Current Opinion in Clinical Nutrition and Metabolic Care最新文献

Purpose of review: Sarcopenic obesity is a newly identified pathological entity defined by an increase in body fat mass with an associated sarcopenia, characterized by loss of muscle mass, strength, and function. Recently, the concomitant presence of skeletal alteration with sarcopenic obesity has been described leading to a new clinical entity defined osteosarcopenic obesity (OSO). Many studies have tried to unravel the metabolic complex mechanism leading to this clinical entity in order to understand the pathophysiology of this complex condition with the aim of posing an early diagnosis to improve the therapeutic approaches. The purpose of this narrative review is to highlight and revise recent studies on this issue.

Recent findings: Recent research in the field of OSO has highlighted the role of nutrition and physical activity in the development and management of these conditions. While molecular and cellular pathways remain partially understood, there is a growing focus on lifestyle interventions as key factors in reducing the impact of OSO. These studies emphasize the need for early diagnosis and appropriate therapeutic strategies to improve quality of life and decrease morbidity and mortality associated with OSO.

Summary: Although the pathophysiological pathways underlying OSO are not fully understood, the clinical implications underscore the need for expanded research in this field. This research is crucial for enabling early diagnosis and implementing effective therapeutic interventions, with the goal of reducing morbidity and mortality and enhancing quality of life.

Purpose of review: To describe the role of Tryptophan (Trp) metabolism and Kynurenine (Kyn) metabolites in nutritional and metabolic changes in cancer.

Recent findings: Trp is in part utilized for protein and neurotransmitters biosynthesis, but more than 95% is implicated in Kyn pathways. In this molecular cascade, metabolites are produced with distinct biological activities regulating the immune response and neurotransmission with potential implications in malnutrition/cachexia during cancer. Immune dysfunction is a phenomenon occurring during cancer and malnutrition. Kyn metabolites regulate lymphocytes activity and recent data in animals showed that the inhibition of indoleamine-2,3-dioxygenase (IDO) via 1-methyl-tryptophan determines partial amelioration of inflammation, but no positive effects on the preservation of muscularity were observed. Kynurenines seem to contribute to muscle catabolism via NAD+ biosynthesis and ROS generation. Trp metabolism via the serotonin biosynthesis is involved in appetite control in cancer. Moreover, kynurenines have a role in determining fatigue in conditions associated with inflammation.

Summary: Trp metabolism has implications in immune and energy balance in cancer. The modulation of Trp and kynurenines have impact on central nervous system mechanisms, including appetite, fatigue, and muscle wasting/cachexia. Research focusing on these clinical implications will open new scenario for therapeutic interventions aimed at counteracting nutritional derangements in cancer.

Purpose of review: To discuss the recent discoveries and limitations of the available literature on emerging circulating biomarkers of cancer cachexia.

Recent findings: Studies on circulating factors in cancer cachexia show promising alternatives for diagnosing the syndrome in a minimally invasive manner in the clinic setting, as well as potential targets for cancer cachexia treatment. Factors secreted by the tumor and the adipose tissue, such as extracellular vesicles and soluble proteins, respectively, have been shown to either directly induce wasting in vitro and in vivo or to be altered in the cachectic phenotype. The detection and characterization of circulating cells allows detection of the precachectic stage and the levels of the soluble immune checkpoint protein programmed death ligand-1 (PD-L1) are correlated with the presence of the hallmarks of cancer cachexia.

Summary: Structural, molecular, and metabolic alterations have been observed in various tissues, revealing the occurrence of sustained inter-compartment crosstalk in cachectic patients. Early diagnosis of cancer cachexia becomes crucial to avoid the establishment of refractory cachexia through the implementation of interventions that may attenuate systemic inflammation and muscle loss. More studies on human cancer cachexia are required in order to address the recently discovered cachexia-associated circulating factors' value as biomarkers of the syndrome.

Purpose of review: This article provides a literature update on original articles published in the past 18 months (May 2022-November 2023) in the dietary management of paediatric Crohn's disease.

Recent findings: There is more data to support the use of exclusive enteral nutrition in the management of active Crohn's disease in children. Several food-based dietary therapies have been proposed for the management of Crohn's disease. There is an interest in precision nutritional therapy in Crohn's disease, but current data are scarce.

Summary: Exclusive enteral nutrition is an effective treatment for paediatric Crohn's disease. Predictors of response to exclusive enteral nutrition include mild disease phenotype and ileal disease involvement, although data remain inconclusive. Adherence to exclusive enteral nutrition is cornerstone to its efficacy. Treatment with exclusive enteral nutrition modifies the gut microbiome, modulates bile acid metabolism and has significant effects on host immune responses. More studies are expected in which drugs need to be combined with dietary therapies and microbial therapeutics. The efficacy of Crohn's disease exclusion diet coupled with partial enteral nutrition is supported by independent studies, but tolerance remains an issue, particularly for long-term disease management. More research is anticipated in precision nutritional therapy in paediatric Crohn's disease, but currently no recommendations can be made.

Purpose of review: In recent years, there has been a burgeoning interest in using machine learning methods. This has been accompanied by an expansion in the availability and ease of use of machine learning tools and an increase in the number of large, complex datasets which are suited to machine learning approaches. This review summarizes recent work in the field and sets expectations for its impact in the future.

Recent findings: Much work has focused on establishing good practices and ethical frameworks to guide the use of machine learning in research. Machine learning has an established role in identifying features in 'omics' research and is emerging as a tool to generate predictive models to identify people at risk of disease and patients at risk of complications. They have been used to identify risks for malnutrition and obesity. Machine learning techniques have also been used to develop smartphone apps to track behaviour and provide healthcare advice.

Summary: Machine learning techniques are reaching maturity and their impact on observational data analysis and behaviour change will come to fruition in the next 5 years. A set of standards and best practices are emerging and should be implemented by researchers and publishers.

Purpose of review: Renal cachexia is a deleterious condition characterized by weight loss, muscle wasting and loss of physical function, quality of life, and increased mortality. Multimodal treatment strategies utilizing exercise and nutrition interventions have been recently suggested although the evidence base is still in its infancy. This paper aimed to review the current literature surrounding the use of exercise and nutrition for renal cachexia.

Main findings: Evidence from systematic reviews and narrative reviews indicates that resistance training (RT) is proven to have beneficial effects on improving muscle strength and in some cases physical function, although effects on muscle mass are mixed and inconclusive. Further, combined RT and aerobic training (AT) may have also beneficial effects on overall functional capacity and there appears to be no superior mode of protocol (inter/intra-dialysis vs. home-based). For nutrition, there is new data from systematic review of studies indicating that oral nutritional supplementation (ONS) may have beneficial effects on nutritional status (e.g. body mass index, plasma albumin and handgrip strength). Omega-3 fatty acids have been shown to have anti-inflammatory effects in haemodialysis patients from two recent systematic reviews, and evidence from other populations groups indicate they may be beneficial for improving muscle mass and strength.

Summary: Evidence is accumulating for individual exercise and nutrition components but specific multimodal treatment studies in renal cachexia need to be urgently undertaken.

Purpose of review: Sarcopenia is a wasting disease, mostly age-related in which muscle strength and mass decline, such as physical performance. With aging, both lower dietary protein intake and anabolic resistance lead to sarcopenia. Moreover, aging and sarcopenia display low-grade inflammation, which also worsen muscle condition. In this review, we focused on these two main targets to study dietary strategies.

Recent findings: The better understanding in mechanisms involved in sarcopenia helps building combined dietary approaches including physical activity that would slow the disease progression. New approaches include better understanding in the choice of quality proteins, their amount and schedule and the association with antioxidative nutrients.

Summary: First, anabolic resistance can be countered by increasing significantly protein intake. If increasing amount remains insufficient, the evenly delivery protein schedule provides interesting results on muscle strength. Quality of protein is also to consider for decreasing risk for sarcopenia, because varying sources of proteins appears relevant with increasing plant-based proteins ratio. Although new techniques have been developed, as plant-based proteins display a lower availability, we need to ensure an adapted overall amount of proteins. Finally, specific enrichment with leucine from whey protein remains the dietary combined approach most studied and studies on citrulline provide interesting results. As cofactor at the edge between anabolic and antioxidative properties, vitamin D supplementation is to recommend. Antioxidative dietary strategies include both fibers, vitamins, micronutrients and polyphenols from various sources for positive effects on physical performance. The ω 3 -polyunsaturated fatty acids also display positive modifications on body composition. Gut microbiota modifiers, such as prebiotics, are promising pathways to improve muscle mass and function and body composition in sarcopenic patients. Nutritional interventions could be enhanced by combination with physical activity on sarcopenia. In healthy older adults, promoting change in lifestyle to get near a Mediterranean diet could be one of the best options. In sarcopenia adults in which lifestyle changes appears unprobable, specific enrichement potentialized with physical activity will help in the struggle against sarcopenia. Longitudinal data are lacking, which makes it hard to draw strong conclusions. However, the effects of a physical activity combined with a set of nutrition interventions on sarcopenia seems promising.

Purpose of review: To assess the most relevant articles on the impact of iodine supply in at-risk populations, namely infants and young children, pregnant and lactating women.

Recent findings: The 2022 Iodine Global Network Annual Report confirmed the dramatic decrease of severe iodine deficiency over the last 30 years, thanks to universal iodine iodization. However, mild to moderate deficiency is still present in many countries, where recent data showed a decrease of iodine intake and an impairment of iodine status. Unfortunately, there is yet no validated biomarker to classify the iodine status at the individual level. Available data show that there is no clear evidence to link mild-to-moderate iodine deficiency to adverse health outcomes in pregnant and lactating women as well as in infants and children. The description of a negative impact of maternal iodine excess on neurodevelopment of infants is of concern.

Summary: Optimization of salt iodization (e.g. careful increase in iodine concentration in salt, use by food industry in processed foods) combined with targeted, personalized supplementation under medical supervision if needed (e.g. low intake of iodine rich foods, vegan diet) seems currently preferable to blanket supplementation.

Purpose of review: Emerging evidence suggests that the gut microbiota and its metabolites regulate neurodevelopment and cognitive functioning via a bi-directional communication system known as the microbiota-gut-brain axis (MGBA).

Recent findings: The MGBA influences brain development and function via the hypothalamic-pituitary axis, the vagal nerve, immune signaling, bacterial production of neurotransmitters, and microbial metabolites like short-chain fatty acids, tryptophan derivatives, and bile acids. Animal studies show fetal neurodevelopment is mediated by maternal microbiota derivatives, immune activation, and diet. Furthermore, manipulation of the microbiota during critical windows of development, like antibiotic exposure and fecal microbiota transplantation, can affect cognitive functioning and behavior in mice. Evidence from human studies, particularly in preterm infants, also suggests that a disrupted gut microbiota colonization may negatively affect neurodevelopment. Early microbial signatures were linked to favorable and adverse neurodevelopmental outcomes.

Summary: The link between the gut microbiota and the brain is evident. Future studies, including experimental studies, larger participant cohort studies with longitudinal analyses of microbes, their metabolites, and neurotransmitters, and randomized controlled trials are warranted to further elucidate the mechanisms of the MGBA. Identification of early, predictive microbial markers could pave the way for the development of novel early microbiota-based intervention strategies, such as targeted probiotics, and vaginal or fecal microbiota transplantation, aimed at improving infant neurodevelopment.

Purpose of review: The essential micronutrients are corner stones in the functional and physical development. Early deficiency has life-long consequences. While awareness about iron deficiency is relatively high, it remains lower for other micronutrients. This review aims at reporting on recent data and attracting attention to the high prevalence of micronutrient deficiencies in school-age and adolescent individuals.

Recent findings: Iron deficiency anaemia remains highly prevalent worldwide and the most frequent deficiency but can be corrected with simple tools ranging from food fortification, nutritional intervention, and to supplements. The link between micronutrient (MN) deficiency and neurobehavioral disorders is increasingly established and is worrying even in Western countries. Paediatric individuals are prone to imbalanced diets and picky eating behaviour, and their diets may then become incomplete: the highest risk for deficiency is observed for iron, zinc and vitamin D.

Summary: There is not much new information, but rather confirmation of the importance of health policies. Well conducted randomized controlled trials confirm that deficiencies can be corrected efficiently including with food fortification, and result in clinical benefits. Individual complementation should be considered in children and adolescents with proven deficiency.