From the faecal samples, the SCFA content of the samples to be determined by capillary gas chromatography. SCFA to be quantified against authentic standards of acetate, propionate, butyrate, valerate and the branched chain fatty acids iso-butyrate and iso-valerate. The lower limit for reliable detection of each product is 0.2 mM. DNA to be extracted at University of Aberdeen using the FastDNA spin kit for faeces following the manufacturer's instructions and quantitative PCR (qPCR). Samples and standards are prepared in 96 well plate format, enabling the use of a multichannel pipettes for setting up the running plate. PCR primer sets and amplification conditions are as described in previous studies.