Can the Reduction of Iron Availability Caused by Tea Consumption Change the Gut Microbiota Composition and Disrupt Host Body-iron Status

NCT05019573 | Unknown DMC

• 1 other identifier: UREC 20/04
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

Iron is an essential micronutrient for nearly all living organisms, including microbes. The adult human body contains approximately 3-5 g of iron (45-55 mg/kg of body weight in adult women and men, respectively). Iron-deficiency related anaemia (IDA) is a major public health problem that affects more than 2 billion people globally and this represents 24.8% of the world's population. According to World Health Organisation (WHO), iron deficiency is the most common cause of anaemia worldwide, with infants, children and women at higher risk, making it a global public health problem. Much iron deficiency is a result of poor iron dietary absorption since iron is poorly absorbed (\~15%). Absorption inhibition factors (iron chelators) like phytate and tannins, found in tea and vegetables have been reported to act as potent iron uptake inhibitors. Despite its health benefits, tea-containing polyphenols (tannins) have been associated with reduction and disruption of iron absorption, acting as inhibitors of non-haem iron uptake, potentially resulting in poor iron status. However, most studies on the effect of tea on iron absorption are largely based on isotope-labelled single meal studies and animal studies. Iron is a requirement of many microorganisms, as such changes in iron availability can also have an impact on the gut microbiota. Long-term controlled human intervention studies to investigate the effect of tea on iron absorption and the effect on gut microbiota composition are scarce. In addition, the impact of dietary tannins on the gut microbiota is not understood. Thus, this proposed human intervention trial will investigate the combined effect of tea-tannins on iron status, inflammation and gut microbiota composition. This will be the first study to consider this combination of factors.

Conditions

Focus of Study: 1- Effect of Tea Consumption on Gut Microbiota; Focus of Study: 2- Effect of Tea Consumption on Body-iron Status

Outcome Measures

Primary Outcomes (5)

• Composition and diversity of the faecal microbiota of the individuals consuming tea/placebo during the 4 weeks intervention

  Changes in composition and diversity of faecal microbiota in response to black tea intervention assessed by next generation sequences NGS

  4 weeks intervention

• Levels of faecal and urine metabolites of the individuals consuming tea/placebo during the 4 weeks intervention

  Changes of metabolic profile during the intervention will be estimated in faecal and urine samples using Nuclear Magnetic Resonance (NMR)

  4 weeks intervention

• Levels of ferritin (ng/mL) as body-iron status indicators of the individuals consuming tea/placebo during the 4 weeks intervention

  Ferritin will be monitored through blood samples collected during study visits.

  4 weeks intervention

• Changes in the concentration (pg/mL) of inflammation markers in plasma of the individuals consuming tea/placebo using enzyme-linked immunosorbent assays (ELISAs)

  gut inflammation will be assessed by measuring concentration (pg/mL) of gut inflammatory markers as plasma intestinal fatty acid-binding protein and cytokines from plasma (e.g. IL-10, IL-6, TNFα). Samples will be analysed using enzyme-linked immunosorbent assays (ELISAs)

  4 weeks intervention

• Changes in the concentration (mcg/g) of faecal calprotectin (gut inflammatory marker) during tea intervention using enzyme-linked immunosorbent assays (ELISAs)

  Gut inflammation will be assessed measuring concentration (mcg/g) of calprotectin. Increase in the levels of Calprotectin indicates the migration of neutrophils to the intestinal mucosa, which occurs during intestinal inflammation.

  4 weeks intervention

Secondary Outcomes (2)

• Assessment of stool consistency

  4 weeks intervention

• Assessment of gastrointestinal symptoms

  4 weeks intervention

Study Arms (2)

Black tea group

EXPERIMENTAL

Volunteers meeting inclusion/exclusion criteria will be given an appropriate number of black tea samples twice a day with main meals for the 4 weeks of the treatment.

Dietary Supplement: Black tea

Placebo group

PLACEBO COMPARATOR

Volunteers meeting inclusion/exclusion criteria will be given an appropriate number of placebo tea samples twice a day with main meals for the 4 weeks of the treatment.

Dietary Supplement: Placebo

Interventions

Black tea DIETARY_SUPPLEMENT

Black tea twice a day for 4 weeks

Black tea group

Placebo DIETARY_SUPPLEMENT

Placebo tea twice a day for 4 weeks

Placebo group

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• University of Reading: lead
• Unilever R&D: collaborator

Study Sites (1)

University of Reading

Reading, United Kingdom

Location

MeSH Terms

Interventions

Tea

Intervention Hierarchy (Ancestors)

Plant Preparations; Biological Products; Complex Mixtures; Beverages; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: SCREENING
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principle Investigator

Model Details: A randomised, double-blind (subject/investigator), placebo controlled, parallel study.

Study Record Dates

• First Submitted: June 15, 2021
• First Posted: August 25, 2021
• Study Start: September 20, 2021
• Primary Completion: December 10, 2021
• Study Completion: January 10, 2022
• Last Updated: August 25, 2021

Record last verified: 2021-08

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF

Locations

GB (1)