Dietary fibres and gut microbiome response in obese subjects

INTERVENTION: This pilot project will be of crossover design with randomised order of dietary intervention in up to 20 obese subjects with anthropometry indicating metabolic risk (BMI >30 kg m‐2 and waist circumference indicating metabolic risk). Four separate dietary interventions will occur, each with daily consumption of the cereal product for a 3 week period. These interventions include (a low fibre control (<1g dietary fibre), two moderate fibre cereals‐ sorghum and oats (3g dietary fibre) and a high fibre cereal‐ oat (providing 12g dietary fibre) and there will be a 3‐week washout between test phases. CONDITION: Obesity PRIMARY OUTCOME: Changes in gut microbiome composition. Stool samples willl be taken from participants at the beginning and end of each trial period. Samples will be taken by participants at home using OMNIGENE‐GUT kits. These kits stabilise DNA for microbiome analysis to determine bacteria composition and diversity. Changes in plasma LPS concentrations. Blood samples will be taken from participants at the beginning and end of each trial period. Samples will be centrifuged and plasma will be stored at ‐80 degrees celsius. Plasma will undergo Hycult Biotech Limulus Amebocyte Lysate assay to determine LPS concentrations. Changes in SCFA production. Blood samples will be taken from participants at the beginning and end of each trial period. Samples will be centrifuged and plasma will be stored at ‐80 degrees celsius. Plasma will undergo gas chromatography/mass spectrometry to determine SCFA concentrations. SECONDARY OUTCOME: Blood Pressure. This will be measured using Omron automatic blood pressure cuff measure. This will be taken on participant arrival to each dietary counselling session. Changes in anthropometrical measures. This will involve body weight and BMI using a digital scale and stadiometer and waist circumference using a plastic measuring tape. INCLUSION CRITERIA: Obese (BMI 30kg/m2‐40kg/m2) Aged between 18 and 60 years Weight stable (<3kg weight loss or gain in the past 12 months).