistency, stool SCFAs and intestinal microbiota evaluated. Subjects consumed 100 mL per day of a probiotic beverage containing 1.0 × 10(8) CFU/mL of LcS for 14 days. LcS were enumerated using a culture method and the colony identity confirmed by ELISA. Fourteen days after ingestion, the amount of LcS recovered from fecal samples was between 6.86 ± 0.80 and 7.17 ± 0.57 Log10 CFU/g of feces (mean ± SD). The intestinal microbiotas were analyzed by denaturing gradient gel electrophoresis. Principal component analysis showed that consuming LcS significantly changed fecal microbiota profiles. According to redundancy analysis, the amounts of 25 bacterial strains were significantly correlated with LcS intake (P < 0.05), 11 of them positively and fourteen negatively. Concentrations of acetic acid and propionic acid in feces were significantly lower during the ingestion period than during the baseline period (P < 0.05). These results confirm that LcS can survive passage through the gastrointestinal tract of Chinese people; however, they were found to have little ability to persist once their consumption had ceased. Furthermore, consumption of probiotic beverages containing LcS can modulate the composition of the intestinal microbiota on a long-term basis, resulting in decreased concentrations of SCFAs in the gut.

Oral administration of Lactobacillus paracasei NCC 2461 for the modulation of grass pollen allergic rhinitis: a randomized, placebo-controlled study during the pollen season

Background

The efficacy of Lactobacillus paracasei NCC 2461 in modulating allergic rhinitis was previously evaluated in two exploratory clinical studies. Oral administration with NCC 2461 reduced specific subjective symptoms following nasal provocation tests with controlled grass pollen allergen concentrations. Our aim was to confirm the anti-allergic effect of NCC 2461 in grass pollen allergic subjects exposed to natural doses of allergens during the pollen season.

Findings

A double-blind, randomized, placebo-controlled, parallel study was conducted with 131 grass pollen allergic subjects from May to July 2012 in concomitance with the pollen season in Berlin. NCC 2461 or placebo was administered daily for an 8-week period to adult subjects with clinical history of allergic rhinitis to grass pollen, positive skin prick test and IgE to grass pollen. During the 8 weeks, symptoms and quality of life questionnaires were filled out, and plasma was collected for IgE analysis at screening and at the end of the intervention. All subjects were included within a 5-day interval, ensuring exposure to similar air pollen counts for each individual during the trial period. The results obtained show that symptoms increased with pollen loads, confirming a natural exposure to the allergen and presence of pollen-induced allergic rhinitis in the subjects. However, no significant differences were observed in allergic rhinitis symptoms scores, quality of life, or specific IgE levels between subjects receiving NCC 2461 as compared to placebo administration.

Conclusion

In contrast to previous findings, oral administration of NCC 2461 did not show a beneficial effect on allergic rhinitis in a field trial. The influence of study design, allergen exposure and intervention window on the efficacy of NCC 2461 in modulating respiratory allergy should be further evaluated.

Electronic supplementary material

The online version of this article (doi:10.1186/s13601-015-0085-4) contains supplementary material, which is available to authorized users.

World Allergy Organization-McMaster University Guidelines for Allergic Disease Prevention (GLAD-P): Probiotics

BACKGROUND

Prevalence of allergic diseases in infants, whose parents and siblings do not have allergy, is approximately 10% and reaches 20-30% in those with an allergic first-degree relative. Intestinal microbiota may modulate immunologic and inflammatory systemic responses and, thus, influence development of sensitization and allergy. Probiotics have been reported to modulate immune responses and their supplementation has been proposed as a preventive intervention.

OBJECTIVE

The World Allergy Organization (WAO) convened a guideline panel to develop evidence-based recommendations about the use of probiotics in the prevention of allergy.

METHODS

We identified the most relevant clinical questions and performed a systematic review of randomized controlled trials of probiotics for the prevention of allergy. We followed the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to develop recommendations. We searched for and reviewed the evidence about health effects, patient values and preferences, and resource use (up to November 2014). We followed the GRADE evidence-to-decision framework to develop recommendations.

RESULTS

Currently available evidence does not indicate that probiotic supplementation reduces the risk of developing allergy in children. However, considering all critical outcomes in this context, the WAO guideline panel determined that there is a likely net benefit from using probiotics resulting primarily from prevention of eczema. The WAO guideline panel suggests: a) using probiotics in pregnant women at high risk for having an allergic child; b) using probiotics in women who breastfeed infants at high risk of developing allergy; and c) using probiotics in infants at high risk of developing allergy. All recommendations are conditional and supported by very low quality evidence.

CONCLUSIONS

WAO recommendations about probiotic supplementation for prevention of allergy are intended to support parents, clinicians and other health care professionals in their decisions whether to use probiotics in pregnancy and during breastfeeding, and whether to give them to infants.

Probiotics to counteract biofilm-associated infections: promising and conflicting data

Altered bowel flora is currently thought to play a role in a variety of disease conditions, and the use of Bifidobacterium spp. and Lactobacillus spp. as probiotics has been demonstrated to be health-promoting, even if the success of their administration depends on the applied bacterial strain(s) and the targeted disease. In the last few decades, specific probiotics have been shown to be effective in the treatment or the prevention of acute viral gastroenteritis, pediatric post-antibiotic-associated diarrhea, some pediatric allergic disorders, necrotizing enterocolitis in preterm infants, inflammatory bowel diseases and postsurgical pouchitis. The potential application of probiotics is continuously widening, with new evidence accumulating to support their effect on the prevention and treatment of other disease conditions, including several oral diseases, such as dental caries, periodontal diseases and oral malodor, as well as genitourinary and wound infections. Considering the increasingly widespread ability of pathogens to generate persistent biofilm-related infections, an even more attractive proposal is to administer probiotics to prevent or counteract biofilm development. The response of biofilm-based oral, intestinal, vaginal and wound infections to probiotics treatment will be reviewed here in light of the most recent results obtained in this field.

Expert consensus document. The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic

An expert panel was convened in October 2013 by the International Scientific Association for Probiotics and Prebiotics (ISAPP) to discuss the field of probiotics. It is now 13 years since the definition of probiotics and 12 years after guidelines were published for regulators, scientists and industry by the Food and Agriculture Organization of the United Nations and the WHO (FAO/WHO). The FAO/WHO definition of a probiotic--"live microorganisms which when administered in adequate amounts confer a health benefit on the host"--was reinforced as relevant and sufficiently accommodating for current and anticipated applications. However, inconsistencies between the FAO/WHO Expert Consultation Report and the FAO/WHO Guidelines were clarified to take into account advances in science and applications. A more precise use of the term 'probiotic' will be useful to guide clinicians and consumers in differentiating the diverse products on the market. This document represents the conclusions of the ISAPP consensus meeting on the appropriate use and scope of the term probiotic.

Non-alcoholic fatty liver disease, diet and gut microbiota

Non-alcoholic fatty liver disease (NAFLD) is a severe liver disease that is increasing in prevalence with the worldwide epidemic of obesity and its related insulin-resistance state. Evidence for the role of the gut microbiota in energy storage and the subsequent development of obesity and some of its related diseases is now well established. More recently, a new role of gut microbiota has emerged in NAFLD. The gut microbiota is involved in gut permeability, low-grade inflammation and immune balance, it modulates dietary choline metabolism, regulates bile acid metabolism and produces endogenous ethanol. All of these factors are molecular mechanisms by which the microbiota can induce NAFLD or its progression toward overt non-alcoholic steatohepatitis. Modification of the gut microbiota composition and/or its biochemical capacity by specific dietary or pharmacological interventions may advantageously affect host metabolism. Large-scale intervention trials, investigating the potential benefit of prebiotics and probiotics in improving cardiometabolic health in high-risk populations, are fervently awaited.

Future for probiotic science in functional food and dietary supplement development

PURPOSE OF REVIEW

The purpose of this study is to provide an update of probiotic science evolving from classical approaches to the development of next-generation probiotics, parallel to advances in the understanding of the complexity of the gut microbiome and its role in human health.

RECENT FINDINGS

The probiotic concept is based on the notion that the gut ecosystem contributes to human physiology and, consequently, its modulation may help to maintain health and reduce disease risk. The understanding of the complexity of the gut microbiota and the specific components associated with progression from health to disease is rapidly increasing, thanks to the use of high-throughput and next-generation sequencing techniques in progressively better controlled epidemiological studies. Evidence on microbiome-mediated effects by intervention with classical probiotics on humans is, however, limited. The new information is helping to set a rationale for selection of a next generation of probiotics. Candidates include Clostridia clusters IV, XIVa and XVIII, Faecalibacterium prausnitzii, Akkermansia muciniphila and Bacteroides uniformis, the effects of which have been evaluated in preclinical trials with promising results for inflammatory and diet-related disorders. Yet, the extent to which new probiotic formulations consisting of nonconventional indigenous gut bacteria will be effective on humans at a population level or in personalized nutrition strategies remains to be explored.

SUMMARY

Understanding the role that indigenous intestinal bacteria and their ecological interactions play in human health and disease based on epidemiological, intervention and mechanistic studies will provide a robust rationale for selection of probiotic strains and facilitate the optimization of integrated dietary strategies to efficiently modulate the human gut microbiome, leading to improvements in nutrition and clinical practice.