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High intake of dairy during energy restriction does not affect energy balance or the intestinal microflora compared with low dairy intake in overweight individuals in a randomized controlled trial.
Bendtsen, LQ, Blædel, T, Holm, JB, Lorenzen, JK, Mark, AB, Kiilerich, P, Kristiansen, K, Astrup, A, Larsen, LH
Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme. 2018;(1):1-10
Abstract
During weight loss, dairy calcium is proposed to accelerate weight and fat-mass loss through increased fecal fat excretion. The primary objective was to investigate if a high-dairy energy-restricted diet is superior to low dairy in terms of changes in body weight, body composition, and fecal fat excretion over 24 weeks. Secondary objectives included fecal energy and calcium excretion, resting energy expenditure, blood pressure, lipid metabolism, and gut microbiota. In a randomized, parallel-arm intervention study, 11 men and 69 women (body mass index, 30.6 ± 0.3 kg/m2; age, 44 ± 1 years) were allocated to a 500-kcal (2100 kJ) -deficit diet that was either high (HD: 1500 mg calcium/day) or low (LD: 600 mg calcium/day) in dairy products for 24 weeks. Habitual calcium intake was ∼1000 mg/day. Body weight loss (HD: -6.6 ± 1.3 kg, LD: -7.9 ± 1.5 kg, P = 0.73), fat-mass loss (HD: -7.8% ± 1.3%, LD: -8.5% ± 1.1%, P = 0.76), changes in fecal fat excretion (HD: -0.57 ± 0.76 g, LD: 0.46 ± 0.70 g, P = 0.12), and microbiota composition were similar for the groups over 24 weeks. However, total fat-mass loss was positively associated with relative abundance of Papillibacter (P = 0.017) independent of diet group. Consumption of a high-dairy diet did not increase fecal fat or accelerate weight and fat-mass loss beyond energy restriction over 24 weeks in overweight and obese adults with a habitual calcium intake of ∼1000 mg/day. However, this study indicates that Papillibacter is involved in body compositional changes.
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Dietary modulation of the gut microbiota--a randomised controlled trial in obese postmenopausal women.
Brahe, LK, Le Chatelier, E, Prifti, E, Pons, N, Kennedy, S, Blædel, T, Håkansson, J, Dalsgaard, TK, Hansen, T, Pedersen, O, et al
The British journal of nutrition. 2015;(3):406-17
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Abstract
The gut microbiota has been implicated in obesity and its progression towards metabolic disease. Dietary interventions that target the gut microbiota have been suggested to improve metabolic health. The aim of the present study was to investigate the effect of interventions with Lactobacillus paracasei F19 or flaxseed mucilage on the gut microbiota and metabolic risk markers in obesity. A total of fifty-eight obese postmenopausal women were randomised to a single-blinded, parallel-group intervention of 6-week duration, with a daily intake of either L. paracasei F19 (9.4 × 1010 colony-forming units), flaxseed mucilage (10 g) or placebo. Quantitative metagenomic analysis of faecal DNA was performed to identify the changes in the gut microbiota. Diet-induced changes in metabolic markers were explored using adjusted linear regression models. The intake of flaxseed mucilage over 6 weeks led to a reduction in serum C-peptide and insulin release during an oral glucose tolerance test (P< 0.05) and improved insulin sensitivity measured by Matsuda index (P< 0.05). Comparison of gut microbiota composition at baseline and after 6 weeks of intervention with flaxseed mucilage showed alterations in abundance of thirty-three metagenomic species (P< 0.01), including decreased relative abundance of eight Faecalibacterium species. These changes in the microbiota could not explain the effect of flaxseed mucilage on insulin sensitivity. The intake of L. paracasei F19 did not modulate metabolic markers compared with placebo. In conclusion, flaxseed mucilage improves insulin sensitivity and alters the gut microbiota; however, the improvement in insulin sensitivity was not mediated by the observed changes in relative abundance of bacterial species.