Research Information System
CURRENT MICROBIOLOGY, vol.79, 2022 (Journal Indexed in SCI)
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 efects on cancer formation. A total of 83 strains were
isolated from the stool samples and identifed using MALDI-Biotyper. Fourteen of the isolates were identifed as Candida
spp., three isolates were identifed as Cryptococcus neoformans, 55 isolates were identifed as lactic acid bacteria, and the
remaining isolates belonged to diferent 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 fuconazole, voriconazole, amphotericin B, and itraconazole varied. Fiftynine 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 efect
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.