A Personal Microbiome-dependent Glucose Response in Healthy Young Volunteers

University of Copenhagen31 enrolled

Overview

Individuals eating identical meals present high variability in post-meal blood glucose response making comparisons challenging. This study evaluates in 40 healthy and fasted participants whether the postprandial glucose response upon a standardized breakfast is dependent on gut microbial richness. Gastric emptying rate, intestinal transit time, insulin, appetite hormones and measures of the intestinal microbiome and fermentation will also be analyzed in the context of postprandial glucose metabolism.

Elevated blood glucose levels constitute a major risk factor for pre-diabetic and diabetic patients. Postprandial glucose tests have been used for decades to monitor and compare glucose responses. Yet, individuals eating identical meals present high variability in post-meal blood glucose response making comparisons challenging. A recent landmark study showed that the inter-individual variation of postprandial glucose responses was associated with multiple person-specific factors including faecal microbiome factors. Gut microbial richness has for a long time been considered a hallmark of gut health and stability. Furthermore, microbial richness has been associated with colonic transit time, which together with the gastric emptying rate appear to be major determinants of the initial glycaemic response to carbohydrate-containing meals. Therefore, the aim of the study is to investigate whether postprandial glucose responses are associated with gut microbial richness, as well as secondary measures including gastric emptying rate, intestinal transit time and gut microbial composition and fermentation. In an acute-meal study, 40 healthy fasted participants will consume a standardized breakfast including one tablet of paracetamol (for estimating gastric emptying rate) and 300 mL of juice.

Study Type

INTERVENTIONAL

Allocation

Purpose

BASIC_SCIENCE

Masking

NONE

Enrollment

Conditions

Blood Glucose, High

Interventions

Standardized breakfastOTHER

One tablet of paracetamol (500 mg) and a glass of water (150 mL) is consumed followed by a breakfast consisting of white bread, butter, jam, and juice (300 mL) and

Eligibility

Sex: ALLMin age: 18 YearsMax age: 40 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * BMI \< 27 * Willing to eat lentils, tomatoes, spaghetti, bread, butter, strawberry jam, and drink juice * Known ability to tolerate paracetamol * No current use of medication (oral contraceptive pill and mild antidepressants is allowed) * Did not take antibiotics, diarrhoea inhibitors and laxatives in the 6 previous months * Willing to collect and deliver a faecal sample on the intervention day * Willing to eat corn and fill out a self-reported corn-intestinal transit time questionnaire * Willing to consume a paracetamol tablet (500 mg paracetamol) Exclusion Criteria: * Any condition that makes the project responsible researcher to doubt the feasibility of the volunteer's participation * Pregnant or lactating women * Suffering from irritable bowel disease (IBS), small intestine bacterial overgrowth (SIBO) or inflammatory bowel disease (IBD) * Current chronic or infectious disease * Current diagnosis of diabetes * Blood donations within 3 months before participating in the current trial or participation in other scientific experiments * Frequent intake of painkillers (paracetamol)

Locations (1)

Department of Nutrition, Exercise and Sports, University of Copenhagen

Frederiksberg, Denmark

Outcomes

Primary Outcomes

Postprandial plasma glucose at 60 min as a function of gut microbial richness

We test whether there is an inverse association between baseline fecal gut microbial richness and postprandial plasma glucose at 60 min after a standardised meal including 0.5 g paracetamol

Time frame: 60 min

Secondary Outcomes

Fasting (baseline) plasma glucose as a function of gut microbial diversity/richness

We test whether there is an inverse association between fasting plasma glucose and baseline fecal gut microbial richness (cross-sectionally)

Time frame: 0 min

Maximum plasma glucose concentration as a function of gut microbial diversity/richness

We test associations between gut microbial diversity/richness and maximum postprandial plasma glucose concentration \[Cmax\] after a standardised meal including 0.5 g paracetamol.

Time frame: 0, 15, 30, 60, 90 and 120 min

Postprandial plasma glucose extremes as a function of gut microbial diversity/richness

We test associations between gut microbial diversity/richness and the difference from the postprandial plasma glucose peak to the glucose level after 60 min or at the postprandial minimum between 30-120 min after a standardised meal including 0.5 g paracetamol.

Time frame: 0, 15, 30, 60, 90 and 120 min

Time to plasma glucose maximum concentration as a function of gut microbial diversity/richness

We test associations between gut microbial diversity/richness and the time to the postprandial plasma glucose maximum concentration \[Cmax\] after a standardised meal including 0.5 g paracetamol

Time frame: 0, 15, 30, 60, 90 and 120 min

Postprandial plasma glucose AUC as a function of gut microbial richness/diversity

Data from ClinicalTrials.gov

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