Blood Glucose, High
Conditions
Keywords
Glucose tolerance, Gut microbiota, Microbial richness, Gastric emptying, Metabolomics
Brief summary
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.
Detailed description
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.
Interventions
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
Sponsors
Technical University of Denmark
University of Copenhagen
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
Acute meal test
Eligibility
Sex/Gender
ALL
Age
18 Years to 40 Years
Healthy volunteers
Yes
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)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Postprandial plasma glucose at 60 min as a function of gut microbial richness | 60 min | 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 |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Maximum plasma glucose concentration as a function of gut microbial diversity/richness | 0, 15, 30, 60, 90 and 120 min | We test associations between gut microbial diversity/richness and maximum postprandial plasma glucose concentration \[Cmax\] after a standardised meal including 0.5 g paracetamol. |
| Postprandial plasma glucose extremes as a function of gut microbial diversity/richness | 0, 15, 30, 60, 90 and 120 min | 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 to plasma glucose maximum concentration as a function of gut microbial diversity/richness | 0, 15, 30, 60, 90 and 120 min | 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 |
| Fasting (baseline) plasma glucose as a function of gut microbial diversity/richness | 0 min | We test whether there is an inverse association between fasting plasma glucose and baseline fecal gut microbial richness (cross-sectionally) |
| Postprandial glucose 0-60 min as a function of gastric emptying | 0, 15, 30, 60 min | We test associations between gastric emptying measured as AUC 0-60 min of postprandial paracetamol concentration profiles in blood and postprandial plasma glucose at 60 min during a standardised meal including 0.5 g paracetamol |
| Gastric emptying and postprandial glucose 0-120 min | 0, 15, 30, 60, 90 and 120 min | We test associations between gastric emptying measured as AUC 0-120 min of postprandial paracetamol concentration profiles in blood and postprandial plasma glucose AUC 0-120 min during a standardised meal test with intake of 0.5 g paracetamol |
| Postprandial plasma glucose AUC as a function of gut microbial richness/diversity | 0, 15, 30, 60, 90 and 120 min | We test associations between gut microbial diversity/richness and AUC 0-120 min for plasma glucose after a standardised meal including 0.5 g paracetamol |
Other
| Measure | Time frame | Description |
|---|---|---|
| Lipid metabolism | 0, 15, 30, 60, 90 and 120 min | Bile acids in blood (fasting and postprandially) and in feces (baseline) |
| Glucagon like peptide 1 (GLP-1) | 0, 15, 30, 60, 90 and 120 min | Plasma glucagon like peptide 1 (GLP-1) measured in fasting and postprandial plasma samples |
| Peptide tyrosine tyrosine (PYY) | 0, 15, 30, 60, 90 and 120 min | PYY measured in fasting and postprandial plasma samples |
| Ghrelin | 0, 15, 30, 60, 90 and 120 min | Ghrelin measured in fasting and postprandial plasma samples |
| Gastric inhibitory polypeptide (GIP) | 0, 15, 30, 60, 90 and 120 min | GIP measured in fasting and postprandial plasma samples |
| Cholecystokinin (CCK) | 0, 15, 30, 60, 90 and 120 min | CCK measured in fasting and postprandial plasma samples |
| Gastric emptying | 0, 15, 30, 60, 90 and 120 min | Gastric emptying measured as postprandial paracetamol concentration profiles in blood |
| Saliva microbiome | 0 min | Determination of saliva microbiome composition at baseline |
| Feces short-chain fatty acids | 0 min | Feces short-chain fatty acids measured in all fecal samples collected at baseline |
| Feces pH | 0 min | Feces pH measured in all fecal samples collected at baseline |
| Feces energy | 0 min | Feces energy measured in all fecal samples collected at baseline by bomb calorimetry |
| Stool consistency | 0 min | Consistency of stool sample collected at baseline assessed by the Bristol stool scale |
| Intestinal transit time | Before intervention | Participants are instructed to observe the time it takes corn to travel through their gastrointestinal system five days prior to the intervention |
| Defecation patterns | Before intervention | Average number of poops per day and average stool consistency as assessed by Bristol stool scale |
| Gastrointestinal symptoms | Before intervention | Gastrointestinal symptoms measured on a 10 cm visual analog scale (VAS) |
| Postprandial breath exhalation | 0, 60, 150 min | Fasting and postprandial breath hydrogen/methane exhalation |
| Fecal microbiome | 0 min | Determination of fecal microbiome composition at baseline |
| Urine metabolome | 0, 0-150 min | Urine metabolome as determined by untargeted metabolic profiling by LC-QTOF of all urine samples collected before the meal and postprandially from 0-150 min |
| Fecal metabolome | 0 min | Fecal metabolome as determined by untargeted metabolic profiling by LC-QTOF of ethanolic extracs from all baseline fecal samples collected before the intervention |
| Plasma metabolome | 0, 15, 30, 60, 90 and 120 min | Plasma metabolome as determined by untargeted metabolic profiling by LC-QTOF of ethanolic extracs from all fasting and postprandial plasma samples |
| Glucose metabolism | 0, 15, 30, 60, 90 and 120 min | Plasma glucose measured in fasting and postprandial plasma samples |
| Plasma Insulin | 0, 15, 30, 60, 90 and 120 min | Plasma insulin measured in fasting and postprandial plasma samples |
| Plasma short-chain fatty acids | 0, 15, 30, 60, 90 and 120 min | Plasma short-chain fatty acids measured in fasting and postprandial plasma samples |
Countries
Denmark
Outcome results
None listed