Biopolymer encapsulation for improved probiotic delivery: Advancements and challenges

Probiotics, known for their health benefits as living microorganisms, hold significant importance across various fields, including agriculture, aquaculture, nutraceuticals, and pharmaceuticals. Optimal delivery and storage of probiotic cells are essential to maximize their effectiveness. Biopolymers, derived from living sources, plants, animals, and microbes, offer a natural solution to enhance probiotic capabilities and they possess distinctive qualities such as stability, flexibility, biocompatibility, sustainability, biodegradability, and antibacterial properties, making them ideal for probiotic applications. These characteristics create optimal environments for the swift and precisely targeted delivery of probiotic cells that surpass the effectiveness of unencapsulated probiotic cells. Various encapsulation techniques using diverse biopolymers are employed for this purpose. These techniques are not limited to spray drying, emulsion, extrusion, spray freeze drying, layer by layer, ionic gelation, complex coacervation, vibration technology, electrospinning, phase separation, sol-gel encapsulation, spray cooling, fluidized, air suspension coating, compression coating, co-crystallization coating, cyclodextrin inclusion, rotating disk, and solvent evaporation methods. This review addresses the latest advancements in probiotic encapsulation materials and techniques, bridging gaps in our understanding of biopolymer-based encapsulation systems. Specifically, we address the limitations of current encapsulation methods in maintaining probiotic viability under extreme environmental conditions and the need for more targeted and efficient delivery mechanisms. Focusing on the interactions between biopolymers and probiotics reveals how customized encapsulation approaches can enhance probiotic stability, survival, and functionality. Through detailed comparative analysis of the effectiveness of various encapsulation methods, we identify key strategies for optimizing probiotic deployment in challenging conditions such as high-temperature processing, acidic environments, and gastrointestinal transit. The findings presented in this review highlight the superior performance of novel encapsulation methods using biopolymer blends and advanced technologies like electrospinning and layer-by-layer assembly, which provide enhanced protection and controlled release of probiotics by offering insights into the development of more robust encapsulation systems that ensure the sustained viability and bioavailability of probiotics, thus advancing their application across multiple industries. In conclusion, this paper provides the foundation for future research to refine encapsulation techniques to overcome the challenges of probiotic delivery in clinical and commercial settings.

Dietary complex probiotic supplementation changed the composition of intestinal short-chain fatty acids and improved the average daily gain of weaned piglets

Probiotics are a group of active microorganisms that form colonies within the body and alter the composition of the flora in a specific area to provide benefits to the host. In this study, a total of 96 Duroc × Landrace × Yorkshire weaned piglets with an initial body weight (BW) of 8.56 ± 0.53 kg were employed in a randomized complete block design for a 28-day experiment. Pigs were randomly divided into two treatment groups: the control group (CON) and the complex probiotic group (CON + 0.2% probiotics), respectively. The study found that through the 28-day experiment, the average daily gain (ADG) of the complex probiotic group was significantly higher than that of the CON (p < 0.05). However, compared with the CON, the feed conversion efficiency significantly decreased on days 0-14 (p < 0.05). The addition of dietary complex probiotic significantly increased the villus height (VH) of duodenum and ileum, acetate, propionate, butyrate, and total short-chain fatty acids (SCFAs) in feces, and decreased fecal methyl mercaptans, acetic acid, and CO2 (p < 0.05). It concluded that feeding weaned piglets 0.2% complex probiotic increased the VH of duodenum and ileum, as well as changed the content of SCFAs in feces. This ultimately led to an increase in ADG.

Technological characterisation and probiotic traits of yeasts isolated from Sha'a, a Cameroonian maize-based traditional fermented beverage

The current trend in starter selection is to combine both technological and probiotic properties to standardise and make functional artisanal fermented beverages such as Sha'a whose properties are very variable due to the lack of a known starter. The objective of this work was to study technological and probiotic properties of yeasts isolated from Sha'a sold in Bamenda, Bafoussam, Bonabérie, Dschang, Foumbot, Mbouda and Njombé (Cameroon). The isolated yeasts were studied for their ability to produce CO₂ from glucose, to grow in the presence of 8% ethanol, 20% glucose and pH 3, to assimilate maltose and to produce ethanol. Then, the survival of the pre-selected isolates was assessed in simulated gastric (pH 2 and 3) and intestinal juices, followed by self-aggregation, co-aggregation, hydrophobicity, haemolysin, gelatinase, biogenic amine production, antibiotic and antifungal susceptibility, bile salt hydrolase and antiradical activity. The selected isolates were identified by sequencing the 5.8S/28S rRNA gene. From the 98 isolates obtained, 66 produced CO₂ from glucose and 16 were then selected for their ability to grow in the presence of 8% ethanol, 20% glucose, pH 3 and maltose. The overall survival of isolates ranged from 4.12 ± 1.63 to 104.25 ± 0.19% (LT16) and from 0.56 ± 0.20 to 96.74 ± 1.60% (LT66) at pH 3 and pH 2 respectively. All of them have remarkable surface hydrophobicity properties. Based on principal component analysis, 5 isolates were selected as the best. However, only 3 of them, LT16 (the most promising), LT25 identified as Saccharomyces cerevisiae and LT80 as Nakaseomyces delphensis, do not produce a virulence factor. The latter can deconjugate bile salts with a maximum percentage of 60.54 ± 0.12% (LT16) and the highest inhibition of DPPH° radicals was 55.94 ± 1.14% (LT25). In summary, the yeast flora of Sha'a contains yeasts capable of fermenting and producing ethanol while producing bioactive compounds that would benefit the consumer.

Effect of the Inclusion of Bacillus spp. in Growing-Finishing Pigs' Diets: A Meta-Analysis

This meta-analysis determined the effect of Bacillus spp. on growth performance of growing−finishing pigs and then assessed causes for the heterogeneity of responses detected using meta-regression. A database of 22 articles published from 2000 to 2020 was identified, and 9 articles fitted the selection criteria and were integrated in the final database. Statistical analysis was performed to analyze the effect size for ADG, average daily feed intake (ADFI), and F:G ratio using a standardized means difference (SMD) at a 95% confidence interval. A meta-regression analysis was used to investigate the cause of heterogeneity, using the individual SMD for each study assessment as the outcome and the associated SE as the measure of variance. Dietary Bacillus spp. supplementation had no effect on ADFI (SMD: −0.052, p = 0.138) and numerically increased ADG (SMD: 0.113, p = 0.081) and reduced the F:G ratio SMD: −0.127, p < 0.001). Meta-regression outcomes suggested that the number of animals per group was an essential component promoting heterogeneity in ADG. Overall, the inclusion of Bacillus spp. (median 486 mg/d) in growing−finishing pigs can increase ADG and can decrease the F:G ratio.

Potential bioaccessibility of phenolic acids in whole wheat products during in vitro gastrointestinal digestion and probiotic fermentation

Health benefits of whole wheat products are partially attributed by their unique phenolic compounds. This study investigated effect of simulated gastrointestinal digestion and probiotic fermentation on releasing of phenolic acids from whole wheat foods (bread, cookie, and pasta). Kinetics results showed that more phenolic acids were released within the first hour of gastric and intestinal digestions compared to the prolonged digestion. Lactobacillus rhamnosus GG, a common probiotic strain, released additional phenolic acids from the digestive residues during fermentation. Simulated digestion released more soluble trans-ferulic acid than chemical extraction in breads (17.69 to 102.71 µg/g), cookie (15.81 to 54.43 µg/g), and pasta (4.88 to 28.39 µg/g). Phenolic acid composition of whole wheat products appeared to be better estimated by digestion methods than the chemical extraction method. The unique insoluble-bound nature and fermentability of wheat phenolic acids may lead to a mechanistic understanding of whole grain consumption for potential colorectal cancer prevention.

Evaluation of indigenous lactic acid bacteria of raw mare milk from pastoral areas in Xinjiang, China, for potential use in probiotic fermented dairy products

In the present study 114 lactic acid bacteria strains, isolated from raw mare milks from pastoral areas for ethnic minorities in northwest China, were screened for probiotic traits, and their characteristics were compared with those of Lactobacillus rhamnosus GG, a commercial strain. Among the 114 strains identified, the most common species was Pediococcus pentosaceus (n = 52), followed by Leuconostoc lactis (n = 35), Lactobacillus helveticus (n = 7), Lactobacillus plantarum (n = 6), Lactobacillus kefiri (n = 5), Lactobacillus curvatus (n = 4), Lactobacillus paracasei (n = 3), and Lactococcus garvieae (n = 3). Based on acid and bile salt tolerance, 15 strains were further selected. All selected strains were subjected to a series of in vitro tests to assess their technological properties, including cell surface hydrophobicity (13.6-56.2%), autoaggregation ability (9.26-38.30%), coaggregation ability, and heat and lysozyme survival rates (84.74-94.01% and 80.52-99.37%, respectively). In vitro antagonism showed that Lb. plantarum (M5-19, M8-60, M8-59) exhibited the most strong inhibitory activity against 7 tested pathogens. Moreover, antibiotic resistance and hemolytic activity were investigated for safety assessment. No strain exhibited hemolytic activity, and most of the strains were sensitive to a series of 14 antibiotics of clinical importance. Ultimately, the principal component analysis of all data obtained above showed that 2 Lb. plantarum strains (M8-59, M8-60) and Lb. paracasei M1-36 exhibited the best potential for their inclusion as adjunct functional cultures in local fermented dairy products.

Effects of Bacillus subtilis on growth performance, serum parameters, digestive enzyme, intestinal morphology, and colonic microbiota in piglets

The present study was conducted to investigate effects of Bacillus subtilis on growth performance, serum parameters, digestive enzymes, intestinal morphology, and colonic microbiota in piglets. A total of 72 piglets were weighed and randomly allotted into three treatments (four replication pens per treatment with six piglets/pen) for a 28-day experiment. The dietary treatments were as follows: basal diet (control group, CTR), basal diet supplementation with antibiotic (antibiotic group, ABT), and basal diet supplementation with 0.1% Bacillus subtilis (probiotic group, PBT). The average daily gain of body weight increased in both the ABT and PBT groups, and dietary antibiotics decreased the feed:gain ratio (F:G), as compared to the CTR group (P < 0.05). Both ABT and PBT piglets had increased serum triglycerides and lipase, amylase, maltase activities and villus height:crypt depth ratio (V/C) in ileum (P < 0.05). The PBT group also showed an increase in serum glucose and villus height in the ileum (P < 0.05). Dietary antibiotics increased Lactobacillus johnsonii, as compared to the CTR group, but decreased bacterial diversity and increased Escherichia coli, as compared to the PBT group (P < 0.05). Piglets dietary with B. subtilis modulated the microbiota by increasing the abundance of Firmicutes (L. johnsonii, L. reuteri) and decreasing the abundance of E. coli, as compared to the control group (P < 0.05). These results indicate that dietary of B. subtilis improves growth performance and intestinal health and can be a promising alternative to antibiotics in piglets diet.

The impact of probiotic supplementation on metabolic health in healthy women of reproductive age: a systematic review

Products containing probiotics are targeted at healthy or at-risk individuals as a preventative measure to minimise disease risk. Most studies assessing the efficacy of probiotics in humans include a mixture of healthy and unhealthy populations, while studies that focus solely on female populations are largely limited to pregnancy or those with health conditions. Pre-conception is a significant time-point during the life-course, and improving female health status during this period may positively influence future offspring. The objective of this review is to assess the effect of probiotics administered in oral capsule formulation, on metabolic and immune markers in healthy, non-pregnant women of reproductive age. This review followed the PRISMA guidelines. Pubmed, EMBASE, CINAHL, and Web of Science were searched for relevant studies. English language articles relating to randomised-controlled trials were included. The search returned 3250 publications after duplicates were removed. Title (2516), abstract (642), and full text (87) screening excluded 3993 studies from consideration. Five papers were identified with outcomes of interest, and analysis of these showed no conclusive evidence that probiotic capsule supplementation elicited positive effects in this healthy population. This study highlights the need for further research to investigate the role that probiotics play during the pre-conception period, on female metabolic and immune health.

Production of probiotic Mozzarella cheese by incorporating locally isolated Lactobacillus acidophilus

Purpose

The present study was conducted to isolate and screen the potential probiotic strains for incorporation in Mozzarella cheese.

Methods

Probiotic cultures were isolated from different randomly purchased yogurt samples and were identified as Lactobacillus sp., Bifidobacteria sp., and Pediococcus sp. after morphological and biochemical characterization. Heat tolerance of isolates was tested at 55 °C and 65 °C to determine the survival of isolates in conditions similar to commercial cheese production. Lactobacillus acidophilus (S2) showed remarkable heat tolerance among all strains and was therefore selected to assess the probiotic potential. It showed good survival at acidic pH values (2–3). Moreover, it also showed > 50% tolerance to bile salt and was resistant to antibiotics, chloramphenicol, tetracycline, gentamycin, and vancomycin and also exhibited anti-microbial activity against Salmonella typhimurium, Escherichia coli, and Staphylococcus aureus. Thus, heat-tolerant Lactobacillus acidophilus (S2) isolate was an ideal strain for incorporation in Mozzarella cheese as probiotics. Three types of cheeses viz., cheese A with free cells of Lactobacillus acidophilus (S2), cheese B with encapsulated cells of Lactobacillus acidophilus (S2), and control cheese having no probiotics, were made.

Result

Microbiological analysis of prepared cheese revealed lesser loss of Lactobacillus acidophilus (S2) from encapsulated form (3.41 × 108 CFU/mL) compared to free cells of Lactobacillus acidophilus (S2) (1.10 × 107 CFU/mL). Coliforms were observed in control cheese after 10 days of storage, whereas no coliforms were observed in cheese A and cheese B even after 15 days of storage. Organoleptic properties of cheese A and cheese B were almost the same with an acceptability score of 2.7 ± 0.1 and 2.65 ± 0.1, respectively. Control cheese got the lowest scores after 15 days of storage.

Conclusion

The addition of probiotics in cheese not only prolongs the shelf-life of cheese but also increases the organoleptic properties of the cheese, making cheese a good delivery system for probiotics.

Influence of the efficacy of a probiotic complex containing Bacillus subtilis and Pichia farinosa on the growth performance and fecal microbiota of finishing pigs

A total of 120 finish pigs [(Landrace × Yorkshire) × Duroc; 52.61 ± 2.37 kg] were randomly allotted into three treatments for a 70 d trial to evaluate the growth performance and fecal microbiota counts in finishing pigs. Treatment groups were (i) basal diet (CON), (ii) CON + 0.1% probiotic complex (TRT1), and (iii) CON + 0.2% probiotic complex (TRT2). Each treatment consisted of eight replicate pens with five pigs per pen. The average daily gain and fecal Lactobacillus counts of TRT2 were increased (P < 0.05) compared with CON treatment. The result showed that 0.2% complex probiotic was more effective than 0.1%.

Technological properties and probiotic potential of yeasts isolated from traditional low-salt fermented Chinese fish Suan yu

This study aims to investigate the technological properties of yeast strains isolated from traditional low-salt fermented Suan yu fish as starter culture. A step-by-step approach was used to determine the technological properties of the isolated yeast strains. The enzymatic activity (catalase, urease, β-glucosidase, protease, and lipase) under adverse conditions (pH, salt, and temperature) were evaluated. Principal component analysis was used to assess data. Twenty-five strains with desirable technological properties were selected for evaluation of probiotic traits (tolerance at pH 2.5 and 0.3% bile salts, antimicrobial activity, hydrophobic properties, and biofilm production). These isolates were identified by sequencing the D1/D2 region of 26S rDNA. Finally, seven isolates with desirable probiotic traits were analyzed for their ability to survive through gastric transit using a gastrointestinal simulation model. An In vitro test showed that isolates 3, 12, 19, 24, and 43 exhibited high survival levels (60%-70%), similar to those of the indicator strain (Saccharomyces cerevisiae). The results suggest that five isolates (S. cerevisiae strains 3, 12, 19, 24, and 43) showed desirable technological properties and probiotic traits and therefore can be used as functional starter cultures to produce fermented fish products. PRACTICAL APPLICATIONS: Researchers have investigated the activity of LAB as functional and probiotic microorganisms; however, information on the probiotic potential of yeasts remains limited. Yeasts are microorganisms that present and induce biochemical changes in several fermented meat and fish products. In the present study, the technological and probiotic properties of 52 isolates from Suan yu were investigated to identify potential probiotic strains for starter cultures. Our results suggest that five isolated S. cerevisiae strains showed desirable technological properties and probiotic traits and therefore can be used as functional starter cultures to produce fermented fish products, and other fermented foods. Functional yeast isolates are used to effectively improve the quality of fermented fish products for consumer acceptance. This study has focused on the possibility to produce a functional Suan yu using a potential probiotic S. cerevisiae as starter culture to enhance health benefits.

Exploitation of autochthonous Tuscan sourdough yeasts as potential starters

The increasing demand for healthy baked goods boosted studies on sourdough microbiota with beneficial metabolic traits, to be used as potential functional starters. Here, yeast populations of traditional sourdoughs collected from four Tuscan bakeries were investigated. Among 200 isolated strains, 78 were randomly selected and molecularly characterized. Saccharomyces cerevisiae was dominant, representing the only species detected in three out of the four sourdoughs. The fourth one harbored also Kazachstania humilis. Inter-delta regions analysis revealed a high intraspecific polymorphism discriminating 16 biotypes of S. cerevisiae isolates, which clustered based on their origin. Representative isolates from each biotype group were individually used to ferment soft and durum wheat flour, aiming at evaluating their pro-technological, nutritional and functional features. During fermentation under standardized conditions, all strains were able to grow of ca. 2 log cycles, but only S. cerevisiae L10Y, D18Y and D20Y had a significantly shorter latency phase in both flours. Overall, the highest volumes were reached after 16 h of fermentation in both soft and durum fermented dough. S. cerevisiae D2Y produced the highest dough volume increase. K. humilis G23Y was the only strain able to increase the total free amino acids concentration of the doughs. Overall, values of phytase activity were significantly higher in durum compared to the corresponding soft fermented dough. K. humilis G23Y and S. cerevisiae D20Y, D24Y showed a threefold higher phytase activity than spontaneously fermented control, and the highest concentration of total phenols. Almost all the strains led to increases of antioxidant activity, without significant differences among them. Investigations on the resistance of the strains to simulated gastric and intestinal conditions, that is considered a pre-requisite for the selection of probiotics, revealed the ability to survive in vitro by many of the strains considered. This study proposed the best performing yeast strains selected among autochthonous sourdough yeasts based on their pro-technological, nutritional and functional traits to be used as starters for making sourdough baked goods or functional cereal-based beverages. Although some yeast strains combined several technological and nutritional traits, the association of more selected strains seemed to be a requisite to get optimal sourdough characteristics.

Prospective study of probiotic supplementation results in immune stimulation and improvement of upper respiratory infection rate

The human gut microbiota is an important environmental factor for human health with evolutionarily conserved roles in immunity, metabolism, development, and behavior of the host. Probiotic organisms are claimed to offer several functional properties including stimulation of immune system. The purpose of this study is to investigate the effects of a probiotic supplementation on adult volunteers who have contracted the common cold four or more times in the past year. This study is a single center, double-blind, randomized, controlled, prospective trial. Subjects received a probiotic drink containing Lactobacillus paracasei (at least 3 × 107 colony forming units (CFU) ml-1), Lactobacillus casei 431® (at least 3 × 107 CFU ml-1) and Lactobacillus fermentium PCC® (at least 3 × 106 CFU ml-1) or an identical placebo without probiotics for a 12-week study period. The consumption of probiotics significantly reduced the incidence of upper respiratory infection (p < 0.023) and flu-like symptoms with an oral temperature higher than 38 °C (p < 0.034) as compared to the placebo group. Subjects that consumed probiotics demonstrated a significantly higher level of IFN-γ in the serum (p < 0.001) and sIgA in the gut (p < 0.010) as compared to the placebo group and a significant higher level of serum IFN-γ (p < 0.001) and gut sIgA (p < 0.001) as compared to their baseline test results. In contrast, there were no significant differences in the serum IL-4, IL-10, IgA, IgG or IgM between the probiotics and the placebo groups. Results of this study demonstrated that probiotics were safe and effective for fighting the common cold and influenza-like respiratory infections by boosting the immune system.

Probiotics, prebiotics, and microencapsulation: A review

The development of a suitable technology for the production of probiotics is a key research for industrial production, which should take into account the viability and the stability of the organisms involved. Microbial criteria, stress tolerance during processing, and storage of the product constitute the basis for the production of probiotics. Generally, the bacteria belonging to the genera Lactobacillus and Bifidobacterium have been used as probiotics. Based on their positive qualities, probiotic bacteria are widely used in the production of food. Interest in the incorporation of the probiotic bacteria into other products apart from dairy products has been increasing and represents a great challenge. The recognition of dose delivery systems for probiotic bacteria has also resulted in research efforts aimed at developing probiotic food outside the dairy sector. Producing probiotic juices has been considered more in the recent years, due to an increased concern in personal health of consumers. This review focuses on probiotics, prebiotics, and the microencapsulation of living cells.

Influence of Chitosan Coating on Mechanical Stability of Biopolymer Carriers with Probiotic Starter Culture in Fermented Whey Beverages

The aim of this study was to improve the mechanical stability of biopolymer carriers and cell viability with addition of chitosan coating during fermentation process and product storage. Dairy starter culture (1% (w/v)) was diluted in whey and mixed with sodium alginate solution and the beads were made using extrusion technique. The mechanical stability of coated and uncoated beads, the release behavior, and the viability of encapsulated probiotic dairy starter culture in fermented whey beverages were analyzed. The mechanical properties of the beads were determined according to force-displacement and engineering stress-strain curves obtained after compression testing. It was observed that addition of chitosan as a coating on the beads as well as the fermentation process increased the elastic modulus of the calcium alginate-whey beads and cell survival. The current study revealed that the coating did not significantly improve the viability of probiotics during the fermentation but had an important influence on preservation of the strength of the carrier during storage. Our results indicate that whey-based substrate has positive effect on the mechanical stability of biopolymer beads with encapsulated probiotics.

Immune system stimulation by probiotic microorganisms

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

Effects of dietary probiotics on growth performance, faecal microbiota and serum profiles in weaned piglets

This study was conducted to evaluate the effects of dietary supplementation with probiotics on growth performance, faecal microbiota, and serum profiles in weaned piglets. Large White × Landrace piglets (n = 144) weaned at 35–37 days of age were selected and divided into four groups, and the piglets from each group were assigned randomly to six pens (replicates) with six animals each. Each group was fed one of four diets for 5 weeks: a basal diet without antibiotics and probiotics (control), or the basal diet supplemented with Lactobacillus plantarum GF103, Bacillus subtilis B27, or a mixture of L. plantarum GF103 and B. subtilis B27. During the first 2 weeks of the supplementation, the piglets supplemented with probiotics had lower (P < 0.05) average daily feed intake than control piglets. The feed conversion ratio was improved (P < 0.05) in probiotic-supplemented groups compared with that of control. The population of E. coli in faeces of the piglets supplemented with L. plantarum GF103 was lower (P < 0.05) than that of control piglets. On day 14, dietary supplementation of the combination of L. plantarum GF103 and B. subtilis B27 increased (P < 0.05) the serum concentrations of total protein, globulin, and creatinine, but decreased (P < 0.05) the ratio of serum albumin to serum globulin, compared with the basal diet. On day 14, dietary supplementation with probiotics increased (P < 0.05) the serum IgM concentration compared with the basal diet. Supplementation of B. subtilis B27 or the combination of L. plantarum GF103 and B. subtilis B27 increased (P < 0.05) the serum IgA concentration at the end of the trial. These results suggest that dietary probiotics improved growth performance and enhanced immune responses at the early stage of the post-weaning period in piglets.

Probiotics in the gastrointestinal diseases of the elderly

Changes of the gut microflora in elderly appear to involve a reduction in numbers of healthy bacteria (lactobacilli and bifidobacteria) and an increase in numbers of potentially pathogenic species. These changes are generally described as gastrointestinal disorders and infections. This review analyses benefits of probiotics in old people, with particular interesting for the latest researches relevant to elderly people, e.g. trials examining enteric infections, antibiotic-associated diarrhea and Clostridium difficile associated diarrhea, functional bowel problems (constipation and irritable bowel syndrome), inflammatory bowel diseases, stimulation of the immune system and prevention of cancer. A growing number of researches indicates that some probiotic strains may help to maintain the health in old people, suggesting both health and cost-saving benefits in offering fermented dairy products. These benefits include: establishment of balanced intestinal microflora; improving colonization resistance and or prevention of diarrhea; reduction of fecal enzymes; reduction of serum cholesterol; reduction of potential mutagenes; reduction of lactose intolerance; synthesis of vitamins; predigestion of proteins.

Biotechnologies for the management of genetic resources for food and agriculture

In recent years, the land area under agriculture has declined as also has the rate of growth in agricultural productivity while the demand for food continues to escalate. The world population now stands at 7 billion and is expected to reach 9 billion in 2045. A broad range of agricultural genetic diversity needs to be available and utilized in order to feed this growing population. Climate change is an added threat to biodiversity that will significantly impact genetic resources for food and agriculture (GRFA) and food production. There is no simple, all-encompassing solution to the challenges of increasing productivity while conserving genetic diversity. Sustainable management of GRFA requires a multipronged approach, and as outlined in the paper, biotechnologies can provide powerful tools for the management of GRFA. These tools vary in complexity from those that are relatively simple to those that are more sophisticated. Further, advances in biotechnologies are occurring at a rapid pace and provide novel opportunities for more effective and efficient management of GRFA. Biotechnology applications must be integrated with ongoing conventional breeding and development programs in order to succeed. Additionally, the generation, adaptation, and adoption of biotechnologies require a consistent level of financial and human resources and appropriate policies need to be in place. These issues were also recognized by Member States at the FAO international technical conference on Agricultural Biotechnologies for Developing Countries (ABDC-10), which took place in March 2010 in Mexico. At the end of the conference, the Member States reached a number of key conclusions, agreeing, inter alia, that developing countries should significantly increase sustained investments in capacity building and the development and use of biotechnologies to maintain the natural resource base; that effective and enabling national biotechnology policies and science-based regulatory frameworks can facilitate the development and appropriate use of biotechnologies in developing countries; and that FAO and other relevant international organizations and donors should significantly increase their efforts to support the strengthening of national capacities in the development and appropriate use of pro-poor agricultural biotechnologies.

Comparative proteomic analysis of Lactobacillus plantarum for the identification of key proteins in bile tolerance

Background

Lactic acid bacteria are commonly marketed as probiotics based on their putative or proven health-promoting effects. These effects are known to be strain specific but the underlying molecular mechanisms remain poorly understood. Therefore, unravelling the determinants behind probiotic features is of particular interest since it would help select strains that stand the best chance of success in clinical trials. Bile tolerance is one of the most crucial properties as it determines the ability of bacteria to survive in the small intestine, and consequently their capacity to play their functional role as probiotics. In this context, the objective of this study was to investigate the natural protein diversity within the Lactobacillus plantarum species with relation to bile tolerance, using comparative proteomics.

Results

Bile tolerance properties of nine L. plantarum strains were studied in vitro. Three of them presenting different bile tolerance levels were selected for comparative proteomic analysis: L. plantarum 299 V (resistant), L. plantarum LC 804 (intermediate) and L. plantarum LC 56 (sensitive). Qualitative and quantitative differences in proteomes were analyzed using two-dimensional electrophoresis (2-DE), tryptic digestion, liquid chromatography-mass spectrometry analysis and database search for protein identification. Among the proteins correlated with differences in the 2-DE patterns of the bacterial strains, 15 have previously been reported to be involved in bile tolerance processes. The effect of a bile exposure on these patterns was investigated, which led to the identification of six proteins that may be key in the bile salt response and adaptation in L. plantarum: two glutathione reductases involved in protection against oxidative injury caused by bile salts, a cyclopropane-fatty-acyl-phospholipid synthase implicated in maintenance of cell envelope integrity, a bile salt hydrolase, an ABC transporter and a F0F1-ATP synthase which participate in the active removal of bile-related stress factors.

Conclusions

These results showed that comparative proteomic analysis can help understand the differential bacterial properties of lactobacilli. In the field of probiotic studies, characteristic proteomic profiles can be identified for individual properties that may serve as bacterial biomarkers for the preliminary selection of strains with the best probiotic potential.

Translating complex science into life-course health promoting strategies

These days, we are bombarded with nutrition information from diverse sources and of varying quality. There has been a dramatic increase in communication channels, including more television channels with airtime to fill, and the emergence of the Internet and 'new media' such as social networking sites. Part of this culture is to deliver ever changing and novel angles. The background 'noise' that this creates can make delivery of evidence-based advice about healthy eating that generally carries less novelty value, a huge challenge. This paper illustrates ways in which complex scientific information can be translated into meaningful health promoting strategies that can be applied across the life course. The examples used are nutrition in the context of healthy ageing, communicating the concept of energy density in the context of satiety, healthy hydration, health effects of probiotics and resources for use by teachers in the classroom. This selection of examples demonstrates the processes adopted at the British Nutrition Foundation to identify the evidence base for a particular topic and then to communicate this information to various target audiences. The British Nutrition Foundation's approach typically starts with preparation of a detailed review of the evidence, often with the involvement of external expertise, followed by peer review. For much of this work conventional science communication routes are used, but use is also made of the Internet and various forms of new media.

Potential benefits of probiotics--main findings of an in-depth review

Media reports on probiotics have been conflicting which has led to increased confusion among the general population and also among health professionals. To disentangle myths and reality, the British Nutrition Foundation has carried out a review on probiotics and health. There is good evidence that probiotics are effective in preventing antibiotic-associated diarrhoea and, although only few studies have been carried out so far, probiotic microorganisms also seem to have the potential to prevent the potentially fatal Clostridium difficile-associated diarrhoea. A limited number of studies that are available on the effectiveness of probiotics on constipation have shown conflicting results, but promising results have been found for certain strains. Irritable bowel syndrome symptoms have been found to be reduced by consuming probiotic strains, although a high placebo effect has been observed in some of the studies. The field of probiotics is relatively new and more studies will be needed to allow firm conclusions on the effectiveness of probiotic microorganisms for certain health issues.