Inclusion Criteria:  Age: 18-60 years Gender: Male or Female Volunteers agree to sign an informal written consent form General good health Normal haemoglobin and serum ferritin levels  Exclusion Criteria:  Regular tea drinkers Use of antibiotics, prebiotics or probiotics (in food products or as supplements), laxatives, anti-spasmodic, anti-diarrhoea drugs, (e.g. Orlistat, Lactulose) in the last 4 weeks prior to, or during the study period. Use of any iron supplement in the last 6 months prior to the study period. If participants have received bowel preparation for investigative procedures in the 4 weeks prior to the study. Surgical resection of any part of the bowel. If you have any chronic gut disorder/disease, such as IBS, IBD, etc. or other conditions that might affect the gut environment, e.g. coeliac disease. If participants are taking any medication that could affect the iron absorption (e.g. lansoprazole, omeprazole). Those with gluten allergies (e.g. Celiac disease) must be excluded as the placebo may contain gluten If participants are pregnant or are lactating. If participants have a BMI > 30 kg/m2. Severe allergy or any history of severe abnormal drug reaction, drug or alcohol abuse