Short-term dietary restriction in old mice rejuvenates the aging-induced structural imbalance of gut microbiota

Dietary emulsifier polysorbate 80 exposure accelerates age-related cognitive decline

Gut microbial homeostasis is crucial for the health of cognition in elderly. Previous study revealed that polysorbate 80 (P80) as a widely used emulsifier in food industries and pharmaceutical formulations could directly alter the human gut microbiota compositions. However, whether long-term exposure to P80 could accelerate age-related cognitive decline via gut-brain axis is still unknown. Accordingly, in this study, we used the senescence accelerated mouse prone 8 (SAMP8) mouse model to investigate the effects of the emulsifier P80 intake (1 % P80 in drinking water for 12 weeks) on gut microbiota and cognitive function. Our results indicated that P80 intake significantly exacerbated cognitive decline in SAMP8 mice, along with increased brain pathological proteins deposition, disruption of the blood-brain barrier and activation of microglia and neurotoxic astrocytes. Besides, P80 intake could also induce gut microbiota dysbiosis, especially the increased abundance of secondary bile acids producing bacteria, such as Ruminococcaceae, Lachnospiraceae, and Clostridium scindens. Moreover, fecal microbiota transplantation from P80 mice into 16-week-old SAMP8 mice could also exacerbated cognitive decline, microglia activation and intestinal barrier impairment. Intriguingly, the alterations of gut microbial composition significantly affected bile acid metabolism profiles after P80 exposure, with markedly elevated levels of deoxycholic acid (DCA) in serum and brain tissue. Mechanically, DCA could activate microglial and promote senescence-associated secretory phenotype production through adenosine triphosphate-binding cassette transporter A1 (ABCA1) importing lysosomal cholesterol. Altogether, the emulsifier P80 accelerated cognitive decline of aging mice by inducing gut dysbiosis, bile acid metabolism alteration, intestinal barrier and blood brain barrier disruption as well as neuroinflammation. This study provides strong evidence that dietary-induced gut microbiota dysbiosis may be a risk factor for age-related cognitive decline.

Short-term consumption of highly processed diets varying in macronutrient content impair the sense of smell and brain metabolism in mice

OBJECTIVE

Food processing greatly contributed to increased food safety, diversity, and accessibility. However, the prevalence of highly palatable and highly processed food in our modern diet has exacerbated obesity rates and contributed to a global health crisis. While accumulating evidence suggests that chronic consumption of such foods is detrimental to sensory and neural physiology, it is unclear whether its short-term intake has adverse effects. Here, we assessed how short-term consumption (<2 months) of three diets varying in composition and macronutrient content influence olfaction and brain metabolism in mice.

METHODS

The diets tested included a grain-based standard chow diet (CHOW; 54% carbohydrate, 32% protein, 14% fat; #8604 Teklad Rodent diet , Envigo Inc.), a highly processed control diet (hpCTR; 70% carbohydrate, 20% protein, 10% fat; #D12450B, Research Diets Inc.), and a highly processed high-fat diet (hpHFD; 20% carbohydrate, 20% protein, 60% fat; #D12492, Research Diets Inc.). We performed behavioral and metabolic phenotyping, electro-olfactogram (EOG) recordings, brain glucose metabolism imaging, and mitochondrial respirometry in different brain regions. We also performed RNA-sequencing (RNA-seq) in the nose and across several brain regions, and conducted differential expression analysis, gene ontology, and network analysis.

RESULTS

We show that short-term consumption of the two highly processed diets, but not the grain-based diet, regardless of macronutrient content, adversely affects odor-guided behaviors, physiological responses to odorants, transcriptional profiles in the olfactory mucosa and brain regions, and brain glucose metabolism and mitochondrial respiration.

CONCLUSIONS

Even short periods of highly processed food consumption are sufficient to cause early olfactory and brain abnormalities, which has the potential to alter food choices and influence the risk of developing metabolic disease.

Gut microbiota might mediate the benefits of high-fiber/acetate diet to cardiac hypertrophy mice

Continuously prolonged cardiac hypertrophy results in maladaptive myocardial remodeling, which affects cardiac function and can eventually lead to heart failure. Short-chain fatty acids (SCFAs), including acetate, propionate, and butyrate, have been reported to be associated with cardiovascular diseases (CVD). Gut microbiota may mediate between dietary fiber and SCFA effects on cardiac hypertrophy. The mice model of isoproterenol (ISO)-induced cardiac hypertrophy was constructed and verified for physiological, functional, and fibrotic alterations in this study. Both high-fiber and acetate diet improved physiological indexes, ameliorated cardiac functions, and relieved fibrotic alterations in model mice hearts; collectively, cardiac hypertrophy in mice receiving both high-fiber and acetate diet improved. Following 16s rDNA sequencing and integrative bioinformatics, analyses indicated that both high-fiber and acetate diet caused alterations in mice gut microbiota compared with the ISO group, including OTU composition and abundance. In conclusion, high-fiber and acetate diet improve the physiological status, cardiac functions, and fibrotic alterations in ISO-induced hypertrophic mice. Besides, considering the alterations in mice gut microbiota in response to single ISO, both high-fiber and acetate diet treatment, gut microbiota might mediate the favorable benefits of both high-fiber and acetate diet on cardiac hypertrophy.

Characterization of gut microbiota in mouse models of aging and sarcopenia

Gut microbiota play vital roles in the maintenance of human health and in various diseases. We aimed to investigate the association of gut microbiota with aging and sarcopenia. This study contained two experimental designs using the ICR mouse model for 1) determining the association between aging and gut microbiota (by analyzing murine fecal samples) and 2) determining the association between sarcopenia and gut microbiota in mice treated with microorganisms or dexamethasone. The composition of the gut microbiota was determined by next-generation sequencing. Marginally significant differences were observed in taxon composition of the gut microbiota depending on age; particularly, the abundance of the genusAlistipes increased with increasing age. In addition, the abundance of the class Bacteroidia decreased with increasing age, whereas that of the genus Oscillibacter increased. The microbiome composition differed between young mice and aging mice with sarcopenia. Moreover, the gut microbiota in aging and sarcopenia showed altered abundances of Alistipes, Lachnospiraceae, and Bacteroides. Although the sample size was small, these results point to similarities in the gut microbiota between aging and sarcopenia and to differences between young and old individuals. The results on gut microbiota obtained in this study form a basis for studying the development of sarcopenia in geriatric animal models in the future.

A nexus of dietary restriction and gut microbiota: Recent insights into metabolic health

In recent times, dietary restriction (DR) has received considerable attention for its promising effects on metabolism and longevity. Previous studies on DR have mainly focused on the health benefits produced by different restriction patterns, whereas comprehensive reviews of the role of gut microbiota during DR are limited. In this review, we discuss the effects of caloric restriction, fasting, protein restriction, and amino acid restriction from a microbiome perspective. Furthermore, the underlying mechanisms by which DR affects metabolic health by regulating intestinal homeostasis are summarized. Specifically, we reviewed the impacts of different DRs on specific gut microbiota. Additionally, we put forward the limitations of the current research and suggest the development of personalized microbes-directed DR for different populations and corresponding next-generation sequencing technologies for accurate microbiological analysis. DR effectively modulates the composition of the gut microbiota and microbial metabolites. In particular, DR markedly affects the rhythmic oscillation of microbes which may be related to the circadian clock system. Moreover, increasing evidence supports that DR profoundly improves metabolic syndrome, inflammatory bowel disease, and cognitive impairment. To summarize, DR may be an effective and executable dietary manipulation strategy for maintaining metabolic health, however, further investigation is needed to elucidate the underlying mechanisms.

Gut microbiota mediates the inhibition of lymphopoiesis in dietary-restricted mice by suppressing glycolysis

Dietary restriction (DR) is one of the most robust interventions shown to extend health-span and remains on the forefront of anti-aging intervention studies, though conflicting results have been shown on its effect on lifespan both in rodents and primates. The severe inhibitory effects on the lymphoid lineage by DR remains one of its major negative downsides which reduces its overall beneficial effects on organismal health. Yet, the underlying mechanism of how DR suppresses the lymphoid system remains to be explored. Here, we show that antibiotic ablation of gut microbiota significantly rescued the inhibition of lymphopoiesis by DR. Interestingly, glycolysis in lymphocytes was significantly down-regulated in DR mice and pharmacological inhibition of glycolysis reverted this rescue effect of lymphopoiesis in DR mice with ablated gut microbiota. Furthermore, DR remarkably reconstructed gut microbiota with a significant increase in butyrate-producing bacterial taxa and in expression of But, a key gene involved in butyrate synthesis. Moreover, supplemental butyrate feeding in AL mice suppressed glycolysis in lymphoid cells and mimicked the inhibition of lymphopoiesis in AL mice. Together, our study reveals that gut microbiota mediates the inhibition on lymphopoiesis via down-regulation of glycolysis under DR conditions, which is associated with increased butyrate-synthesis. Our study uncovered a candidate that could potentially be targeted for ameliorating the negative effects of DR on lymphopoiesis, and therefore may have important implications for the wider application of DR and promoting healthy aging.

Aqueous extract from Astragalus membranaceus can improve the function degradation and delay aging on Drosophila melanogaster through antioxidant mechanism

Astragali radix is the dry root of the leguminous plants Astragalus membranaceus (Fisch.) Bge. Var. mongholicus (Bge.) Hsiao and Astragalus membranaceus (Fisch.) Bge. Astragali radix is mostly used clinically as a decoction. A number of pharmacological studies shows that Astragalus extract can increase telomerase activity, and has anti-oxidation, anti-inflammatory, immune regulation, anti-cancer, lowering blood lipid, lowering blood sugar and other effects. However, the anti-aging mechanism of aqueous extract from Astragali Radix (ARE) is still unclear. In this study, we evaluated the anti-aging effect of ARE on Drosophila melanogaster (D. melanogaster) and investigated the underlying mechanism. The results of lifespan assay showed that 1.25 mg/mL of ARE can significantly prolong the lifespan of D. melanogaster in a natural aging model, and protect against H2O2 and paraquat. Meanwhile, ARE can improve flies climbing ability and food intake. Metabolomics and the glutamate content assay suggested that ARE prevented an age-dependent increase in glutamate levels in D. melanogaster. Furthermore, ARE showed a dose-dependent effect on the scavenging ability of DPPH in vitro. Superoxide dismutase and catalase activities in the aging group also increased after the intervention of ARE. The data and the findings described here support the notion that ARE may play a preventive role in aging by improving the climbing ability, eliminating harmful free radicals accumulated in D. melanogaster and triggering antioxidant responses.

Effects of dietary restriction on gut microbiota and CNS autoimmunity

Multiple sclerosis (MS) is the most common central nervous system (CNS) autoimmune disease. It is due to the interplay of genetic and environmental factors. Current opinion is that diet could play a pathogenic role in disease onset and development. Dietary restriction (DR) without malnutrition markedly improves health and increases lifespan in multiple model organisms. DR regimens that utilize continuous or intermittent food restriction can induce anti-inflammatory, immuno-modulatory and neuroendocrine adaptations promoting health. These adaptations exert neuroprotective effects in the main MS animal model, experimental autoimmune encephalomyelitis (EAE). This review summarizes the current knowledge on DR-induced changes in gut microbial composition and metabolite production and its impact on underlying functional mechanisms. Studies demonstrating the protective effects of DR regimens on EAE and people with MS are also presented. This is a rapidly developing research field with important clinical implications for personalized dietary interventions in MS prevention and treatment.

Effects of anti-aging interventions on intestinal microbiota

Identifying ways to deal with the challenges presented by aging is an urgent task, as we are facing an aging society. External factors such as diet, exercise and drug therapy have proven to be major elements in controlling healthy aging and prolonging life expectancy. More recently, the intestinal microbiota has also become a key factor in the anti-aging process. As the intestinal microbiota changes with aging, an imbalance in intestinal microorganisms can lead to many age-related degenerative diseases and unhealthy aging. This paper reviews recent research progress on the relationship between intestinal microorganisms and anti-aging effects, focusing on the changes and beneficial effects of intestinal microorganisms under dietary intervention, exercise and drug intervention. In addition, bacteriotherapy has been used to prevent frailty and unhealthy aging. Most of these anti-aging approaches improve the aging process and age-related diseases by regulating the homeostasis of intestinal flora and promoting a healthy intestinal environment. Intervention practices based on intestinal microorganisms show great potential in the field of anti-aging medicine.

Microbiota and body weight control: Weight watchers within?

Background

Despite several decades of research, managing body weight remains an unsolved clinical problem. Health problems associated with dysregulated body weight, such as obesity and cachexia, exhibit several gut microbiota alterations. There is an increased interest in utilising the gut microbiota for body weight control, as it responds to intervention and plays an important role in energy extraction from food, as well as biotransformation of nutrients.

Scope of the review

This review provides an overview of the role of the gut microbiota in the physiological and metabolic alterations observed in two body weight dysregulation-related disorders, namely obesity and cachexia. Second, we assess the available evidence for different strategies, including caloric restriction, intermittent fasting, ketogenic diet, bariatric surgery, probiotics, prebiotics, synbiotics, high-fibre diet, and fermented foods – effects on body weight and gut microbiota composition. This approach was used to give insights into the possible link between body weight control and gut microbiota configuration.

Major conclusions

Despite extensive associations between body weight and gut microbiota composition, limited success could be achieved in the translation of microbiota-related interventions for body weight control in humans. Manipulation of the gut microbiota alone is insufficient to alter body weight and future research is needed with a combination of strategies to enhance the effects of lifestyle interventions.

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The gut microbiota is involved in the control of nutrient availability, appetite, and body weight.

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Both obesity and cachexia are associated with altered gut microbiota.

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Specific dietary and surgical approaches positively impact body weight and gut microbiota.

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Manipulation of the gut microbiota alone is insufficient to alter body weight in humans.

Effect of feed restriction on the intestinal microbial community structure of growing ducks

In poultry, feed restriction is common feeding management to limit poultry nutrients intake so that poultry only intake the essential energy, meeting the basic need of growth and development. Our study investigated whether feeding restriction affects the diversity of the intestinal microbiota of growing breeding ducks. In this research, the 60-120-day-old ducks were raised in restricted and free-feeding groups. After slaughtering, the carcass traits and the cecal contents were collected for 16S rRNA sequencing analysis. After feeding restriction, the growth rate of ducks was limited, the weight and rate of abdominal fat decreased, and the rate of chest and leg muscles increased. In addition, feeding restriction can also change the diversity of intestinal microorganisms in breeding ducks, such as the increase of Firmicutes abundance and the decrease of Bacteroidetes abundance. After analyzing of correlation, significant correlations between gut microbiota and carcass phenotypes were found. The results indicated that gut microbiota might be involved in the life activities associated with phenotypic changes. This study proved the effect of feeding methods on the intestinal microbiota of ducks, providing a theoretical basis of the microbial angle for raising ducks in a feeding-restricted period.

Immune Memory in Aging: a Wide Perspective Covering Microbiota, Brain, Metabolism, and Epigenetics

Non-specific innate and antigen-specific adaptive immunological memories are vital evolutionary adaptations that confer long-lasting protection against a wide range of pathogens. Adaptive memory is established by memory T and B lymphocytes following the recognition of an antigen. On the other hand, innate immune memory, also called trained immunity, is imprinted in innate cells such as macrophages and natural killer cells through epigenetic and metabolic reprogramming. However, these mechanisms of memory generation and maintenance are compromised as organisms age. Almost all immune cell types, both mature cells and their progenitors, go through age-related changes concerning numbers and functions. The aging immune system renders the elderly highly susceptible to infections and incapable of mounting a proper immune response upon vaccinations. Besides the increased infectious burden, older individuals also have heightened risks of metabolic and neurodegenerative diseases, which have an immunological component. This review discusses how immune function, particularly the establishment and maintenance of innate and adaptive immunological memory, regulates and is regulated by epigenetics, metabolic processes, gut microbiota, and the central nervous system throughout life, with a focus on old age. We explain in-depth how epigenetics and cellular metabolism impact immune cell function and contribute or resist the aging process. Microbiota is intimately linked with the immune system of the human host, and therefore, plays an important role in immunological memory during both homeostasis and aging. The brain, which is not an immune-isolated organ despite former opinion, interacts with the peripheral immune cells, and the aging of both systems influences the health of each other. With all these in mind, we aimed to present a comprehensive view of the aging immune system and its consequences, especially in terms of immunological memory. The review also details the mechanisms of promising anti-aging interventions and highlights a few, namely, caloric restriction, physical exercise, metformin, and resveratrol, that impact multiple facets of the aging process, including the regulation of innate and adaptive immune memory. We propose that understanding aging as a complex phenomenon, with the immune system at the center role interacting with all the other tissues and systems, would allow for more effective anti-aging strategies.

The interplay between diet, gut microbes, and host epigenetics in health and disease

The mechanisms linking the function of microbes to host health are becoming better defined but are not yet fully understood. One recently explored mechanism involves microbe-mediated alterations in the host epigenome. Consumption of specific dietary components such as fiber, glucosinolates, polyphenols, and dietary fat has a significant impact on gut microbiota composition and function. Microbial metabolism of these dietary components regulates important epigenetic functions that ultimately influences host health. Diet-mediated alterations in the gut microbiome regulate the substrates available for epigenetic modifications like DNA methylation or histone methylation and/or acetylation. In addition, generation of microbial metabolites such as butyrate inhibits the activity of core epigenetic enzymes like histone deacetylases (HDACs). Reciprocally, the host epigenome also influences gut microbial composition. Thus, complex interactions exist between these three factors. This review comprehensively examines the interplay between diet, gut microbes, and host epigenetics in modulating host health. Specifically, the dietary impact on gut microbiota structure and function that in-turn regulates host epigenetics is evaluated in terms of promoting protection from disease development.

Polyphenols from Arctium lappa L ameliorate doxorubicin-induced heart failure and improve gut microbiota composition in mice

In this study, the ameliorative effect of purified polyphenols from Arctium lappa L (ALPP) on doxorubicin (DOX)-induce heart failure was investigated. Results indicated that ALPP pretreatment significantly reduced the activities of casein kinase and lactate dehydrogenase, lowered the levels of inflammatory indexes (TNF-α and NO), and alleviated antioxidant stress in DOX-induce mice, thus leading to a reduced heart failure syndrome. In addition, according to 16s high-throughput sequencing, the increased abundance of Lactobacillaceae, Muribaculaceae, and Ruminococcaceae and the decreased abundance of Proteobacteria, Enterobacteriaee, and Escherichia_Shigella were observed in ALPP treatment group. ALPP could significantly enhance the abundance of bacteria producing short chain fatty acids (SCFAs) and then promote the increase of SCFAs. Consequently, ALPP might be a therapeutic alternative in the treatment of DOX-induced heart failure. PRACTICAL APPLICATIONS: The effect of Arctium lappa L (ALPP) on doxorubicin (DOX)-induced heart failure was investigated. It provided experimental basis for further studies on the biological activity of polyphenols from ALPP. The results demonstrated that ALPP could significantly ameliorate DOX-induced heart failure and improve the gut microbiota composition. The obtained results could provide the potential application of ALPP as an alternative therapy for heart failure in the functional food industry.

The Role of Intestinal Dysbacteriosis Induced Arachidonic Acid Metabolism Disorder in Inflammaging in Atherosclerosis

Background

Aging induced chronic systemic inflammatory response is an important risk factor for atherosclerosis (AS) development; however, the detailed mechanism is yet to be elucidated.

Objective

To explore the underlying mechanism of how aging aggravates AS advancement.

Methods

A young (five-week-old, YM) and aged group (32-week-old, OM) male apoE^-/- mice with a high fat diet were used as models, and age-matched male wild-type C57BL/6J (WT) mice were used as controls. AS lesion size, serum lipid profile, cytokines, and gut microbiota-derived LPS were analyzed after 32 weeks of diet intervention. A correlation analysis between the 16S rRNA sequencing of the feces and serum metabolomics profiles was applied to examine the effect of their interactions on AS.

Results

ApoE^-/- mice developed severe atherosclerosis and inflammation in the aorta compared to the WT groups, and aged apoE^-/- mice suffered from a more severe AS lesion than their younger counterparts and had low-grade systemic inflammation. Furthermore, increased levels of serum LPS, decreased levels of SCFAs production, as well as dysfunction of the ileal mucosal barrier were detected in aged mice compared with their younger counterparts. There were significant differences in the intestinal flora composition among the four groups, and harmful bacteria such as Lachnospiraceae_FCS020, Ruminococcaceae_UCG-009, Acetatifactor, Lachnoclostridium and Lactobacillus_gasseri were significantly increased in the aged apoE^-/- mice compared with the other groups. Concurrently, metabolomics profiling revealed that components involved in the arachidonic acid (AA) metabolic pathway such as 20-HETE, PGF2α, arachidonic acid, and LTB4 were significantly higher in the aged AS group than in the other groups. This suggested that metabolic abnormalities and disorders of intestinal flora occurred in AS mice.

Conclusions

Aging not only altered the gut microbiome community but also substantially disturbed metabolic conditions. Our results confirm that AA metabolism is associated with the imbalance of the intestinal flora in the AS lesions of aged mice. These findings may offer new insights regarding the role of gut flora disorders and its consequent metabolite changed in inflammaging during AS development.

Diagnostic Values of Epicardial Adipose Tissue Thickness with Right Common Carotid Artery Elasticity and Intima-Media Thickness for Middle-Aged and Elderly Patients with Coronary Heart Disease

Background

Coronary heart disease (CHD) is the most common cardiovascular disease which greatly threatens the health of middle-aged and elderly people.

Objective

To explore the correlations of epicardial adipose tissue (EAT) thickness with right common carotid artery elasticity and intima-media thickness (IMT) in middle-aged and elderly patients with CHD by ultrasound.

Methods

A total of 132 patients diagnosed with CHD by coronary angiography (CAG) from February 2019 to August 2020 were enrolled and divided into single-vessel disease group (n=38), double-vessel disease group (n=52), and three-vessel disease group (n=42), and 52 healthy subjects were selected as control group. Their general data, biochemical indices, EAT thickness, right common carotid artery elasticity indices, and IMT were compared. The correlations of EAT thickness with right common carotid artery elasticity indices and IMT were studied by Pearson's analysis. The predictive values of EAT thickness and IMT for CHD were analyzed by receiver operating characteristic curves.

Results

With increasing number of diseased branches, EAT thickness, stiffness parameters β (β), strain elastic modulus (Ep), pulse wave velocity β (PWV-β) and IMT increased, arterial compliance (AC) decreased (P<0.05), but argumentation index (AI) did not change significantly. EAT thickness had significant positive correlations with β, Ep, PWV-β and IMT, negative correlation with AC, and no significant correlation with AI. The areas under the curves of EAT thickness and IMT for predicting CHD were 0.806 and 0.784, respectively.

Conclusion

EAT thickness is significantly correlated with right common carotid artery elasticity and IMT in middle-aged and elderly patients with CHD, and EAT thickness and IMT have high predictive values. The three indices are crucial for CHD diagnosis.

The microbiome links between aging and lupus

BACKGROUND AND AIMS

Many forms of immune dysregulation, which lead to inflammaging and senescence, have been demonstrated in patients with systemic lupus erythematosus (SLE; lupus) and in the aging population. The discovery of the microbiome and its association with human health and pathology has led it to be the center of investigation as a major contributor to the pathogenesis of immunosenescence in both populations. Similar alterations to the microbiome in the form of dysbiosis, that are demonstrated in both aging and in lupus patients, may help explain the significant overlap in clinical manifestations seen in these groups.

METHODS

We performed an extensive literature review, utilizing the Pubmed search engine and Google Scholar for studies evaluating the microbiome in two groups, elderly populations and lupus patients (both murine and human models), between the years 2000-2019. We searched for the terms: microbiome, dysbiosis, lupus, elderly, aging and inflammaging, which yielded hundreds of articles, of which 114 were used for preparation of this paper. We compared the similarities between the populations.

RESULTS

We found that the similar processes of immune dysregulation, in both aging populations and lupus patients, extend to the microbiome, in the form of dysbiosis. Some of these similarities include loss of microbiota biodiversity, increased representation of microbes that are associated with inflammation and disease (i.e Proteobacteria, Bacteroidetes), a relative decrease in protective microbes with "anti-inflammatory" properties (i.e Firmicutes) and a subsequent compromise to the intestinal barrier, leading to leakage of proinflammatory microbial components in both groups.

CONCLUSIONS

We conclude that there are several similar alterations in the composition and function of the microbiome of lupus patients and aging individuals, leading to immunosenescence, which may also be a contributing mechanism in lupus. It seems in fact that the microbiome of SLE may actually be analogous to immunosenescence. This knowledge may help the continuous efforts in finding a solution for both conditions.

Gut Microbiota during Dietary Restrictions: New Insights in Non-Communicable Diseases

In recent decades, there has been a growing interest in dietary restrictions for their promising effects on longevity and health span. Indeed, these strategies are supposed to delay the onset and burden of non-communicable diseases (NCDs) such as obesity, diabetes, cancer and neurological and gastrointestinal inflammatory diseases. At the same time, the gut microbiota has been shown to play a crucial role in NCDs since it is actively involved in maintaining gut homeostasis through its impact on nutrients metabolism, gut barrier, and immune system. There is evidence that dietary restrictions could slow down age-related changes in the types and numbers of gut bacteria, which may counteract gut dysbiosis. The beneficial effects on gut microbiota may positively influence host metabolism, gut barrier permeability, and brain functions, and subsequently, postpone the onset of NCDs prolonging the health span. These new insights could lead to the development of novel strategies for modulating gut microbiota with the end goal of treating/preventing NCDs. This review provides an overview of animal and human studies focusing on gut microbiota variations during different types of dietary restriction, in order to highlight the close relationship between gut microbiota balance and the host's health benefits induced by these nutritional regimens.

Housing temperature influences exercise training adaptations in mice

Exercise training is a powerful means to combat metabolic diseases. Mice are extensively used to investigate the benefits of exercise, but mild cold stress induced by ambient housing temperatures may confound translation to humans. Thermoneutral housing is a strategy to make mice more metabolically similar to humans but its effects on exercise adaptations are unknown. Here we show that thermoneutral housing blunts exercise-induced improvements in insulin action in muscle and adipose tissue and reduces the effects of training on energy expenditure, body composition, and muscle and adipose tissue protein expressions. Thus, many reported effects of exercise training in mice are likely secondary to metabolic stress of ambient housing temperature, making it challenging to translate to humans. We conclude that adaptations to exercise training in mice critically depend upon housing temperature. Our findings underscore housing temperature as a critical parameter in the design and interpretation of murine exercise training studies.

Exercise has been shown to be an effective approach to ameliorate metabolic disease in mice housed at ambient temperatures, a condition of mild cold stress to mice. Here the authors show that molecular and metabolic adaptations to exercise are blunted when mice are housed in thermoneutral conditions.

The Potential Role of Gut Microbiota in the Prevention and Treatment of Lipid Metabolism Disorders

Due to changes in lifestyle, diet structure, and aging worldwide, the incidence of metabolic syndromes such as hyperlipidemia, hypertension, diabetes, and obesity is increasing. Metabolic syndrome is considered to be closely related to cardiovascular disease and severely affects human health. In recent years, researchers have revealed that the gut microbiota, through its own or interacting metabolites, has a positive role in regulating metabolic syndrome. Therefore, the gut microbiota has been a new "organ" for the treatment of metabolic syndrome. The role has not been clarified, and more research is necessary to prove the specific role of specific strains. Probiotics are also believed to regulate metabolic syndromes by regulating the gut microbiota and are expected to become a new preparation for treating metabolic syndromes. This review focuses on the regulation of lipid metabolism disorders by the gut microbiota through the effects of bile acids (BA), short-chain fatty acids (SCFAs), bile salt hydrolase (BSH), and genes such as ABCG5 and ABCG8, FXR, NPC1L, and LDL-R.