Identification of Human Intestinal Microbiota of 92 Men by Data Mining for 5 Characteristics, i.e., Age, BMI, Smoking Habit, Cessation Period of Previous Smokers and Drinking Habit

Abstract

The intestinal microbiota compositions of 92 men living in Japan were identified following consumption of identical meals for 3 days. Fecal samples were analyzed by terminal restriction fragment length polymorphism with 4 primer-restriction enzyme systems, and the 120 obtained operational taxonomic units (OTUs) were analyzed by Data mining software focusing on the following 5 characteristics, namely, age, body mass index, present smoking habit, cessation period of previous smokers and drinking habit, according to the answers of the subjects. After performing Data mining analyses with each characteristic, the details of the constructed Decision trees precisely identified the subjects or discriminated them into various suitable groups. Through the pathways to reach the groups, practical roles of the related OTUs and their quantities were clearly recognized. Compared with the other identification methods for OTUs such as bicluster analyses, correlation coefficients and principal component analyses, the clear difference of this Data mining technique was that it set aside most OTUs and emphasized only some closely related ones. For example for a selected characteristic, such as smoking habit, only 7 OTUs out of 120 were able to identify all smokers, and the remaining 113 OTUs were thought of as data noise for smoking. Data mining analyses were affirmed as an effective method of subject discrimination for various physiological constitutions. The species of bacteria that were closely related to heavy smokers, i.e., HaeIII-291, were also discussed.

Keywords: decision tree; discrimination of subjects; human intestinal microbiota; identical meals; node; operational taxonomic units; terminal restriction fragment length polymorphism.

Fig. 1.

Decision-tree (Dt) of ‘smoking habit’ with 120 OTUs. OTUs: 27B + 33HA + 20 M + 40A; Arrows: Terminal nodes of ‘B’, smokers; Dotted arrow: gathered node of nonsmokers, ‘A’. Each box is called ‘node’, a group of subjects, of which components were shown. Along the pathway of Dt, name and cutoff value of OTU, which was estimated with C&RT method, and played a role of dividing, were indicated. Upper side of Fig. 1. were less amount of OTUs quantities, and lower side did higher amount comparatively.

Fig. 2.

Circumstances of the ‘OTU-HA291 quantities’ with 5 smoking categories. N-5: Node-5 shown in Fig. 1 and Table 2.

Fig. 3.

Drinking habits of 45 men out of 92 subjects. N-7 – N-21 were cited in Table 4.