GutFibreGeneration
Research type
Research Study
Full title
Pilot Clinical Trial: The Effects of a Dietary Fibre Blend on Metabolic Profiles and the Gut Microbiome in a Transgenerational Cohort
IRAS ID
273043
Contact name
Gary Frost
Contact email
Sponsor organisation
Imperial College London
Clinicaltrials.gov Identifier
Clinicaltrials.gov Identifier
N/A, N/A
Duration of Study in the UK
1 years, 1 months, 27 days
Research summary
Summary of Research:
Dietary fibres, complex sugars found in fruit and vegetables, cannot be digested by humans and instead they reach the large intestine intact and there they are broken down by gut bacteria. A high intake of dietary fibres which results in a rich gut bacteria population is associated with good health such as lower risk of obesity. Westernised diets, rich in animal fats and proteins but low in dietary fibres, have become more common around the world in the past few decades. Research in mice has suggested that diets low in dietary fibres over generations leads to loss of gut bacteria diversity. There is currently no information on whether adoption of Westernised diets has had a similar impact on the gut bacteria of humans from different generations. The aim of this study it to examine the effect of chronic intake over 4 weeks of a dietary fibre supplement on gut microbiota, metabolic profiles and clinical outcomes (glucose, insulin levels etc) in healthy individuals from 2 or 3 generations (grandmother, mother and daughter or mother and daughter) when compared to placebo. Volunteers will undergo a screening visit at Imperial Clinical Research Facility at Hammersmith Hospital during which they will provide written informed consent and afterwards have their eligibility assessed. Eligible participants will be asked to take dietary supplements for 8 weeks (4 weeks dietary fibre and 4 weeks placebo with a wash-out period of 4 weeks in between). There will be 4 study visits at Imperial Clinical Research Facility at Hammersmith Hospital where participants will have blood samples taken to examine clinical outcomes in response to the dietary supplements. In addition, participants will donate stool and urine samples at each study visit to examine the effects of the dietary intervention on the gut bacteria and their metabolic profiles.Research Summary:
This randomised cross-over controlled trial examined the impact of a dietary fibre mix (containing equal proportions of inulin, pectin and oat-beta-glucan) on the gut microbiota, short-chain fatty acids, glucose, insulin and subjective appetite in mothers and daughters compared to a cellulose control. Both supplements were taken in a randomised oder over a two-week period with a two-week wash-out period in between.
Eight pairs of mother-daughter completed all four study visits. Although the volunteers recruited in this study were healthy, the mothers had significantly higher LDL-cholesterol, HbA1c and total cholesterol compared to the daughters.
The dietary fibre mix supplement led to a significant increase in stool propionate production among daughters compared to their baseline level. At the baseline of the cellulose control the daughters had a significantly higher production of stool acetate production compared to mothers. None of the supplements led to significant changes in alpha and beta diversity among both generations. There were generational differences at lower taxonomic gut microbiota levels following the intake of both supplements.
In terms of the impact of the two supplements on glucose and insulin levels, the following were identified. The cellulose control increased significantly the peak glucose concentration in mothers compared to baseline. The mothers had a significantly higher glucose postprandial curve compared to daughters following the cellulose control intake. The dietary fibre mix intervention did not have any impact on the glucose levels in both generations. Regarding insulin, there was no impact of the cellulose control on both generations. The dietary fibre mix supplement led to a significantly lower insulin postprandial curve in mothers compared to their baseline levels. The daughters had a significantly higher postprandial insulin curve compared to mothers after the dietary fibre mix supplement intake.
The cellulose control intake led to significantly higher subjective appetite feelings among daughters compared to their baseline levels. There was no impact of the cellulose control on subjective appetite feelings among mothers. The dietary fibre mix also increased appetite feelings in daughters compared to mothers.
Overall, the results of this trial showed that there both generations responded differently to the supplements that were investigated. Larger cohort studies are needed to validate the results of this study given the small sample size of the current study.REC name
London - Fulham Research Ethics Committee
REC reference
21/LO/0164
Date of REC Opinion
18 Mar 2021
REC opinion
Further Information Favourable Opinion