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Probiotic Supplementation Improves Cognitive Function and Mood with Changes in Gut Microbiota in Community-Dwelling Older Adults: A Randomized, Double-Blind, Placebo-Controlled, Multicenter Trial.
Kim, CS, Cha, L, Sim, M, Jung, S, Chun, WY, Baik, HW, Shin, DM
The journals of gerontology. Series A, Biological sciences and medical sciences. 2021;76(1):32-40
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Aging is characterized by progressive decline in biological functions of the organism. Diet is one of the critical lifestyle factors for physical and mental well-being throughout the life span, including later life. The aim of this study was to investigate the effects of probiotics consumption on intestinal and brain health in elders over the age of 65. This study is a randomised, double-blind, placebo-controlled, multicentre trial. All participants, study coordinators, and researchers were blinded throughout the entire study. Sixty-three participants were randomized, with 31 and 32 subjects in the placebo and probiotics group, respectively. Results demonstrate that probiotics have system-wide effects on the gut–brain axis in healthy community-dwelling older adults by promoting cognitive and mental health and changing the gut microbial composition. Authors conclude that their findings provide evidence that probiotics have health-promoting properties as part of a healthy diet in the general population of independently living older adults.
Abstract
Probiotics have been proposed to ameliorate cognitive impairment and depressive disorder via the gut-brain axis in patients and experimental animal models. However, the beneficial role of probiotics in brain functions of healthy older adults remains unclear. Therefore, a randomized, double-blind, and placebo-controlled multicenter trial was conducted to determine the effects of probiotics on cognition and mood in community-dwelling older adults. Sixty-three healthy elders (≥65 years) consumed either placebo or probiotics containing Bifidobacterium bifidum BGN4 and Bifidobacterium longum BORI for 12 weeks. The gut microbiota was analyzed using 16S rRNA sequencing and bioinformatics. Brain functions were measured using the Consortium to Establish a Registry for Alzheimer's disease, Satisfaction with life scale, stress questionnaire, Geriatric depression scale, and Positive affect and negative affect schedule. Blood brain-derived neurotrophic factor (BDNF) was determined using enzyme-linked immunosorbent assay. Relative abundance of inflammation-causing gut bacteria was significantly reduced at Week 12 in the probiotics group (p < .05). The probiotics group showed greater improvement in mental flexibility test and stress score than the placebo group (p < .05). Contrary to placebo, probiotics significantly increased serum BDNF level (p < .05). Notably, the gut microbes significantly shifted by probiotics (Eubacterium and Clostridiales) showed significant negative correlation with serum BDNF level only in the probiotics group (RS = -0.37, RS = -0.39, p < .05). In conclusion, probiotics promote mental flexibility and alleviate stress in healthy older adults, along with causing changes in gut microbiota. These results provide evidence supporting health-promoting properties of probiotics as a part of healthy diet in the older adults.
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Timing of food intake predicts weight loss effectiveness.
Garaulet, M, Gómez-Abellán, P, Alburquerque-Béjar, JJ, Lee, YC, Ordovás, JM, Scheer, FA
International journal of obesity (2005). 2013;37(4):604-11
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As obesity is a multifactorial disease, dietary interventions must take into account a range of physiological and psychological variables. There is emerging evidence linking energy regulation to the circadian clock, emphasizing that the timing of eating may play a role in weight regulation. The aim of this study was to evaluate the role of food timing in weight loss effectiveness among 420 overweight or obese participants during a 20-week weight loss treatment. Participants were grouped as either early or late eaters for consuming their main meal, and their energy intake, expenditure, appetite hormones, CLOCK genotype, sleep duration and chronotype were studied. In this study, those who ate their main meal late lost significantly less weight than early eaters. The findings of this study indicate that timing of food intake relates to long-term weight loss effectiveness in humans. These findings may help in developing therapeutic strategies for weight loss that incorporates the timing of food consumption with the traditional energy balance and macronutrient composition.
Abstract
BACKGROUND There is emerging literature demonstrating a relationship between the timing of feeding and weight regulation in animals. However, whether the timing of food intake influences the success of a weight-loss diet in humans is unknown. OBJECTIVE To evaluate the role of food timing in weight-loss effectiveness in a sample of 420 individuals who followed a 20-week weight-loss treatment. METHODS Participants (49.5% female subjects; age (mean ± s.d.): 42 ± 11 years; BMI: 31.4 ± 5.4 kg m(-2)) were grouped in early eaters and late eaters, according to the timing of the main meal (lunch in this Mediterranean population). 51% of the subjects were early eaters and 49% were late eaters (lunch time before and after 1500 hours, respectively), energy intake and expenditure, appetite hormones, CLOCK genotype, sleep duration and chronotype were studied. RESULTS Late lunch eaters lost less weight and displayed a slower weight-loss rate during the 20 weeks of treatment than early eaters (P=0.002). Surprisingly, energy intake, dietary composition, estimated energy expenditure, appetite hormones and sleep duration was similar between both groups. Nevertheless, late eaters were more evening types, had less energetic breakfasts and skipped breakfast more frequently that early eaters (all; P<0.05). CLOCK rs4580704 single nucleotide polymorphism (SNP) associated with the timing of the main meal (P=0.015) with a higher frequency of minor allele (C) carriers among the late eaters (P=0.041). Neither sleep duration, nor CLOCK SNPs or morning/evening chronotype was independently associated with weight loss (all; P>0.05). CONCLUSIONS Eating late may influence the success of weight-loss therapy. Novel therapeutic strategies should incorporate not only the caloric intake and macronutrient distribution - as is classically done - but also the timing of food.
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Diets with high or low protein content and glycemic index for weight-loss maintenance.
Larsen, TM, Dalskov, SM, van Baak, M, Jebb, SA, Papadaki, A, Pfeiffer, AF, Martinez, JA, Handjieva-Darlenska, T, Kunešová, M, Pihlsgård, M, et al
The New England journal of medicine. 2010;363(22):2102-13
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The recommended diet composition for best preventing and managing obesity has remained inconclusive. The aim of this trial is to test the efficacy of moderate fat diets that vary in protein content and glycaemic index for preventing weight regain after weight loss. After completing an 8-week low calorie diet, participants were assigned to a low protein and low-glycaemic-index diet, a low-protein and high-glycaemic-index diet, a high-protein and low-glycaemic index diet, a high-protein and high-glycaemic-index diet or a control diet. A total of 548 participants adhered to and completed the 26-week intervention following the 8-week intensive weight loss programme. This study found that participants assigned to the high-protein and low-glycaemic index diet maintained the initial weight loss and had a higher rate of completion compared with the other diets. The authors conclude that this diet composition appears to be ideal for prevention of weight regain in obese patients following successful weight loss.
Abstract
BACKGROUND Studies of weight-control diets that are high in protein or low in glycemic index have reached varied conclusions, probably owing to the fact that the studies had insufficient power. METHODS We enrolled overweight adults from eight European countries who had lost at least 8% of their initial body weight with a 3.3-MJ (800-kcal) low-calorie diet. Participants were randomly assigned, in a two-by-two factorial design, to one of five ad libitum diets to prevent weight regain over a 26-week period: a low-protein and low-glycemic-index diet, a low-protein and high-glycemic-index diet, a high-protein and low-glycemic-index diet, a high-protein and high-glycemic-index diet, or a control diet. RESULTS A total of 1209 adults were screened (mean age, 41 years; body-mass index [the weight in kilograms divided by the square of the height in meters], 34), of whom 938 entered the low-calorie-diet phase of the study. A total of 773 participants who completed that phase were randomly assigned to one of the five maintenance diets; 548 completed the intervention (71%). Fewer participants in the high-protein and the low-glycemic-index groups than in the low-protein-high-glycemic-index group dropped out of the study (26.4% and 25.6%, respectively, vs. 37.4%; P=0.02 and P=0.01 for the respective comparisons). The mean initial weight loss with the low-calorie diet was 11.0 kg. In the analysis of participants who completed the study, only the low-protein-high-glycemic-index diet was associated with subsequent significant weight regain (1.67 kg; 95% confidence interval [CI], 0.48 to 2.87). In an intention-to-treat analysis, the weight regain was 0.93 kg less (95% CI, 0.31 to 1.55) in the groups assigned to a high-protein diet than in those assigned to a low-protein diet (P=0.003) and 0.95 kg less (95% CI, 0.33 to 1.57) in the groups assigned to a low-glycemic-index diet than in those assigned to a high-glycemic-index diet (P=0.003). The analysis involving participants who completed the intervention produced similar results. The groups did not differ significantly with respect to diet-related adverse events. CONCLUSIONS In this large European study, a modest increase in protein content and a modest reduction in the glycemic index led to an improvement in study completion and maintenance of weight loss. (Funded by the European Commission; ClinicalTrials.gov number, NCT00390637.).