Screening of lactic acid bacteria with cholesterol-lowering and triglyceride-lowering activity in vitro and evaluation of probiotic function

Evaluation of probiotic bifidobacteria strains from Iranian traditional dairy products for their anti-hyperlipidemic potential

This study investigated the therapeutic potential of probiotic bifidobacteria, isolated from Iranian fermented dairy products, in a hyperlipidemic animal model. Bifidobacterium strains were extracted from traditional dairy samples and screened using physiological and phenotypic examinations, 16S rRNA analysis, and probiotic properties such as tolerance to gastrointestinal juice, antimicrobial activity, and antibiotic susceptibility. The ability of the screened bifidobacteria to reduce serum and liver lipids in vivo was tested using male Wistar rats. Six strains of bifidobacteria were isolated from traditional Iranian fermented dairy. These strains showed promising in vitro activity in lowering triglyceride and cholesterol, tolerance to simulated gastrointestinal juice, the ability to adhere to Caco-2 cells, acceptable antibiotic susceptibility, and a broad spectrum of antibacterial activity. The diet supplemented with isolated bifidobacteria significantly reduced serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), liver tissue lipid levels, and hepatic enzymes in animals when compared to a high-fat diet without strains (p < 0.01). Additionally, the potential probiotic-supplemented diet significantly increased bile acid excretion in the feces and upregulated hepatic CYP7A1 expression levels (p < 0.05), while NPC1L1, ACAT2, and MTP gene expressions in small intestinal cells were downregulated (p < 0.05). Bifidobacteria isolated from Iranian traditional dairy showed potential for use in the production of fermented foods that have hypolipemic activity in the host.

Harnessing the Health and Techno-Functional Potential of Lactic Acid Bacteria: A Comprehensive Review

This review examines the techno-functional properties of lactic acid bacteria (LABs) in the food industry, focusing on their potential health benefits. We discuss current findings related to the techno-functionality of LAB, which includes acidification, proteolytic and lipolytic features, and a variety of other biochemical activities. These activities include the production of antimicrobial compounds and the synthesis of exopolysaccharides that improve food safety and consumer sensory experience. LABs are also known for their antioxidant abilities, which help reduce oxidative reactions in foods and improve their functional properties. In addition, LABs' role as probiotics is known for their promising effects on gut health, immune system modulation, cholesterol control, and general wellbeing. Despite these advantages, several challenges hinder the effective production and use of probiotic LABs, such as maintaining strain viability during storage and transport as well as ensuring their efficacy in the gastrointestinal tract. Our review identifies these critical barriers and suggests avenues for future research.

Isolation and Identification of Lactococcus lactis and Weissella cibaria Strains from Fermented Beetroot and an Investigation of Their Properties as Potential Starter Cultures and Probiotics

The presence of certain microorganisms in dairy products or silage is highly desirable. Among them are probiotic strains of lactic acid bacteria (LAB), which show many beneficial features, including antimicrobial properties that support the development of beneficial microflora; in addition, owing to their biochemical activity, they influence the nutritional, dietary, and organoleptic properties of food products. Before being placed on the market, each strain requires separate testing to determine its probiotic properties and effectiveness. The aim of this study was to isolate LAB strains from a pickled beetroot sample that could be used in the dairy industry and with the potential to be considered as a probiotic in the future. Two strains identified using the MALDI technique were selected—Lactococcus lactis and Weissella cibaria. The optimal growth conditions of the strains were determined, and their proteolytic properties were assessed with the use of the o-PA reagent and spectrophotometry. The lipid profile was analyzed using the SALDI (surface-assisted laser desorption/ionization) technique and silver nanoparticles. High-performance liquid chromatography was used to assess the ability of the strains to synthesize beneficial metabolites, such as B vitamins (B2, B3, and B9) or lactic acid, and gas chromatography was used to analyze the substances responsible for organoleptic properties. Moreover, the ability to inhibit the growth of pathogenic strains was also tested in the selected strains. Both tested strains demonstrated the desired properties of starter cultures for future use in functional food production, showing that fermented plant products can serve as valuable potential probiotic sources.

Fermented Carrot Pulp Regulates the Dysfunction of Murine Intestinal Microbiota

It was the focus of attention that probiotic control drink was packed with prebiotic nutrients and lactic acid bacteria. So, this study is aimed at revealing that the fermented carrot pulp regulation and protection function to the intestinal microecological disorders usually induced by antibiotic treatment. First, we study on lactobacillus fermentation conditions and effects on the secondary metabolism of fermented carrot juice, get its phenolic acids up, and get its flavonoids down. Then, establishment of the dysbacteriosis mouse model was used to validate the fermented carrot pulp prevention and treatment of intestinal microbiota imbalance. After the antibiotic treatment, the mice showed impotence, laziness, slow movement, weight loss, thin feces, dull hair, and anal redness, while the mice in the control group were all normal in terms of the mental state, diet, weight, and bowl movement. Along with the treatment, the abnormal conditions of the mice in the model group and natural recovery group improved in different degrees, indicating that the fermentation treatment is of help to the intestinal microbiota recovery. The fermentation-treated group of mice recovered close to normal that the diarrhea disappeared, and the weight gain, mental state, and the feces became normal. The serum antioxidant (SOD, GSH, and MDA) levels of the mice were checked. The superoxide dismutase (SOD) levels and glutathione (GSH) levels in the ordinary fermentation-treated group and probiotic fermentation-treated group were significantly increased compare to the natural recovery group. The malondialdehyde (MDA) levels showed great differences between the fermentation-treated groups and the blank group. At last, the 16sRNA analysis revealed that the microbiota richness and diversity in probiotic fermentation (J) are much higher than those in the model group (H), ordinary fermentation group (I), and blank group (G). Groups J and I are of significantly higher antioxidant level than group H; however, only the glutathione (GSH) level in group J increased dramatically but not those in the other three groups. Antibiotic treatment-induced mouse intestinal microecological disorder reduce the microbiota richness and diversity. Prebiotics fermented carrot pulp treatment can help in the recovery from the microbiota richness and diversity level prior to the antibiotic treatment, which suggests it can regulate and protect the murine intestinal microbiome.

Lipidomic analysis of lactic acid bacteria strains by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Analysis by MALDI-TOF mass spectrometry and gas chromatography-mass spectrometry was used to characterize the lipid profile of 3 lactic acid bacteria strains. By gas chromatography coupled with mass spectrometry, 23 fatty acids were identified. Dominant acids were palmitic (C16:0), oleic (C18:1), and α-linoleic acid (C18:3n-3) for Lactobacillus paracasei; for Lactococcus lactis they were palmitic (C16:0), gondoic (C20:1), myristoleic (C14:1), and eicosadienoic acid (C20:2), respectively; and in the case of Lactobacillus curvatus were C18:1, C18:2n-6, and C16:0, respectively. The effect of the medium on fatty acid composition was also determined. In addition, the fatty acid profile was also compared using MALDI MS analysis. The MALDI-TOF MS was used for qualitative analysis and identification of bacterial lipids. Phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylcholine, triacylglycerols, and ceramides were the most abundant species in lactic acid bacteria. One hundred different combinations of fatty acids in polar and nonpolar lipids have been identified, including 11 phospholipids (18 phosphatidylglycerol, 16 phosphatidylethanolamine, 10 phosphatidylinositol, 8 phosphatidylcholine, 4 lyso-phosphatidylethanolamine, 3 lyso-phosphatidylcholine, 3 phosphatidylserine, 1 lyso-phosphatidic acid, 1 lyso-phosphatidylglycerol, 1 lyso-phoshatidylinositol, and 1 phosphatidic acid), 23 triacylglycerols, 9 ceramides, and 2 sphingomyelin. The most abundant fatty acids identified were C16:0, C16:1, C18:0, and C18:3. Obtained lipid profiles allowed to distinguish the tested bacterial strains.

In vitro Probiotic Potential and Safety Evaluation (Hemolytic, Cytotoxic Activity) of Bifidobacterium Strains Isolated from Raw Camel Milk

The present study was designed to isolate Bifidobacterium strains from raw camel milk and to investigate their probiotic characteristics. Among 35 isolates, 8 were identified as Gram-positive, catalase negative, non-spore forming, non-motile and V or Y shaped rods. B-2, B-5, B-11, B-19 and B-28 exhibited good survival at low pH and high bile salt concentration. Most of the isolates were resistant to nalidixic acid, fusidic acid, polymyxin B, neomycin, streptomycin, gentamicin, rifampicin and kanamycin. Furthermore, the production of exopolysaccharides (EPS), adhesion characteristics, antioxidant properties, antagonistic activities, nitrite reduction and cholesterol assimilation were also studied. Isolate B-11 was chosen because it exhibited most of the probiotic properties among all the tested isolates. It is identified as the member of Bifidobacterium longum group through 16S rRNA gene sequencing and named as B. longum B-11. B. longum B-11 was further selected for in vivo attachment to rat intestine and scanning electron micrographs revealed that attachment of a large number of rods shaped bacterial cell. Our findings suggest that B. longum B-11 processes excellent attributes to be used as potential probiotic in the development of functional probiotic food.