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

Longfei Zhang; Hengxian Qu; Xiaoxiao Liu; Qiming Li; Yang Liu; Wenqiong Wang; Dawei Chen; Lixia Xiao; Ruixia Gu

doi:10.1002/fsn3.3018

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

Food Sci Nutr. 2022 Aug 22;10(12):4247-4257. doi: 10.1002/fsn3.3018. eCollection 2022 Dec.

Authors

Longfei Zhang^{1

2

3}, Hengxian Qu^{1

2

3}, Xiaoxiao Liu^{1

2

3}, Qiming Li⁴, Yang Liu^{1

2

3}, Wenqiong Wang^{1

2

3}, Dawei Chen^{1

2

3}, Lixia Xiao^{1

2

3}, Ruixia Gu^{1

2

3}

Affiliations

¹ College of Food Science and Engineering Yangzhou University Yangzhou China.
² Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control Yangzhou China.
³ Jiangsu Dairy Biotechnology Engineering Research Center, Kang Yuan Dairy Co. Ltd Yangzhou University Yangzhou China.
⁴ New Hope Group Chengdu China.

Abstract

Traditional fermented products and human intestines are rich sources of Lactobacillus strains which may have remarkable probiotic properties. In the present study, the probiotic properties of 40 Lactobacillus 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 t-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 (p < .05). The results of PCA showed that the first principal component (PC1) score of human strains was significantly higher than that of nonhuman strains (p < .01). And some probiotic Lactobacillus 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 Lactobacillus rhamnosus GG (LGG) were divided into cluster I. The four strains, all isolated from human tracts, have been selected. Thus, human Lactobacillus 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 Lactobacillus visually and effectively.

Keywords: Lactobacillus; PCA; heat‐map analysis; human and nonhuman resources; physiological characteristics; unsupervised clustering.