Impact ofSaccharomyces Cerevisiaeon Viability of ProbioticLactobacillus Rhamnosusin Fermented Milk under Ambient Conditions

Influence of metabolic guilds on a temporal scale in an experimental fermented food derived microbial community

The influence of community diversity, which can be measured at the level of metabolic guilds, on community function is a central question in ecology. Particularly, the long-term temporal dynamic between a community's function and its diversity remains unclear. We investigated the influence of metabolic guild diversity on associated community function by propagating natural microbial communities from a traditionally fermented milk beverage diluted to various levels. Specifically, we assessed the influence of less abundant microbial types, such as yeast, on community functionality and bacterial community compositions over repeated propagation cycles amounting to ∼100 generations. The starting richness of metabolic guilds had a repeatable effect on bacterial community compositions, metabolic profiles, and acidity. The influence of a single metabolic guild, yeast in our study, played a dramatic role on function, but interestingly not on long-term species sorting trajectories of the remaining bacterial community. Our results together suggest an unexpected niche division between yeast and bacterial communities and evidence ecological selection on the microbial communities in our system.

Sour Beer with Lacticaseibacillus paracasei subsp. paracasei F19: Feasibility and Influence of Supplementation with Spondias mombin L. Juice and/or By-Product

This study aimed to evaluate the probiotic strain Lacticaseibacillus (L.) paracasei subsp. paracasei F19 (F19) with the yeast Saccharomyces cerevisiae US-05 (US-05), using Spondias mombin L. ('taperebá' or 'cajá') juice and by-product, in four sour-type beer formulations: control, with bagasse, juice, and juice and bagasse. The viability of F19 was evaluated by pour-plating and PMA-qPCR. Fermentability, in addition to physicochemical and sensory parameters, and aroma and flavor, were evaluated during brewery by using Headspace Solid-Phase Microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). F19 was successful in fermenting bagasse in a MRS medium (9.28 log CFU/mL in 24 h) but had a low viability in hopped wort, growing better in formulations without bagasse or juice. No difference between formulations was observed regarding sensory acceptability, and the HS-SPME/GC-MS revealed different flavors and aroma compounds. In conclusion, the production of a potential probiotic sour beer with F19 and US-05 is feasible regarding probiotic viability. However, S. mombin, as juice or bagasse, threatened probiotic survival. Different flavors and aroma compounds were detected, whereas no difference between formulations was found regarding sensory acceptability. The moderate alcohol content achieved is important for bacterial survival and for the development of a probiotic beer with health claims.

Isolation of Yeasts from Some Homemade Fermented Cow-Milk Products of Sikkim and Their Probiotic Characteristics

Dahi and chhurpi are the homemade, mildly acidic and mouthfeel fermented dairy products of Sikkim in India. Since yeasts co-exist among traditional fermented dairy foods, we believe that some species of yeasts may have some probiotic properties. Hence, the present study is aimed at screening some probiotic yeasts from dahi and chhurpi. A total of 3438 yeasts were isolated from 40 samples of dahi (1779 isolates) and 40 chhurpi (1659 isolates) and were preliminarily screened for probiotic properties on the basis of survival in low pH, resistance to bile salts and the percentage of hydrophobicity, out of which only 20 yeasts were selected for in vitro and genetic screening of probiotic properties. Saccharomyces cerevisiae DJT-2 and Debaryomyces prosopidis CPA-55 showed the highest hydrophobicity of 97.54% and 98.33%, respectively. S. cerevisiae DRC-42 and S. cerevisiae CGI-29 showed 93.88% and 91.69% auto-aggregation, respectively. All yeasts showed co-aggregation properties against pathogenic bacteria. Kluyveromyces marxianus DPA-41 and Pichia kudriavzevii CNT-3 showed excellent deconjugation activities. Probiotic genes for acid tolerance, bile tolerance, adhesion and antimicrobial activity were detected in S. cerevisiae DAO-17, K. marxianus DPA-41, S. cerevisiae CKL-10 and P. kudriavzevii CNT-3. Based on the results of in vitro and genetic screening of probiotic yeasts strains, S. cerevisiae DAO-17 (dahi), S. cerevisiae CKL-10 (chhurpi), P. kudriavzevii CNT-3 (chhurpi) and K. marxianus DPA-41(dahi) were selected as the potential probiotic yeasts.

Associations of gut microbiota with dyslipidemia based on sex differences in subjects from Northwestern China

BACKGROUND

The gut microbiota (GM) has been proven to play a role in the regulation of host lipid metabolism, which provides a new theory about the pathogenesis of dyslipidemia. However, the associations of GM with dyslipidemia based on sex differences remain unclear and warrant elucidation.

AIM

To investigate the associations of GM features with serum lipid profiles based on sex differences in a Chinese population.

METHODS

This study ultimately recruited 142 participants (73 females and 69 males) at Honghui Hospital, Xi’an Jiaotong University. The anthropometric and blood metabolic parameters of all participants were measured. According to their serum lipid levels, female and male participants were classified into a high triglyceride (H_TG) group, a high total cholesterol (H_CHO) group, a low high-density lipoprotein cholesterol (L_HDL-C) group, and a control (CON) group with normal serum lipid levels. Fresh fecal samples were collected for 16S rRNA gene sequencing. UPARSE software, QIIME software, the RDP classifier and the FAPROTAX database were used for sequencing analyses.

RESULTS

The GM composition at the phylum level included Firmicutes and Bacteroidetes as the core GM. Different GM features were identified between females and males, and the associations between GM and serum lipid profiles were different in females and males. The GM features in different dyslipidemia subgroups changed in both female patients and male patients. Proteobacteria, Lactobacillaceae, Lactobacillus and Lactobacillus_salivarius were enriched in H_CHO females compared with CON females, while Coriobacteriia were enriched in L_HDL-C females. In the comparison among the three dyslipidemia subgroups in females, Lactobacillus_salivarius were enriched in H_CHO females, and Prevotellaceae were enriched in L_HDL-C females. Compared with CON or H_TG males, Prevotellaceae, unidentified_Ruminococcaceae, Roseburia and Roseburia_inulinivorans were decreased in L_HDL-C males (P value < 0.05), and linear discriminant analysis effect size analysis indicated an enrichment of the above GM taxa in H_TG males compared with other male subgroups. Additionally, Roseburia_inulinivorans abundance was positively correlated with serum TG and total cholesterol levels, and Roseburia were positively correlated with serum TG level. Furthermore, Proteobacteria (0.724, 95%CI: 0.567-0.849), Lactobacillaceae (0.703, 95%CI: 0.544-0.832), Lactobacillus (0.705, 95%CI: 0.547-0.834) and Lactobacillus_salivarius (0.706, 95%CI: 0.548-0.835) could distinguish H_CHO females from CON females, while Coriobacteriia (0.710, 95%CI: 0.547-0.841), Coriobacteriales (0.710, 95%CI: 0.547-0.841), Prevotellaceae (0.697, 95%CI: 0.534-0.830), Roseburia (0.697, 95%CI: 0.534-0.830) and Roseburia_inulinivorans (0.684, 95%CI: 0.520-0.820) could discriminate H_TG males from CON males. Based on the predictions of GM metabolic capabilities with the FAPROTAX database, a total of 51 functional assignments were obtained in females, while 38 were obtained in males. This functional prediction suggested that cellulolysis increased in L_HDL-C females compared with CON females, but decreased in L_HDL-C males compared with CON males.

CONCLUSION

This study indicates associations of GM with serum lipid profiles, supporting the notion that GM dysbiosis may participate in the pathogenesis of dyslipidemia, and sex differences should be considered.

The possibility of a halal mix probiotic medium for the cultivation of Lactobacillus plantarum N16 and Saccharomyces cerevisiae

This study aimed to determine the effects of interaction between media type (halal mix preparation) and culture mixtures of Lactobacillus plantarum N16 and Saccharomyces cerevisiae (probiotics). A completely randomised factorial design (CRFD) consisting of 2 factors and three replications was used, where factor A was a mixture of Lactobacillus plantarum N16 and Saccharomyces cerevisiae at a ratio of 1:1 (A1); 1:2 (A2) and 2:1 (A3) and factor B was the type of growth media, that is, control (B1), whey tofu, molasses, and fish waste flour (B2), and coconut water, onggok flour and shrimp waste flour (B3). The variables measured were viability, cell biomass, and pH. The results showed interactions between factors A and B, which were significantly different (p <0.05) in terms of viability, cell biomass, and pH. Based on the results of the study, it can be concluded that the mixture of Lactobacillus plantarum N16 and Saccharomyces cerevisiae at a ratio of 2:1 (A3), using coconut water, onggok flour, and shrimp waste flour (B3) as medium and incubated at 36 °C for 24 hours was the best medium. It had a 2.37 viability, 42.33 mg/ml biomass cell, and a pH of 2.37.

The Novel Strain of Gluconobacter oxydans H32 Isolated from Kombucha as a Proposition of a Starter Culture for Sour Ale Craft Beer Production

Acetic acid bacteria (AAB) has found applications in food technology, including beverages and vinegar. Generally, AAB shows several beneficial properties and has technological usefulness. Properly selected and tested strains of this group of bacteria may constitute a new and interesting solution among starter cultures for functional food. Therefore, the study aimed to develop a sour beer technology, based on the novel strain Gluconobacter oxydans H32. The microbiological, physical-chemical (HPLC method), and sensory (QDP method) quality were determined during 6 months of storage of dark and light beer samples. The AAB count at the beginning of storage was approximately 8 log CFU mL−1, and 6 log CFU mL−1 after 6 months of storage. As a result of the metabolic activity, acetic acid, gluconic acid, and ascorbic acid were detected in the samples. The light beer had a significantly better sensory quality, especially sample BPGL with the addition of G. oxydans H32 starter culture. It was found that it is possible to develop a functional beer with the novel strain Gluconobacter oxydans H32. These Sour Ale craft beers were not only a good source of H32 strain but also its pro-health metabolites.

Recent innovations in the production of selected specialty (non-traditional) beers

Customer demand for product diversity is the key driving force for innovations in the brewing industry. Specialty beers are regarded as a distinct group of beers different from two major types, lagers and ales, without established definitions or boundaries. Specialty beers, including low- to no-alcohol beer, low carbohydrate beer, gluten-free beer, sour beer, probiotic beer, and enriched beer, are exclusively brewed and developed keeping in mind their functionality, the health and wellbeing of the consumer, and emerging market trends. Compared with conventional beer-brewing, the production of specialty beers is technologically challenging and usually requires additional process steps, unique microorganisms, and special equipment, which in turn may incur additional costs. In addition, the maintenance of quality and stability of the products as well as consumer acceptability of the products are major challenges to successful commercialization. A harmonious integration of traditional brewing practices and modern technological approaches may hold potential for future developments. In the present review, latest developments in the fermentative production of selected specialty beers are discussed.

Probiotic and Potentially Probiotic Yeasts-Characteristics and Food Application

Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. Besides the well-known and tested lactic acid bacteria, yeasts may also be probiotics. The subject of probiotic and potentially probiotic yeasts has been developing and arising potential for new probiotic products with novel properties, which are not offered by bacteria-based probiotics available on the current market. The paper reviews the first probiotic yeast Saccharomyces cerevisiae var. boulardii, its characteristics, pro-healthy activities and application in functional food production. This species offers such abilities as improving digestion of certain food ingredients, antimicrobial activities and even therapeutic properties. Besides Saccharomyces cerevisiae var. boulardii, on this background, novel yeasts with potentially probiotic features are presented. They have been intensively investigated for the last decade and some species have been observed to possess probiotic characteristics and abilities. There are yeasts from the genera Debaryomyces, Hanseniaspora, Pichia, Meyerozyma, Torulaspora, etc. isolated from food and environmental habitats. These potentially probiotic yeasts can be used for production of various fermented foods, enhancing its nutritional and sensory properties. Because of the intensively developing research on probiotic yeasts in the coming years, we can expect many discoveries and possibly even evolution in the segment of probiotics available on the market.

Polymicrobial interaction between Lactobacillus and Saccharomyces cerevisiae: coexistence-relevant mechanisms

The coordination of single or multiple microorganisms are required for the manufacture of traditional fermented foods, improving the flavour and nutrition of the food materials. However, both the additional economic benefits and safety concerns have been raised by microbiotas in fermented products. Among the fermented products, Lactobacillus and Saccharomyces cerevisiae are one of the stable microbiotas, suggesting their interaction is mediated by coexistence-relevant mechanisms and prevent to be excluded by other microbial species. Thus, aiming to guide the manufacture of fermented foods, this review will focus on interactions of coexistence-relevant mechanisms between Lactobacillus and S. cerevisiae, including metabolites communications, aggregation, and polymicrobial biofilm. Also, the molecular regulatory network of the coexistence-relevant mechanisms is discussed according to omics researches.

Antimicrobial mechanisms and applications of yeasts

Yeasts and humans have had a close relationship for millenia. Yeast have been used for food production since the first human societies. Since then, alternative uses have been discovered. Nowadays, antibiotic resistance constitutes a pressing need worldwide. In order to overcome this threat, one of the most important strategies is the search for new antimicrobials in natural sources. Moreover, biopreservation based on natural sources has emerged as an alternative to more common chemical preservatives. Yeasts constitute an underexploited source of antagonistic activity against other microorganisms. Here, we compile a summary of the antagonistic activity of yeast origin against other yeast and other microorganisms, such as bacteria or parasites. We present the mechanisms of action used by yeasts to display these activities. We also provide applications of these antagonistic activities in food industry and agriculture, medicine and veterinary, where yeast promise to play a pivotal role in the near future.

Enhanced lactic acid bacteria viability with yeast coincubation under acidic conditions

The enhancing effects of yeasts on the viability of lactic acid bacteria (LAB) under acidic conditions were investigated. Meyerozyma guilliermondii, coaggregative with both LAB strains under acidic conditions, significantly enhanced the viability of Lactobacillus pentosus and L. paracasei in pH 3.0 lactic acid (LA) buffer at 10°C (p < 0.05). Non-coaggregative yeasts (Saccharomyces cerevisiae, Schizosaccharomyces pombe, and Cyberlindnera saturnus) also significantly enhanced the LAB viability (p < 0.05), and physical contact between LAB and yeasts was not essential for the viability-enhancing effect, indicating that the coaggregation had no relation to the enhancing mechanism. Although yeast metabolites and LA assimilation had no enhancing effect, hydrogen peroxide (H₂O₂) decreased after yeast coincubation, and H₂O₂ elimination improved L. pentosus viability. H₂O₂ elimination alone did not sufficiently improve L. paracasei viability, but the addition of antioxidants was effective. These results suggest that the antioxidant activity of yeast increased the LAB viability under acidic conditions.

A Big World in Small Grain: A Review of Natural Milk Kefir Starters

Milk kefir is a traditional fermented milk product whose consumption is becoming increasingly popular. The natural starter for kefir production is kefir grain, which consists of various bacterial and yeast species. At the industrial scale, however, kefir grains are rarely used due to their slow growth, complex application, bad reproducibility and high costs. Instead, mixtures of defined lactic acid bacteria and sometimes yeasts are applied, which alter sensory and functional properties compared to natural grain-based milk kefir. In order to be able to mimic natural starter cultures for authentic kefir production, it is a prerequisite to gain deep knowledge about the nature of kefir grains, its microbial composition, morphologic structure, composition of strains on grains and the impact of environmental parameters on kefir grain characteristics. In addition, it is very important to deeply investigate the numerous multi-dimensional interactions among different species, which play important roles on the formation and the functionality of grains.

Utility of Feed Enzymes and Yeast Derivatives in Ameliorating Deleterious Effects of Coccidiosis on Intestinal Health and Function in Broiler Chickens

Coccidiosis induced necrotic lesions impair digestive capacity and barrier function in concurrence with increased risks for secondary bacterial infections. The industry has been successful in controlling coccidiosis with anticoccidials and vaccination. However, concerns over Eimeria species resistant to anticoccidials, gaps in vaccination and restriction on antibiotics is stimulating research and application of alternative and/or complimentary strategies for coccidiosis control. The aim of this paper is to appraise literature on the utility of feed enzymes and yeast derivatives in modulating coccidiosis. Feed enzymes can complement endogenous enzymes (protease, amylase, and lipase) that may become insufficient in coccidiosis afflicted birds. Coccidiosis in the upper small intestine creates conditions that enhances efficacy of phytase and there are reports indicating supplemental phytase can mitigate the negative impact of coccidiosis on bone quality. Increase in intestinal short chain fatty acids due supplemental fiber degrading enzymes has been linked with reduced survivability of Eimeria. There is evidence whole yeast (live or dead) and derivatives can modulate coccidiosis. Immunomudulation properties of the yeast derivatives have been shown to enhance cellular and humoral immunity in Eimeria challenge models which is critical for effectiveness of coccidial vaccination. Moreover, yeast nucleotides have been shown to be beneficial in stimulating healing of intestinal mucosal surface. Other novel work has shown that certain yeast cells can produce derivatives with anticoccidial compounds effective in attenuating oocysts shedding. Yeast cell surface has also been shown to be an effective oral Eimeria vaccine delivery vehicle. Overall, while further refinement research is warranted to address inconsistencies in responses and commercial application, there is evidence feed enzymes and yeast derivatives could complement strategies for maintaining intestinal function to bolster growth performance in broilers compromised with coccidiosis. However, broilers receive diets containing several feed additives with distinct mode of actions and yet there is dearth of empirical data on the expected responses.Future evaluations should consider combinations of additives to document animal responses and potential synergies.

Enhanced Exopolysaccharide Production by Lactobacillus rhamnosus in Co-Culture with Saccharomyces cerevisiae

Lactobacillus strains are known to produce exopolysaccharides (EPS) with recognized health benefits (i.e. prebiotic and immunomodulation) but production is limited by low yields. Co-culture has been shown to improve metabolite productivity, particularly bacteriocins and EPS. Although lactic acid bacteria (LAB) and yeasts are found in several fermented products, the molecular mechanisms linked to the microbial interactions and their influences on EPS biosynthesis are unclear. The aim of the present study was to investigate the effect of co-culture on EPS production by three Lactobacillus rhamnosus strains (ATCC 9595, R0011, and RW-9595M) in association with Saccharomyces cerevisiae. Fermentation, in both mono and co-culture, was carried out and the expression of key LAB genes was monitored. After 48 h, results revealed that EPS production was enhanced by 39%, 49%, and 42% in co-culture for R0011, ATCC 9595, and RW-9595M, respectively. Each strain showed distinctive gene expression profiles. For a higher EPS production, higher EPS operon expression levels were observed for RW-9595M in co-culture. The construction of gene co-expression networks revealed common correlations between the expression of genes related to the EPS operons, sugar metabolism, and stress during EPS production and microbial growth for the three strains. Our findings provide insight into the positive influence of inter-kingdom interactions in stimulating EPS biosynthesis, representing progress toward the development of a bio-ingredient with broad industrial applications.

Interactions among yeast and probiotic bacteria enhance probiotic properties and metabolism offering augmented protection to Artemia franciscana against Vibrio anguillarum

The interactions of the probiotics Bacillus subtilis, Lactococcus lactis and Lactobacillus plantarum with the yeast Saccharomyces cerevisiae were examined in terms of probiotic and biochemical characteristics. Yeast supernatant had a positive effect on the aggregation biofilm formation capacity and hydrophobicity of probiotics, and resulted in increased lactic acid levels, reduced pH values as well as lower RS and FAN levels of probiotics. The effect of probiotics supernatants on yeast was more complex but best results were obtained in the yeast: probiotic CFS ratio of 1:2 for B. subtilis and of 2:1 for the other probiotics. The observed effects depended on the volume ratio of the cell free supernatant to the culture it was applied on. Best results were obtained by the volume ratio probiotic: yeast of (2:1) for B. subtilis and of (1:2) probiotic: yeast for L. plantarum and L. lactis. These ratios were used for further evaluation in vitro against V. anguillarum, resulting in reduced survival and attachment properties of the pathogen. Moreover, the administration of the corresponding combination of bacteria and yeast to Artemia nauplii greatly improved their survival following a challenge with the pathogen. Our results demonstrate that yeast enhances the protective effect of probiotics in a strain specific manner.

The association between early life antibiotic use and allergic disease in young children: recent insights and their implications

INTRODUCTION

Greater prescribing of antibiotics to infants has coincided with an epidemic of allergic disease. Through meta-analytic synthesis, accumulating evidence from prospective or database cohorts suggests a link between infant antibiotic treatment and the development of atopy. Stronger associations seen with multiple course and broad-spectrum antibiotic treatment add to biological plausibility. A major bias, confounding by indication, has been addressed in studies on antibiotic treatment of conditions which do not precede allergic disease. Areas covered: Our review provides an up-to-date synthesis of the current literature on associations between infant antibiotic exposure and future allergic disease. We discuss methods that assist in reducing study bias and look at new insights from studies of the infant gut microbiome. Expert commentary: Large-scale profiling of the gut microbiome provides a new tool for disentangling biases found in observational studies of infant antibiotic use. To date, microbial dysbiosis of the infant gut has been reported to predict allergic disease independent of antibiotic exposure up to 3 months after birth. However, these studies have not accounted for antibiotic treatment in later infancy. Continued study of the infant gut microbiome, mycobiome, or resistome will provide a closer link to antibiotic treatment or refute it as a cause of allergic disease.

Effect of dietary supplementation with Yarrowia lipolytica or Saccharomyces cerevisiae yeast and probiotic additives on growth performance, basic nutrients digestibility and biochemical blood profile in piglets

The objective of the study was to compare the efficiency of dietary supplementation of two species of yeast, Yarrowia lipolytica (YL) and Saccharomyces cerevisiae (SC), with or without the addition of a probiotic, on growth performance, basic nutrients digestibility and blood profile in piglets. The experiment was conducted on 360 weaned piglets (180 barrows and 180 gilts). Each treatment comprised 60 piglets. The piglets (27-day-old) were assigned to the following dietary treatments: (a) basal control (C) diet, (b) C diet + probiotic (Bacillus licheniformis and Bacillus subtilis-2 × 10⁹  CFU/kg of feed), (c) C diet + 3% Y. lipolytica (YL-2 × 10¹⁰  CFU/g), (d) C diet + 3%YL + probiotic, (e) C diet + 3% S. cerevisiae (SC-3 × 10¹⁰  CFU/g) and (f) C diet + 3% SC + probiotic. Blood for analysis was collected from a total of 36 piglets at the end of the experiment, that is, 56 days after weaning. During the entire experiment, significantly greater weight gain was observed in the piglets receiving YL. The addition of the probiotic supplement and SC yeast reduced the daily feed intake during day 16-56 and from day 0 to 56 of the experiment. A better feed conversion ratio (FCR) during day 0-56 of the experiment was noted after addition of the probiotic and yeast. The use of YL yeast in diets for piglets had a more beneficial effect on weight gain and FCR than SC. Moreover, the addition of YL modulates lipid metabolism in piglets, as indicated by the reduced levels of TCH, LDL and TG and increased level of HDL in the plasma. The combined use of either YL or SC with a probiotic is not recommended in piglet rearing, as it does not substantially improve growth performance and health in comparison with yeast alone.

Antimicrobial activity of preparations after combined cultivation of lactic acid bacteria and yeast strains

Use of antimicrobials in both human and animal populations over the past several decades has led to the emergence of multidrug-resistant bacteria populations that are resistant to many commercially available drugs. For example, acquired resistance to first-line antimicrobial agents increasingly complicates the management of extra-intestinal infections due to Escherichia coli, which are a major source of illness and death. The continued development of new classes of natural antimicrobial agents, possessing antibacterial activity, has become of increasing importance for medicine and veterinary. So, selection of lactic acid bacteria and yeast strains for their combined cultivation with the aim of increasing of the activity is topical. It was shown that during combined cultivation of the lactic acid bacteria with probiotic properties and yeast strains, antimicrobial activity depends on the genus and species to which the strain of lactic acid bacteria and yeast belongs. They inhibited the growth of multidrug-resistant bacteria with better efficiency. Increasing of the antimicrobial activity can be explained by the synergetic effect of products of cultures metabolism and by interaction between lactic acid bacteria cells with the cell wall of yeasts. Our data showed perspectives of combined cultivation of yeast and lactic acid bacteria for creation of a new class of antimicrobial preparations with high antibacterial activity and broad spectrum of action. Preparation can be recommended for treatment of animals.

Influence of commercial inactivated yeast derivatives on the survival of probiotic bacterium Lactobacillus rhamnosus HN001 in an acidic environment

This study evaluated the influence of three inactivated yeast derivatives (IYDs) used in wine production, namely OptiRed^®, OptiWhite^® and Noblesse^®, on the viability of the probiotic strain Lactobacillus rhamnosus HN001 in an acidic environment. Addition of the IYDs at 3 g/L significantly enhanced the survival of the probiotic bacteria by 2.75–4.05 log cycles after 10-h exposure in a pH 3.0 buffer. Acid stress assay with IYD components obtained after centrifugation and filtration revealed that water-soluble compounds were responsible for improving the acid tolerance of L. rhamnosus HN001 for all three preparations. Differences in protective effect amongst the IYDs on L. rhamnosus HN001 were observed when permeates and retentates of the water-soluble extracts, obtained through ultrafiltration with a 2 kDa membrane, were assayed against the lactic acid bacterium. Chemical analysis of the water-soluble components suggests that low molecular weight polysaccharides, specific free amino acids and/or antioxidants in the 2 kDa permeates could have contributed to the enhanced survival of L. rhamnosus HN001 during acid stress. The contrast amongst the 2 kDa retentates’ viability enhancing property may have been attributed to the differences in size and structure of the higher molecular weight carbohydrates and proteins, as the survival of the probiotic did not relate to the concentration of these compounds. These results suggests that oenological IYDs could potentially be applied to probiotic foods for enhancing the acid tolerance of the beneficial microorganisms, and consequently prolonging the shelf life of these products.

Impact of coculturing Bifidobacterium animalis subsp. lactis HN019 with yeasts on microbial viability and metabolite formation

AIMS

To evaluate the impact of coculturing Bifidobacterium animalis subsp. lactis HN019 with yeasts on microbial viability and metabolite production.

METHODS AND RESULTS

Monocultures and bacteria-yeast cocultures of B. lactis HN019 and 10 different yeast strains belonging to different species in skim milk media were fermented at 37°C. The presence of yeasts enhanced the growth rate and metabolic activities of B. lactis HN019, which might be attributed to their antioxidative properties. The viability of yeasts, when cocultured with bifidobacteria, was either unaffected or suppressed, depending on the strain. When the B. lactis HN019 monoculture and cocultures with Saccharomyces cerevisiae EC-1118, Pichia kluyveri FrootZen and Kluyveromyces lactis KL71 were fermented to pH 4·7, there were no significant differences in their organic acid composition. On the other hand, cocultures produced significantly higher quantities of alcohols and/or esters than the monoculture. Coculturing B. lactis HN019 with yeasts did not improve the viability of the probiotic during storage at 10°C for 8 weeks, as the bifidobacteria itself demonstrated satisfactory survival in the fermented SMM.

CONCLUSIONS

Coculturing B. lactis HN019 with yeasts accelerated the growth of the bifidobacteria and increased the production aroma-active volatile metabolites.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrates the potential of utilizing specific yeast species as starter or adjunct cultures to simultaneously improve the growth of fastidious bifidobacteria and modulate the organoleptic properties of fermented food products.

Probiotic supplementation for management of cardiovascular risk factors in adults with type II diabetes: A systematic review and meta-analysis

BACKGROUND & AIMS

The effectiveness of probiotics in control of hypertension and dyslipidemia in diabetic patients remains unclear. Therefore, we systematically reviewed relevant data to elucidate the effects of probiotics on blood pressure and lipid profile of type 2 diabetic patients.

METHODS

We searched PubMed, ISI Web of Knowledge, Scopus, The Cochrane Library, ClinicalTrials.gov, ProQuest Dissertations and Theses databases until May 2016. The primary outcomes were systolic blood pressure (SBP) and diastolic blood pressure (DBP), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG). Other biochemical response and adverse effects were considered as secondary outcomes. Data was extracted from included studies and pooled in meta-analysis whenever possible (both standardized mean difference (SMD) analysis and weighted mean difference (WMD) analysis were performed).

RESULTS

Eleven eligible randomized controlled trial (n = 641) were identified. Pooling data from these trials demonstrated probiotic consumption significantly decreased SBP (WMD, -3.28 mmHg; 95% confidence interval [CI], -5.38 to -1.18), DBP (WMD, -2.13 mmHg; 95% CI, -4.5 to 0.24), LDL-C (WMD, 8.32 mg/dl; 95% CI, -15.24 to -1.4), TC (WMD, -12.19 mg/dl; 955 CI -17.62 to -6.75) and TG (WMD, -24.48 mg/dl; 95% CI, -33.77 to -11.18) in type 2 diabetic patients compared with placebo. The methodological quality varied across trials included in this study.

CONCLUSION

This systematic review suggests probiotics supplementation may be helpful for control of dyslipidemia and hypertension in type 2 diabetic patients. Conducting more trails with large sample size and long follow-up time still is necessary to develop clinical practice guidelines for management of cardiovascular risk factors in patient with type 2 diabetes.

Effect of green Spanish-style Manzanilla packaging conditions on the prevalence of the putative probiotic bacteria Lactobacillus pentosus TOMC-LAB2

This work focuses on the persistence of the putative probiotic bacteria Lactobacillus pentosus TOMC‐LAB2 on green Spanish‐style Manzanilla olives according to different packaging conditions and storage temperatures. The lactic acid bacteria population decreased with time but the highest survival counts (and lowest yeasts) at the end of storage (8 months) were observed in plastic pouches under nitrogen atmosphere and glass jars with brine stored at 20°C. Molecular techniques showed a 100% presence of the putative probiotic bacteria in biofilms adhered to olive epidermis, while it was absent in PPB (plastic pouches with brine) and in olives stored at 7°C. No changes in NaCl, pH or combined acidity were observed during the storage except for a slight increase in titratable acidity at 20°C. The color of the fruits was stable but degraded at 20°C for olives in plastic pouches with brine.

Enhancement of bifidobacteria survival by Williopsis saturnus var. saturnus in milk

The viability of three strains of probiotic Bifidobacterium lactis that were inoculated into UHT milk was examined with and without the presence of the yeast, Williopsis saturnus var. saturnus NCYC 22, in polypropylene tubes at 30 °C. The B. lactis viable cell count for strains HN019 and BB-12 remained above 6.0 Log cfu/ml, while strain B94 had 5.7 Log cfu/ml after six weeks of incubation in the presence of the co-inoculated yeast. Incubating the bifidus milk without added yeast under anaerobic condition did not improve the survival of B. lactis HN019, indicating that oxygen removal may not be responsible for W. saturnus NCYC 22’s viability enhancing property. The addition of yeast supernatant or non-viable yeast also did not show any stabilising effects, suggesting that physical contact and/or interaction between viable W. saturnus and B. lactis plays an important role in sustaining the viability of the probiotic. W. saturnus NCYC 22 could increase the survival of B. lactis in bifidus milk under ambient temperature regardless of the initial concentration of yeast cells inoculated due to yeast growth. This study demonstrated the viability enhancing effect of viable W. saturnus NCYC 22 on B. lactis HN019, which could help towards extending the shelf-life of dairy beverages containing probiotic bifidobacteria.