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Background: Chemical carcinogens may be produced by metabolic activity of microbes residing in gastrointestinal system. Researches suggest that the consumption of probiotic cultures may decrease the risk of cancer. The aim of this study was to evaluate inhibitory effects of probiotic cultures on mutant and cancerous cells.
Materials and methods: In this experimental study, antimutagenic effects of probiotic cultures, including Bifidobacterium bifidus, Bifidobacterium longum, Lactobacillus acidophilus, Lactobacillus bulgaricus, Lactobacillus rhamnosus and Streptococcus thermophillus, were assessed by the Salmonella/ microsome assay upon sodium azid and nitrosamine by Ames test.
Results: There were anticancer and antimutagenic activities of probiotic cultures. Anticarcinogenic effects of probiotic cultures were mostly above 40%, representing their potent anticarcinogenic activities.
Conclusion: This study showed that probiotic cultures have potent anticarcinogenic and antimutagenic activities.

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Background: Diarrhea is one of the most important causes of death in the world. Shigella is one of the causes of diarrheal diseases. Global studies have also shown that the prevalence of this bacterium as well as the resistance in Shigella are strongly increasing. Also, the resistance of Shigella species to third generation cephalosporins is increasing. The purpose of this study was to investigate the effect of Lactobacillus plantarum probiotics on the survival rate and also to investigate the expression of surface factors related to survival and bacterial biofilm.
Materials and methods: In this study, a sample of Shigella bacteria was prepared according to ATCC standard from Pasteur Institute of Iran and Lactobacillus plantarum isolated from dairy products was used. Samples were freshly cultured in culture medium. Then the effect of Lactobacillus plantarum on Shigella was co-cultured in 96-well plates in the presence of 1% glucose. After 24 hours RNA extraction and cDNA synthesis were performed and the survival and expression of the genes for the production of binding factors and bacterial biofilm were evaluated by Real Time technique.
Results: This study showed that the co-cultivation of Lactobacillus plantarum could significantly reduce the population of Shigella bacteria and also significantly reduced the expression of genes related to BSSS and OSPE 2 binding factors.
Conclusion: The results of this study showed that Lactobacillus plantarum could have an effect on the control and recovery process of Shigella bacteria.
 

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Background: Biological and microbial synthesis processes of nanoparticles are a safe and useful option compared to physical and chemical methods due to their compatibility with the environment and nature and their cost-effectiveness. Probiotics have beneficial effects in improving the body's immune system and are a suitable alternative in the treatment of bacterial infections. The aim of this study was the synthesis of protein nanoparticles containing silver with the probiotic bacteria Bifidobacterium breve.
Materials and methods: First, probiotic bacteria Bifidobacterium breve were cultured and then silver albumin nanoparticles (Ag-Alb-NPs) were synthesized. X-ray diffraction (XRD), infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and dynamic light scattering (DLS) tests to investigate the physical and chemical properties of Ag-Alb-NPs used.
Results: Ag-Alb-NPs had spherical, crystalline, semi-crystalline morphology and structure. They had O-H, N-H and C-H bonds, C=C bonds in aromatic rings and C-N bonds in amine compounds and O-H and C-H bonds in CH2 and CH3 groups, N-H, C-O bonds in the structure of C-O-C and C-OH functional groups. In addition, DLS results of albumin-silver nanoparticles and silver nanoparticles showed that they were 259 and 85.3 nm in size, respectively, and the graph was of single peak type.
Conclusion: In general, it was concluded that the synthesized Ag-Alb-NPs had suitable structural and physicochemical characteristics that can be used for future studies.
 

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Background: The alfalfa plant with the scientific name Medicago Sativa is called the queen of forages due to its high nutritional value. On the other hand, studies have shown that alfalfa has an effect on the intestinal microbial composition and its function. Inulin is also a compound with natural prebiotic properties that is used in various products. The aim of this study was to investigate carbohydrates, and in-vitro antimicrobial and the prebiotic activities of alfalfa extract compared to inulin.
Materials and methods: Extraction from the aerial part of alfalfa was done by maceration method. Then the carbohydrates and prebiotic effect of alfalfa extract compared to inulin on the growth of two bacteria lacticasei bacillus casei and lactiplanti bacillus plantarum and also its effect on the antimicrobial activity of their supernatant were investigated.
Results: Alfalfa extract showed more prebiotic properties than inulin, so that growth and antimicrobial effect of two bacteria, Lacticasei bacillus casei and Lactiplanti bacills plantarum, in the medium containing 2.5% extract were more than the medium containing inulin with the same amount.
Conclusion: In this study, an acceptable prebiotic property was obtained for alfalfa extract compared to the inulin, which makes alfalfa a suitable candidate for further studies to modulate the intestinal microbiome of humans and animals.