Dietary fruit and vegetable intake, gut microbiota, and type 2 diabetes: results from two large human cohort studies

Diet-Gene Interaction Between Fruit Intake and CMIP rs2925979 Polymorphism in Relation to Type 2 Diabetes: A Family-Based Study in Northern China

Background/Objectives: This study aimed to investigate the association between dietary intake and the risk of type 2 diabetes mellitus (T2DM) in a rural northern Chinese population, and to explore potential gene-diet interactions that may influence T2DM susceptibility. Methods: A total of 1747 participants (1138 with T2DM and 609 without) were included, using baseline data from a family-based cohort study in rural northern China. Demographic characteristics, lifestyle factors, and medical history were collected via standardized questionnaires. Dietary intake was assessed using a semi-quantitative food frequency questionnaire, and anthropometric measurements were conducted according to standardized protocols. Based on findings from previous genome-wide association studies, several T2DM-related single-nucleotide polymorphisms were selected for genotyping. Generalized linear models accounting for familial clustering were employed to examine the associations between dietary intake and T2DM risk, and to assess gene-diet interaction. Results: A significant inverse association was observed between fruit intake and T2DM risk. Furthermore, a significant interaction was found between fruit consumption and the CMIP rs2925979 polymorphism: the protective effect of higher fruit intake was evident among individuals carrying the T allele but not among those with the CC genotype. Conclusions: These findings suggest that genetic variation may modify metabolic responses to dietary factors, particularly fruit intake. The results underscore the importance of considering gene-diet interactions in the prevention of T2DM.

Circulating linoleic acid and its interplay with gut microbiota during pregnancy for gestational diabetes mellitus

BACKGROUND

Circulating linoleic acid (LA) levels have been reported to be associated with various metabolic outcomes. However, the role of LA and its interplay with gut microbiota in gestational diabetes mellitus (GDM) remains unclear. This study aimed to investigate the longitudinal association between circulating LA levels during pregnancy and the risk of GDM, and the potential role of gut microbiota.

METHODS

A nested case-control study was conducted within the ongoing Tongji-Huaxi-Shuangliu Birth Cohort in Chengdu, China. Blood and fecal samples were collected during early and middle pregnancy from 807 participants. GDM was diagnosed in middle pregnancy using the International Association of Diabetes and Pregnancy Study Groups criteria. Plasma LA levels were measured using gas chromatography-mass spectrometry, and gut microbiota was analyzed through 16S rRNA gene sequencing and shotgun metagenomic sequencing. A two-sample Mendelian randomization study was conducted using data from the IEU OpenGWAS database and the FinnGen consortium.

RESULTS

Elevated plasma LA levels were associated with a lower risk of GDM in both early (P for trend = 0.002) and middle pregnancy (P for trend = 0.02). Consistently, Mendelian randomization analysis revealed that each unit increase in LA was associated with a 16% reduction in GDM risk (odds ratio: 0.84, 95% confidence interval: 0.72, 0.95). In early pregnancy, higher plasma LA levels were correlated with higher adiponectin levels (P < 0.001) and lower levels of triglycerides (P < 0.001), HbA1c (P = 0.04), and C-peptide (P = 0.04). The LA-accociated microbiota mediated the relationship between LA and C-peptide (P = 0.01). Additionally, the inverse association between LA and GDM was modified by Bilophila (P for interaction = 0.03), with a stronger association observed in participants with lower Bilophila levels in early pregnancy. Metagenomic analyses further showed that the LA-associated pathway (D-galacturonate degradation I) and its key enzyme (EC 4.2.1.7) were associated with metabolic traits.

CONCLUSIONS

Our study provides evidence for an inverse causal association between plasma LA levels during pregnancy and GDM risk, which is both mediated and modified by gut microbiota.

Longitudinal Association Between the Consumption of Vegetables, Fruits, and Red Meat and Diabetes Disease Burden: An Analysis of Multiple Global Datasets

Background: Dietary factors, such as vegetable, fruit, and red meat consumption, have varying effects on the disease burden of diabetes, the world's third leading health concern. This study aims to evaluate the global impact of vegetable/fruit/red meat consumption on disease burdens. Methods: Diabetes disease burden, vegetable/fruit/red meat consumption, and covariates data were obtained from the Global Burden of Disease Study (GBD) 2021, Food and Agriculture Organization (FAO), and WHO, respectively, and matched by country/region and year. Global vector maps assessed the status of diabetes disease burden and the consumption of three dietary factors in 2021, and their trends from 2010 to 2021 were illustrated through local regression curves. Generalized additive mixed models (GAMMs) were used to analyze relationships, with weights assigned based on log-transformed values relative to the mean population of each country. Results: A comprehensive dataset spanning 2010-2021, encompassing 175 countries/regions, was successfully matched and utilized in the analysis. In 2021, Oceania had the highest diabetes burden, whereas East Asia had a lower one. Globally, the disease burden increased from 2010 to 2021, accompanied by rising per capita vegetable and fruit consumption but declining red meat consumption. Vegetable consumption was inversely correlated with the age-standardized incidence rate (ASIR) and exhibited a "J-shaped" curve with the age-standardized mortality rate (ASMR) and age-standardized disability-adjusted life year (DALY) rate (ASDR) (nadir at approximately 80 kcal/capita/day (kcal/cap/day). Fruit consumption had a "U-shaped" relationship with ASDR (nadir at approximately 100 kcal/cap/day). Red meat consumption was negatively correlated to ASIR and had a "U-shaped" relationship with ASMR and ASDR (nadir at 200 kcal/cap/day). Conclusions: The global diabetes disease burden is heavy, and dietary consumption varies widely. Vegetable-related risks differ between diabetics and non-diabetics. Proper fruit consumption decreases ASDR. Moderate red meat increases can reduce the disease burden, but excessive consumption increases ASMR and ASDR.

Smoking-related gut microbiota alteration is associated with obesity and obesity-related diseases: results from two cohorts with sibling comparison analyses

BACKGROUND

Individuals who smoke tend to have a lower body mass index (BMI) but face an increased risk of obesity-related diseases. This study investigates this paradox from the perspective of gut microbiota.

METHODS

We conducted microbiome analyses to identify smoking-related microbial genera and created a smoking-related microbiota index (SMI) using 16S rRNA sequencing data from 4000 male participants in WELL-China cohort and Lanxi cohort. We employed logistic regression to explore the association between SMI and obesity indices derived from dual-energy X-ray absorptiometry. Cox regression analyses were conducted to explore the association of SMI with incident of obesity-related diseases. To further control for unmeasured familial confounders, sibling comparison analyses were conducted using between-within (BW) model.

RESULTS

The smoking-related microbiota index (SMI) showed a positive association with BMI and other obesity indices. Further analyses revealed that SMI is linked to obesity-related diseases, with hazard ratios (95% confidence intervals) of 1.97 (1.41-2.75) for incident diabetes, 1.31 (1.01-1.71) for major adverse cardiovascular events, and 1.70 (1.05-2.75) for obesity-related cancers. Results from sibling comparison analyses reinforced these findings.

CONCLUSIONS

While smoking may reduce weight through various mechanisms, alterations in gut microbiota related to smoking are associated with weight gain. Further research is required to determine if changes in the smoking-related microbiome contribute to weight gain following smoking cessation.

Association of the EAT-Lancet diet, serial measures of serum proteome and gut microbiome, and cardiometabolic health: a prospective study of Chinese middle-aged and elderly adults

BACKGROUND

The EAT-Lancet diet was reported to be mutually beneficial for the human cardiometabolic system and planetary health. However, mechanistic evidence linking the EAT-Lancet diet and human cardiometabolic health is lacking.

OBJECTIVES

We aimed to investigate the role of blood proteins in the association between the EAT-Lancet diet and cardiometabolic health and explore the underlying gut microbiota-blood protein interplay.

METHODS

Our study was based on a prospective cohort including 3742 Chinese participants enrolled from 2008-2013 with serum proteome data repeatedly measured ≤3 times (Nproteome = 7514) and 1195 with gut metagenomic data measured ≤2 times over 9 y (Nmicrobiota = 1695). Least absolute shrinkage and selection operator and multivariable linear regression were used to explore the associations of the EAT-Lancet diet (assessed by semi-quantitative food frequency questionnaire) with serum proteins and gut microbes. Linear mixed-effect model and logistic regression were used to examine the associations of selected proteins with 11 cardiometabolic risk factors and 4 cardiometabolic diseases, respectively. Mediation analysis was used to identify potential mediation effects. Multiple comparisons were adjusted using the Benjamini-Hochberg method.

RESULTS

The mean (standard deviation) age of enrolled participants was 58.4 (6.1) y (31.6% men). The EAT-Lancet diet was prospectively associated with 4 core proteins, including α-2-macroglobulin (A2M) (pooled β: 0.12; 95% confidence interval [CI]: 0.05, 0.2), retinol-binding protein 4 (pooled β: -0.14; 95% CI: -0.24, -0.04), TBC1 domain family member 31 (pooled β: -0.11; 95% CI: -0.22, 0), and adenylate kinase 4 (pooled β: -0.19; 95% CI: -0.3, -0.08). The identified proteins were prospectively associated with cardiometabolic diseases (pooled odds ratio ranged from 0.8-1.18) and risk factors (pooled β ranged from -0.1 to 0.12), mediating the association between the EAT-Lancet diet and blood triglycerides. We then identified 5 gut microbial biomarkers of the EAT-Lancet diet, and discovered a potential gut microbiota-blood protein interplay (EAT-Lancet diet→Rothia mucilaginosa→A2M) underlying the EAT-Lancet diet-cardiometabolic health association.

CONCLUSIONS

Our study presents key molecular evidence to support the role of EAT-Lancet diet adherence in promoting cardiometabolic health.

Gut microbiota-derived imidazole propionate: an emerging target for the prevention and treatment of cardiometabolic diseases

Despite significant advancements in prevention and treatment, cardiometabolic diseases continue to pose a high burden of incidence and mortality. The chronic progression of these diseases necessitates the identification of early and complementary therapeutic targets to elucidate and mitigate residual risks in patient care. The gut microbiota acts as a sentinel between internal and external environments, transmitting modified risks associated with these factors to the host. Imidazole propionate (ImP), a histidine metabolite originating from the gut microbiota, gained attention after being found to impair glucose tolerance and insulin signaling several years ago. Epidemiological studies over the past five years have demonstrated a robust correlation between ImP and an increased risk of onset of type 2 diabetes (T2D) and obesity, exacerbation of kidney traits in chronic kidney disease (CKD), progression of atherosclerotic plaques, and elevated mortality rates in heart failure (HF). These findings suggest that ImP may serve as a pivotal target for the prevention and treatment of cardiometabolic diseases. Mechanistic insights have uncovered associations between ImP and insulin resistance, impaired glucose metabolism, chronic inflammation, and intestinal barrier damage. This review provides a comprehensive summary of the current evidence regarding the association between ImP and cardiometabolic impairment, highlighting its potential in advancing personalized approaches to disease prevention and management, and exploring the intricate interplay of diet, gut microbiota, and ImP in cardiovascular metabolic impairment. Overall, this review offers valuable insights into the multifaceted roles of ImP in cardiometabolic diseases, identifies current knowledge gaps, and discusses future research directions.

Distinct Gut Microbiota Profiles in Normal Weight Obesity and Their Association With Cardiometabolic Diseases: Results From Two Independent Cohort Studies

BACKGROUND

Normal weight obesity (NWO) is characterized by excess body fat in individuals with normal body mass index (BMI). This study aimed to investigate gut microbiota alterations in NWO and their potential associations with cardiometabolic diseases (CMD) risk in two independent cohorts.

METHODS

Our NWO-CMD mortality analysis included 168 099 adults with normal BMI from two large open-access databases, while our NWO-gut microbiota study involved 5467 adults with normal BMI from two independent cohorts: the WELL-China cohort and the Lanxi cohort. NWO was defined as having a normal BMI (18.5-23.9 kg/m2) but an excess per cent body fat (PBF, ≥ 25% in men and ≥ 35% in women). Normal weight lean was defined as having a normal BMI and normal PBF. The 16S rRNA gene sequencing method was used to analyse gut microbiota data.

RESULTS

The study comprised 3620 (64.0% female, median age 58 years) and 1847 (64.3% female, median age 56 years) participants from the WELL-China and Lanxi cohorts. In our meta-analysis, NWO is associated with 26% (95% CI: 1.07-1.41) higher risk of CMD mortality. Gut microbial analyses indicated that the NWO group exhibited reduced levels of observed species (p = 0.009 and p = 0.013) and Chao 1 index (p = 0.002 and p = 0.002) and altered gut microbial compositions (p = 0.009 and p < 0.001) compared with the NWL group. Seven genera were consistently observed to be associated with NWO in both two cohorts (all Q < 0.25). Among them, five (Fusobacterium, Ruminococcus gnavus group, Ruminococcus torques group, Coprococcus and Christensenellaceae_R7_group) have been previously linked to obesity, while the other two (Phascolarctobacterium and Clostridia_UCG-014) were minimally reported. We also found statistically significant differences in the microbial composition between the NWO group and the obesity group (p = 0.001 and p = 0.001). Furthermore, the NWO-related gut microbiome was associated with an elevated risk of hypertension, dyslipidaemia and metabolic syndrome, the corresponding HR (95% CIs) were 1.11 (1.01-1.22), 1.19 (1.10-1.29) and 1.17 (1.05-1.30) in the WELL-China cohort and 1.14 (1.02-1.27), 1.15 (1.02-1.29) and 1.16 (1.02-1.32) in the Lanxi cohort.

CONCLUSIONS

These two large cohorts provided reliable evidence that gut microbiota alterations in NWO resemble those found in obesity, yet also display unique aspects. This distinct microbiota profile may contribute to heightened cardiometabolic risks in adults with normal BMI.

Hydrolyzable tannins and pectin are glycolipid lowering ingredients in Phyllanthus emblica Linn.: Valid interaction with gut action targets

Phyllanthus emblica L., a distinctive fruit, is rich in polyphenols and polysaccharide. However, there is a lack of knowledge regarding the role of these compounds as glycolipid lowering ingredients. In this study, the glycolipid lowering ingredients and their effects have been determined by gradually comparing varieties, parts, and components, splitting components, and calculating combined index via their interactions with digestion enzymes, bile acids, cholesterol micelles and probiotics. Results indicated that the glycolipid lowering ingredients were polyphenols and polysaccharide, which located in the pulp, and not influenced by the variety. Pectin with multiple structural domains, and hydrolyzable tannins, i.e. gallic acid, ellagic acid and their derivatives interacted with multiple gut action targets could regulate glycolipid digestion, absorption and metabolism. Polysaccharide and polyphenols demonstrated a synergistic effect in lowering glycolipid by interacting with gut action targets. These findings highlight the potential for further investigation and utilization of glycolipid lowering ingredients in fruits.

Different levels of physical activity and risk of developing type 2 diabetes among adults with prediabetes: a population-based cohort study

OBJECTIVES

This study aimed to evaluate the association between different levels of physical activity and risk of developing type 2 diabetes (T2D) mellitus among adults with prediabetes in Chinese population.

METHODS

This prospective population-based cohort study included 12,424 participants (mean [SD] age, 52.8 [16.8] years; 82.2% men) with prediabetes at 2014 survey of the Kailuan study. Physical activity information was collected through the International Physical Activity Questionnaire-Short Form and categorized by metabolic equivalent (MET) of task as low, moderate, and high. Cox regression models were built to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between physical activity levels and incident T2D.

RESULTS

During a median follow-up of 3.6 years, 2,207 (17.8%) participants developed T2D. The incident rate of T2D were 55.83/1000, 35.14/1000, and 39.61/1000 person-years in the low, moderate, and high physical activity level group, respectively. Both moderate (HR 0.57, 95% CI 0.49 to 0.67) and high (HR 0.76, 95% CI 0.66 to 0.89) physical activity levels were associated with lower risks of developing T2D compared to low physical activity level (P for trend < 0.001). The association between high physical activity level and T2D was primarily observed in participants without metabolic syndrome (P for interaction < 0.001). Moreover, participants with moderate or high levels of physical activity had significantly decreased fasting blood glucose levels during follow-up when compared to those with low level (P group*time < 0.001).

CONCLUSION

This study suggested that individuals with prediabetes might benefit from moderate and high levels of physical activity.

Nut consumption, gut microbiota, and body fat distribution: results of a large, community-based population study

OBJECTIVE

We aimed to investigate the relationships among nut consumption, gut microbiota, and body fat distribution.

METHODS

We studied 2255 Chinese adults in the Lanxi Cohort living in urban areas in Lanxi City, China. Fat distribution was assessed by dual-energy x-ray absorptiometry, and nut consumption was assessed using food frequency questionnaires. 16S ribosomal RNA (rRNA) sequencing was performed on stool samples from 1724 participants. Linear regression and Spearman correlation were used in all analyses. A validation study was performed using 1274 participants in the Lanxi Cohort living in rural areas.

RESULTS

Nut consumption was beneficially associated with regional fat accumulation. Gut microbial analysis suggested that a high intake of nuts was associated with greater microbial α diversity. Six genera were found to be associated with nut consumption, and the abundance of genera Anaerobutyricum, Anaerotaenia, and Fusobacterium was significantly associated with fat distribution. Favorable relationships between α diversity and fat distribution were also observed. Similar relationships between gut microbiota and fat distribution were obtained in the validation analysis.

CONCLUSIONS

We have shown that nut consumption is beneficially associated with body fat distribution and gut microbiota diversity and taxonomy. Furthermore, the microbial features related to high nut intake are associated with a favorable pattern of fat distribution.

Associations of plant-based foods, red and processed meat, and dairy with gut microbiome in Finnish adults

PURPOSE

Population-based studies on the associations of plant-based foods, red meat or dairy with gut microbiome are scarce. We examined whether the consumption of plant-based foods (vegetables, potatoes, fruits, cereals), red and processed meat (RPM) or dairy (fermented milk, cheese, other dairy products) are related to gut microbiome in Finnish adults.

METHODS

We utilized data from the National FINRISK/FINDIET 2002 Study (n = 1273, aged 25-64 years, 55% women). Diet was assessed with 48-hour dietary recalls. Gut microbiome was analyzed using shallow shotgun sequencing. We applied multivariate analyses with linear models and permutational ANOVAs adjusted for relevant confounders.

RESULTS

Fruit consumption was positively (beta = 0.03, SE = 0.01, P = 0.04), while a dairy subgroup including milk, cream and ice-creams was inversely associated (beta=-0.03, SE 0.01, P = 0.02) with intra-individual gut microbiome diversity (alpha-diversity). Plant-based foods (R2 = 0.001, P = 0.03) and dairy (R2 = 0.002, P = 0.01) but not RPM (R2 = 0.001, P = 0.38) contributed to the compositional differences in gut microbiome (beta-diversity). Plant-based foods were associated with several butyrate producers/cellulolytic species including Roseburia hominis. RPM associations included an inverse association with R. hominis. Dairy was positively associated with several lactic producing/probiotic species including Lactobacillus delbrueckii and potentially opportunistic pathogens including Citrobacter freundii. Dairy, fermented milk, vegetables, and cereals were associated with specific microbial functions.

CONCLUSION

Our results suggest a potential association between plant-based foods and dairy or their subgroups with microbial diversity measures. Furthermore, our findings indicated that all the food groups were associated with distinct overall microbial community compositions. Plant-based food consumption particularly was associated with a larger number of putative beneficial species.

Dietary fructose: from uric acid to a metabolic switch in pediatric metabolic dysfunction-associated steatotic liver disease

Fructose consumption in pediatric subjects is rising, as the prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH). Despite increasing evidence supporting the detrimental effects of fructose in the development of Metabolic Syndrome (MetS) and its related comorbidities, the association between fructose intake and liver disease remains unclear, mainly in youths. The current narrative review aims to illustrate the correlation between fructose metabolism and liver functions besides its impact on obesity and MASLD in pediatrics. Fructose metabolism is involved in the liver through the classical lipogenic pathway via de novo lipogenesis (DNL) or in the alternative pathway via uric acid accumulation. Hyperuricemia is one of the main features of MALSD patients, underlining how uric acid is growing interest as a new marker of disease. Observational and interventional studies conducted in children and adolescents, who consumed large amounts of fructose and glucose in their diet, were included. Most of these studies emphasized the association between high fructose intake and weight gain, dyslipidemia, insulin resistance, and MASLD/MASH, even in normal-weight children. Conversely, reducing fructose intake ameliorates liver fat accumulation, lipid profile, and weight. In conclusion, fructose seems a potent inducer of both insulin resistance and hepatic fat accumulation.

Dried fruit intake and lower risk of type 2 diabetes: a two-sample mendelian randomization study

BACKGROUND

Previous studies have shown controversy about whether dried fruit intake is associated with type 2 diabetes. This study aimed to examine the potential causal effect of dried fruit intake on type 2 diabetes by conducting a two-sample Mendelian randomization study.

METHODS

We used genome-wide association study (GWAS) summary statistics for MR analysis to explore the causal association of dried fruit intake with T2D. The inverse-variance weighted (IVW) method was used as the main analytical method for MR analysis. In addition, the MR-Egger method and the weighted median method were applied to supplement the IVW method. Furthermore, Cochrane's Q test, MR-Egger intercept test, and leave-one-out analysis were used to perform sensitivity analysis. The funnel plot was used to assess publication bias.

RESULTS

The results from the IVW analysis indicated that dried fruit intake could reduce the risk of T2D [odds ratio (OR) = 0.392, 95% confidence interval (CI): 0.241-0.636, p-value = 0.0001]. In addition, the result of additional method Weighted median is parallel to the effects estimated by IVW. Furthermore, the sensitivity analysis illustrates that our MR analysis was unaffected by heterogeneity and horizontal pleiotropy. Finally, the results of the leave-one-out method showed the robustness of our MR results. And the funnel plot shows a symmetrical distribution.

CONCLUSION

Our study provides evidence for the benefits of dried fruit intake on T2D. Therefore, a reasonable consumption of dried fruit may provide primary prevention.

Suboptimal diet quality is associated with the incidence of type 2 diabetes mellitus in middle-aged and older populations in China: evidence from a population-based cross-sectional study

The association between dietary quality and type 2 diabetes mellitus (T2DM) based on the Chinese Dietary Balance Index (DBI-16) is seldom reported. We hypothesized that poor dietary quality might increase the risk of T2DM in the middle-aged and older populations. A total of 1816 individuals (≥50 years) were included in the study. Demographic characteristics and dietary intake data were collected. Logistic regression and restricted cubic spline (RCS) analyses were conducted to explore the association between DBI-16 indexes and the risk of T2DM. The insufficient intake of vegetables and dairy might decrease the risk of T2DM (ORVegetable = 0.77, 95% CI = 0.60-0.97; ORDairy = 0.58, 95% CI = 0.35-0.96), but the individuals with insufficient intake of fruit were more likely to have a higher risk of T2DM (ORfruit = 2.26, 95% CI = 1.69-3.06). Compared with the subjects with the lowest quartile of Low Bound Score (LBS) or Diet Quality Distance (DQD), the individuals with Q2 and Q3 level of LBS (ORQ2 = 1.40, 95% CI = 1.03-1.90, P = .033; ORQ3 = 1.52, 95% CI = 1.11-2.08, P < .01) or DQD (ORQ2 = 1.45, 95% CI = 1.06-1.99, P = .021; ORQ3 = 1.64, 95% CI = 1.20-2.24, P < .01) showed increased risk of T2DM with a nonlinear association observed by RCS analysis. We concluded that imbalanced dietary intake, especially insufficient daily fruit intake, might predict an increased risk of T2DM in the middle-aged and elderly Chinese.

Ketogenic diet-induced bile acids protect against obesity through reduced calorie absorption

The low-carbohydrate ketogenic diet (KD) has long been practiced for weight loss, but the underlying mechanisms remain elusive. Gut microbiota and metabolites have been suggested to mediate the metabolic changes caused by KD consumption, although the particular gut microbes or metabolites involved are unclear. Here, we show that KD consumption enhances serum levels of taurodeoxycholic acid (TDCA) and tauroursodeoxycholic acid (TUDCA) in mice to decrease body weight and fasting glucose levels. Mechanistically, KD feeding decreases the abundance of a bile salt hydrolase (BSH)-coding gut bacterium, Lactobacillus murinus ASF361. The reduction of L. murinus ASF361 or inhibition of BSH activity increases the circulating levels of TDCA and TUDCA, thereby reducing energy absorption by inhibiting intestinal carbonic anhydrase 1 expression, which leads to weight loss. TDCA and TUDCA treatments have been found to protect against obesity and its complications in multiple mouse models. Additionally, the associations among the abovementioned bile acids, microbial BSH and metabolic traits were consistently observed both in an observational study of healthy human participants (n = 416) and in a low-carbohydrate KD interventional study of participants who were either overweight or with obesity (n = 25). In summary, we uncover a unique host-gut microbiota metabolic interaction mechanism for KD consumption to decrease body weight and fasting glucose levels. Our findings support TDCA and TUDCA as two promising drug candidates for obesity and its complications in addition to a KD.

Gut Microbiota Fermentation of Digested Almond-Psyllium-Flax Seed-Based Artisan Bread Promotes Mediterranean Diet-Resembling Microbial Community

Different modifications of the standard bread recipe have been proposed to improve its nutritional and health benefits. Here, we utilized the in vitro Human Gut Simulator (HGS) to assess the fermentation of one such artisan bread by human gut microbiota. Dried and milled bread, composed of almond flour, psyllium husks, and flax seeds as its three main ingredients, was first subjected to an in vitro protocol designed to mimic human oro-gastro-intestinal digestion. The bread digest was then supplied to complex human gut microbial communities, replacing the typical Western diet-based medium (WM) of the GHS system. Switching the medium from WM to bread digest resulted in statistically significant alterations in the community structure, encoded functions, produced short-chain fatty acids, and available antioxidants. The abundances of dietary fiber degraders Enterocloster, Mitsuokella, and Prevotella increased; levels of Gemmiger, Faecalibacterium, and Blautia decreased. These community alterations resembled the previously revealed differences in the distal gut microbiota of healthy human subjects consuming typical Mediterranean vs. Western-pattern diets. Therefore, the consumption of bread high in dietary fiber and unsaturated fatty acids might recapitulate the beneficial effects of the Mediterranean diet on the gut microbiota.

Cohort Profile: Guangzhou Nutrition and Health Study (GNHS): A Population-based Multi-omics Study

BACKGROUND

The Guangzhou Nutrition and Health Study (GNHS) aims to assess the determinants of metabolic disease in nutritional aspects, as well as other environmental and genetic factors, and explore possible biomarkers and mechanisms with multi-omics integration.

METHODS

The population-based sample of adults in Guangzhou, China (baseline: 40-83 years old; n = 5,118) was followed up about every 3 years. All are tracked via on-site follow-up and health information systems. We assessed detailed information on lifestyle factors, physical activities, dietary assessments, psychological health, cognitive function, body measurements, and muscle function. Instrument tests included dual-energy X-ray absorptiometry scanning, carotid artery and liver ultrasonography evaluations, vascular endothelial function evaluation, upper-abdomen and brain magnetic resonance imaging, and 14-day real-time continuous glucose monitoring tests. We also measured multi-omics, including host genome-wide genotyping, serum metabolome and proteome, gut microbiome (16S rRNA sequencing, metagenome, and internal transcribed spacer 2 sequencing), and fecal metabolome and proteome.

RESULTS

The baseline surveys were conducted from 2008 to 2015. Now, we have completed 3 waves. The 3rd and 4th follow-ups have started but have yet to end. A total of 5,118 participants aged 40-83 took part in the study. The median age at baseline was approximately 59.0 years and the proportion of female participants was about 69.4%. Among all the participants, 3,628 (71%) completed at least one on-site follow-up, with a median duration of 9.48 years.

CONCLUSION

The cohort will provide data that will be influential in establishing the role of nutrition in metabolic diseases with multi-omics.

Mediterranean Dietary Pattern for Healthy and Active Aging: A Narrative Review of an Integrative and Sustainable Approach

The global population is on a trajectory of continuous growth, with estimates projecting an increase from 7.7 billion in 2019 to approximately 9.7 billion by 2050. Longevity is also expected to rise rapidly, with advancements in healthcare contributing to increased life expectancies and an increase in the maximum lifespan. The aging process is accompanied by different changes, often leading to a decline in daily life activities and an increased susceptibility to disease. Age-related changes can cause cellular damage and subsequent cellular death. Oxidative stress and inflammation play significant roles in this process contributing to molecular damage and mitochondrial dysfunction. Active aging has been associated with improved quality of life and a reduced risk of morbidity and premature mortality. In this context, the Mediterranean diet has emerged as a promising approach to promoting healthy aging and sustainability. The phytochemical compounds within the Mediterranean diet have been linked to a lower risk of developing cardiovascular disease, type 2 diabetes, obesity, cancer and neurodegenerative diseases. The findings of peer-reviewed articles regarding the use of the Mediterranean diet as a healthy and sustainable dietary pattern written in Portuguese, Spanish or English were included in this narrative literature review. This dietary pattern's emphasis on the consumption of fresh and local food aligns with both health and environmental sustainability goals. This work provides a comprehensive review of the benefits of the Mediterranean diet and its components in a healthy aging process and highlights the importance of this dietary pattern as a sustainable approach.

Association of the short-chain fatty acid levels and dietary quality with type 2 diabetes: a case-control study based on Henan Rural Cohort

Evidence of the relationship between fecal short-chain fatty acids (SCFA) levels, dietary quality and type 2 diabetes mellitus (T2DM) in rural populations is limited. Here, we aimed to investigate the association between fecal SCFA levels and T2DM and the combined effects of dietar quality on T2DM in rural China. In total, 100 adults were included in the case-control study. Dietary quality was assessed by the Alternate Healthy Eating Index 2010 (AHEI-2010), and SCFA levels were analysed using the GC-MS system. Generalised linear regression was conducted to calculate the OR and 95 % CI to evaluate the effect of SCFA level and dietary quality on the risk of T2DM. Finally, an interaction was used to study the combined effect of SCFA levels and AHEI-2010 scores on T2DM. T2DM participants had lower levels of acetic and butyric acid. Generalised linear regression analysis revealed that the OR (95 % CI) of the highest acetic and butyric acid levels were 0·099 (0·022, 0·441) and 0·210 (0·057, 0·774), respectively, compared with the subjects with the lowest tertile of level. We also observed a significantly lower risk of T2DM with acetic acid levels > 1330·106 μg/g or butyric acid levels > 585·031 μg/g. Moreover, the risks of higher acetic and butyric acid levels of T2DM were 0·007 (95 % CI: 0·001, 0·148), 0·005 (95 % CI: 0·001, 0·120) compared with participants with lower AHEI-2010 scores (all P < 0·05). Acetate and butyrate levels may be important modifiable beneficial factors affecting T2DM in rural China. Improving dietary quality for body metabolism balance should be encouraged to promote good health.

Sugar types, genetic predictors of the gut microbiome, and the risk of chronic kidney disease: a prospective cohort study

Background: Emerging studies suggest that focusing on the intake of specific types or sources of sugars may yield greater benefits in preventing chronic kidney disease (CKD). Objective: We aimed to investigate the associations between free and non-free sugar intakes and CKD risk as well as the potential sugar type-gut microbiome interactions. Methods: A total of 138 064 participants from the UK Biobank were included in this prospective study. The free and non-free sugar intakes were assessed using repeated web-based 24-hour dietary recalls. A cause-specific competing risk model was used to estimate hazard ratios (HRs) and the corresponding confidence intervals (CIs) of incident CKD, treating deaths before incident CKD as competing events. Results: During a median follow-up of 10.5 years, 2,923 participants (2.1%) developed CKD. The free sugar intake was positively associated with the risk of CKD (HRquartile 4 vs. quartile 1 = 1.32, 95% CI = 1.18, 1.47), with a nonlinear relationship (P for nonlinearity = 0.01, the risk increased rapidly after free sugars made up 10% of the total energy). The non-free sugar intake was inversely associated with CKD risk (HRquartile 4 vs. quartile 1 = 0.68, 95% CI = 0.60, 0.77), with an L-shaped nonlinear curve (p for nonlinearity = 0.01, the turning point was at 13.5% of the total energy). We found that the associations between free sugar and non-free sugar intakes and CKD risk were more pronounced in participants with high genetically predicted gut microbial abundance. Furthermore, a significant interaction was observed between the genetically predicted gut microbial abundance and non-free sugar intake (P for interaction = 0.04). Conclusion: A higher intake of free sugars was associated with an elevated risk of CKD, whereas a higher intake of non-free sugars was associated with a reduced risk of CKD. The impact of free sugar intake and non-free sugar intake may be modified by the gut microbial abundance.

The Development and Evaluation of a Literature-Based Dietary Index for Gut Microbiota

The aim of the study was to develop and evaluate a novel dietary index for gut microbiota (DI-GM) that captures dietary composition related to gut microbiota profiles. We conducted a literature review of longitudinal studies on the association of diet with gut microbiota in adult populations and extracted those dietary components with evidence of beneficial or unfavorable effects. Dietary recall data from the National Health and Nutrition Examination Survey (NHANES, 2005-2010, n = 3812) were used to compute the DI-GM, and associations with biomarkers of gut microbiota diversity (urinary enterodiol and enterolactone) were examined using linear regression. From a review of 106 articles, 14 foods or nutrients were identified as components of the DI-GM, including fermented dairy, chickpeas, soybean, whole grains, fiber, cranberries, avocados, broccoli, coffee, and green tea as beneficial components, and red meat, processed meat, refined grains, and high-fat diet (≥40% of energy from fat) as unfavorable components. Each component was scored 0 or 1 based on sex-specific median intakes, and scores were summed to develop the overall DI-GM score. In the NHANES, DI-GM scores ranged from 0-13 with a mean of 4.8 (SE = 0.04). Positive associations between DI-GM and urinary enterodiol and enterolactone were observed. The association of the novel DI-GM with markers of gut microbiota diversity demonstrates the potential utility of this index for gut health-related studies.

The Effects of Diet Intervention on the Gut Microbiota in Type 2 Diabetes Mellitus: A Systematic Review

The GI tract hosts a dynamic community known as the gut microbiota, which encompasses thriving bacteria that actively contribute to the physiological functions of the human body. The intricacies of its composition are profoundly influenced by dietary preferences, where the quality, quantity, and frequency of food consumption play a pivotal role in either fostering or impeding specific bacterial strains. Type 2 diabetes mellitus (T2DM) is a prevalent and deleterious condition that originates from excessive hyperglycemia. Do lifestyle interventions targeting dietary adjustments, nutritional supplements, physical activity, and weight management programs exhibit a significant relationship in altering the composition of the gut microbiome and managing T2DM? This paper aims to evaluate the effects of lifestyle interventions on patients with T2DM and the implications of these changes on disease outcomes and progression. Lifestyle interventions can significantly impact the management of T2DM, especially those targeting dietary adjustments, nutritional supplements, physical activity, and weight management programs. The adoption of a high-fiber diet and increased fruit consumption have shown positive impacts on both insulin sensitivity and the composition of the gut microbiota. Additionally, promising outcomes emerge from supplementing with Omega-3 fatty acids, Vitamin K2 (MK-7), and transglucosidase, which influence insulin levels, glycemic control, and gut microbiota composition. Personalized diet interventions and the transformative effects of the Mediterranean diet present positive outcomes in metabolic control. The intensity of exercise plays a pivotal role in shaping the composition of the gut microbiota, with moderate-intensity continuous exercise displaying positive effects on anti-inflammatory microbes. Chronic exercise showcases favorable impacts on glycemic control and systemic inflammation. Emphasizing the intricate relationship between dietary habits, gut microbiota, and the risk of T2DM underscores the potential of the gut microbiota as a universal biomarker for assessing diabetes risk. Nutritional supplements and exercise interventions provide potential avenues for the management of T2DM, emphasizing the necessity for tailored strategies. Further research is encouraged to delve into the long-term effects and intricate interplay between lifestyle factors and the gut microbiome, enhancing our understanding of T2DM pathophysiology for targeted therapeutic approaches.

Effects and mechanisms of anti-diabetic dietary natural products: an updated review

Diabetes is a global public health issue, characterized by an abnormal level of blood glucose. It can be classified into type 1, type 2, gestational, and other rare diabetes. Recent studies have reported that many dietary natural products exhibit anti-diabetic activity. In this narrative review, the effects and underlying mechanisms of dietary natural products on diabetes are summarized based on the results from epidemiological, experimental, and clinical studies. Some fruits (e.g., grape, blueberry, and cherry), vegetables (e.g., bitter melon and Lycium barbarum leaves), grains (e.g., oat, rye, and brown rice), legumes (e.g., soybean and black bean), spices (e.g., cinnamon and turmeric) and medicinal herbs (e.g., Aloe vera leaf and Nigella sativa), and vitamin C and carotenoids could play important roles in the prevention and management of diabetes. Their underlying mechanisms include exerting antioxidant, anti-inflammatory, and anti-glycation effects, inhibiting carbohydrate-hydrolyzing enzymes, enhancing insulin action, alleviating insulin resistance, modulating the gut microbiota, and so on. This review can provide people with a comprehensive knowledge of anti-diabetic dietary natural products, and support their further development into functional food to prevent and manage diabetes.

Effect of Blueberry Supplementation on a Diet-Induced Rat Model of Prediabetes-Focus on Hepatic Lipid Deposition, Endoplasmic Stress Response and Autophagy

Blueberries, red fruits enriched in polyphenols and fibers, are envisaged as a promising nutraceutical intervention in a plethora of metabolic diseases. Prediabetes, an intermediate state between normal glucose tolerance and type 2 diabetes, fuels the development of complications, including hepatic steatosis. In previous work, we have demonstrated that blueberry juice (BJ) supplementation benefits glycemic control and lipid profile, which was accompanied by an amelioration of hepatic mitochondrial bioenergetics. The purpose of this study is to clarify the impact of long-term BJ nutraceutical intervention on cellular mechanisms that govern hepatic lipid homeostasis, namely autophagy and endoplasmic reticulum (ER) stress, in a rat model of prediabetes. Two groups of male Wistar rats, 8-weeks old, were fed a prediabetes-inducing high-fat diet (HFD) and one group was fed a control diet (CD). From the timepoint where the prediabetic phenotype was achieved (week 16) until the end of the study (week 24), one of the HFD-fed groups was daily orally supplemented with 25 g/kg body weight (BW) of BJ (HFD + BJ). BW, caloric intake, glucose tolerance and insulin sensitivity were monitored throughout the study. The serum and hepatic lipid contents were quantified. Liver and interscapular brown and epidydimal white adipose tissue depots (iBAT and eWAT) were collected for histological analysis and to assess thermogenesis, ER stress and autophagy markers. The gut microbiota composition and the short-chain fatty acids (SCFAs) content were determined in colon fecal samples. BJ supplementation positively impacted glycemic control but was unable to prevent obesity and adiposity. BJ-treated animals presented a reduction in fecal SCFAs, increased markers of arrested iBAT thermogenesis and energy expenditure, together with an aggravation of HFD-induced lipotoxicity and hepatic steatosis, which were accompanied by the inhibition of autophagy and ER stress responses in the liver. In conclusion, despite the improvement of glucose tolerance, BJ supplementation promoted a major impact on lipid management mechanisms at liver and AT levels in prediabetic animals, which might affect disease course.

Gut commensal Christensenella minuta modulates host metabolism via acylated secondary bile acids

A strong correlation between gut microbes and host health has been observed in numerous gut metagenomic cohort studies. However, the underlying mechanisms governing host-microbe interactions in the gut remain largely unknown. Here we report that the gut commensal Christensenella minuta modulates host metabolism by generating a previously undescribed class of secondary bile acids with 3-O-acylation substitution that inhibit the intestinal farnesoid X receptor. Administration of C. minuta alleviated features of metabolic disease in high fat diet-induced obese mice associated with a significant increase in these acylated bile acids, which we refer to as 3-O-acyl-cholic acids. Specific knockout of intestinal farnesoid X receptor in mice counteracted the beneficial effects observed in their wild-type counterparts. Finally, we showed that 3-O-acyl-CAs were prevalent in healthy humans but significantly depleted in patients with type 2 diabetes. Our findings indicate a role for C. minuta and acylated bile acids in metabolic diseases.

Gut microbial ecology and exposome of a healthy Pakistani cohort

BACKGROUND

Pakistan is a multi-ethnic society where there is a disparity between dietary habits, genetic composition, and environmental exposures. The microbial ecology of healthy Pakistani gut in the context of anthropometric, sociodemographic, and dietary patterns holds interest by virtue of it being one of the most populous countries, and also being a Lower Middle Income Country (LMIC).

METHODS

16S rRNA profiling of healthy gut microbiome of normo-weight healthy Pakistani individuals from different regions of residence is performed with additional meta-data collected through filled questionnaires. The current health status is then linked to dietary patterns through [Formula: see text] test of independence and Generalized Linear Latent Variable Model (GLLVM) where distribution of individual microbes is regressed against all recorded sources of variability. To identify the core microbiome signature, a dynamic approach is used that considers into account species occupancy as well as consistency across assumed grouping of samples including organization by gender and province of residence. Fitting neutral modeling then revealed core microbiome that is selected by the environment.

RESULTS

A strong determinant of disparity is by province of residence. It is also established that the male microbiome is better adapted to the local niche than the female microbiome, and that there is microbial taxonomic and functional diversity in different ethnicities, dietary patterns and lifestyle habits. Some microbial genera, such as, Megamonas, Porphyromonas, Haemophilus, Klebsiella and Finegoldia showed significant associations with consumption of pickle, fresh fruits, rice, and cheese. Our analyses suggest current health status being associated with the diet, sleeping patterns, employment status, and the medical history.

CONCLUSIONS

This study provides a snapshot of the healthy core Pakistani gut microbiome by focusing on the most populous provinces and ethnic groups residing in predominantly urban areas. The study serves a reference dataset for exploring variations in disease status and designing personalized dietary and lifestyle interventions to promote gut health, particularly in LMICs settings.

Nutrition at the Intersection between Gut Microbiota Eubiosis and Effective Management of Type 2 Diabetes

Nutrition is one of the most influential environmental factors in both taxonomical shifts in gut microbiota as well as in the development of type 2 diabetes mellitus (T2DM). Emerging evidence has shown that the effects of nutrition on both these parameters is not mutually exclusive and that changes in gut microbiota and related metabolites such as short-chain fatty acids (SCFAs) and branched-chain amino acids (BCAAs) may influence systemic inflammation and signaling pathways that contribute to pathophysiological processes associated with T2DM. With this background, our review highlights the effects of macronutrients, carbohydrates, proteins, and lipids, as well as micronutrients, vitamins, and minerals, on T2DM, specifically through their alterations in gut microbiota and the metabolites they produce. Additionally, we describe the influences of common food groups, which incorporate varying combinations of these macronutrients and micronutrients, on both microbiota and metabolic parameters in the context of diabetes mellitus. Overall, nutrition is one of the first line modifiable therapies in the management of T2DM and a better understanding of the mechanisms by which gut microbiota influence its pathophysiology provides opportunities for optimizing dietary interventions.

The Associations of Cardiometabolic and Dietary Variables with Clinical Periodontitis in Adults with and without Type 2 Diabetes: A Cross-Sectional Study

Periodontitis is a commonly occurring inflammatory oral disease affecting a large proportion of global and US adults and is characterized by the destruction of the tooth-supporting apparatus. Its etiology is multifactorial, and type 2 diabetes and diet play critical roles in its remission and progression. However, few studies have addressed nutritional and serum vitamin D status in adults with periodontitis in the presence of diabetes. A cross-sectional study (n = 78), and a sub-set of age- and BMI-matched case-control studies (n = 50), were conducted to examine differences in dietary and cardiometabolic variables, and serum vitamin D in adults with periodontitis with or without diabetes. Participants provided fasting blood samples and 24-h diet recalls on at least two different days. Data on health history, body weight, height, nutritional habits, and clinical features of periodontitis were also collected. The Mann-Whitney U Test (with exact p-value estimation by Monte Carlo simulation) was used to examine differences by diabetes status in continuous and ordinal variables. Results revealed significantly lower serum vitamin D, and dietary intake of fruits, vegetables, dairy, vitamins A and C in adults with periodontitis with vs. without diabetes in the sub-study (all p < 0.05). In the overall sample, adults with diabetes presented with higher caries risk measures and lower numbers of teeth than those without diabetes; plaque and bleeding scores did not differ by diabetes status. Finally, a significant associations of food habits was observed, especially consuming protein-rich foods twice a day with a lower bleeding score, and daily consumption of fried or fast foods with a fewer number of teeth present (all p < 0.05). The present findings show significant dietary and serum vitamin D inadequacies among adults with periodontitis, and diabetes further aggravates the observed malnourishment and oral health.

Impact of gut microbiota and associated mechanisms on postprandial glucose levels in patients with diabetes

Diabetes and its complications are serious medical and global burdens, often manifesting as postprandial hyperglycemia. In recent years, considerable research attention has focused on relationships between the gut microbiota and circulating postprandial glucose (PPG). Different population studies have suggested that PPG is closely related to the gut microbiota which may impact PPG via short-chain fatty acids (SCFAs), bile acids (BAs) and trimethylamine N-oxide (TMAO). Studies now show that gut microbiota models can predict PPG, with individualized nutrition intervention strategies used to regulate gut microbiota and improve glucose metabolism to facilitate the precision treatment of diabetes. However, few studies have been conducted in patients with diabetes. Therefore, little is known about the relationships between the gut microbiota and PPG in this cohort. Thus, more research is required to identify key gut microbiota and associated metabolites and pathways impacting PPG to provide potential therapeutic targets for PPG.

Dorzagliatin for Type 2 Diabetes Mellitus: A Systematic Review and Meta-analysis of Randomized Phase II/III Trials

PURPOSE

Dorzagliatin is a glucokinase agonist with effects on type 2 diabetes mellitus (T2DM). This study included a meta-analysis on the efficacy and safety of dorzagliatin in the treatment of T2DM.

METHODS

The Cochrane Central Registry of Controlled Trials, PubMed, and Embase were searched from inception to July 25, 2022. A total of 3 studies including 1333 patients were identified in this meta-analysis.

FINDINGS

Overall, the meta-analysis showed that dorzagliatin remarkably reduced glycated hemoglobin levels versus placebo by 0.66%. The results of the meta-analysis showed a significant reduction in fasting plasma glucose of 6.77 mg/dL between dorzagliatin and placebo. In addition, dorzagliatin reduced 2-hour postprandial glucose (2h-PPG) by 43.87 mg/dL compared with placebo. Furthermore, the meta-analysis of available data revealed a significant reduction in the Homeostasis Model Assessment of Insulin Resistance of 0.07 between dorzagliatin and placebo. The risk of adverse events was slightly higher with dorzagliatin than with placebo.

IMPLICATIONS

Dorzagliatin significantly reduced glycated hemoglobin levels, fasting plasma glucose levels, 2h-PPG, and homeostasis model assessment 2 of insulin resistance in patients with T2DM. It was well tolerated and had good liver and kidney safety profiles.

Dietary protein intake and changes in muscle mass measurements in community-dwelling middle-aged and older adults: A prospective cohort study

BACKGROUND & AIMS

Increasing dietary protein intake can be an efficient strategy to prevent sarcopenia. Nevertheless, due to the discrepancy in the population and their dietary pattern, evidence suggested the effects of dietary protein amount or source on sarcopenia prevention varies. This prospective cohort study investigated the correlation between dietary protein intakes or sources and changes in muscle mass measurements. Additionally, the study explored the link between dietary protein and the prevalence of sarcopenia.

METHODS

Participants aged 40 to 75 were from Guangzhou Nutrition and Health Study (GNHS) 2011-2013 and returned in 2014-2017. Validated 79-item food frequency questionnaires were applied to calculate the amount of total, animal, and plant protein intakes and animal-to-plant protein ratio (APR). The body composition was examined by dual-energy x-ray absorptiometry (DXA) to calculate the appendicular lean mass (ALM) and its index (ASMI). Sarcopenia was diagnosed based on the 2019 Asia Working Group of Sarcopenia's criteria. ANCOVA was utilized to compare the differences of Δ ALM and Δ ASMI across the quartiles of the dietary protein, and linear regression was employed to examine dose-response associations. Multilinear mixed-effect models were employed to evaluate whether protein intake relates to annual changes in ALM and ASMI. Multivariable logistic regressions were performed to analyze the associations between dietary protein and sarcopenia.

RESULTS

In total, 2709 participants during the 3.2-year follow-up period were considered eligible for analysis. Higher dietary protein intakes (total, animal, plant) in both sexes could preserve more ALM and ASMI in a dose-response manner (all P-trend < 0.05). The annual estimated preservations of ASMI were greater in the highest dietary protein intakes (total, animal, plant) quartile than the lowest (0.05-0.13 kg/m2/y, all P < 0.05). In women, the risk of sarcopenia was reduced by 35%-50 % in the highest protein intake (total, animal, plant) quartile than the lowest. The APR did not display any significant associations.

CONCLUSIONS

Higher dietary protein intake, regardless of animal or plant sources, is associated with less muscle loss and a lower prevalence of sarcopenia in middle-aged and older Chinese, particularly women.

CLINICALTRIALS

GOV IDENTIFIER

NCT03179657.

Short-Term Effects of Weight-Loss Meal Replacement Programs with Various Macronutrient Distributions on Gut Microbiome and Metabolic Parameters: A Pilot Study

It has emerged the gut microbiome is crucially linked to metabolic health and obesity. Macronutrient distribution has been discussed as a key parameter in weight-loss programs, but little is known about its impact on the gut microbiome. We investigated the effects of weight-loss meal replacement programs with different macronutrient ratios on the gut microbiota and metabolic parameters in subjects with overweight and obesity. Three low-calorie meal replacement programs with different ratios of carbohydrates, proteins, and lipids were designed: a balanced diet (Group B, 60:15:30), a high-lipid-low-carbohydrate diet (Group F, 35:20:55), and a protein-enriched diet (Group P, 40:25:35). Sixty overweight or obese participants were provided with the meals twice daily for 3 weeks. In all groups, diet intervention resulted in reduced body weight and BMI. The relative abundance of Bacteroidetes and Firmicutes phyla decreased and increased, respectively, which increased the Firmicutes/Bacteroidetes (F/B) ratio in all subjects, particularly in Groups B and P. Alpha- and beta-diversity were augmented at the phylum level in Group P. In conclusion, short-term interventions with weight-loss meal replacement programs increased butyrate-producing bacteria and the F/B ratio. Moreover, the protein-enriched diet significantly increased alpha- and beta-diversity compared to the balanced diet and the high-lipid-low-carbohydrate diet.

Nutri-microbiome epidemiology, an emerging field to disentangle the interplay between nutrition and microbiome for human health

Diet and nutrition have a substantial impact on the human microbiome, and interact with the microbiome, especially gut microbiome, to modulate various diseases and health status. Microbiome research has also guided the nutrition field to a more integrative direction, becoming an essential component of the rising area of precision nutrition. In this review, we provide a broad insight into the interplay among diet, nutrition, microbiome, and microbial metabolites for their roles in the human health. Among the microbiome epidemiological studies regarding the associations of diet and nutrition with microbiome and its derived metabolites, we summarize those most reliable findings and highlight evidence for the relationships between diet and disease-associated microbiome and its functional readout. Then, the latest advances of the microbiome-based precision nutrition research and multidisciplinary integration are described. Finally, we discuss several outstanding challenges and opportunities in the field of nutri-microbiome epidemiology.

The Interaction of Dietary Patterns and Genetic Variants on the Risk of Cardiovascular Diseases in Chinese Patients with Type 2 Diabetes

SCOPE

Diabetes is an important risk factor for cardiovascular disease (CVD), which in turn is the most common and serious complication of diabetes. This study analyzes dietary patterns and single nucleotide polymorphisms (SNPs) in 543 diabetes patients with new-onset cardiovascular events and 461 diabetic patients without.

METHODS AND RESULTS

SNPs are determined and analyzed using real time PCR and gene chip method. Factor analysis and logistic regression are used to determine dietary patterns and evaluate the level of associations and interaction effects, respectively. The legumes and edible fungi pattern and vegetable pattern show a significant negative correlation with complication risk. ADIPOQ rs37563 and legumes and edible fungi pattern have a significant interactive effect on disease, and patients with a high score of C polymorphism genotype (GC + CC) have a lower risk of disease. 5-10-Methylenetetrahydrofolate reductase (MTHFR) rs1801131 and vegetable pattern have a borderline interaction effect on disease, and those patients with TT genotype have a lower risk of disease.

CONCLUSION

These findings provide new insights into the role of the interactive protection of dietary patterns and SNPs. And participants with specific alleles show a lower risk of cardiovascular complications.

Targeting the Gut Microbiota in Kidney Disease: The Future in Renal Nutrition and Metabolism

There is increasing interest in the therapeutic potential of manipulating the gut microbiome of patients with chronic kidney disease (CKD). This is because there is a substantial deviation from a balanced gut microbiota profile in CKD, with many deleterious downstream effects. Nutritional interventions such as plant-based diets with reduced animal protein intake and the use of probiotics, prebiotics, and synbiotics may alter the microbiome. This article aims to briefly describe what is known about the gut microbiome in patients with CKD, factors contributing to gut dysbiosis, and outline important evidence gaps. Future potential therapies, including restoring the microbiota with food and microbiota-based and metabolomic-based therapies, are also discussed.

Population serum proteomics uncovers a prognostic protein classifier for metabolic syndrome

Metabolic syndrome (MetS) is a complex metabolic disorder with a global prevalence of 20%-25%. Early identification and intervention would help minimize the global burden on healthcare systems. Here, we measured over 400 proteins from ∼20,000 proteomes using data-independent acquisition mass spectrometry for 7,890 serum samples from a longitudinal cohort of 3,840 participants with two follow-up time points over 10 years. We then built a machine-learning model for predicting the risk of developing MetS within 10 years. Our model, composed of 11 proteins and the age of the individuals, achieved an area under the curve of 0.774 in the validation cohort (n = 242). Using linear mixed models, we found that apolipoproteins, immune-related proteins, and coagulation-related proteins best correlated with MetS development. This population-scale proteomics study broadens our understanding of MetS and may guide the development of prevention and targeted therapies for MetS.

Evidence for the Beneficial Effects of Brazilian Native Fruits and Their By-Products on Human Intestinal Microbiota and Repercussions on Non-Communicable Chronic Diseases-A Review

Non-communicable chronic diseases (NCDs) are the most widespread cause of mortality worldwide. Intestinal microbiota balance can be altered by changes in the abundance and/or diversity of intestinal microbiota, indicating a role of intestinal microbiota in NCD development. This review discusses the findings of in vitro studies, pre-clinical studies and clinical trials on the effects of Brazilian native fruits, their by-products, as well as their bioactive compounds on human intestinal microbiota and NCD. The major bioactive compounds in Brazilian native fruits and their by-products, and the impacts of their administration on outcomes linked to intestinal microbiota modulation are discussed. Mechanisms of intestinal microbiota affecting NCD could be linked to the modulation of absorption and energy balance, immune and endocrine systems, and inflammatory response. Brazilian native fruits, such as acerola, açaí, baru, buriti, guava, jabuticaba, juçara, and passion fruit, have several bioactive compounds, soluble and insoluble fibers, and a variety of phenolic compounds, which are capable of changing these key mechanisms. Brazilian native fruits and their by-products can help to promote positive intestinal and systemic health benefits by driving alterations in the composition of the human intestinal microbiota, and increasing the production of distinct short-chain fatty acids and phenolic metabolites, thereby enhancing intestinal integrity and homeostasis. Evidence from available literature shows that the modulatory impacts of Brazilian native fruits and their by-products on the composition and metabolic activity of the intestinal microbiota could improve several clinical repercussions associated with NCD, reinforcing the influence of intestinal microbiota in extra-intestinal outcomes.

Types of fiber and gut microbiota composition and diversity among arab females

OBJECTIVES

Dietary fiber is recognized as an important nutrient for gut health. However, research on the relations of different types of fibers (soluble and insoluble) to the human microbiota health is limited. This study aimed to identify whether higher habitual intake of soluble and/or insoluble fiber have a different influence on the composition, diversity, and abundance of microbiota.

METHODS

We examined the fecal microbial composition of 92 healthy females aged 18 and above using the novel shotgun metagenomics sequencing technique. The habitual fiber intake was determined using the Saudi food frequency questionnaire. Pearson's correlation was used for the correlations between total, soluble, and insoluble fiber and gut microbiota. α- and β-diversities were applied to acquire the distinctions in the relative abundances of bacterial taxa.

RESULTS

Our findings show that higher dietary fiber, particularly insoluble fiber, was significantly correlated with the abundances of Bacteroides_u_s, Bacteroides uniformis, and Lactobacillus acidophilus (r = 0.26, 0.29, 0.26, p-value < 0.05, respectively). Non-significant difference was noted in the microbial α-diversity and β-diversity in low and high soluble/insoluble dietary fiber.

CONCLUSIONS

Current findings suggest that insoluble dietary-fiber intake is favorably correlated with the health of the human gut microbiota. However, further investigations are necessary to identify the effect of types of fiber on the specific species identified in this study.

Global burden of non-communicable chronic diseases associated with a diet low in fruits from 1990 to 2019

Background

The aim of this study was to assess the global burden of disease from non-communicable chronic diseases (NCD) due to diet low in fruits from 1990 to 2019.

Methods

Based on data from the Global Burden of Disease (GBD) 2019, the global burden of disease due to diet low in fruits was analyzed for each country or region, disaggregated by disease type, age, sex, and year. The number of deaths and disability-adjusted life years (DALYs), population attributable fraction (PAF), age-standardized mortality rate (ASMR) and age-standardized DALY rate (ASDR) were calculated, and the average annual percentage change (AAPC) was calculated to describe trends in ASMR and ASDR from 1990 to 2019.

Results

From 1990 to 2019, the number of deaths and DALYs due to diet low in fruits increased by 31.5 and 27.4%, respectively. Among the tertiary diseases, ischemic heart disease, stroke, and diabetes and kidney disease were the top three contributors to the global increase in deaths and DALYs. However, both ASMR and ASDR showed a decreasing trend. The fastest decline in ASMR and ASDR was in stroke, with AAPC of -2.13 (95% CI: -2.22, -2.05, p < 0.05) and -0.56 (95% CI: -0.62, -0.51, p < 0.05), respectively. For GBD regions, high PAF occurred mainly in South Asia, Oceania, and sub-Saharan Africa. Age-specific PAF for stroke and ischemic heart disease death attributable to diet low in fruits was significantly negatively associated with age. Diet low in fruits related ASMR and ASDR showed an M-shaped relationship with the socio-demographic index (SDI), but with an overall decreasing trend.

Conclusion

The number of deaths and DALYs due to diet low in fruits continues to increase. Therefore, early nutritional interventions should be implemented by the relevant authorities to reduce the burden of diseases caused by diet low in fruits.

Prevalence and predictors of undiagnosed type 2 diabetes and pre-diabetes among adult Egyptians: a community-based survey

BACKGROUND

The global prevalence of abnormal glycemic level comprising diabetes mellitus (DM) and pre-diabetes (PDM) is rapidly increasing with special concern for the entity silent or undiagnosed diabetes; those unaware of their condition. Identification of people at risk became much easier with the use of risk charts than the traditional methods. The current study aimed to conduct a community-based screening for T2DM to estimate the prevalence of undiagnosed DM and to assess the AUSDRISK Arabic version as a predictive tool in an Egyptian context.

METHODS

A cross-sectional study was conducted among 719 Adults aging 18 years or more and not known to be diabetics through a population-based household survey. Each participant was interviewed to fill demographic and medical data as well as the AUSDRISK Arabic version risk score and undergo testing for fasting plasma glucose (FPG) and oral glucose tolerance test (OGTT).

RESULTS

The prevalence of DM and PDM were 5% and 21.7% respectively. The multivariate analysis revealed that age, being physically inactive, history of previous abnormal glycemic level and waist circumference were the predictors for having abnormal glycemic level among the studied participants. At cut off points ≥ 13 and ≥ 9, the AUSDRISK respectively discriminated DM [sensitivity (86.11%), specificity (73.35%), and area under the curve (AUC): 0.887, 95% CI: 0.824-0.950] and abnormal glycemic level [sensitivity (80.73%), specificity (58.06%), and AUC: 0.767, 95% CI: 0.727-0.807], p < 0.001.

CONCLUSIONS

Overt DM just occupies the top of an iceberg, its unseen big population have undiagnosed DM, PDM or been at risk of T2DM because of sustained exposure to the influential risk factors. The AUSDRISK Arabic version was proved to be sensitive and specific tool to be used among Egyptians as a screening tool for the detection of DM or abnormal glycemic level. A prominent association has been demonstrated between AUSDRISK Arabic version score and the diabetic status.

Differences in gut microbiota and its metabolic function among different fasting plasma glucose groups in Mongolian population of China

BACKGROUND

Many studies reported the association between gut microbiota and type 2 diabetes mellitus (T2D), but it is still unclear which bacterial genus plays a key role and how the metabolic function of gut microbiota changes in the occurrence and development of T2D. Besides, there is a high diabetic prevalence in Mongolian population, which may be partly affected by their high calorie diet. This study identified the main bacterial genus influencing T2D in Mongolian population, and analyzed the changes of metabolic function of gut microbiome. The association between dietary factors and the relative abundance of main bacterial genus and its metabolic function was also studied.

METHODS

Dietary surveys and gut microbiota test were performed on 24 Mongolian volunteers that were divided into T2D (6 cases), PRET2D (6 cases) and Control group (12 cases) according to fasting plasma glucose (FPG) values. The relative abundance and metabolic function of gut microbiome from their fecal samples were measured by metagenomic analysis. Statistic method was used to evaluate the association between dietary factors and the relative abundance of the main bacterial genus or its metabolic function.

RESULTS

This study found that the Clostridium genus may be one of the key bacterial genera affecting the process of T2D. First, the relative abundance of Clostridium genus was significantly different among the three groups. Second, there was a higher relative abundance of metabolic enzymes of gut bacteria in PRET2D and T2D group than that in Control group. Third, a strong correlation between Clostridium genus and many metabolic enzymes was uncovered, many of which may be produced by the Clostridium. Last, carotene intake daily was negatively correlated with the Clostridium but positively correlated with tagaturonate reductase catalyzing interconversions of pentose and glucuronate.

CONCLUSIONS

The gut Clostridium genus may play an important role in the development of T2D and it could be a potential biomarker for T2D in Mongolian population. Meanwhile, the metabolic function of gut bacteria has changed during the early stage of T2D and the changes in carbohydrate, amino acid, lipid or energy metabolism of Clostridium genus may play a critical role. In addition, the carotene intake may affect reproduction and metabolic function of Clostridium genus.

Complex Association Among Diet Styles, Sleep Patterns, and Obesity in Patients with Diabetes

Background

Health risk factors (HRFs), including the adjustment of disturbed sleep patterns (including disorders and duration) and improvement of dietary intake, have become relatively novel and critical strategies to prevent the development of diabesity and treat diabetic complications.

Objective

We aimed to explore 1) whether there was an association between diet styles (including healthy and unhealthy diets) and diabesity; 2) whether sleep patterns could moderate this relationship; and 3) whether there was a complex interaction association between sleep patterns, diet styles, and diabesity.

Methods

The study was based on a national survey conducted by the China National Diabetic Chronic Complications Study Group, this study extracted data from some cities in Anhui Province and obtained basic and lifestyle information using a detailed questionnaire for analysis. The primary exposure was diet styles, and the outcomes were body mass index (BMI) and waist circumference (WC), while HbA1c and FBG and sleep patterns were moderators. Data were pooled using logistic regression and moderation analysis.

Results

The overall response rate was 92.0%. This study ultimately included 1765 participants. The mean age was 57.10 ± 10.0 years. Sociographically, participants with lower educational levels were more likely to have lower levels of WC (χ 2 = 2.73) and BMI (χ 2 = 3.47), were female (t=6.54), were more likely to have lower educational levels (F=13.78) and were older (F=23.75), were more likely to have higher detection rates of sleep disorders and were more likely to have other HRFs (walking, SSBs, HbA1c and TG). Additionally, diet styles were also significantly associated with BMI and WC. In the moderation analysis, SES (socioeconomic status) also affected the correlation between healthy diet style, sleep disorders and WC (β=0.20), neither in BMI nor unhealthy diet style in BMI and WC; the combination effect between diet styles, sleep patterns and HbA1c was associated with WC and BMI.

Conclusion

Complex associations and interactions were found between diet styles, sleep patterns, HbA1c, and diabesity. Therefore, it is necessary to understand the dietary pattern and other HRFS that cause diabesity, so as to strengthen further preventive measures. These results can provide some theoretical basis for the treatment of diabesity in the public health field.

Application of Computational Data Modeling to a Large-Scale Population Cohort Assists the Discovery of Inositol as a Strain-Specific Substrate for Faecalibacterium prausnitzii

Faecalibacterium prausnitzii (F. prausnitzii) is a bacterial taxon in the human gut with anti-inflammatory properties, and this may contribute to the beneficial effects of healthy eating habits. However, little is known about the nutrients that enhance the growth of F. prausnitzii other than simple sugars and fibers. Here, we combined dietary and microbiome data from the American Gut Project (AGP) to identify nutrients that may be linked to the relative abundance of F. prausnitzii. Using a machine learning approach in combination with univariate analyses, we identified that sugar alcohols, carbocyclic sugar, and vitamins may contribute to F. prausnitzii growth. We next explored the effects of these nutrients on the growth of two F. prausnitzii strains in vitro and observed robust and strain-dependent growth patterns on sorbitol and inositol, respectively. In the context of a complex community using in vitro fermentation, neither inositol alone nor in combinations with vitamin B exerted a significant growth-promoting effect on F. prausnitzii, partly due to high variability among the fecal microbiota community from four healthy donors. However, the fecal communities that showed an increase in F. prausnitzii on inulin also responded with at least 60% more F. prausnitzii on any of inositol containing media than control. Future nutritional studies aiming to increase the relative abundance of F. prausnitzii should explore a personalized approach accounting for strain-level genetic variations and community-level microbiome composition.

Blueberry-Mulberry Extract Alleviates Cognitive Impairment, Regulates Gut Metabolites, and Inhibits Inflammation in Aged Mice

Cognitive impairment is associated with aging; however, the underlying mechanism remains unclear. Our previous study found that polyphenol-rich blueberry-mulberry extract (BME) had an antioxidant capability and effectively alleviated cognitive impairment in a mouse model of Alzheimer's disease. Thus, we hypothesized that BME would improve cognitive performance in naturally aging mice and assessed its effects on related signaling pathways. Eighteen-month-old C57BL/6J mice were gavaged with 300 mg/kg/d of BME for 6 weeks. Behavioral phenotypes, cytokine levels, tight junction protein levels, and the histopathology of the brain were assessed, and 16S ribosomal RNA sequencing and targeted metabolome analyses were used for gut microbiota and metabolite measurements. Our results showed that the cognitive performance of aged mice in the Morris water maze test was improved after BME treatment, neuronal loss was reduced, IL-6 and TNF-α levels in the brain and intestine were decreased, and the levels of intestinal tight junction proteins (ZO-1 and occludin) were increased. Further, 16S sequencing showed that BME significantly increased the relative abundance of Lactobacillus, Streptococcus, and Lactococcus and decreased the relative abundance of Blautia, Lachnoclostridium, and Roseburia in the gut. A targeted metabolomic analysis showed that BME significantly increased the levels of 21 metabolites, including α-linolenic acid, vanillic acid, and N-acetylserotonin. In conclusion, BME alters the gut microbiota and regulates gut metabolites in aged mice, which may contribute to the alleviation of cognitive impairment and to inflammation inhibition in both the brain and the gut. Our results provide a basis for future research on natural antioxidant intervention as a treatment strategy for aging-related cognitive impairment.

Whole fresh fruit intake and risk of incident diabetes in different glycemic stages: a nationwide prospective cohort investigation

PURPOSE

Fruit intake is beneficial to several chronic diseases, but controversial in diabetes. We aimed to investigate prospectively the associations of whole fresh fruit intake with risk of incident type 2 diabetes (T2D) in subjects with different glucose regulation capacities.

METHODS

The present study included 79,922 non-diabetic participants aged ≥ 40 years from an ongoing nationwide prospective cohort in China. Baseline fruit intake information was collected by a validated food frequency questionnaire. Plasma HbA1c, fasting and 2 h post-loading glucose levels were measured at both baseline and follow-up examinations. Cox proportional hazards models were used to calculate hazard ratio (HR) and 95% confidence intervals (CI) for incident diabetes among participants with normal glucose tolerance (NGT) and prediabetes, after adjusted for multiple confounders. Restricted cubic spline analysis was applied for dose-response relation.

RESULTS

During a median 3.8-year follow-up, 5886 (7.36%) participants developed diabetes. Overall, we identified a linear and dose-dependent inverse association between dietary whole fresh fruit intake and risk of incident T2D. Each 100 g/d higher fruit intake was associated with 2.8% lower risk of diabetes (HR 0.972, 95%CI [0.949-0.996], P = 0.0217), majorly benefiting NGT subjects with 15.2% lower risk (HR 0.848, 95%CI [0.766-0.940], P = 0.0017), while not significant in prediabetes (HR 0.981, 95%CI 0.957-4.005, P = 0.1268). Similarly, the inverse association was present in normoglycemia individuals with a 48.6% lower risk of diabetes when consuming fruits > 7 times/week comparing to those < 1 time/week (HR 0.514, 95% CI [0.368-0.948]), but not in prediabetes (HR 0.883, 95% CI [0.762-1.023]).

CONCLUSION

These findings suggest that higher frequency and amount of fresh fruit intake may protect against incident T2D, especially in NGT, but not in prediabetes, highlighting the dietary recommendation of higher fresh fruit consumption to prevent T2D in normoglycemia population.

INTERACTION BETWEEN FOOD PYRAMID AND GUT MICROBIOTA. A NEW NUTRITIONAL APPROACH

The food pyramid is a pre-established nutritional education tool. The integration between the intestinal microbiome, food groups, and SCFA-producing bacteria, which benefit from the ingestion of these foods, has the potential to further improve and innovate healthy eating. The diet-microbiome interaction needs to be incorporated into nutrition science, and the food pyramid might assist in this interaction and nutritional learning. Against this context, this brief communication proposes through the food pyramid, the interactions between the intestinal microbiota, food groups, and SCFAs-producing bacteria.

Mechanisms of gut microbiota-immune-host interaction on glucose regulation in type 2 diabetes

Intestinal absorption of food is one of the sources of glucose. Insulin resistance and impaired glucose tolerance caused by lifestyle and diet are the precursors of type 2 diabetes. Patients with type 2 diabetes have trouble controlling their blood sugar levels. For long-term health, strict glycemic management is necessary. Although it is thought to be well correlated with metabolic diseases like obesity, insulin resistance, and diabetes, its molecular mechanism is still not completely understood. Disturbed microbiota triggers the gut immune response to reshape the gut homeostasis. This interaction not only maintains the dynamic changes of intestinal flora, but also preserves the integrity of the intestinal barrier. Meanwhile, the microbiota establishes a systemic multiorgan dialog on the gut-brain and gut-liver axes, intestinal absorption of a high-fat diet affects the host's feeding preference and systemic metabolism. Intervention in the gut microbiota can combat the decreased glucose tolerance and insulin sensitivity linked to metabolic diseases both centrally and peripherally. Moreover, the pharmacokinetics of oral hypoglycemic medications are also influenced by gut microbiota. The accumulation of drugs in the gut microbiota not only affects the drug efficacy, but also changes the composition and function of them, thus may help to explain individual therapeutic variances in pharmacological efficacy. Regulating gut microbiota through healthy dietary patterns or supplementing pro/prebiotics can provide guidance for lifestyle interventions in people with poor glycemic control. Traditional Chinese medicine can also be used as complementary medicine to effectively regulate intestinal homeostasis. Intestinal microbiota is becoming a new target against metabolic diseases, so more evidence is needed to elucidate the intricate microbiota-immune-host relationship, and explore the therapeutic potential of targeting intestinal microbiota.

Ambient air pollution, lifestyle, and genetic predisposition associated with type 2 diabetes: findings from a national prospective cohort study

BACKGROUND

The combined effects of ambient air pollution, lifestyle, and genetic predisposition on incident Type 2 Diabetes (T2D) have not been well documented.

METHODS

A total of 263,733 participants without T2D at baseline were identified from the UK Biobank. Annual concentrations of five air pollutants were estimated using Land Use Regression, while a healthy lifestyle score (HLS) was constructed using 7 major lifestyle factors, and polygenic risk score (PRS) was generated using 73 genetic variants. Cox regression was used to determine the association between air pollution and incident T2D for different HLS/PRS categories. Potential HLS/PRS interactions and population attributable fraction (PAF) were also examined.

RESULTS

During a median follow-up of 11.94 years, 7827 (2.97 %) incident T2D cases were identified. Association between air pollution and incident T2D was stronger among those with higher HLS/PRS in a dose-response fashion. In addition, synergistic interactions between lifestyles and air pollution were observed. Lifestyle was the leading risk factor of T2D with a weighted PAF of 25.54 % (95 % CI: 19.22 %, 27.77 %) for intermediate HLS and 24.24 % (18.24 %, 26.36 %) due to unhealthy HLS. Overall, we estimated that about 25 % of T2D cases could be attributable to air pollution and associated interactions.

CONCLUSIONS

Associations between air pollution and T2D were stronger among individuals with unhealthier lifestyle on an additive interaction scale. Public health interventions that address both reduction of exposure to high levels of air pollution in addition to lifestyle changes may have more benefit on reducing T2D risk than focusing on lifestyle changes alone.

Aberrant amino acid metabolism promotes neurovascular reactivity in rosacea

Rosacea is a chronic skin disorder characterized by abnormal neurovascular and inflammatory conditions on the central face. Despite increasing evidence suggesting that rosacea is associated with metabolic disorders, the role of metabolism in rosacea pathogenesis remains unknown. Here, via a targeted metabolomics approach, we characterized significantly altered metabolic signatures in patients with rosacea, especially for amino acid-related metabolic pathways. Among these, glutamic acid and aspartic acid were highlighted and positively correlated with the disease severity in patients with rosacea. We further demonstrated that glutamic acid and aspartic acid can facilitate the development of erythema and telangiectasia, typical features of rosacea, in the skin of mice. Mechanistically, glutamic acid and aspartic acid stimulated the production of vasodilation-related neuropeptides from peripheral neurons and keratinocytes and induced the release of nitric oxide from endothelial cells and keratinocytes. Interestingly, we provided evidence showing that doxycycline can improve the symptoms of patients with rosacea possibly by targeting the amino acid metabolic pathway. These findings reveal that abnormal amino acid metabolism promotes neurovascular reactivity in rosacea and raise the possibility of targeting dysregulated metabolism as a promising strategy for clinical treatment.