Ulbon hr 20 m

Blood plasma was analysed for glucose and total cholesterol by using commercially available kits (Wako). Caecal digesta (1 g) was suspended in saline (5 ml) and vortexed, and the mixture was then centrifuged (4 °C, 7,800×g, 5 min). The resulting supernatant was used to measure pH by electrode (F-51, Horiba, Kyoto, Japan), and also subjected to the analysis of SCFA, lactate, succinate, ammonia, indole, and skatole concentrations. SCFA was determined by gas chromatography (GC-14B; Shimadzu, Kyoto, Japan) equipped with 0.53 mm ×30 m capillary column (ULBON HR-20M; Shimadzu) as previously reported (Suto, 1973) . D-lactate, L-lactate, and succinate were measured by D/L Lactic Acid Assay Kits and Succinic Acid Assay Kits (Megazyme, Bray, Ireland) according to manufacturer's instructions for the respective kits. Ammonia nitrogen (NH 3 -N) was measured by the phenol-hypochloride reaction method (Weatherburn, 1967) using a microplate reader (ARVO MX; Perkin Elmer, Waltham, MA, USA) at 660 nm. Assays for indole and skatole were carried out by colorimetric methods (Walstra et al., 1999) .