TY - BOOK

T1 - Nutrition, the Gut and the Microbiome

T2 - Associations with Obesity and Metabolic Markers of Obesity-Associated Diseases

AU - Kjølbæk, Louise

N1 - CURIS 2017 NEXS 251

PY - 2017

Y1 - 2017

N2 - Obesity prevalence has nearly doubled between 1980 and 2014, and obesity increases the risk ofdiseases, such as type II diabetes and cardiovascular diseases. Dietary modulation is the mainstrategy applied as a part of primary and secondary prevention of obesity and obesity-associateddiseases, but an optimal diet to improve the success of weight loss maintenance has not reachedconsensus among worldwide expects. During the last decade, it has been observed that the gutmicrobiota composition is associated with obesity and obesity-associated diseases. However, adeeper understanding of how the host metabolism is affected by dietary modulation of the gutmicrobiota is necessarily before microbiota-based dietary recommendations can be applied as astrategy for prevention and treatment of obesity and obesity-associated diseases.The objective for this PhD thesis was to investigate how nutrition affects the gut and themicrobiome in relation to obesity and obesity-associated diseases. The objective was investigatedby the conduct of three studies (KIFU, PROKA, MNG). In KIFU, the effect of habitual calciumintake on faecal fat and energy excretions was investigated by an observational study. The 189participants collected faecal samples for five days and had a 1-day visit where metabolic markersand anthropometric data were collected. In PROKA, the effect of protein supplementation (wheywith/without calcium and soy) on weight maintenance success was investigated by a randomisedcontrolled trial. 220 overweight and obese subjects went through an 8-week weight loss periodfollowed by a 24-week weight maintenance period. Measurements included anthropometry,metabolic markers, appetite sensation and energy expenditure. In MNG, the effect of arabinoxylanoligosaccharides (AXOS) and polyunsaturated fatty acid (PUFA) intakes on the gut microbiotacomposition was investigated by a randomised cross-over study with two 4-week diets periods anda 4-week washout period. Faecal samples and metabolic markers were collected from 30 subjectsbefore and after each diet period.Results showed that habitual dietary calcium intake was not associated with faecal excretions of fatand energy. However it was negatively associated with total and low density lipoprotein (LDL)cholesterol concentrations and systolic blood pressure (BP) (Paper I). Protein supplementation(whey with/without calcium or soy) did not improve success of weight maintenance or metabolicmarkers, compared to carbohydrate in individuals with a normal protein intake, despite sustainedeffects of appetite sensation and energy expenditure (Paper II). AXOS intake had bifidogeniceffects on the gut microbiota composition, and butyrate-producing bacteria were the maincontributors to the change of the bacterial community. Beneficial changes in metabolic markerswere not observed. PUFA intake did not alter gut microbiota composition, but improved systolicand diastolic BP, and resulted in impaired glucose metabolism (Paper III).In conclusion, the current evidence does not support that protein supplementation improves weightmaintenance after a weight loss, compared to carbohydrate, in individuals with a normal proteinintake. Convincing evidence supports that dietary calcium intake improves BP and lipid profile,while an effect on faecal fat and energy excretion in the free living population remains inconclusive.AXOS intake can increase abundance of Bifidobacteria and may stimulate the abundance ofbutyrate producers, whereas the effect of fat quality on gut microbiota modulation is inconclusivedue to the limited literature.

AB - Obesity prevalence has nearly doubled between 1980 and 2014, and obesity increases the risk ofdiseases, such as type II diabetes and cardiovascular diseases. Dietary modulation is the mainstrategy applied as a part of primary and secondary prevention of obesity and obesity-associateddiseases, but an optimal diet to improve the success of weight loss maintenance has not reachedconsensus among worldwide expects. During the last decade, it has been observed that the gutmicrobiota composition is associated with obesity and obesity-associated diseases. However, adeeper understanding of how the host metabolism is affected by dietary modulation of the gutmicrobiota is necessarily before microbiota-based dietary recommendations can be applied as astrategy for prevention and treatment of obesity and obesity-associated diseases.The objective for this PhD thesis was to investigate how nutrition affects the gut and themicrobiome in relation to obesity and obesity-associated diseases. The objective was investigatedby the conduct of three studies (KIFU, PROKA, MNG). In KIFU, the effect of habitual calciumintake on faecal fat and energy excretions was investigated by an observational study. The 189participants collected faecal samples for five days and had a 1-day visit where metabolic markersand anthropometric data were collected. In PROKA, the effect of protein supplementation (wheywith/without calcium and soy) on weight maintenance success was investigated by a randomisedcontrolled trial. 220 overweight and obese subjects went through an 8-week weight loss periodfollowed by a 24-week weight maintenance period. Measurements included anthropometry,metabolic markers, appetite sensation and energy expenditure. In MNG, the effect of arabinoxylanoligosaccharides (AXOS) and polyunsaturated fatty acid (PUFA) intakes on the gut microbiotacomposition was investigated by a randomised cross-over study with two 4-week diets periods anda 4-week washout period. Faecal samples and metabolic markers were collected from 30 subjectsbefore and after each diet period.Results showed that habitual dietary calcium intake was not associated with faecal excretions of fatand energy. However it was negatively associated with total and low density lipoprotein (LDL)cholesterol concentrations and systolic blood pressure (BP) (Paper I). Protein supplementation(whey with/without calcium or soy) did not improve success of weight maintenance or metabolicmarkers, compared to carbohydrate in individuals with a normal protein intake, despite sustainedeffects of appetite sensation and energy expenditure (Paper II). AXOS intake had bifidogeniceffects on the gut microbiota composition, and butyrate-producing bacteria were the maincontributors to the change of the bacterial community. Beneficial changes in metabolic markerswere not observed. PUFA intake did not alter gut microbiota composition, but improved systolicand diastolic BP, and resulted in impaired glucose metabolism (Paper III).In conclusion, the current evidence does not support that protein supplementation improves weightmaintenance after a weight loss, compared to carbohydrate, in individuals with a normal proteinintake. Convincing evidence supports that dietary calcium intake improves BP and lipid profile,while an effect on faecal fat and energy excretion in the free living population remains inconclusive.AXOS intake can increase abundance of Bifidobacteria and may stimulate the abundance ofbutyrate producers, whereas the effect of fat quality on gut microbiota modulation is inconclusivedue to the limited literature.

UR - https://soeg.kb.dk/permalink/45KBDK_KGL/fbp0ps/alma99122806425605763

M3 - Ph.D. thesis

SN - 978-87-7209-045-0

BT - Nutrition, the Gut and the Microbiome

PB - Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen

CY - Copenhagen

ER -