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1.
Gastrointestinal Disorders and Metabolic Syndrome: Dysbiosis as a Key Link and Common Bioactive Dietary Components Useful for their Treatment.
De Filippis, A, Ullah, H, Baldi, A, Dacrema, M, Esposito, C, Garzarella, EU, Santarcangelo, C, Tantipongpiradet, A, Daglia, M
International journal of molecular sciences. 2020;(14)
Abstract
Gastrointestinal (GI) diseases, which include gastrointestinal reflux disease, gastric ulceration, inflammatory bowel disease, and other functional GI disorders, have become prevalent in a large part of the world population. Metabolic syndrome (MS) is cluster of disorders including obesity, hyperglycemia, hyperlipidemia, and hypertension, and is associated with high rate of morbidity and mortality. Gut dysbiosis is one of the contributing factors to the pathogenesis of both GI disorder and MS, and restoration of normal flora can provide a potential protective approach in both these conditions. Bioactive dietary components are known to play a significant role in the maintenance of health and wellness, as they have the potential to modify risk factors for a large number of serious disorders. Different classes of functional dietary components, such as dietary fibers, probiotics, prebiotics, polyunsaturated fatty acids, polyphenols, and spices, possess positive impacts on human health and can be useful as alternative treatments for GI disorders and metabolic dysregulation, as they can modify the risk factors associated with these pathologies. Their regular intake in sufficient amounts also aids in the restoration of normal intestinal flora, resulting in positive regulation of insulin signaling, metabolic pathways and immune responses, and reduction of low-grade chronic inflammation. This review is designed to focus on the health benefits of bioactive dietary components, with the aim of preventing the development or halting the progression of GI disorders and MS through an improvement of the most important risk factors including gut dysbiosis.
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2.
A New Approach to Polycystic Ovary Syndrome: The Gut Microbiota.
Yurtdaş, G, Akdevelioğlu, Y
Journal of the American College of Nutrition. 2020;(4):371-382
Abstract
Polycystic ovary syndrome (PCOS) is a widespread endocrine disease that affects 6% to 20% of women of reproductive age and is associated with high risk of infertility, obesity, and insulin resistance. Although genetic, neuroendocrine, and metabolic causes have been stated to lead to PCOS, the etiology of PCOS remains unclear. Recent studies in humans and rodent models have shown an association between changes in the gut microbiome and the metabolic and clinical parameters of PCOS. In addition, it has been proposed that dysbiosis of gut microbiota may be a potential pathogenetic factor in the development of PCOS. In this context, modification of gut microbiota with probiotic, prebiotic, and synbiotic agents suggests that these products may serve as new treatment options for PCOS. In this review, it is aimed to explain the relationship between PCOS and gut microbiota with possible mechanisms and to examine the new treatment approaches that can be developed in this direction. Key teaching pointsStudies have shown that gut microbiota may be a potential pathogenetic factor in the development of PCOS.Dysbiosis of gut microbiota in women with PCOS appears to be associated with PCOS phenotypes.Studies suggest that insulin resistance, sex hormone concentrations, and obesity may affect the diversity and composition of gut microbiota in women with PCOS.With better understanding of the role of intestinal microbiota in PCOS, interventions including prebiotics, probiotics, and synbiotics can be considered as future treatment options.
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3.
Intestinal fermentation in vitro models to study food-induced gut microbiota shift: an updated review.
Nissen, L, Casciano, F, Gianotti, A
FEMS microbiology letters. 2020;(12)
Abstract
In vitro gut fermentation models were firstly introduced in nutrition and applied microbiology research back in the 1990s. These models have improved greatly during time, mainly over the resemblance to the complexity of digestion stages, the replication of experimental conditions, the multitude of ecological parameters to assay. The state of the science is that the most competitive models shall include a complex gut microbiota, small working volumes, distinct interconnected compartments and rigorous bio-chemical and ecological settings, controlled by a computer, as well as a free-hands accessibility, not to contaminate the mock microbiota. These models are a useful tool to study the impact of a given diet compound, e.g. prebiotics, on the human gut microbiota. The principal application is to focus on the shift of the core microbial groups and selected species together with their metabolites, assaying their diversity, richness and abundance in the community over time. Besides, it is possible to study how a compound is digested, which metabolic pathways are triggered, and the type and quantity of microbial metabolites produced. Further prospective should focus on challenges with pathogens as well as on ecology of gut syndromes. In this minireview an updated presentation of the most used intestinal models is presented, basing on their concept, technical features, as well as on research applications.
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4.
Plausible Biological Interactions of Low- and Non-Calorie Sweeteners with the Intestinal Microbiota: An Update of Recent Studies.
Plaza-Diaz, J, Pastor-Villaescusa, B, Rueda-Robles, A, Abadia-Molina, F, Ruiz-Ojeda, FJ
Nutrients. 2020;(4)
Abstract
Sweeteners that are a hundred thousand times sweeter than sucrose are being consumed as sugar substitutes. The effects of sweeteners on gut microbiota composition have not been completely elucidated yet, and numerous gaps related to the effects of nonnutritive sweeteners (NNS) on health still remain. The NNS aspartame and acesulfame-K do not interact with the colonic microbiota, and, as a result, potentially expected shifts in the gut microbiota are relatively limited, although acesulfame-K intake increases Firmicutes and depletes Akkermansia muciniphila populations. On the other hand, saccharin and sucralose provoke changes in the gut microbiota populations, while no health effects, either positive or negative, have been described; hence, further studies are needed to clarify these observations. Steviol glycosides might directly interact with the intestinal microbiota and need bacteria for their metabolization, thus they could potentially alter the bacterial population. Finally, the effects of polyols, which are sugar alcohols that can reach the colonic microbiota, are not completely understood; polyols have some prebiotics properties, with laxative effects, especially in patients with inflammatory bowel syndrome. In this review, we aimed to update the current evidence about sweeteners' effects on and their plausible biological interactions with the gut microbiota.
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5.
Diets naturally rich in polyphenols and/or long-chain n-3 polyunsaturated fatty acids differently affect microbiota composition in high-cardiometabolic-risk individuals.
Vetrani, C, Maukonen, J, Bozzetto, L, Della Pepa, G, Vitale, M, Costabile, G, Riccardi, G, Rivellese, AA, Saarela, M, Annuzzi, G
Acta diabetologica. 2020;(7):853-860
Abstract
AIMS: Gut microbiota significantly impacts human health and is influenced by dietary changes. We evaluated the effects of diets naturally rich in polyphenols (PP) and/or long-chain n-3 polyunsaturated fatty acids (LCn3) on microbiota composition in an ancillary analysis of a randomized controlled trial in individuals at high cardiometabolic risk. METHODS Seventy-eight individuals with high waist circumference and at least one additional component of the metabolic syndrome were randomized to an isoenergetic 8-week diet: (a) low LCn3 and PP; (b) high LCn3; (c) high PP; or (d) high LCn3 and PP. Microbiota analysis was performed on feces collected before and after the intervention. DGGE analysis of the predominant bacteria, Eubacterium rectale and Blautia coccoides group (Lachnospiraceae, EREC), Clostridium leptum (Ruminococcaceae, CLEPT), Bacteroides spp., Bifidobacteria, and Lactobacillus group was performed. A quantitative real-time PCR was performed for the same group, additionally including Atopobium cluster (Coriobatteriaceae). Before and after the intervention, participants underwent a 75 g OGTT and a high-fat test meal to evaluate glucose and lipid response. RESULTS Adherence to the four diets was optimal. PP significantly increased microbial diversity (p = 0.006) and CLEPT (p = 0.015), while it reduced EREC (p = 0.044). LCn3 significantly increased the numbers of Bifidobacteria (p = 0.041). Changes in CLEPT numbers correlated with changes in early insulin secretion (r = 0.263, p = 0.030). Changes in Atopobium numbers correlated with postprandial triglycerides in plasma (r = 0.266, p = 0.026) and large VLDL (r = 0.313, p = 0.009), and cholesterol in large VLDL (r = 0.319, p = 0.008). CONCLUSIONS Diets naturally rich in PP or LCn3 influenced gut microbiota composition in individuals at high cardiometabolic risk. These modifications were associated with changes in glucose/lipid metabolism.
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6.
Neuroendocrine and Metabolic Effects of Low-Calorie and Non-Calorie Sweeteners.
Moriconi, E, Feraco, A, Marzolla, V, Infante, M, Lombardo, M, Fabbri, A, Caprio, M
Frontiers in endocrinology. 2020;:444
Abstract
Since excessive sugar consumption has been related to the development of chronic metabolic diseases prevalent in the western world, the use of sweeteners has gradually increased worldwide over the last few years. Although low- and non-calorie sweeteners may represent a valuable tool to reduce calorie intake and prevent weight gain, studies investigating the safety and efficacy of these compounds in the short- and long-term period are scarce and controversial. Therefore, future studies will need to elucidate the potential beneficial and/or detrimental effects of different types of sweeteners on metabolic health (energy balance, appetite, body weight, cardiometabolic risk factors) in healthy subjects and patients with diabetes, obesity and metabolic syndrome. In this regard, the impact of different sweeteners on central nervous system, gut hormones and gut microbiota is important, given the strong implications that changes in such systems may have for human health. The aim of this narrative review is to summarize the current evidence for the neuroendocrine and metabolic effects of sweeteners, as well as their impact on gut microbiota. Finally, we briefly discuss the advantages of the use of sweeteners in the context of very-low calorie ketogenic diets.
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7.
Diurnal Rhythmicity Programs of Microbiota and Transcriptional Oscillation of Circadian Regulator, NFIL3.
Kubo, M
Frontiers in immunology. 2020;:552188
Abstract
Circadian rhythms are a very exquisite mechanism to influence on transcriptional levels and physiological activities of various molecules that affect cell metabolic pathways. Long-term alteration of circadian rhythms increases the risk of cardiovascular diseases, hypertension, hypertriglyceridemia, and metabolic syndrome. A drastic change in dietary patterns can affect synchronizing the circadian clock within the metabolic system. Therefore, the interaction between the host and the bacterial community colonizing the mammalian gastrointestinal tract has a great impact on the circadian clock in diurnal programs. Here, we propose that the microbiota regulates body composition through the transcriptional oscillation of circadian regulators. The transcriptional regulator, NFIL3 (also called E4BP4) is a good example. Compositional change of the commensal bacteria influences the rhythmic expression of NFIL3 in the epithelium, which subsequently controls obesity and insulin resistance. Therefore, control of circadian regulators would be a promising therapeutic target for metabolic diseases.
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8.
The Gut Microbiome in Patients with Intestinal Failure: Current Evidence and Implications for Clinical Practice.
Neelis, E, de Koning, B, Rings, E, Wijnen, R, Nichols, B, Hulst, J, Gerasimidis, K
JPEN. Journal of parenteral and enteral nutrition. 2019;(2):194-205
Abstract
Intestinal failure (IF) is the reduction of gut function or mass below a minimum needed to absorb nutrients and fluids, such that patients are dependent on parenteral nutrition (PN). Patients with IF have an altered gut microbiome. Our aim was to review and evaluate the current evidence on gut microbiome and its metabolic activity, as well as its association with disease characteristics in adults and children with IF. We performed a PubMed literature search for articles published after 2000 using the following terms: intestinal, microbiome, microbiota, short-chain fatty acids, short bowel syndrome, and PN. Literature search was restricted to human studies only. The gut microbiome diversity is remarkably reduced, and community structure is altered with a noticeable overabundance of Proteobacteria, especially the Enterobacteriaceae family. A substantial increase in Lactobacillus level is often reported in patients with IF. Gut microbiome characteristics have been associated with poor growth, liver disease, D-lactic acidosis, and duration of intestinal adaptation. Differences in microbiome characteristics have been found between patients receiving PN and those whose guts have adapted and have been weaned off PN. Future research with prospective sample collection should explore the value of the gut microbiome as a biomarker to guide clinical practice and as a modifiable therapeutic target to optimize outcomes of patients with IF.
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9.
Microbes: possible link between modern lifestyle transition and the rise of metabolic syndrome.
Moossavi, S, Bishehsari, F
Obesity reviews : an official journal of the International Association for the Study of Obesity. 2019;(3):407-419
Abstract
The rapid decrease in infectious diseases globally has coincided with an increase in the prevalence of obesity and other components of metabolic syndrome. Insulin resistance is a common feature of metabolic syndrome and can be influenced by genetic and non-genetic/environmental factors. The emergence of metabolic syndrome epidemics over only a few decades suggests a more prominent role of the latter. Changes in our environment and lifestyle have indeed paralleled the rise in metabolic syndrome. Gastrointestinal tract microbiota, the composition of which plays a significant role in host physiology, including metabolism and energy homeostasis, are distinctly different within the context of metabolic syndrome. Among humans, recent lifestyle-related changes could be linked to changes in diversity and composition of 'ancient' microbiota. Given the co-adaptation and co-evolution of microbiota with the immune system over a long period of time, it is plausible that such lifestyle-related microbiota changes could trigger aberrant immune responses, thereby predisposing an individual to a variety of diseases. Here, we review current evidence supporting a role for gut microbiota in the ongoing rise of metabolic syndrome. We conclude that population-level shifts in microbiota can play a mediatory role between lifestyle factors and pathogenesis of insulin resistance and metabolic syndrome.
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10.
Fecal Microbiota Transplantation for the Critically Ill Patient.
Limketkai, BN, Hendler, S, Ting, PS, Parian, AM
Nutrition in clinical practice : official publication of the American Society for Parenteral and Enteral Nutrition. 2019;(1):73-79
Abstract
The gut microbiome has been implicated in a diversity of diseases, such as irritable bowel syndrome, inflammatory bowel disease, hepatic steatosis, metabolic syndrome, obesity, and anxiety. Current research also suggests the presence of a bidirectional relationship between the composition of the gut microbiome and critical illness. In the critical care setting, multiple factors (eg, use of antibiotics, aberrant nutrition, bloodstream infections, bowel ischemia, and abnormal bowel motility) strongly contribute to intestinal dysbiosis. Conversely, early studies have associated intestinal dysbiosis with worse clinical outcomes in the intensive care unit (ICU), such as infection, organ failure, and mortality. The possibility of intestinal dysbiosis influencing these clinical outcomes has prompted the question of whether microbiome manipulation strategies, such as fecal microbiota transplantation (FMT), may have a role in the management of critical illness. After a literature search of FMT used in the ICU for indications other than Clostridium difficile infections, we found 4 case reports that describe the use of FMT in 5 critically ill patients with systemic inflammatory responses and no clear source of infection. This review discusses the relationship between the gut microbiome and critical illness, early data on the use of FMT in critical care, and safety considerations of FMT in the critically ill and immunocompromised populations.