Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 31
Filter
Add more filters










Publication year range
1.
Food Chem ; 457: 139924, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38917563

ABSTRACT

In the present study, we investigated the mechanisms associated with the stabilizing effects of whey protein concentrate-80 (WPC80) and L-ascorbyl 6-palmitate (LAP) on folic acid (FA). Multispectral techniques show that WPC80 binds to FA and LAP mainly through hydrophobic interactions, and that energy is transferred from WPC80 to FA and LAP in a nonradiative form (FA/LAP); The combination of FA/LAP resulted in a change in the conformation and secondary structure content of WPC80, an increase in the absolute zeta potential of the system, and a shift in the particle size distribution towards smaller sizes. The compound system exhibits strengthened antioxidant properties and favorable binding properties. Besides, WPC80 improves the storage stability of FA under different conditions. These results demonstrated that the ternary complex formed by FA co-binding with WPC80 and LAP is an effective way to improve the stability against of FA.

2.
Int J Biol Macromol ; 260(Pt 1): 129480, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38237823

ABSTRACT

Exopolysaccharides (EPS) yield and added concentration of lactic acid bacteria can greatly affect the processing characteristics of fermented milk. In order to investigate the effects and mechanisms of EPS yield and added concentration on fermented milk, researchers extracted EPS from 50 strains of Lactobacillus helvedicus (L. helvedicus) and selected the two strains with the largest difference in EPS yield (L. helvedicus LH18 and L. helvetigus LH33) for subsequent experiments. The physicochemical properties of EPS-LH18 and EPS-LH33 were analyzed. The gel characteristics and protein conformation of fermented milk were studied by means of texture analyzer, rheometer, scanning electron microscopy, nuclear magnetic resonance machine, fluorescence spectrophotometer and circular dichroism. The results indicate that the monosaccharide compositions of EPS-LH18 and EPS-LH33 are the same and have good thermal stability. The texture and rheological properties of L. helveticus LH18 fermented milk are significantly superior to other fermented milk. The reason is that L. helveticus LH18 EPS has the highest yield, which leads to a denser gel structure, lower surface hydrophobicity and free sulfhydryl content of its fermented milk. According to circular dichroism analysis, ß- sheet and random coil are the internal factors leading to the difference in fermented milk gel. In addition, the fermented milk improved even more favorably as the concentration of the two EPS additions increased. As described above, L. helveticus LH18 has the potential to be an excellent yogurt starter, and both of the above EPS can be used as probiotic stabilizer alternatives for fermented dairy products.


Subject(s)
Cultured Milk Products , Lactobacillus helveticus , Probiotics , Animals , Milk/chemistry , Lactobacillus helveticus/metabolism , Fermentation , Cultured Milk Products/microbiology , Yogurt/microbiology
4.
J Dairy Sci ; 105(9): 7190-7202, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35879161

ABSTRACT

Milk protein is one of the major food allergens. As an effective processing method, fermentation may reduce the potential allergenicity of allergens. This study aimed to evaluate the therapeutic potential of co-fermented milk protein using Lactobacillus helveticus KLDS 1.8701 and Lactobacillus plantarum KLDS 1.0386 in cow milk protein allergy (CMPA) management. This study determined the secondary and tertiary structures of the fermented versus unfermented proteins by Fourier-transform infrared spectroscopy and surface hydrophobicity to evaluate its conformational changes. Our results showed that different fermentation methods have significantly altered the conformational structures of the cow milk protein, especially the tertiary structure. Further, the potential allergenicity of the fermented cow milk protein was assessed in Balb/c mice, and mice treated with the unfermented milk and phosphate-buffered saline were used as a control. We observed a significant reduction in allergenicity via the results of the spleen index, serum total IgE, specific IgE, histamine, and mouse mast cell protease 1 in the mice treated with the co-fermented milk protein. In addition, we analyzed the cytokines and transcription factors expression levels of spleen and jejunum and confirmed that co-fermentation could effectively reduce the sensitization of cow milk protein by regulating the imbalance of T helper (Th1/Th2 and Treg/Th17). This study suggested that changes of conformational structure could reduce the potential sensitization of cow milk protein; thus, fermentation may be a promising strategy for developing a method of hypoallergenic dairy products.


Subject(s)
Cattle Diseases , Food Hypersensitivity , Lactobacillus helveticus , Lactobacillus plantarum , Rodent Diseases , Allergens , Animals , Cattle , Female , Fermentation , Food Hypersensitivity/veterinary , Immunity , Immunoglobulin E , Lactobacillus helveticus/metabolism , Lactobacillus plantarum/metabolism , Mice , Mice, Inbred BALB C , Milk/chemistry , Milk Proteins/analysis
5.
J Dairy Sci ; 105(8): 6405-6421, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35840401

ABSTRACT

Infant formula is currently an important food to cope with insufficient breastfeeding. Although 1,3-olein-2-palmitin (OPO) has been used in infant formula, its effects on the immune system, gut microbiota, and metabolites for infants remain unclear. This study constructed a mouse model of colonizing healthy infant feces using antibiotic treatment and fecal microbial transplantation. Thus, the gap between the infant formula supplemented with OPO and human milk in mouse serum biochemistry, immune system, intestinal microbiota, short-chain fatty acid production, and metabolites was evaluated. Our results showed that regarding IL-9, IL-10 levels, fecal secretory IgA, and endotoxin, formula supplemented with OPO and human milk types had comparable levels. Additionally, OPO slightly increased the content of short-chain fatty acids. The 16S rRNA gene sequence analysis and metabonomics analysis demonstrated that feeding different foods affects the gut microbiota of mice; in particular, supplementing formula feeding with OPO enriched the abundance of bifidobacteria. Furthermore, feeding different foods leads to unique intestinal content of metabolites, and the gut microbiota regulates the metabolites' differences. Our results reveal a brand new perspective of OPO regarding gut microbiota and metabolites.


Subject(s)
Gastrointestinal Microbiome , Infant Formula , Animals , Fatty Acids, Volatile/analysis , Feces/microbiology , Gastrointestinal Microbiome/genetics , Humans , Infant Formula/chemistry , Mice , Milk, Human/chemistry , RNA, Ribosomal, 16S/analysis
6.
Food Funct ; 13(9): 4914-4929, 2022 May 10.
Article in English | MEDLINE | ID: mdl-35395665

ABSTRACT

The intestine is the largest digestive and immune organ in the human body, with an intact intestinal mucosal barrier. Lactobacillus plantarum is an important strain of probiotics in the intestine for boosting intestinal immunity to defend against intestinal injury. In the lipopolysaccharide-induced intestinal injury model, mixed L. plantarum (L. plantarum KLDS 1.0318, L. plantarum KLDS 1.0344, and L. plantarum KLDS 1.0386) was suggested to boost intestinal immunity. In detail, compared with LPS-induced mice, mice in the mixed L. plantarum group showed significantly reduced intestine (jejunum, ileum, and colon) tissue injury, pro-inflammatory cytokine (TNF-α, IL-6 and IL-12) levels, myeloperoxidase activities, and serum D-lactate (P < 0.05) content. Moreover, the mixed L. plantarum significantly increased the number of immunocytes (CD4+ T cells, IgA plasma cells) and the expression of tight junction proteins (Claudin1 and Occludin). The results also showed that the mixed L. plantarum significantly down-regulated (P < 0.05) the intestinal protein expression of TLR4, p-IκB, and NF-κB p65. The mixed L. plantarum group increased the relative abundance of the genera, including Lactobacillus, Lachnoclostridium, and Desulfovibrio, which are related to improving the levels of SCFAs (acetic acid, butyric acid) and total bile acid (P < 0.05). Overall, these results indicated that the mixed L. plantarum had great functionality in reducing LPS-induced intestinal injury.


Subject(s)
Intestinal Diseases , Lactobacillus plantarum , Probiotics , Animals , Intestinal Diseases/metabolism , Intestinal Mucosa/metabolism , Lipopolysaccharides/adverse effects , Lipopolysaccharides/metabolism , Mice
7.
J Dairy Sci ; 105(2): 1058-1071, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34802736

ABSTRACT

In recent years, yogurt has been one of the most popular fermented dairy products and is sold worldwide. In this study, pH and titrated acid changes of 4 strains of Lactobacillus delbrueckii ssp. bulgaricus fermented milk during storage were detected. The difference between L. bulgaricus KLDS1.1011 and KLDS1.0207 was significant, with the latter exhibiting reduced acidity levels. Therefore, we determined the complete genome sequence of the 2 strains. Then the expression of specific genes and common genes related to glucose metabolism and proteolysis of L. bulgaricus KLDS1.1011 and KLDS1.0207 were detected by quantitative real-time reverse-transcription PCR. Analysis indicated that the key enzymes in glycometabolism and proteolysis of L. bulgaricus KLDS1.1011 were significantly different than those of L. bulgaricus KLDS1.0207. The contents of lactose and glucose decreased during storage of L. bulgaricus fermented milk, as determined by HPLC, and the contents of lactic acid and galactose increased, with L. bulgaricus KLDS1.1011 increasing less. With skim milk as a raw material, L. bulgaricus KLDS1.1011, KLDS1.0207, and Streptococcus thermophilus S1 were used as fermentation strains to yield yogurt at 42°C, and sensory evaluation was compared with yogurt fermented by commercial starter cultures. Yogurt from L. bulgaricus KLDS1.1011 was the highest-rated. Therefore, the study may provide guidelines for the development of yogurt starters.


Subject(s)
Cultured Milk Products , Lactobacillus delbrueckii , Animals , Fermentation , Hydrogen-Ion Concentration , Lactobacillus delbrueckii/genetics , Streptococcus thermophilus/genetics , Yogurt
8.
Front Immunol ; 12: 770822, 2021.
Article in English | MEDLINE | ID: mdl-34858427

ABSTRACT

Cow mastitis, which significantly lowers milk quality, is mainly caused by pathogenic bacteria such as E. coli. Previous studies have suggested that lactic acid bacteria can have antagonistic effects on pathogenic bacteria that cause mastitis. In the current study, we evaluated the in vitro and in vivo alleviative effects of L. plantarum KLDS 1.0344 in mastitis treatment. In vitro antibacterial experiments were performed using bovine mammary epithelial cell (bMEC), followed by in vivo studies involving mastitis mouse models. In vitro results indicate that lactic acid was the primary substance inhibiting the E. coli pathogen. Meanwhile, treatment with L. plantarum KLDS 1.0344 can reduce cytokines' mRNA expression levels in the inflammatory response of bMEC induced by LPS. In vivo, the use of this strain reduced the secretion of inflammatory factors IL-6, IL-1ß, and TNF-α, and decreased the activity of myeloperoxidase (MPO), and inhibited the secretion of p-p65 and p-IκBα. These results indicate that L. plantarum KLDS 1.0344 pretreatment can reduce the expression of inflammatory factors by inhibiting the activation of NF-κB signaling pathway, thus exerting prevent the occurrence of inflammation in vivo. Our findings show that L. plantarum KLDS 1.0344 has excellent properties as an alternative to antibiotics and can be developed into lactic acid bacteria preparation to prevent mastitis disease.


Subject(s)
Escherichia coli/immunology , Lactobacillus plantarum/immunology , Mammary Glands, Animal/immunology , Mastitis/immunology , Animals , Antibiosis/immunology , Cattle , Cells, Cultured , Cytokines/immunology , Cytokines/metabolism , Epithelial Cells/immunology , Epithelial Cells/metabolism , Epithelial Cells/microbiology , Escherichia coli/metabolism , Escherichia coli/physiology , Female , Inflammation/immunology , Inflammation/metabolism , Lactobacillus plantarum/physiology , Lipopolysaccharides , Mammary Glands, Animal/metabolism , Mammary Glands, Animal/microbiology , Mastitis/chemically induced , Mastitis/microbiology , Mice, Inbred BALB C , NF-kappa B/immunology , NF-kappa B/metabolism , Signal Transduction/immunology
9.
J Dairy Sci ; 104(11): 11499-11508, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34454765

ABSTRACT

Cow milk protein is one of the leading food allergens. This study aimed to develop an effective method for reducing milk sensitization by evaluating antigenicity of fermented skim milk protein using Lactobacillus helveticus KLDS 1.8701, Lactobacillus plantarum KLDS 1.0386, and a combination of both strains. The proteolytic systems of strains in terms of genotype and phenotype are characterized by complete genome sequence, and evaluation the antigenicity of skim milk proteins was determined by ELISA and liquid chromatography with tandem mass spectrometry. Our results showed that the genomes encoded a variety of peptidase genes. For fermented skim milk, the degree of hydrolysis of the combined strains was higher than that of individual strain. Electrophoresis showed that the band color density of α-casein (α-CN) by fermentation of the combined strains was reduced when compared with control group. The fermentation process of the combined strains inhibited α-CN, ß-lactoglobulin, and α-lactalbumin antigenicity by 69.13, 36.10, and 20.92, respectively. Major allergic epitopes of α-CN and ß-lactoglobulin were cleaved by abundant proteases of combined strains. In all, this study showed that the fermentation process involving both L. helveticus and L. plantarum strains could reduce cow milk protein allergenicity through the combination of cell-envelope proteinase and peptidase on α-CN.


Subject(s)
Lactobacillus helveticus , Lactobacillus plantarum , Allergens , Animals , Cattle , Female , Fermentation , Milk Proteins
10.
AMB Express ; 11(1): 95, 2021 Jun 27.
Article in English | MEDLINE | ID: mdl-34176008

ABSTRACT

Sugarcane molasses are considered a potential source for bioethanol's commercial production because of its availability and low market price. It contains high concentrations of fermentable sugars that can be directly metabolized by microbial fermentation. Heterofermentative lactic acid bacteria, especially Lactiplantibacillus casei, have a high potential to be a biocatalyst in ethanol production that they are characterized by strong abilities of carbohydrate metabolism, ethanol synthesis, and high alcohol tolerance. This study aimed to evaluate the feasibility of producing ethanol by Lactiplantibacillus casei used the ethanologen engineering strain L. casei E1 as a starter culture and cane molasses as substrate medium. The effects of environmental factors on the metabolism of L. casei E1 were analyzed by high-performance liquid chromatography (HPLC) system, and the gene expression of key enzymes in carbon source metabolism was detected using quantitative real-time PCR (RT-qPCR). Results showed that the strain could grow well, ferment sugar quickly in cane molasses. By fermenting this bacterium anaerobically at 37 °C for 36 h incubation in 5 °BX molasses when the fermenter's pH was controlled at 6.0, ethanol yield reached 13.77 g/L, and carbohydrate utilization percentage was 78.60%. RT-qPCR results verified the strain preferentially ferment glucose and fructose of molasses to ethanol at the molecular level. In addition, the metabolism of sugars, especially fructose, would be inhibited by elevating acidity. Our findings support the theoretical basis for exploring Lactic acid bacteria as a starter culture for converting sugarcane molasses into ethanol.

11.
Food Funct ; 12(15): 7017-7028, 2021 Aug 02.
Article in English | MEDLINE | ID: mdl-34152341

ABSTRACT

Cumulative studies have suggested that probiotic bacterial strains could be an effective alternative in inhibiting conditions caused by foodborne and vaginal pathogens. The use of genomic techniques is becoming highly useful in understanding the potential of these beneficial microorganisms. This study presents some genomic and in vitro properties of the Streptococcus thermophilus SMQ-301 strain against foodborne and vaginal pathogens (Staphylococcus aureus, Escherichia coli, and Gardnerella vaginalis) to validate its use in dairy food formulations. Genomic analyses include bacteriocin production, stress response systems, antioxidant capability, and RAST-based functional annotation. In vitro investigations focused on the antimicrobial effects of the S. thermophilus SMQ-301 cell-free solution (CFS) against the selected pathogens after enzymatic actions and pH treatments, assessment of cytotoxic effects using murine RAW264.7 cells, and assessment of organic acid production levels using supplementary carbon sources. The results show that the S. thermophilus SMQ-301 genome possesses essential pathways for stress management, antioxidant activities, and bacteriocin production. For the first time, the bacteriocin-producing peptides of S. thermophilus SMQ-301 are reported, which gives an insight into its inhibitory potential. In vitro, the CFS of S. thermophilus SMQ-301 had significant (P < 0.05) antimicrobial effects on the selected pathogens, with S. aureus ATCC25923 being the most resistant. All antimicrobial activities of the CFS against the selected pathogens were eliminated at pH 6.5 and 7.0. S. thermophilus SMQ-301 CFS yielded the highest lactic (25.58 ± 0.24 mg mL-1) and acetic (5.53 ± 0.12 mg mL-1) acid production levels, with 1% fructooligosaccharide (P < 0.05). The S. thermophilus SMQ-301 strain also lowered murine RAW264.7 cell activities from 101.77% (control) to 80.16% (T5 - RAW264.7 cells + 1 × 109 CFU mL-1 cells) (P < 0.05). This study showed that although the S. thermophilus SMQ-301 strain had excellent genomic characteristics, the in vitro effects varied markedly against all three pathogens. In all, the S. thermophilus SMQ-301 strain has promising applications as a potential probiotic in the food and allied industries.


Subject(s)
Anti-Bacterial Agents , Biological Products , Probiotics , Streptococcus thermophilus , Animals , Bacteria/drug effects , Cell Survival/drug effects , Genome, Bacterial/genetics , Genomics , Mice , RAW 264.7 Cells , Streptococcus thermophilus/genetics , Streptococcus thermophilus/metabolism , Streptococcus thermophilus/physiology
12.
Food Funct ; 12(7): 3280, 2021 Apr 07.
Article in English | MEDLINE | ID: mdl-33877250

ABSTRACT

Correction for 'Suppressive effects of Streptococcus thermophilus KLDS 3.1003 on some foodborne pathogens revealed through in vitro, in vivo and genomic insights' by Smith Etareri Evivie et al., Food Funct., 2020, 11, 6573-6587, DOI: .

13.
Food Funct ; 12(6): 2784-2798, 2021 Mar 21.
Article in English | MEDLINE | ID: mdl-33751009

ABSTRACT

Many infants on an exclusive breastfeeding regimen are often fed inadequate amounts, and this creates an imbalance between the overall effects of breast milk and commercial infant formulas. We comparatively analyzed the impact of human milk and two infant formulas in modulating the intestinal microbiota and the immune systems of mice colonized by healthy infant feces. The results showed that compared to infant formula, human milk decreased the levels of alanine transaminase, alkaline phosphatase, and total protein. Also, it improved the immune system through the level of cytokines (CD4+ lymphocytes, Th1, Th2, Th17, and Treg cells) and immunity indicators (IL-2, IL-4, IL-9, and sIgA). Human milk decreased intestinal mucosal permeability compared to infant formula. Bacterial 16S rRNA gene sequence analysis revealed that human milk increased the abundance of Akkermansia and Bacteroides, while infant formula increased the abundance of Lactobacillus and Escherichia_Shigella. Collectively, our results showed that human milk is more suitable for infants than the two commercial infant formulas based on intestinal microbiota and immune system analyses. These findings thus support a theoretical basis for the development of infant formulas.


Subject(s)
Gastrointestinal Microbiome , Infant Formula , Milk, Human , Adult , Animals , Cytokines/metabolism , Feces/microbiology , Gastrointestinal Microbiome/drug effects , Gastrointestinal Microbiome/physiology , Humans , Infant, Newborn , Intestinal Absorption , Intestine, Large/drug effects , Intestine, Large/pathology , Male , Mice , Mice, Inbred C57BL
14.
Front Microbiol ; 12: 788040, 2021.
Article in English | MEDLINE | ID: mdl-35250903

ABSTRACT

Colon cancer is the most common type of malignant tumor. The cytotoxicity effect of lactic acid bacteria may be active by inhibiting cancer cell proliferation, producing anticancer compounds, and inducing apoptosis in cancer cells, but the mechanism is unclear. Our previous study revealed that Lactobacillus acidophilus KLDS1.0901 has good probiotic properties. In this study, We screened out the highest inhibition rate of L. acidophilus KLDS1.0901 and assessed the effects on the proliferation of HT-29, Caco-2, and IEC-6 cells. Then, the apoptosis mechanism of HT-29 cells was studied when treated with L. acidophilus KLDS1.0901. Results showed that L. acidophilus KLDS1.0901 inhibited the proliferation of HT-29 and Caco-2 cells in a dose-dependent manner and reached the maximum under the condition of multiplicity of infection (MOI) = 100 (rate of Lactobacillus to cells) at 48 h. With the increase in time and MOI, reactive oxygen species in HT-29 cells, the apoptosis rates of HT-29 cells were increased, and the amount of blue fluorescence of the cells was also increased after Hoechst 33258 staining. Furthermore, L. acidophilus KLDS1.0901 reduced the mitochondrial membrane potential of HT-29 cells. Notably, 1,133 differentially expressed genes were screened by transcriptomics research, including 531 up-regulated genes and 602 down-regulated genes. These genes were involved in the nuclear factor κB and PI3K-AKT signaling pathways related to the apoptosis of HT-29 cells. These findings suggested that L. acidophilus KLDS1.0901 has the potential to be used in the development of a new type of functional foods for adjuvant treatment of colon cancer.

15.
J Agric Food Chem ; 68(51): 15345-15357, 2020 Dec 23.
Article in English | MEDLINE | ID: mdl-33300339

ABSTRACT

Studies on the possible alternative supplements to breastmilk are gaining research interests. Although milk from cow, goat, and mare is nutritious, its effects on the relationship between the immune system, metabolites, and gut microbiota remain unclear. This study aimed to comprehensively evaluate the effects of cow, goat, and mare milk on the immune system, metabolites, and gut microbiota of mice colonized by healthy infant feces using human milk as a standard. We examined the serum biochemistry parameters, immunity indicators, T cells, gut microbiota abundance, and metabolites. Results showed that the impact of human milk on alanine transaminase, glutamic oxaloacetic transaminase, total protein, globulin, and glucose values was different from the cow, goat, and mare milk types. The effects of mare milk on the percentage of CD4+ T, Th1, Th2, Th17, and Treg cells, and the levels of IL-2, IL-4, sIgA, and d-lactic acid in the serum of the human microbiota-associated mice were comparable to those of human milk. Also, bacterial 16S rRNA gene sequence analysis revealed that human milk enriched the relative abundance of Akkermansia and Bacteroides, cow milk increased the relative abundance of Lactobacillus, goat milk increased the relative abundance of Escherichia-Shigella, and mare milk improved the relative abundance of Klebsiella. Besides, mare milk was similar to human milk in the concentration of the metabolites we analyzed. Our findings suggest that mare milk can positively modulate the gut microbiota and immunity status of infants and thus could be a possible replacement for human milk.


Subject(s)
Gastrointestinal Microbiome , Immune System/immunology , Milk/metabolism , Animals , Bacteria/classification , Bacteria/genetics , Bacteria/isolation & purification , Cattle , Diet , Feces/microbiology , Female , Goats , Horses , Humans , Infant , Male , Mice , Mice, Inbred C57BL , Milk/chemistry , Milk, Human/chemistry , Milk, Human/metabolism
16.
Front Microbiol ; 11: 580931, 2020.
Article in English | MEDLINE | ID: mdl-33072051

ABSTRACT

Human milk is compatible with infant intestinal microbiota and is vital for infant health. However, most infants do not receive sufficient exclusive breastfeeding, and the effects of including other types of animal milk on the gut microbiota of infants are unclear. Therefore, the objective of this study was to elucidate the impact of milk from various animal sources on infant fecal microbiota through in vitro fermentation. The types of milk assessed include cow milk, goat milk, camel milk, mare milk, human milk, and infant formula milk. Here we determined the gas pressure, pH, and microbiota after 24 h fermentation. Results showed that mare milk had the lowest gas pressure rating, with levels similar to human milk. More so, pH analysis demonstrated that other milk types were identical to human milk. Bacterial 16S rRNA gene sequence analysis revealed that all milk types increased the abundance of Bifidobacterium and Lactobacillus, which was proportional to the lactose content of milk. Moreover, mare milk also significantly increased the relative abundance of Akkermansia. Collectively, results from mare milk (gas pressure, pH, and microbiota) were comparable to that of human milk, and thus support the theoretical basis for exploring the development of a mare milk-based infant formula.

17.
Front Microbiol ; 11: 583070, 2020.
Article in English | MEDLINE | ID: mdl-33072056

ABSTRACT

Globally, foodborne diseases (FBDs) result in millions of sicknesses and deaths annually. Cumulative evidence suggests that the use of probiotic lactic acid bacteria (LAB) strains could be a viable alternative in inhibiting the activities of foodborne pathogens. This study aims to evaluate the in vitro antimicrobial, cytotoxic, and tolerance levels of Lactobacillus bulgaricus KLDS 1.0207 against two notable foodborne pathogens - Escherichia coli ATCC25922 and Staphylococcus aureus ATCC25923. Afterward, a 48 BALB/c mice-trial was used to assess its ameliorative effects on weight and serum biochemical parameters. Results showed that the cell-free supernatant (CFS) of this strain significantly inhibited both pathogens, but these effects were abolished at pH 6.5 and 7.0 (P < 0.05). Also, 6.96 ± 0.02 log CFU mL-1 of L. bulgaricus KLDS 1.0207 was still viable after three hours in simulated gastric juice and at pH 3.0, indicating that this strain was a potential probiotic candidate. Also, inflammatory activities in RAW264.7 cells were significantly inhibited using 109 CFU mL-1 of L. bulgaricus KLDS 1.0207 cells (P < 0.05). Significant weight losses were also prevented in the T LBSA (from 19.42 ± 1.04 to 19.55 ± 0.55 g) and T LBEC (from 22.86 ± 0.90 to 14.77 ± 9.86 g) groups compared to their respective model groups (T SA - from 21.65 ± 1.80 to 20.14 ± 1.84, and T EC - from 21.45 ± 0.82 to 14.45 ± 9.70 g). Besides, there was a slight weight gain in the S. aureus prevention group (T LBSA ) compared to the model group (T SA ). Serum biochemical analyses revealed that the total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), and some mineral levels were markedly increased by S. aureus and E. coli administrations but were reversed to normalcy in both prevention groups (T LBSA and T LBEC ). Interestingly, high-density lipoprotein (HDL) levels, which were initially disrupted in the model groups, were restored in the prevention groups (T LBSA and T LBEC ). This study presents L. bulgaricus KLDS 1.0207 as a promising probiotic candidate with antimicrobial, anti-inflammatory, acid, and bile tolerant and lipid-regulating applications. It also gives valuable insights for targeted future in vivo treatment and prevention studies involving other probiotic LAB candidates. Future in vivo studies elucidating specific mechanisms behind the in vitro antimicrobial, cytotoxic, and in vivo ameliorative effects are warranted.

18.
Food Funct ; 11(7): 6573-6587, 2020 Jul 22.
Article in English | MEDLINE | ID: mdl-32647845

ABSTRACT

Foodborne diseases (FBDs) remain a persistent global challenge and recent research efforts suggest that lactic acid bacteria (LAB) strains can contribute towards their prevention and treatment. This study investigates the genetic properties of Streptococcus thermophilus KLDS 3.1003 as a potential probiotic and health-promoting LAB strain as well as its in vitro and in vivo activities against two foodborne pathogens. In vitro, its antimicrobial activities and tolerance levels in simulated bile salts and acids were determined. The cytotoxic effects of the LAB strain in RAW264.7 cells were also evaluated. For in vivo evaluation, 24 BALB/c mice were orally administered control and trial diets for 14 days. Genomic analyses of this strain's bacteriocin configuration, stress response system and multidrug resistance genes were annotated to validate in vitro and in vivo results. In vitro antimicrobial results show that the cells and CFS of S. thermophilus KLDS 3.1003 could inhibit both pathogens with the former being more effective (P < 0.05). In addition, its cell-free supernatant (CFS) could inhibit the growth of both pathogens, with catalase treatment having the highest effect against it. More so, after 3 h of incubation, survivability levels of S. thermophilus KLDS 3.1003 were significantly high (P < 0.05). LPS-induced RAW264.7 cell activities were also significantly reduced by 108-109 CFU mL-1 of S. thermophilus KLDS. In vivo, significant weight losses were inhibited in the TSTEC group compared to the TSTSA group (P < 0.05). Moreover, pathogen-disrupted blood biochemical parameters like HDL, LDL, TP, TG, AST, ALT and some minerals were restored in the respective prevention groups (TSTEC and TSTSA). Genomic analyses showed that S. thermophilus KLDS 3.1003 has bacteriocin-coding peptides, which accounts for its antimicrobial abilities in vitro and in vivo. S. thermophilus KLDS 3.1003 is also endowed with intact genes for acid tolerance, salt-resistance, cold and heat shock responses and antioxidant activities, which are required to promote activities against the selected foodborne pathogens. This study showed that S. thermophilus KLDS 3.1003 has the genomic capacity to inhibit foodborne pathogens' growth in vitro and in vivo, thus qualifying it as a potential probiotic, antimicrobial and bio-therapeutic candidate.


Subject(s)
Foodborne Diseases/therapy , Genomics , Probiotics/therapeutic use , Streptococcus thermophilus/genetics , Streptococcus thermophilus/physiology , Animals , Anti-Infective Agents/therapeutic use , Bacteriocins , Bile Acids and Salts/pharmacology , Catalase , Hydrogen-Ion Concentration , Lipopolysaccharides/adverse effects , Mice , RAW 264.7 Cells , Streptococcus thermophilus/drug effects
19.
Food Funct ; 11(5): 4571-4581, 2020 May 01.
Article in English | MEDLINE | ID: mdl-32400792

ABSTRACT

Folate is an essential B vitamin and its deficiency is common in many parts of the world. Natural folate produced by microorganisms may be an alternative to chemically synthesized folic acid (FA) as a dietary supplement. Previously, two lactic acid bacteria (LAB) strains, a high folate-producing Lactococcus lactis subsp. lactis KLDS4.0325 and a weak folate-producing Lactococcus lactis subsp. lactis KLDS4.0613, were identified. The aim of this study was to evaluate the effect of milk fermented with L. lactis KLDS4.0325 (folate-enriched fermented milk, FEFM) in alleviating folate deficiency status using murine folate deficiency models. In addition, the link between gut microbiota diversity and folate levels in mice was investigated. Results showed that FEFM increased FA and 5-methyltetrahydrofolate (5-MTHF) concentrations in the whole blood and liver, and decreased plasma homocysteine (Hcy) levels. 16S rDNA sequence analysis also revealed that the supplementation of FEFM (containing 0.6 µg mL-1 folate) and 0.6 µg d-1 FA (FEFM + LFA) significantly improved the poor status of the gut microbiota composition caused by folate deficiency, and the effect was better than that with 1.2 µg d-1 FA (HFA) supplementation. Our findings show that FEFM can be used as a folate-fortified food to alleviate folate deficiency effectively. In addition, it may be considered as a partial or total replacement for synthetic FA.


Subject(s)
Folic Acid Deficiency/diet therapy , Folic Acid/blood , Lactococcus lactis , Milk/chemistry , Animals , Disease Models, Animal , Female , Fermentation , Folic Acid Deficiency/blood , Functional Food , Mice , Mice, Inbred BALB C
20.
Front Microbiol ; 10: 782, 2019.
Article in English | MEDLINE | ID: mdl-31057507

ABSTRACT

Foodborne pathogens are a major source of morbidity and mortality worldwide. For this cause, exploring various effective ways of suppressing their spread is at the forefront of many research projects. The current study aims to investigate the in vitro organic acid production of S. thermophilus KLDS 3.1003 and L. bulgaricus KLDS 1.0207 strains, their in vivo suppression of and immuno-modulatory effects against E. coli ATCC 25922 and S. aureus ATCC 25923 pathogens. First, lactic and acetic acid production using three carbon sources - 1% glucose (control), 1% sucrose, and 1% fructo-oligosaccharides (FOS) - was determined by HPLC. For the in vivo section, a total of 40 BALB/c mice were purchased and divided into 10 treatment groups (control and nine treatments). Animals were given 1 week to acclimatize and then fed treatment diets for 14 days. Afterward, hematological (RBC, WBC, HB, PLT, Neutrophils, Eosinophils, Lymphocytes, and Monocytes) and histopathological analyses were carried out. All analyses were done in triplicate. Results show that lactic and acetic acid productions for both strains increased with supplementation and were highest after 1% FOS addition. Regardless of carbon source, L. bulgaricus KLDS 1.0207 produced higher (P < 0.05) amounts of lactic and acetic acids than S. thermophilus KLDS 3.1003. Also, generally better hematological parameters in probiotic groups than the control (P < 0.05) were observed. In some instances, mice in probiotic treatment groups had better immunity levels (lymphocytes, monocytes, neutrophils, eosinophils) than those in the control and pathogen groups. Histopathological studies showed that no anomalies were associated with S. thermophilus KLDS 3.1003 and L. bulgaricus KLDS 1.0207 administration. In conclusion, S. thermophilus KLDS 3.1003 and L. bulgaricus KLDS 1.0207 strains are not only probiotic candidates but can have therapeutic applications.

SELECTION OF CITATIONS
SEARCH DETAIL