This is a placebo controlled, cross-over, randomized, double blinded study. The intervention food products will be taken as diet prebiotic supplements: 1. Wheat Bran Extract rich in arabinoxylan oligosaccharides : 15g/d (up to 10 g total additional dietary fibre per day). 2. Placebo product maltodextrin:equal amounts of a digestible carbohydrate.

Primary endpoints are faecal microbiota analysis and faecal metabolite analysis (particularly, short chain fatty acid). Secondary endpoint is serum cholesterol, glucose, HDL and bowel function, gastrointestinal tolerance, quality of life and food frequency (by the use of questionnaires).

Participants will be identified and recruited at the HNU and RIHN. Participants will be informed about the study aims and procedures and will be pre-screened on the basis of inclusion/exclusion criteria. If eligible, they will sign the informed consent and enter the study with visit 0 where a clinical and biochemical evaluation of the health status will be performed. If subjects are still eligible for the study according to all the exclusion criteria, they will be included into the trial and randomised to receive the active supplementation or placebo at visit 1 (day 5). Volunteers will be invited to commence the study in batches of 5 people.

Following 5 days of maintenance diet (their usual diet), on visit 1 (day 5) volunteers would bring their fresh faecal sample to HNU, blood sample and blood pressure measurement will be taken during their visit. The placebo or fibre supplements will be given to them, enough for the next 5 days. On visit 2 (day 10), volunteers would come to HNU to deliver their faecal sample and the next 5 days' worth of placebo or fibre supplements will be provided. Volunteers will return to HNU for visit 3 (day 15) to deliver their faecal sample, blood sample and blood pressure measurement will be taken on site. There will be a wash out period of 5 days with no study product provided to the volunteers. On visit 4 (day 20), the study intervention would then cross-over and the volunteers will deliver their faecal sample to HNU. Blood sample and blood pressure measurement will be taken and the volunteers will be given the next set of products, enough for the next 5 days. On visit 5 (day 25), volunteers would come to HNU to deliver their faecal sample and the next 5 days' worth of placebo or fibre supplement will be given to them. At the end of the second intervention (day 30), volunteers will come in for visit 6 to deliver their faecal sample and have blood sample and blood pressure measurement taken.

The study will end with 5 days of wash out period, where volunteers consume their own usual diet. Volunteers would come to HNU for a final visit 7 (day 35), faecal sample will be collected at the end of the wash out period.

Inclusion Criteria:

• Males and females aged 60 years and above
• Body mass index 20-32 kg/m2

Exclusion Criteria:

• Fructose intolerance/ or any of the ingredients in the prebiotic mix
• On prescription antibiotics within the past 3 months
• Bowel disorder
• Vegetarian or vegan
• Eating disorders and food intolerances (restricted eating)
• Wheat and gluten allergy, coeliac disease
• Alcohol and/or other substance abuse
• Regular intake of prebiotic or probiotic supplements
• Smoking
• Psychiatric disorders resulting in perceived inability to give informed consent (including severe depression, lithium treatment, schizophrenia, severe behavioural disorders)
• Lipid/Cholesterol lowering medication (as cholesterol is one of the endpoints of the study)