Comparison and selection of probiotic from human intestinal tract and traditional fermented food in vitro via PCA, unsupervised clustering algorithm, and heat-map analysis.

Traditional fermented products and human intestines are rich sources of strains which may have remarkable probiotic properties. In the present study, the probiotic properties of 40 strains isolated from intestinal tracts of longevity population and traditional fermented food in China were determined, including the survival rates in simulated gastric acid and bile salt, aggregation, hydrophobicity, adhesion rate, antioxidant ability (ferric reducing antioxidant power), and antimicrobial ability. The differences between human strains and nonhuman strains were compared via -test and principal component analysis (PCA). The significant differences were found in the survival rate at 0.3% bile salt, adhesion ability of the strains, and antioxidant ability of the fermentation broth ( < .05). The results of PCA showed that the first principal component (PC1) score of human strains was significantly higher than that of nonhuman strains ( < .01). And some probiotic were selected for further application based on the unsupervised clustering algorithm, heat-map analysis, and K-means algorithm. Four strains, CS128, CS39, CS01, and CS1301, along with GG (LGG) were divided into cluster I. The four strains, all isolated from human tracts, have been selected. Thus, human has better probiotic potential and application prospects than strains from the nonhuman source. PCA, the unsupervised clustering algorithm, and heat-map analysis can be used to analyze and select visually and effectively.