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The Role of a High-Fat, High-Fructose Diet on Letrozole-Induced Polycystic Ovarian Syndrome in Prepubertal Mice
This study aims to investigate the effects of a high-fat, high-fructose (HF/HFr) diet on metabolic/endocrine dysregulations associated with letrozole (LET)-induced Polycystic Ovarian Syndrome (PCOS) in prepubertal female mice. Thirty-two prepubertal C57BL/6 mice were randomly divided into four groups of eight and implanted with LET or a placebo, with simultaneous administration of an HF/HFr/standard diet for five weeks. After sacrifice, the liver and blood were collected for selected biochemical analyses. The ovaries were taken for histopathological examination. The LET+HF/HFr group gained significantly more weight than the LET-treated mice. Both the LET+HF/HFr and the placebo-treated mice on the HF/HFr diet developed polycystic ovaries. Moreover the LET+HF/HFr group had significantly elevated testosterone levels, worsened lipid profile and indices of insulin sensitivity. In turn, the HF/HFr diet alone led to similar changes in the LET-treated group, except for the indices of insulin sensitivity. Hepatic steatosis also occurred in both HF/HFr groups. The LET-treated group did not develop endocrine or metabolic abnormalities, but polycystic ovaries were seen. Since the HF/HFr diet can cause substantial metabolic and reproductive dysregulation in both LET-treated and placebo mice, food items rich in simple sugar—particularly fructose—and saturated fat, which have the potential to lead to PCOS progression, should be eliminated from the diet of young females.
Association Between Adherence to the Mediterranean Diet and Metabolic Syndrome and Its Components Among Polish Postmenopausal Women: A Cross-Sectional Study
Background/Objectives: The decrease in estrogen levels during menopause is associated with an increase in visceral fat accumulation, which can contribute to the development of metabolic syndrome (MetS). While some studies have suggested a link between the Mediterranean diet (MedDiet) and the reduced incidence of MetS and its components in the general population, these findings have not been confirmed among postmenopausal women. Therefore, this study investigated the association between the adherence to the MedDiet and the odds of having MetS, and established the food groups responsible for this effect in postmenopausal women. Methods: This cross-sectional study involved 312 postmenopausal women who underwent anthropometric measurements and blood parameter assessment. Adherence to the MedDiet was assessed using the Alternate Mediterranean Diet score (the aMED score), and MetS was defined based on the updated 2022 criteria. Results: After adjusting for potential confounders, adherence to the MedDiet was inversely associated with central obesity and hypertension. For each one-point increase in the aMED score (indicating a better adherence to the MedDet), the odds of central obesity and hypertension were significantly reduced by 33% (OR = 0.669, 95% CI: 0.518; 0.866, p = 0.002) and by 18% (OR = 0.817, 95% CI: 0.689; 0.969, p = 0.020), respectively. A greater consumption of nuts and fish was associated with lower odds of central obesity (OR = 0.972, 95% CI: 0.950; 0.995; p = 0.016) and (OR = 0.989, 95%CI: 0.979; 1.000; p = 0.043), respectively, whereas high processed red meat consumption was associated with hypertension (OR = 1.004, 95% CI: 1.000; 1.008, p = 0.048). Conclusions: A greater adherence to the MedDiet was associated with lower odds of central obesity and hypertension among postmenopausal women; however, it did not translate to a reduced likelihood of having MetS. A higher consumption of nuts and fish was associated with lower odds of central obesity, whereas a higher consumption of red, processed meats was associated with higher odds of hypertension. Longitudinal studies are needed to determine the causality of these relationships.
The effects of time-restricted eating and Ramadan fasting on gut microbiota composition: a systematic review of human and animal studies
Abstract Context It is well known that the microbiome undergoes cyclical diurnal rhythms. It has thus been hypothesized that meal timing may affect gut microbial composition, function, and host health. Objective This review aims to examine the effects of time-restricted eating (TRE) and Ramadan fasting (RF) on the composition of the gut microbiota in animal and human studies. The associations between composition of microbiota and host metabolic parameters are also examined. Data Sources A search was performed on the PubMed, Cochrane, Scopus, and Web of Science databases up to December 31, 2022. The search strategy was performed using the Medical Subject Heading (MeSH) terms “intermittent fasting” and “gastrointestinal microbiome” and the key words “Ramadan fasting” and “microbes.” Data Extraction Seven human studies (4 TRE and 3 RF) and 9 animal studies (7 TRE, 2 RF-like) were retrieved. Data Analysis TRE and RF in human studies lead to an increase in gut microbial community alpha-diversity. In animal studies (both TRE and RF-like), fasting is not associated with improved alpha-diversity, but enhancement of microbial fluctuation is observed, compared with high-fat diet ad libitum groups. Within Firmicutes and Bacteroidetes phyla, no specific direction of changes resulting from fasting are observed in both animals and human. After TRE or RF, a greater abundance of the Faecalibacterium genus is observed in human studies; changes in Lactobacillus abundance are found in animal studies; and increases in Akkermansia are seen both in humans and in animals fed a feed-pellet diet. Only 2 human studies show a beneficial correlation between microbiota changes and host metabolic (HDL cholesterol) or anthropometric parameters (body mass index). Conclusions These findings support the importance of both regimens in improving the gut microbiota composition. However, based on results of animal studies, it can be suggested that diet remains the essential factor in forming the microbiota’s environment. Systematic Review Registration PROSPERO registration no. CRD42021278918.
Effects of dietary seaweed on obesity-related metabolic status: a systematic review and meta-analysis of randomized controlled trials
Abstract Context Seaweed is a promising source of anti-obesity agents, including polysaccharides, proteins, polyphenols, carotenoids, and n-3 long-chain polyunsaturated fatty acids. The anti-obesity effects of such compounds may be due to several mechanisms, including inhibition of lipid absorption and metabolism, effect on satiety, and inhibition of adipocyte differentiation. Objective The aim of this study was to assess the evidence from human randomized controlled trials for the effects of seaweed on body-weight status as well as lipid and nonlipid parameters in adults with overweight and obesity. Data Sources Four databases—Medline, Scopus, Web of Science, and Cochrane Library—were searched from December 2022 to June 2023 using the following key words: Seaweed OR fucoxanthin OR alginates OR fucoidans OR phlorotannin’s OR macroalgae OR marine algae AND obesity OR overweight OR BMI OR body mass index. Data Extraction Eleven interventional studies (10 parallel and 1 crossover) were extracted. Data Analysis Meta-analysis showed a significant effect, favoring the intervention group for BMI (body mass index) (standardized mean difference [SMD]: -0.40; 95% CI: -0.65 to -0.16 kg/m2; P = 0.0013) and percentage of fat mass (SMD: -1.48; 95% CI: -2.66% to -0.30%, P = 0.0138). The results were seen when refined or extracted brown seaweed (BMI) or only refined brown seaweed (% fat mass) were administered to participants for at least 8 weeks. Moreover, a significant overall effect of seaweed supplementation on total cholesterol (SMD: -7.72; 95% CI: -12.49 to -2.95 mg/dL; P = 0.0015) and low-density-lipoprotein cholesterol (SMD: -7.33; 95% CI: -11.64 to -3.02 mg/dL; P < 0.001) was noted. Any significant effects of seaweed on glucose metabolism were not shown. Conclusion Edible seaweed supplementation shows potential for managing obesity and disorders of the blood lipid profile when administered to participants for at least 8 weeks. Systematic Review Registration PROSPERO registration no. CRD42022378484 (www.crd.york.ac.uk/PROSPERO).
Effects of Probiotics Supplementation on Gastrointestinal Symptoms in Athletes: A Systematic Review of Randomized Controlled Trials
This study examines the effectiveness of probiotic supplementation on gastrointestinal (GI) symptoms, the gut barrier function, and inflammatory markers in athletes based on data from randomised controlled trials. Searches were conducted in PubMed, the Cochrane Library, and the Web of Science up to October 2021. The protocol for this review was registered with PROSPERO (CRD42021284938). Two reviewers independently screened the titles, abstracts, and full texts to identify articles on the influence of probiotics or symbiotics on GI symptoms, gut barrier function, and cytokines, and the quality of the studies was assessed using RoB2. Ten articles involving 822 athletes were included in this review. A single strain Lactobacillus bacteria was used in three studies, seven studies used a Lactobacillus and Bifidobacterium multi-strain cocktail, and one study used this cocktail with a prebiotic. Only slight evidence was found for a positive effect of probiotics on GI symptoms in athletes during training, exercise, and competition, so it was not possible to identify the best product for managing GI symptoms in athletes. Due to the small number of studies, it was also difficult to find a direct association between the reduced exercise-induced perturbations in cytokines, gut barrier function, and GI symptoms after probiotic supplementation.
