Characterization of Some Microorganisms from Human Stool Samples and Determination of Their Effects on CT26 Colorectal Carcinoma Cell Line.

The present study aimed to isolate and identify the potential probiotic, pathobiont, and pathogenic microorganisms in the stool samples of 12 healthy individuals and evaluate their in vitro effects on cancer formation. A total of 83 strains were isolated from the stool samples and identified using MALDI-Biotyper. Fourteen of the isolates were identified as Candida spp., three isolates were identified as Cryptococcus neoformans, 55 isolates were identified as lactic acid bacteria, and the remaining isolates belonged to different 11 bacterial genera. Important microbial properties for cancer prevention and some probiotic properties were examined. All strains maintained their viability under acidic conditions and in media containing bile salts. Of the bacterial strains, 62.5% were resistant to ampicillin, chloramphenicol, gentamicin, erythromycin, kanamycin, penicillin, streptomycin, tetracycline, and vancomycin. All yeast strains were resistant to ketoconazole and susceptible to nystatin. The susceptibility of the strains to fluconazole, voriconazole, amphotericin B, and itraconazole varied. Fifty-nine percent of the strains produced EPS and 21.7% showed proteolytic activity (PA). Of the strains, 15.7% both produced exopolysaccharides (EPS) and had PA. The antioxidant activity (AOA) varied depending on the strains. The pathobiont and pathogenic microorganisms promoted tumor formation, while potential probiotic microorganisms had a suppressive effect on tumor formation (P > 0.01). One yeast (Candida kefyr MK17) and three lactic acid bacteria strains (Lacticaseibacillus paracasei MK73, Lactiplantibacillus plantarum MK55, Limosilactobacillus mucosae MK45) have superior potential thanks to their anticarcinogenic properties as well as tolerance to gastrointestinal tract conditions. Stool samples of each individual contain various potential probiotic, pathobiont, and pathogenic microorganisms.

CD40, CD45 CTLA-4 levels are elevated in healthy older adults.

BACKGROUND: The immune system changes with age. In this study we characterized immune changes by performing immunologic screening profiles on ageing individuals. METHODS: This study was performed at Akdeniz University, in the Faculty of Medicine, Department of Immunology. Healthy volunteers consisted of a younger group (22 donors) and an older group (45 individuals). All subjects had no serious health problems (i.e. chronic heart, lung, liver or immunological diseases) and were taking no prescribed medications. Flow cytometry analysis was used to evaluate CD3, CD4, CD8, CD16, CD19, CD28, CD40, CD45, CD56, CD80, CD86, CTLA-4 and ELISA for IL-1 beta, IL-2, IL-6, IL-10, IFN-gamma, TNF-alpha expression In addition, NK activity and induced cytokine expression (by bioassay and ELISA, respectively) were evaluated. RESULTS: No statistical differences were observed between the two groups in expression of CD3, CD8, CD19, CD80, CD86, CD16, CD 56, or CD28. A higher frequency of expression of CD4, CTLA-4, CD40, and CD45 was seen in older subjects by comparison with younger subjects. Cytokine profiles expressed by stimulated monocytes and lymphocytes from the two groups showed no difference in IL-1 beta, IL-2, IL-6, IL-10, TNF-alpha, and IFN-gamma production levels. CONCLUSIONS: We found increased expression levels of CD40 and CD45 levels in healthy older (age: 59.42 +/- 5.89) versus younger individuals (age: 30.32 +/- 2.29). CTLA-4 expression levels were also higher in older subjects, with no difference in CD28 expression levels between younger/older individuals.