Diet, Nutrition and Metabolic Health

As a medicinal and edible plant, Chinese yam (CY) can promote the enrichment of intestinal probiotics. Mucilage polysaccharides, diosgenin and taxifolin are the dominant components of CY. The purpose of this study was to investigate whether the impact of Chinese yam on gut microbiome structure and metabolism is attributable to its components. In the in vitro gastrointestinal digestion and colon fermentation system, the changes in gut microbiota composition and function were determined by 16S rRNA sequencing, and the levels of bacterial metabolites including short-chain fatty acids (SCFAs) and indole-like metabolites were detected by gas chromatography and an enzyme-linked immunoassay. The results show that CY, mucilage polysaccharides, diosgenin and taxifolin could increase the microbial diversity index. Furthermore, probiotics including Lactobacillus and Bacteroides were significantly increased, while harmful bacteria such as Escherichia and Proteus declined. CY could increase the production of SCFAs including acetic acid and butyric acid. Of note, CY and diosgenin displayed similar impacts on enhancing the abundance of Clostridium and promoting the production of indole-3-lactic acid and lactic acid. These findings provide evidence supporting Chinese yam as a natural food to regulate intestinal health. Diosgenin as a component of CY contributes mostly to the impact on regulating intestinal flora. Full article

The quality of carbohydrates has metabolic consequences in people with prediabetes. However, the causality of short-chain fermentable carbohydrate intakes and metabolic parameters has not been explored in the prediabetic or diabetic population. We investigated associations between different types of carbohydrates, including fermentable oligosaccharides, disaccharides, monosaccharides, polyols (FODMAPs), and polysaccharides (dietary fibre), and body composition and glucose/insulin responses in subjects with prediabetes. In this prospective cross-sectional study, 177 subjects with impaired glucose tolerance (IGT) (mean age: 60 (54–62) years, 41% men) underwent an assessment of body composition and completed six-point oral glucose tolerance tests (OGTT), Homeostatic Model Assessment of Insulin Resistance (HOMA2-IR), insulin sensitivity, detailed 3-day food records, and physical activity questionnaire. Daily habitual FODMAP intake decreased progressively with increasing BMI, ranging from 7.9 (6.2–12.7) g/d in subjects with normal BMI and 6.6 (4.6–9.9) g/d in subjects with overweight to 5.8 (3.8–9.0) g/d in subjects with obesity (p = 0.038). After adjustment for age and gender, galactooligosaccharides (GOSs) were negatively correlated with body fat (Standardised Beta coefficient β = −0.156, p = 0.006) and positively associated with insulin sensitivity (β = 0.243, p = 0.001). This remained significant after adjustment for macronutrients, fibre, and physical activity (p = 0.035 and p = 0.010, respectively). In individuals with IGT, higher dietary GOS intake was associated with lower body fat and higher insulin sensitivity independent of macronutrients and fibre intake, calling for interventional studies to evaluate the effect of FODMAP intake in prediabetes. Full article

Defects in mitochondrial fatty acid β-oxidation (FAO) impair metabolic flexibility, which is an essential process for energy homeostasis. Very-long-chain acyl-CoA dehydrogenase (VLCADD; OMIM 609575) deficiency is the most common long-chain mitochondrial FAO disorder presenting with hypoglycemia as a common clinical manifestation. To prevent hypoglycemia, triheptanoin—a triglyceride composed of three heptanoates (C7) esterified with a glycerol backbone—can be used as a dietary treatment, since it is metabolized into precursors for gluconeogenesis. However, studies investigating the effect of triheptanoin on glucose homeostasis are limited. To understand the role of gluconeogenesis in the pathophysiology of long-chain mitochondrial FAO defects, we injected VLCAD-deficient (VLCAD^−/−) mice with ¹³C₃-glycerol in the presence and absence of heptanoate (C7). The incorporation of ¹³C₃-glycerol into blood glucose was higher in VLCAD^−/− mice than in WT mice, whereas the difference disappeared in the presence of C7. The result correlates with ¹³C enrichment of liver metabolites in VLCAD^−/− mice. In contrast, the C7 bolus significantly decreased the ¹³C enrichment. These data suggest that the increased contribution of gluconeogenesis to the overall glucose production in VLCAD^−/− mice increases the need for gluconeogenesis substrate, thereby avoiding hypoglycemia. Heptanoate is a suitable substrate to induce glucose production in mitochondrial FAO defect. Full article

Nutrition and health knowledge (NHK) is linked to people’s dietary behavior and health outcomes. However, studies on the associations between NHK and chronic diseases are limited. This study aimed to examine the association of NHK with five specific chronic diseases (diabetes/hyperglycemia, hypertension, dyslipidemia, coronary heart disease (CHD), and stroke) in central China. Individual NHK and disease status were investigated using a self-reporting questionnaire. We further added up the number of chronic diseases and used this as a secondary outcome. A total of 21,559 adults were enrolled in this cross-sectional study. NHK score was significantly inversely associated with diabetes/hyperglycemia, hypertension, CHD, and stroke (all p-trends < 0.001). Moreover, an inverse association was found between NHK and the number of chronic diseases, especially among responders with three or more chronic diseases. Stratified analyses showed that the above association was more likely to be stronger among younger, female, highly educated, and inner-city residents. However, NHK was negatively associated with dyslipidemia in less educated people and positively correlated with dyslipidemia in highly educated people. NHK showed an inverse relationship with specific chronic diseases and the number of chronic diseases. Improving NHK might be a key strategy for easing the global burden of chronic diseases. Full article

Although nutrient profiling systems can empower consumers towards healthier food choices, there is still a need to assess diet quality to obtain an overall perspective. The purpose of this study was to develop a diet profiling algorithm (DPA) to evaluate nutritional diet quality, which gives a final score from 1 to 3 with an associated color (green-yellow-orange). It ranks the total carbohydrate/total fiber ratio, and energy from saturated fats and sodium as potentially negative inputs, while fiber and protein are assumed as positive items. Then, the total fat/total carbohydrate ratio is calculated to evaluate the macronutrient distribution, as well as a food group analysis. To test the DPA performance, diets of a lactating women cohort were analyzed, and a correlation analysis between DPA and breast milk leptin levels was performed. Diets classified as low quality showed a higher intake of negative inputs, along with higher energy and fat intakes. This was reflected in body mass index (BMI) and food groups, indicating that women with the worst scores tended to choose tastier and less satiating foods. In conclusion, the DPA was developed and tested in a sample population. This tool can be easily implemented in digital nutrition platforms, contributing to real-time dietary follow-up of patients and progress monitoring, leading to further dietary adjustment. Full article

Few studies have investigated the effect of a monosaturated diet high in ω-9 on osteoporosis. We hypothesized that omega-9 (ω-9) protects ovariectomized (OVX) mice from a decline in bone microarchitecture, tissue loss, and mechanical strength, thereby serving as a modifiable dietary intervention against osteoporotic deterioration. Female C57BL/6J mice were assigned to sham-ovariectomy, ovariectomy, or ovariectomy + estradiol treatment prior to switching their feed to a diet high in ω-9 for 12 weeks. Tibiae were evaluated using DMA, 3-point-bending, histomorphometry, and microCT. A significant decrease in lean mass (p = 0.05), tibial area (p = 0.009), and cross-sectional moment of inertia (p = 0.028) was measured in OVX mice compared to the control. A trend was seen where OVX bone displayed increased elastic modulus, ductility, storage modulus, and loss modulus, suggesting the ω-9 diet paradoxically increased both stiffness and viscosity. This implies beneficial alterations on the macro-structural, and micro-tissue level in OVX bone, potentially decreasing the fracture risk. Supporting this, no significant differences in ultimate, fracture, and yield stresses were measured. A diet high in ω-9 did not prevent microarchitectural deterioration, nevertheless, healthy tibial strength and resistance to fracture was maintained via mechanisms independent of bone structure/shape. Further investigation of ω-9 as a therapeutic in osteoporosis is warranted. Full article

(1) Background: There has been a growing interest in understanding the causes of obesity and developing effective prevention strategies. Lifestyle change programs are often considered the gold standard for weight reduction, and they can help individuals with obesity achieve an annual weight loss of around 8–10%. The aim of this review was to evaluate the effect of food during the winter holidays. This knowledge will serve as a valuable foundation for the development of targeted interventions and prevention programs. (2) Methods: We conducted a systematic search of the literature via one database (PubMed). The search was limited to studies published in English in the last 10 years, with adult participants, but without specifying limits regarding the study design. We excluded articles that addressed intermittent fasting diets or weight loss intervention methods during the holidays through various diets. (3) In separate sections, we analyzed the psychological causes of gaining weight during the winter holidays, behavioral patterns, prevention strategies and the nutritional composition of the different types of food served during the festive period. Results: Using the combination of the terms “holiday and obesity”, “holiday and weight gain”, “festive season and obesity”, and “festive season and weight gain” we obtained 216 results involving the addressed topic. Thus, only ten articles remained after screening, with a total of 4627 participants. Most participants experienced weight fluctuations during the study period, particularly during holidays. One concerning observation was that most of the weight gained during these periods was maintained even after the end of the studies, especially in those with obesity. A supervised exercise program and a controlled diet at work over the Christmas period are effective strategies for avoiding weight gain and its deleterious effects in people with metabolic syndrome or weight problems. (4) In addition, attention must be focused on the psycho-social factors during the holidays because for some people it is a stressful period and can cause a much higher caloric consumption. The simplest method to approach during the holidays is to implement small tips and tricks during this period that will prevent individuals from gaining extra pounds. Conclusions: It is essential to acknowledge that obesity is a multifaceted condition that requires a comprehensive and multidisciplinary approach to address its underlying factors and provide ongoing assistance to individuals in their weight-management endeavors. Even the most effective short-term interventions are likely to produce continued positive outcomes with persistent intervention and support. Full article

Metabolic (dysfunction) associated fatty liver disease (MAFLD) is recognized as the most prevalent chronic liver disease globally. However, its pathogenesis remains incompletely understood. Recent advancements in the gut-liver axis offer novel insights into the development of MAFLD. Polysaccharides, primarily derived from fungal and algal sources, abundantly exist in the human diet and exert beneficial effects on glycometabolism, lipid metabolism, inflammation, immune modulation, oxidative stress, and the release of MAFLD. Numerous studies have demonstrated that these bioactivities of polysaccharides are associated with their prebiotic properties, including the ability to modulate the gut microbiome profile, maintain gut barrier integrity, regulate metabolites produced by gut microbiota such as lipopolysaccharide (LPS), short-chain fatty acids (SCFAs), and bile acids (BAs), and contribute to intestinal homeostasis. This narrative review aims to present a comprehensive summary of the current understanding of the protective effects of polysaccharides on MAFLD through their interactions with the gut microbiota and its metabolites. Specifically, we highlight the potential molecular mechanisms underlying the prebiotic effects of polysaccharides, which may give new avenues for the prevention and treatment of MAFLD. Full article