, 2012). The DGGE band signals were calculated by Quantity One software (Bio-Rad Laboratories Inc., Tokyo, Japan). The signal intensities and band position in each lane were divided into a spectrum of 100 variables. Principal component analysis (PCA) was run using R software and performed according to a previous report (Date et al., 2012). The first objective of this study was to develop a rapid and simple method for screening candidate prebiotic foods and their components. In order to develop the screening method, we focused on the metabolic profiles from intestinal microbiota incubated in vitro with feces. In our previous study ( Date et al., 2010), metabolic dynamics and microbial

variability from the in vitro incubation with glucose were characteristically observed, and the

substrate was completely consumed within 12 h of incubation. In addition, the metabolic dynamics Selleck Ibrutinib from the in vitro incubation with FOS, raffinose, and stachyose (known as prebiotic foods) were characteristically varied in 1H NMR-based metabolic profiles. Therefore, we decided that 12 h after incubation was the best sampling point for evaluation and comparison of metabolic profiles generated by intestinal microbiota incubated with various substrates. The metabolic profiles PF-01367338 from incubation with FOS, raffinose, stachyose, pectin from apple, kelp, wheat-bran, starch from wheat, Japanese mustard spinach, chlorella, glucan, arrowroot, starch from arrowroot, agar, carrageenan, JBO, JBOVS, onion, or control (no addition of substrate) were measured by an NMR-based metabolomics approach (Fig. S1). Plots of PCA scores for these data demonstrated that the metabolic profiles clustered to two groups (Fig. 1A). One group included the metabolic profiles from the incubation with FOS, raffinose, stachyose, JBO, JBOVS, and onion. The other metabolic profiles obtained from the incubation with pectin from apple, kelp, wheat-bran, starch from wheat, Japanese Dimethyl sulfoxide mustard spinach, chlorella, glucan, arrowroot, starch from arrowroot, agar, or carrageenan were clustered with

the controls. Because the FOS, raffinose, and stachyose are well known prebiotic foods, JBO, JBOVS, and onion were potential candidate prebiotic foods. To identify the factors contributing to these clusterings, analysis of loading plots based on the 1H NMR spectra was performed to provide information on the spectral position responsible for the position of coordinates in the corresponding scores plots (Fig. 1B). The results indicated that lactate and acetate contributed to the clustering for both the ‘candidate prebiotic food group’ and the ‘control group’ because the peaks of acetate and lactate in the ‘candidate prebiotic food group’ were shifted (Fig. S1). Furthermore, the pH levels were relatively low and the lactate production levels were relatively high in the ‘candidate prebiotic food group’ compared with the ‘control group’ (Fig. 1C).