Probiotic Strain Lactobacillus Plantarum Research Articles

Freeze-dried Lactobacillus plantarum 299v increases iron absorption in young females-Double isotope sequential single-blind studies in menstruating women.

BackgroundThe probiotic strain Lactobacillus plantarum 299v has earlier been shown to increase iron absorption when added to foods. However, it is not known if the same probiotic strain in a freeze-dried format included in a capsule increases the iron absorption.ObjectiveThe aim of this study was to test the hypotheses that non-heme iron absorption from a light meal is promoted by a simultaneous intake of freeze-dried Lactobacillus plantarum 299v (Lp299v, DSM 9843).Study designWith a single blinded placebo controlled sequential design, iron absorption from a light breakfast meal administered with or without capsules containing 1010 cfu freeze-dried Lp299v was studied in healthy female volunteers of fertile age. The methodology used was a double isotope technique (59Fe and 55Fe). Two studies were performed using the same protocol.ResultsIn study 1, the absorption of iron from a meal without Lp299v was found to be 17.4 ± 13.4%, and from an identical meal with Lp299v was found to be 22.4 ± 17.3% (mean ± SD). This difference was statistically significant (p = 0.040, n = 14).In study 2, the absorption of iron from a meal without Lp299v was found to be 20.9 ± 13.1%, and from an identical meal with Lp299v found to be 24.5 ± 12.0% (mean ± SD, n = 28), which again was statistically significant (p = 0.003).ConclusionFreeze-dried Lp299v enhances the absorption of iron when administered together with a meal with a high iron bioavailability.Trial registrationClinicalTrials.gov Identifier: NCT02131870

Viability and Stress Response of Putative Probiotic Lactobacillus plantarum Strains in Honey Environment.

Due to problem of preservation of dairy products which serve as a matrix for probiotics, it is challenging to use these probiotics as food supplements in many developing countries. To determine the suitability of the Lactobacillus strains for exploitation as probiotics in honey, we investigated the effect of their storage on the viability, functionality, and the mechanism associated with their protective effect. Three isolates obtained from our laboratory collection were identified through amplification of the 16S rRNA gene. The viability of the strains in honey at different storage conditions was studied. Three genes (hdc, gtf, and clpL) responsible for the resistance of bacteria in acidic environments were screened. SDS-PAGE analysis of total protein was performed to observe protein profile changes of the strains after exposure to honey. All the three isolates, namely, GGU, GLA51, and GLP56, were identified as Lactobacillus plantarum strains. After 28days of storage in honey at 4°C, viable cell concentrations of the three strains were higher than 2.04 × 106CFU/ml. During the same period at room temperature, only the Lactobacillus plantarum GLP56 strain remained viable with a cell concentration of 1.86 × 104CFU/ml. The clpL gene coding for ATPase was detected in all the three strains. The protein of molecular weight ~ 50 kDa was absent in the protein profile of Lactobacillus plantarum GGU after 60days of storage in honey at 4°C. The Lactobacillus plantarum GLP56, Lactobacillus plantarum GLA51, and Lactobacillus plantarum GGU strains exposed to honey can withstand acidic environmental stress but their viability declines over time.

Genetic Variation of pln Loci Among Probiotic Lactobacillus plantarum Group Strains with Antioxidant and Cholesterol-Lowering Ability.

In the present study, 14 different plantaricin-encoding genes of pln loci were studied and compared to available sequences from public domain database of probiotic Lactobacillus plantarum strains. Based upon the presence and absence of selected genes, pln locus was grouped into eight clusters. Further, quantitative real-time PCR (qRT-PCR) analysis for seven genes has discriminated the complex pln locus into five types which includes WCFS1 (in Lactobacillus plantarum subsp. plantarum MCC 2976 and MCC 2974 and Lactobacillus paraplantarum MCC 2978), closely related to J51 (in Lb. paraplantarum MCC 2973 and MCC 2977), J23 (in Lb. plantarum MTCC 5422), NC8 (in Lb. paraplantarum MTCC 9483), and a new E1 type (in Lb. plantarum subsp. plantarum E1). It was observed that the plnA, EF, NC8βα, NC81F, NC8HK, and G were expressed in E1 strain. Further, southern hybridization confirmed the chromosome-encoded plantaricin in Lb. plantarum group (LPG) strains. Several PCR assays and DNA sequence analysis of the regions amplified in pln loci of E1 isolate suggested a hybrid variant of NC8 and J51 plantaritypes. This indicates the wide distribution of plantaricin with remarkable variation, diversity, and plasticity among the LPG strains of vegetable origin. Further, the selected strains were able to reduce the growth of Kocuria rhizophila ATCC 9341 by 40-54% within 6h of co-incubation under in vitro pathogen exclusion assay. These isolates also possessed cholesterol-lowering and antioxidant activity suggesting their application in the development of functional foods.

Development of fermented oat flour beverage as a potential probiotic vehicle

Dairy products have conventionally been used as carriers of probiotics. However, lactose intolerance, cholesterol, allergenic milk proteins, and the trend towards vegetarianism motivated the search for non-dairy products as potential probiotic carriers. Cereals may represent an excellent choice due to their high nutritional value and consumption all around the world. In the present study, an oat based fermented product ‘probiotic fermented oat flour’ (PFOF) was developed using a probiotic strain Lactobacillus plantarum M-13 and honey. The bacterial isolate L. plantarum M-13 has previously been characterized for several probiotic functional attributes. For PFOF development, process variables, i.e., concentrations of oat flour (8.0% w/v) and honey (3.0% w/v), and incubation time (48 h) were optimized based on a Box-Behnken design. Optimization enhanced the viable cell count of L. plantarum M-13 in PFOF from 14.4 log cfu/ml (unoptimized conditions) to 16.9 log cfu/ml, i.e. by 17.4%. With respect to linear terms, the variable incubation time had the most substantial positive influence on viable cell count of L. plantarum M-13, while with respect to interactive terms, the variables incubation time and honey had the maximum effect. Good viability of L. plantarum M-13 was observed in PFOF over a period of three wk of storage at room temperature and with refrigeration. Furthermore, sugar content decreased and lactic acid content increased during storage. The PFOF remained free of Enterobacteriaceae contamination, although fungal and yeast contaminants were found.

In Situ β-Glucan Fortification of Cereal-Based Matrices by Pediococcus parvulus 2.6: Technological Aspects and Prebiotic Potential.

Bacterial exopolysaccharides produced by lactic acid bacteria are of increasing interest in the food industry, since they might enhance the technological and functional properties of some edible matrices. In this work, Pediococcus parvulus 2.6, which produces an O2-substituted (1,3)-β-d-glucan exopolysaccharide only synthesised by bacteria, was proposed as a starter culture for the production of three cereal-based fermented foods. The obtained fermented matrices were naturally bio-fortified in microbial β-glucans, and used to investigate the prebiotic potential of the bacterial exopolysaccharide by analysing the impact on the survival of a probiotic Lactobacillus plantarum strain under starvation and gastrointestinal simulated conditions. All of the assays were performed by using as control of the P. parvulus 2.6’s performance, the isogenic β-glucan non-producing 2.6NR strain. Our results showed a differential capability of P. parvulus to ferment the cereal flours. During the fermentation step, the β-glucans produced were specifically quantified and their concentration correlated with an increased viscosity of the products. The survival of the model probiotic L. plantarum WCFS1 was improved by the presence of the bacterial β-glucans in oat and rice fermented foods under starvation conditions. The probiotic bacteria showed a significantly higher viability when submitted to a simulated intestinal stress in the oat matrix fermented by the 2.6 strain. Therefore, the cereal flours were a suitable substrate for in situ bio-fortification with the bacterial β-glucan, and these matrices could be used as carriers to enhance the beneficial properties of probiotic bacteria.

Survival of spray-dried and free-cells of potential probiotic Lactobacillus plantarum 564 in soft goat cheese.

A high viability of probiotics in food product, with a living cells threshold of 107 /cfu/g (colony-forming units/g) is a challenge to achieve in food production. Spray drying is an efficient and economic industrial method for probiotic bacterial preservation and its application in food products. In this study, the survival of free and spray-dried cells of potential probiotic strain Lactobacillus plantarum 564 after production and during 8weeks of storage of soft acid coagulated goat cheese was investigated, as well as compositional and sensory quality of cheese. Total bacterial count of spray-dried Lb. plantarum 564 cells were maintained at the high level of 8.82log/cfu/g in cheese after 8weeks of storage, while free-cell number decreased to 6.9log/cfu/g. However, the chemical composition, pH values and sensory evaluation between control cheese (C1 sample made with commercial starter culture) and treated cheese samples (C2 and C3, made with the same starter, with the addition of free and spray-dried Lb. plantarum 564 cells, respectively) did not significantly differ. High viability of potential probiotic bacteria and acceptable sensory properties indicate that spray-dried Lb. plantarum 564 strain could be successfully used in the production of soft acid coagulated goat cheeses.

Fermentation of sarshir (kaymak) by lactic acid bacteria: antibacterial activity, antioxidant properties, lipid and protein oxidation and fatty acid profile.

The antioxidant and antibacterial activities of fermented sarshir (traditional dairy food), with three probiotic Lactobacillus plantarum strains (LP3, AF1, and LU5), were investigated. The oxidative stability and the lipid profile of non-fermented and fermented sarshir were compared, in addition to radical scavenging activity, as well as peroxide, anisidine and carbonyl values (PV, AnV and CV, respectively). The strong antibacterial activity of fermented sarshir against common pathogenic bacteria, including Gram-negative Escherichia coli O157: H7 ATCC 35150 and Pseudomonas aeruginosa ATCC 27853, as well as Gram-positive Bacillus cereus ATCC 10876 and Staphylococcus aureus ATCC 25923, was established. Among the strains examined, L. plantarum LP3 exhibited the highest radical scavenging activity (53.1 ± 1.8%) and lowest PV (3.0 meq kg-1 ), AnV (1.31 ± 0.06) and CV (1.4 ± 0.08). The pH of sarshir decreased from 6.2 ± 0 to 3.5 ± 0.1 during 14 h of fermentation. Incorporated bacterial cells exhibited notable viability during 10 days of cold storage (4 °C). The fermentation of sarshir by L. plantarum strains, especially LP3, resulted in beneficial changes in radical scavenging activity, as well as PV, AnV and carbonyl values, in addition to a broad spectrum of inhibitory activity against strains of P. aeruginosa, E. coli O157:H7, B. cereus and S. aureus. © 2017 Society of Chemical Industry.

Potential for prevention of non‐O157 Shiga toxin‐producing Escherichia coli contamination in traditionally fermented African maize gruel by fermentative probiotic Lactobacillus plantarum

SummaryNon‐O157 Shiga toxin‐producing Escherichia coli (STEC) are a frequent cause of STEC‐related infections such as diarrhoea. Fermentation by presumptive probiotic Lactobacillus plantarum strain B411 isolated from cereal fermentation was investigated to prevent the growth of acid‐adapted (AA) and non‐acid‐adapted (NAA) non‐O157 STEC in traditionally fermented maize gruel, a widely used complementary food in Africa. L. plantarum strain B411 possessed probiotic characteristics and antimicrobial activity against selected pathogenic bacteria. Growth of AA and NAA non‐O157 STEC strains was substantially inhibited by 3.6 and 4.8 log reductions, respectively, in the maize gruel fermented with the L. plantarum B411, while their growth was only inhibited by 1.0 and 1.2 log reductions, respectively, by traditional fermentation alone. Inclusion of fermentative strains of L. plantarum exhibiting probiotic activity is a feasible method to ensure safety of traditionally fermented African cereal porridges through inhibition of non‐O157 STEC.

Improvement of colitis by Lactobacillus plantarum LS/07 and inulin

The objective of this study was to investigate the effect of the probiotic strain Lactobacillus plantarum LS/07 and prebiotic inulin on the activity of β-glucuronidase, transcription nuclear factor kappa B (NFκB), myeloperoxidase (MPO), cytokine levels (IL-6, IL-8, IL-13), and counts of coliforms and lactobacilli in rats with dextran sulphate sodium (DSS) induced acute colitis. Sprague-Dawley rats were divided into groups: control (C), acute colitis (AC), prebiotic (Pre), and probiotic (Pro). Dextran sulphate sodium induced inflammatory process in the colonic tissue, increased the activity of β-glucuronidase (P < 0.05), increased counts of coliforms, decreased lactobacilli counts (P < 0.05), and activated production of the measured indicators NFκB, MPO, IL-6, IL-8, except of IL-13. Diet supplemented with L. plantarum and inulin alleviated DSS induced inflammatory process by inhibiting production of IL-6, IL-8, activities of NFκB and MPO, and by stimulation of IL-13. These results indicate that the dietary intake of Lactobacillus plantarum LS/07 and inulin suppressed the expression of markers playing an important role in the inflammatory process, which predisposes their use in prevention or treatment of acute colitis.

Antiviral Effects of a Probiotic Metabolic Products against Transmissible Gastroenteritis Coronavirus

The Transmissible Gastroenteritis Virus (TGEV) causes severe diarrhea and other symptoms which end up in death in young piglets. We have studied the protective effects of the probiotic Lactobacillus plantarum strain N4(Lp) which metabolic products were added to the swine testis (ST) cells with three different orders using MTT cell proliferation assay and CPE analysis. Metabolic products led to dose-dependent rescue of viability of infected cells in a certain order: pre-treatment, post-infection, co-incubation. Pre-treatment of cells with probiotic metabolic products reduced viral proliferation up to 78% at non-cytotoxic concentration 1/4 dilution. The viral yields in pretreatment groups were reduced by over three log10 units. Quantitative real-time PCR revealed the optimal inhibition of TGEV RNA replication was 24 h apply pretreatment way that up to 71% of N gene. Analysised the composition of metabolic products by GC-MS revealed the major component is sugars. Then Exopolysaccharides (EPS) was extracted and showed inhibition effect that co-incubation with TGEV.

Evaluation of the potential use of probiotic strain Lactobacillus plantarum 299v in lactic fermentation of button mushroom fruiting bodies.

The available literature does not provide data on the application of probiotic strains in mushroom processing. The aim of the study was to evaluate the potential to use the L. plantarum 299v strain with documented probiotic properties in the process of lactic fermentation of button mushroom fruiting bodies (Agaricus bisporus). Fresh button mushroom fruiting bodies and cultures of lactic acid bacteria L. plantarum Ib and a probiotic strain L. plantarum 299v were the material analysed. Sensory evaluation was performed with a 5-point scale, an instrumental method of colour measurement based on the CIA L*a*b* scale, total phenolic compounds were determined with the Folin method, antioxidant properties were assayed with the DPPH radical test, and reducing power was determined using the FRAP method. After a week-long lactic fermentation, the pH value in the samples declined to a level of 3.6 (L. plantarum Ib) and 3.75 (L. plantarum 299v); these values persisted or decreased slightly during the period of maturation of the fermented samples under refrigeration. Fermented mushrooms were assigned high grades in the organoleptic evaluation. The colour analysis revealed significant changes in the values of the L*a*b* parameters in the fermented product, in comparison with fresh mushrooms. Blanching contributed to a significant decrease in the content of total phenolic compounds in the mushroom fruiting bodies and to a decline in antioxidant activity. Mushrooms fermented with the probiotic strain were characterised by higher phenolic compound content and higher antioxidant activity. L. plantarum 299v strain with documented probiotic properties can be applied in fermentation of button mushroom fruiting bodies. Products obtained with the use of both strains were characterised by good sensory properties. The type of strain used in the lactic fermentation of mushroom fruiting bodies had an effect on the phenolic compound content and antioxidant properties of the final product.

Ability of Lactobacillus plantarum LS/07 to modify intestinal enzymes activity in chronic diseases prevention.

The ability of probiotic strain Lactobacillus plantarum LS/07 to modify the activity of intestinal bacterial enzymes - β-glucuronidase (β-GLUCUR), β-galactosidase (β-GAL), and β-glucosidase (β-GLU) in prevention of chronic diseases - cancer, atherosclerosis and dysbiosis was investigated. The male Sprague-Dawley rats were randomly divided into 12 experimental groups: controls groups - C (control), AT (atherosclerotic), CC (carcinogenic), dysbiotic groups - each group in combination with antibiotics (ATB), probiotics groups - in combinatioan with probiotic (PRO) alone, and each group with combination of antibiotic and probiotic (ATB+PRO). In the control group the β-glucuronidase activity did not change throughout the experiment. High fat diet in atherosclerotic group significantly increased the activity of β-glucuronidase (P<0.001) and β-glucosidase (P<0.01). Azoxymethane application in carcinogenic group significantly increased β-glucuronidase (P<0.01), but reduced β-glucosidase (P<0.01) activity. Daily application of probiotics alone and in combination with antibiotic increased β-galactosidase, of β-glucosidase, and decreased β-glucuronidase activity. In control antibiotic group we observed significant increase in β-glucuronidase (P<0.05) and decreased β-glucosidase (P<0.01) activity which can be caused by the change of microflora in favor of coliform bacteria. These findings indicate the positive effects of probiotic Lactobacillus plantarum LS/07 and suggest its use in disease prevention in human medicine and some animal species.

Effect of Flavonoid-Rich Extract of Glycyrrhiza glabra on Gut-Friendly Microorganisms, Commercial Probiotic Preparations, and Digestive Enzymes

ABSTRACTFlavonoid-rich extract prepared from Glycyrrhiza glabra has been found to be beneficial in patients with functional dyspepsia and was reported to possess some gut health-promoting properties such as antioxidant, anti-inflammatory and anti-Helicobacter pylori activities. In the present study, the flavonoid-rich extract of Glycyrrhiza glabra was evaluated for its compatibility with probiotic strains (Lactobacillus casei, Lactobacillus fermentum, Lactobacillus plantarum, and Streptococcus thermophilus), commercial probiotic drinks, and digestive enzymes (pancreatic α-amylase, α-glucosidase, phytase, xylanase, and pancreatic lipase). Results of this study indicated that the flavonoid-rich extract of Glycyrrhiza glabra is compatible with the tested probiotic strains, probiotic drinks and digestive enzymes.

Effect of Lactobacillus plantarum LS/07 on Intestinal Bacterial Enzyme Activities in the Prevention of Cancer, Atherosclerosis and Dysbiosis

Abstract The effect of the probiotic strain Lactobacillus plantarum LS/07 on intestinal bacterial enzyme activities – β-glucuronidase (β-GLUCUR), β-galactosidase (β-GAL), and β-glucosidase (β-GLU) in the prevention of cancer, atherosclerosis and dysbiosis was investigated. Male Sprague-Dawley rats were randomly divided into 12 experimental groups: C (control group), AT (atherosclerotic group), CC (carcinogenic group), and then each group in combination with antibiotics and probiotics individually and each group in double combination on antibiotic and probiotic. In the control group the β-glucuronidase activity did not change throughout the experiment. High fat diet in the atherosclerotic group significantly increased the activity of β-glucuronidase (p&lt;0.001) and β-glucosidase (p&lt;0.01). Azoxymethane application in the carcinogenic group significantly increased β-glucuronidase (p&lt;0.01), but reduced β-glucosidase (p&lt;0.01). Daily application of probiotics individually and in double combination with antibiotics increased the activity of β-galactosidase, and β-glucosidase, and positively decreased the level of β-glucuronidase. In the control antibiotic group β-glucuronidase was significantly increased (p&lt;0.05), and β-glucosidase decreased (p&lt;0.01) which can be caused by a change of microflora in favor of coliform bacteria. These finding indicate the positive effects of probiotic Lactobacillus plantarum LS/07 which allows its use in disease prevention in human and veterinary medicine.

Augmentation of T helper type 1 immune response through intestinal immunity in murine cutaneous herpes simplex virus type 1 infection by probiotic Lactobacillus plantarum strain 06CC2

We previously found that Lactobacillus plantarum strain 06CC2 showed probiotic potential, and its oral administration effectively induced Th1 cytokine production and activated the Th1 immune response associated with intestinal immunity in mice. In this study, to evaluate its potential as a versatile oral adjuvant for treatment of viral infection, we assessed the immunomodulatory activity of 06CC2 on murine cutaneous herpes simplex virus type 1 (HSV-1) infection, in which a major immune defense system is a delayed-type hypersensitivity (DTH) reaction based on activation of the Th1 immune response, in relation to its oral efficacy for alleviation of herpetic symptoms. In the HSV-1 infection model, oral administration of 06CC2 (20mg/mouse) twice daily for seven days starting two days before infection was significantly effective in delaying the development of skin lesions in the early phase of infection and reducing virus yields in the brain on day 4 after infection. In addition, 06CC2 significantly augmented the DTH reaction to inactivated HSV-1 antigen and elevated interferon (IFN)-γ production by HSV-1 antigen from splenocytes. On day 2, natural killer (NK) cell activity was significantly elevated, and the elevation was still observed on day 4. Furthermore, gene expressions of interleukin-12 receptor β2 and IFN-γ in Peyer's patches were augmented on day 4 by 06CC2 administration. Thus, 06CC2 was suggested to alleviate herpetic symptoms in mice in correlation with augmentation of the Th1 immune responses associated with NK cell activity through intestinal immunity. Strain 06CC2 may be a versatile oral adjuvant to activate Th1 immune response.

Prebiotic synthesis from rice using Aspergillus oryzae with solid state fermentation

Prebiotic synthesis from economical substrates (glutinous rice and rice bran) using Aspergillus oryzae TISTR 3102 and TISTR 3222 with solid state fermentation (SSF) was explored. The pH value, alpha-glucosidase activity and total reducing sugar (TRS) concentration were monitored during incubation with different substrate ratios of 1:1 and 1:2 weight per weight (w/w). After 7 d incubation under SSF in glutinous rice and rice bran at 1:2 w/w, the highest alpha-glucosidase activity (4.49 Unit/mL) and TRS concentration (16.84 g/L) were detected. The product mixtures consisted of several reducing sugars as prebiotic compounds, especially panose and isomaltotriose. The prebiotic properties were investigated for their growth stimulation on two probiotic strains (Lactobacillus plantarum and Lactobacillus acidophilus) and the inhibition of two pathogens (Escherichia coli and Salmonella paratyphi). These product mixtures under solid state fermentation (SSF) using A. oryzae in variable rice ratios displayed high efficiency with regard to prebiotic properties and were deemed appropriate for prebiotic production.

Effects of supplementation with L. plantarum TN8 encapsulated in alginate-chitosan in broiler chickens

This study was undertaken to investigate the effects of supplementation of probiotic strain Lactobacillus plantarum TN8 encapsulated in sodium alginate-chitosan or a commercial blend of essential oils on total cholesterol, High Density Lipoprotein (HDL), Low Density Lipoprotein (LDL) and growth performance of broiler chickens. The results showed that the broiler chickens supplemented with encapsulated L. plantarum TN8 or essential oil has a higher growth than the control group. After 35days, the weight means were 1860 and 1880g respectively in dietary supplementation with probiotic or essential oil, while they are 1800g in the control group. The evolution of the feed consumption and feed conversion per week showed that the supplementation of encapsulated TN8 strain or essential oil in broiler chickens food has a positive influence on their appetite. Similarly, supplementation of the feed with this encapsulated strain significantly reduced the rate of cholesterol (HDL and LDL) as well as the contents of triglycerides in broiler chickens. Through our study, it appears that the use of the probiotic supplementation or essential oil to broilers were found to be better than the control group of chickens, resulting in a significant economic impact and promoting effect on health.

Influence of Lactobacillus plantarum WCFS1 on post-acidification, metabolite formation and survival of starter bacteria in set-yoghurt

The objectives of this study were to evaluate the growth and survival of the model probiotic strain Lactobacillus plantarum WCFS1 in co-culture with traditional yoghurt starters and to investigate the impact of preculturing on their survival and metabolite formation in set-yoghurt. L. plantarum WCFS1 was precultured under sublethal stress conditions (combinations of elevated NaCl and low pH) in a batch fermentor before inoculation in milk. Adaptive responses of L. plantarum WCFS1 were evaluated by monitoring bacterial population dynamics, milk acidification and changes in volatile and non-volatile metabolite profiles of set-yoghurt. The results demonstrated that sublethal preculturing did not significantly affect survival of L. plantarum WCFS1. On the other hand, incorporation of sublethally precultured L. plantarum WCFS1 significantly impaired the survival of Lactobacillus delbrueckii subsp. bulgaricus which consequently reduced the post-acidification of yoghurt during refrigerated storage. A complementary metabolomics approach using headspace SPME-GC/MS and 1H NMR combined with multivariate statistical analysis revealed substantial impact of sublethally precultured L. plantarum WCFS1 on the metabolite profiles of set-yoghurt. This study provides insight in the technological implications of non-dairy model probiotic strain L. plantarum WCFS1, such as its good stability in fermented milk and the inhibitory effect on post-acidification.

Abrupt suspension of probiotics administration may increase host pathogen susceptibility by inducing gut dysbiosis.

In this study, we investigated the risk associated with suspension of probiotics administration in tilapia, an animal model that may mimic immune-compromised conditions in humans. Tilapias were fed for 14 days using a probiotics-supplemented diet, followed by a three-day suspension of probiotics treatment and a subsequent challenge by Aeromonas hydrophila. Unexpectedly, the suspension of a probiotic strain Lactobacillus plantarum JCM1149 significantly triggered susceptibility of the host to A. hydrophila. We further observed that suspension of JCM1149 resulted in host gut microbiota dysbiosis and the subsequent disorder in the intestinal metabolites (bile acids, amino acids, and glucose) and damage in the intestinal epithelium, giving rise to a condition similar to antibiotics-induced gut dysbiosis, which collectively impaired tilapia’s gut health and resistance to pathogenic challenges. Additionally, we determined that JCM1149 adhered relatively poorly to tilapia intestinal mucosa and was rapidly released from the gastrointestinal tract (GIT) after suspension, with the rapid loss of probiotic strain probably being the direct cause of gut dysbiosis. Finally, three other probiotic Lactobacillus strains with low intestinal mucosa binding activity showed similar rapid loss phenotype following administration suspension, and induced higher host susceptibility to infection, indicating that the risk is a generic phenomenon in Lactobacillus.

Lactobacillus plantarum strains for multifunctional oat-based foods

Fermented oat-based foods offer attractive prospects within the market of non-dairy functional products, since they are suitable substrates for the delivery of probiotic microorganisms, and are significant sources of dietary fiber, both insoluble and soluble such as β-glucan, good quality fat and other phytochemicals important for human health.In the present work, whole oat flour was fermented with probiotic Lactobacillus plantarum strains to produce new functional foods with improved nutritional and technological features. Viability of the probiotic and the main technological, physico-chemical, nutritional and sensorial parameters were monitored at 7, 14 and 21 days of cold storage. The microbial survival was higher than 5x108 cfu g-1 at the end of the shelf life. After the fermentation step, viscosity was higher in products inoculated with the exopolysaccharide-producing L. plantarum strain Lp90. However, a subsequent viscosity reduction was detected in all the samples throughout the storage period, consistent with the observed concentration decrease of the oat β-glucan. Vitamin B2 content was about two-fold higher in products fermented by the riboflavin-overproducing LpB2, and in these samples the riboflavin concentration further increased during cold storage. (Less)