Effects of Maple Syrup on Gut Microbiota Diversity and Metabolic Syndrome

Impact of Free Sugar Replacement by Maple Syrup on Prevention of Metabolic Disorders Associated With Overweight in Humans : Role of Gut Microbiota

It has been suggested that the actual obesity epidemy is related to chronic overconsumption of added or free sugars. The increasing popularity of artificial sweeteners attest the population willingness to reduce added sugars intake and to use alternatives to alleviate health impact of free sugar overconsumption. However, recent findings suggest that artificial sweeteners may rather contribute to obesity epidemy and its associated adverse health effects, potentially via a negative impact on gut microbiota. It has been shown in various studies that, for the same amount of sucrose, unrefined sugars (such as maple syrup) are associated with favorable metabolic effects. The polyphenols contained in maple syrup, especially lignans, could contribute to these positive effects. Indeed, the strong impact of those biomolecules on the modulation of gut microbiota and on gastro-intestinal and metabolic health has been demonstrated in several studies. It is therefore highly relevant to test the hypothesis that the substitution of refined sugar by an equivalent amount of maple syrup (5% of daily energy intake) result in a lesser metabolic deterioration, by the modulation of maple syrup on gut microbiota, than the one observed with refined sugar.

Overweight, Microbiota, Endotoxemia, Metabolic Syndrome, Non-Alcoholic Fatty Liver Disease, Insulin Resistance

Substitution of refined sugar by an equivalent quantity of maple syrup (5% of daily energy intake) in the participant diet. A dietitian will help study subjects to target added sugar sources in their usual diet and suggest ways to substitute it with maple syrup.

Substitution of refined sugar by an equivalent quantity of maple-flavored sucrose syrup (5% of daily energy intake) in the participant diet. A dietitian will help study subjects to target added sugar sources in their usual diet and suggest ways to substitute it with the placebo (sucrose syrup).

Evaluation of gastrointestinal symptoms and stool consistency using standardized questionnaires (the gastrointestinal symptom rating scale (GSRS) and Bristol stool chart)

Evaluation of plasma glucose, insulin and c-peptide concentration using a 3-hour oral glucose tolerance test

Evaluation of plasma triglycerides (TG), Total cholesterol, LDL, HDL, Apolipoprotein B and free fatty acids end of two dietary treatment

Evaluation of metabolome: camu-camu derived metabolites, short chain fatty acids, branched chain fatty acids, bile acids, phenolic compounds

Inclusion Criteria: BMI between 23 and 40 kg/m2 At least one of the following: Fasting triglyceride > 1,35 mmol/L, Fasting insulinemia > 42 pmol/L, fasting glycemia between 5,5 and 6,9 mmol/L and glycated haemoglobin (HbA1c) between 5.7 and 6.4 % Understanding of spoken and written french Accept to follow study instructions If there is natural health product consumption, the dose and frequency of consumption must be stable since 3 months or more Exclusion Criteria: Smoking Any metabolic disorder requiring medication or affecting glucose or lipid metabolism Aversion for maple taste Allergy or intolerance for maple syrup or for an ingredient of the placebo syrup Alcohol consumption of > 2 drinks / day Weight change > 5% of body weight in the last 3 months Being in a weight loss attempt Antibiotics intake in the last 3 months Regular probiotics intake in the last 3 months Major surgical operation in the last 3 months or planned in the next months Gastrointestinal malabsorption Cirrhosis Chronic kidney disease Pregnant or breastfeeding women or women planning pregnancy in the next months Participation in another clinical trial