Distinct gut microbiota signatures associated with progression of atherosclerosis in people living with HIV.

BACKGROUND: The relationship of microbiota composition dynamics and the progression of subclinical atherosclerosis in people with HIV (PWH) remains unknown. METHODS: 96-week, prospective, longitudinal study in virologically-suppressed PWH. Carotid intima-media thickness (cIMT) measurements and stool samples were obtained at baseline, 48-week and 96-week visits. cIMT progression was defined as an increase >10% and/or detection of new carotid plaque. To profile the gut microbiome, amplification and sequencing of 16S ribosomal-RNA (V3-V4 variable regions) were carried out following the Illumina protocol. Sequencing was performed with MiSeq platform. RESULTS: 191, 190 and 167 patients had available fecal samples for microbiome analysis at the baseline, 48- and 96-week visits, respectively. 87 (43%) participants showed atherosclerosis progression, and 54 (26.7%) presented new carotid plaque. No significant differences were observed in adjusted α-diversity indices between groups defined by cIMT progression. Beta-diversity determined through principal coordinate analysis distances showed that the groups exhibited distinct microbial profiles (PERMANOVA p-value = 0.03). Longitudinal analysis with ANCOM-BC2 adjusted for traditional cardiovascular risk factors, MSM and nadir CD4 count revealed that cIMT progression was consistently associated with Agathobacter and Ruminococcus_2, while non-progression was consistently associated with Prevotella_7. CONCLUSION: Progression of atherosclerosis in PWH might be associated with distinctive signatures in the gut microbiota.

Almond (Prunus dulcis) Bagasse as a Source of Bioactive Compounds with Antioxidant Properties: An In Vitro Assessment.

The presence of components of nutritional interest makes fresh almond bagasse an interesting by-product for obtaining functional ingredients. Stabilization through a dehydration process is an interesting option for its integral use, ensuring its conservation and management. Subsequently, it can be turned into powder, facilitating its use as an ingredient. The aim of this paper was to determine the effects of hot air drying at 60 and 70 °C and lyophilization on the release of phenolic components and antiradical capacity in in vitro gastrointestinal digestion and colonic fermentation, as well as on growing microbiota composition by applying high throughput sequencing. The novelty of this study lies in this holistic approach; considering both technological and physiological aspects related to gastrointestinal digestion and colonic fermentation will provide the best conditions for functional foods. The results obtained showed that lyophilization provides a powder with a total phenol content and antiradical capacity higher than hot air drying. Furthermore, in dehydrated samples, both in vitro digestion and colonic fermentation revealed a phenol content and anti-radical capacity superior to those existing in undigested products. In addition, after colonic fermentation, beneficial bacteria species have been identified. Obtaining powders from almond bagasse is presented as an interesting opportunity for the valorization of this by-product.

Effects of different foods and cooking methods on the gut microbiota: an in vitro approach.

To support personalized diets targeting the gut microbiota, we employed an in vitro digestion-fermentation model and 16S rRNA gene sequencing to analyze the microbiota growing on representative foods of the Mediterranean and Western diets, as well as the influence of cooking methods. Plant- and animal-derived foods had significantly different impacts on the abundances of bacterial taxa. Animal and vegetable fats, fish and dairy products led to increases in many taxa, mainly within the Lachnospiraceae. In particular, fats favored increases in the beneficial bacteria Faecalibacterium, Blautia, and Roseburia. However, butter, as well as gouda cheese and fish, also resulted in the increase of Lachnoclostridium, associated to several diseases. Frying and boiling produced the most distinct effects on the microbiota, with members of the Lachnospiraceae and Ruminococcaceae responding the most to the cooking method employed. Nevertheless, cooking effects were highly individualized and food-dependent, challenging the investigation of their role in personalized diets.

Nutritional Supplementation to Increase Influenza Vaccine Response in Children Living With HIV: A Pilot Clinical Trial.

Aims: Vaccine response is poor among children living with HIV. The gut microbiota has been identified as a potential target to improve vaccine immunogenicity, but data are scarce in the context of HIV infection. Methods: Pilot, double-blind, randomized placebo-controlled trial in which 24 HIV-infected children were randomized to receive a mixture of symbiotics, omega-3/6 fatty acids, and amino acids or placebo for 4 weeks, each in combination with ART, and were then immunized against influenza. Vaccine response and safety of the nutritional supplementation were the primary outcomes. Results: Eighteen HIV-infected children completed the follow-up period (mean age 11.5 ± 4.14 years, 61% female). The nutritional supplement was safe but did not enhance the response to the influenza vaccine. A 4-fold rise in antibody titers was obtained in only 37.5% of participants in the intervention arm vs. 40% in the placebo. No immunological or inflammatory predictors of vaccine response were identified. Conclusions: In this exploratory study, a 4-week course of symbiotics did not increase influenza vaccine immunogenicity in HIV-infected children. Larger studies are warranted to address the potential of modulating the microbiome in children living with HIV.

Effects of enriched seafood sticks (heat-inactivated B. animalis subsp. lactis CECT 8145, inulin, omega-3) on cardiometabolic risk factors and gut microbiota in abdominally obese subjects: randomized controlled trial.

PURPOSE: To assess the effects of enriched seafood sticks with postbiotic and bioactive compounds on CMD risk factors and the gut microbiota in abdominally obese individuals. METHODS: Randomized, double-blind, parallel, placebo-controlled trial with abdominally obese individuals. Participants (n = 120) consumed 50 g/day of enriched seafood sticks containing SIAP: (1010 colony forming units (CFUs) of heat-inactivated B. animalis subsp. lactis CECT8145, 370 mg/day omega 3 and 1.7 g/day inulin), or 50 g/day of placebo seafood sticks for 12 weeks. At 12 weeks, an acute single-dose study of 4 h was performed. RESULTS: Sustained SIAP2 consumption significantly decreased the insulin by - 5.25 mg/dL and HOMA-IR (homeostatic Model Assessment of Insulin Resistance) by - 1.33. In women, SIAP2 consumption significantly decreased the pulse pressure (PP) by - 4.69 mmHg. Gut microbiota analysis showed a negative association between glycemic parameter reduction and Alistipes finegoldii and Ruminococcaceae, and between PP reduction and Prevotella 9-ASV0283 and Christensenellaceae. In the acute single dose-study 4-h, SIAP2 consumption produced a lower increase in the postprandial circulating triglyceride levels [23.9 (7.03) mg/dL (mean [standard error])] than the observed with placebo [49.0 (9.52)] mg/dL. CONCLUSION: In abdominally obese individuals, enriched seafood sticks induce a potential protection against type 2 diabetes development by the reduction in the insulin and HOMA-IR; and in cardiovascular disease, in women, by the PP reduction. These effects are accompanied by partial changes in the gut microbiota composition. The enriched seafood sticks reduce the atherogenic triglyceride postprandial concentrations. Our results support the use of enriched seafood sticks as a complementary strategy in the management of CMD risk factors. REGISTRATION NUMBER OF CLINICAL TRIAL: ( www. CLINICALTRIALS: gov ): NCT03630588 (August 15, 2018).

Interactions among the mycobiome, bacteriome, inflammation, and diet in people living with HIV.

While the intestinal microbiome seems a major driver of persistent immune defects in people with HIV (PWH), little is known about its fungal component, the mycobiome. We assessed the inter-kingdom mycobiome-bacteriome interactions, the impact of diet, and the association with the innate and adaptive immunity in PWH on antiretroviral therapy. We included 24 PWH individuals and 12 healthy controls. We sequenced the Internal Transcribed Spacer 2 amplicons, determined amplicon sequence variants, measured biomarkers of the innate and adaptive immunity in blood and relations with diet. Compared to healthy controls, PWH subjects exhibited a distinct and richer mycobiome and an enrichment for Debaryomyces hansenii, Candida albicans, and Candida parapsilosis. In PWH, Candida and Pichia species were strongly correlated with several bacterial genera, including Faecalibacterium genus. Regarding the links between the mycobiome and systemic immunology, we found a positive correlation between Candida species and the levels of proinflammatory cytokines (sTNF-R2 and IL-17), interleukin 22 (a cytokine implicated in the regulation of mucosal immunity), and CD8+ T cell counts. This suggests an important role of the yeasts in systemic innate and adaptive immune responses. Finally, we identified inter-kingdom interactions implicated in fiber degradation, short-chain fatty acid production, and lipid metabolism, and an effect of vegetable and fiber intake on the mycobiome. Therefore, despite the great differences in abundance and diversity between the bacterial and fungal communities of the gut, we defined the changes associated with HIV, determined several different inter-kingdom associations, and found links between the mycobiome, nutrient metabolism, and systemic immunity.

Targeting the Gut Microbiota of Vertically HIV-Infected Children to Decrease Inflammation and Immunoactivation: A Pilot Clinical Trial.

Aims: Children with HIV exhibit chronic inflammation and immune dysfunction despite antiretroviral therapy (ART). Strategies targeting persistent inflammation are needed to improve health in people living with HIV. The gut microbiota likely interacts with the immune system, but the clinical implications of modulating the dysbiosis by nutritional supplementation are unclear. Methods: Pilot, double-blind, randomized placebo-controlled trial in which 24 HIV-infected on ART were randomized to supplementation with a daily mixture of symbiotics, omega-3/6 fatty acids and amino acids, or placebo four weeks, in combination with ART. We analyzed inflammatory markers and T-cell activation changes and their correlations with shifts in fecal microbiota. Results: Twenty-four HIV-infected children were recruited and randomized to receive a symbiotic nutritional supplement or placebo. Mean age was 12 ± 3.9 years, 62.5% were female. All were on ART and had HIV RNA < 50/mL. We did not detect changes in inflammatory (IL-6, IL-7, IP-10), microbial translocation (sCD14), mucosal integrity markers (IFABP, zonulin) or the kynurenine to tryptophan ratio, or changes in markers of the adaptive immune response in relation to the intervention. However, we found correlations between several key bacteria and the assessed inflammatory and immunological parameters, supporting a role of the microbiota in immune modulation in children with HIV. Conclusions: In this exploratory study, a four-week nutritional supplementation had no significant effects in terms of decreasing inflammation, microbial translocation, or T-cell activation in HIV-infected children. However, the correlations found support the interaction between gut microbiota and the immune system.

Relationship of Diet to Gut Microbiota and Inflammatory Biomarkers in People with HIV.

While changes in microbiome composition have been associated with HIV, the effect of diet and its potential impact on inflammation remains unclear. Methods: Twenty-seven people living with HIV (PWH) on antiretroviral therapy (ART) were studied. A comprehensive dietary analysis was performed and two types of dietary patterns were determined. We explored the associations of each dietary pattern with gut microbiota and plasma inflammatory biomarkers. Results: We appreciated two dietary patterns, Mediterranean-like (MEL) and one Western-like (WEL). Compared to participants with the WEL pattern, participants with MEL pattern showed higher abundance of Lachnospira (p-value = 0.02) and lower levels of the inflammatory biomarkers D-dimer (p-value = 0.050) and soluble TNF-alpha receptor 2 (sTNFR2) (p-value = 0.049). Men who have sex with men (MSM) with MEL pattern had lower abundance of Erysipelotrichaceae (p-value < 0.001) and lower levels of D-dimer (p-value = 0.026) than MSM with WEL pattern. Conclusion: MEL pattern favours Lachnospira abundance, and protects against Erysipelotrichaceae abundance and higher levels of the inflammatory biomarkers D-dimer and sTNFR2, precursors of inflammatory processes in HIV-infected patients. Our study contributes to understanding the determinants of a healthier diet and its connections with gut microbiota and inflammation.

Effect of roasting conditions on cocoa bioactivity and gut microbiota modulation.

Cocoa is a highly consumed food with beneficial effects on human health. Cocoa roasting has an important influence on its sensory and nutritional characteristics; therefore, roasting could also play a role in cocoa bioactivity. Thus, the aim of this paper is to unravel the effect of cocoa roasting conditions on its antioxidant capacity and modifications of gut microbiota after in vitro digestion-fermentation. HMF and furfural, chemical markers of non-enzymatic browning, were analyzed in unroasted and roasted cocoa powder at different temperatures, as well as different chocolates. The antioxidant capacity decreased with roasting, most probably due to the loss of phenolic compounds during heating. In the case of the evaluated chocolates, the antioxidant capacity was 2-3 times higher in the fermented fraction. On the other hand, HMF and furfural content increased during roasting due to increasing temperatures. Moreover, unroasted and roasted cocoa powder have different effects on gut microbial communities. Roasted cocoa favored butyrate production, whereas unroasted cocoa favored acetate and propionate production in a significant manner. In addition, unroasted and roasted cocoa produced significantly different gut microbial communities in terms of composition. Although many bacteria were affected, Veillonella and Faecalibacterium were some of the most discriminant ones; whereas the former is a propionate producer, the latter is a butyrate producer that has also been linked to positive effects on the inflammatory health of the gut and the immune system. Therefore, unroasted and roasted cocoa (regardless of the roasting temperature) promote different bacteria and a different SCFA production.

An extended reconstruction of human gut microbiota metabolism of dietary compounds.

Understanding how diet and gut microbiota interact in the context of human health is a key question in personalized nutrition. Genome-scale metabolic networks and constraint-based modeling approaches are promising to systematically address this complex problem. However, when applied to nutritional questions, a major issue in existing reconstructions is the limited information about compounds in the diet that are metabolized by the gut microbiota. Here, we present AGREDA, an extended reconstruction of diet metabolism in the human gut microbiota. AGREDA adds the degradation pathways of 209 compounds present in the human diet, mainly phenolic compounds, a family of metabolites highly relevant for human health and nutrition. We show that AGREDA outperforms existing reconstructions in predicting diet-specific output metabolites from the gut microbiota. Using 16S rRNA gene sequencing data of faecal samples from Spanish children representing different clinical conditions, we illustrate the potential of AGREDA to establish relevant metabolic interactions between diet and gut microbiota.

Gut Microbiota Profile and Its Association with Clinical Variables and Dietary Intake in Overweight/Obese and Lean Subjects: A Cross-Sectional Study.

We aimed to differentiate gut microbiota composition of overweight/obese and lean subjects and to determine its association with clinical variables and dietary intake. A cross-sectional study was performed with 96 overweight/obese subjects and 32 lean subjects. Anthropometric parameters were positively associated with Collinsella aerofaciens, Dorea formicigenerans and Dorea longicatena, which had higher abundance the overweight/obese subjects. Moreover, different genera of Lachnospiraceae were negatively associated with body fat, LDL and total cholesterol. Saturated fatty acids (SFAs) were negatively associated with the genus Intestinimonas, a biomarker of the overweight/obese group, whereas SFAs were positively associated with Roseburia, a biomarker for the lean group. In conclusion, Dorea formicigenerans, Dorea longicatena and Collinsella aerofaciens could be considered obesity biomarkers, Lachnospiraceae is associated with lipid cardiovascular risk factors. SFAs exhibited opposite association profiles with butyrate-producing bacteria depending on the BMI. Thus, the relationship between diet and microbiota opens new tools for the management of obesity.

Enrichment of Food With Tannin Extracts Promotes Healthy Changes in the Human Gut Microbiota.

Food and food bioactive components are major drivers of modulation of the human gut microbiota. Tannin extracts consist of a mix of bioactive compounds, which are already exploited in the food industry for their chemical and sensorial properties. The aim of our study was to explore the viability of associations between tannin wood extracts of different origin and food as gut microbiota modulators. 16S rRNA amplicon next-generation sequencing (NGS) was used to test the effects on the gut microbiota of tannin extracts from quebracho, chestnut, and tara associated with commercial food products with different composition in macronutrients. The different tannin-enriched and non-enriched foods were submitted to in vitro digestion and fermentation by the gut microbiota of healthy subjects. The profile of the short chain fatty acids (SCFAs) produced by the microbiota was also investigated. The presence of tannin extracts in food promoted an increase of the relative abundance of the genus Akkermansia, recognized as a marker of a healthy gut, and of various members of the Lachnospiraceae and Ruminococcaceae families, involved in SCFA production. The enrichment of foods with tannin extracts had a booster effect on the production of SCFAs, without altering the profile given by the foods alone. These preliminary results suggest a positive modulation of the gut microbiota with potential benefits for human health through the enrichment of foods with tannin extracts.

Effect of Mastiha supplementation on NAFLD: The MAST4HEALTH Randomised, Controlled Trial.

SCOPE: Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease with poor therapeutic strategies. Mastiha possesses antioxidant/anti-inflammatory and lipid-lowering properties. The authors investigate the effectiveness of Mastiha as a nonpharmacological intervention in NAFLD. METHODS AND RESULTS: Ninety-eight patients with NAFLD in three countries (Greece, Italy, Serbia) are randomly allocated to either Mastiha or Placebo for 6 months, as part of a multicenter, randomized, double-blind, placebo-controlled, parallel-group clinical trial. The authors assess NAFLD severity via magnetic resonance imaging (MRI) scanning and LiverMultiScan technique and evaluate the effectiveness of Mastiha through medical, anthropometric, biochemical, metabolomic, and microbiota assessment. Mastiha is not superior to Placebo on changes in iron-corrected T1 (cT1) and Liver Inflammation Fibrosis score (LIF) in entire patient population; however, after BMI stratification (BMI ≤ 35 kg m-2 and BMI > 35 kg m-2 ), severely obese patients show an improvement in cT1 and LIF in Mastiha versus Placebo. Mastiha increases dissimilarity of gut microbiota, as shown by the Bray-Curtis index, downregulates Flavonifractor, a known inflammatory taxon and decreases Lysophosphatidylcholines-(LysoPC) 18:1, Lysophosphatidylethanolamines-(LysoPE) 18:1, and cholic acid compared to Placebo. CONCLUSION: Mastiha supplementation improves microbiota dysbiosis and lipid metabolite levels in patients with NAFLD, although it reduces parameters of liver inflammation/fibrosis only in severely obese patients.

Fecal microbiota transplantation in HIV: A pilot placebo-controlled study.

Changes in the microbiota have been linked to persistent inflammation during treated HIV infection. In this pilot double-blind study, we study 30 HIV-infected subjects on antiretroviral therapy (ART) with a CD4/CD8 ratio < 1 randomized to either weekly fecal microbiota capsules or placebo for 8 weeks. Stool donors were rationally selected based on their microbiota signatures. We report that fecal microbiota transplantation (FMT) is safe, not related to severe adverse events, and attenuates HIV-associated dysbiosis. FMT elicits changes in gut microbiota structure, including significant increases in alpha diversity, and a mild and transient engraftment of donor's microbiota during the treatment period. The greater engraftment seems to be achieved by recent antibiotic use before FMT. The Lachnospiraceae and Ruminococcaceae families, which are typically depleted in people with HIV, are the taxa more robustly engrafted across time-points. In exploratory analyses, we describe a significant amelioration in the FMT group in intestinal fatty acid-binding protein (IFABP), a biomarker of intestinal damage that independently predicts mortality. Gut microbiota manipulation using a non-invasive and safe strategy of FMT delivery is feasible and deserves further investigation. Trial number: NCT03008941.

Exploiting the Microbiota for the Diagnosis of Anal Precancerous Lesions in Men Who Have Sex With Men.

BACKGROUND: While the microbiota has been associated with human papillomavirus malignant transformation, it is unclear whether anal bacteria could improve the low specificity of anal cytology for the screening of high-grade intraepithelial squamous neoplasia (HSIL). METHODS: We recruited men who have sex with men undergoing anal cytology and high-resolution anoscopy. We assessed the microbiota composition from fecal samples and cytobrush anal samples using 16S ribosomal DNA sequencing in participants with or without biopsy-proven HSIL (bHSIL). We selected bacterial biomarkers based on their linear discriminant analysis. We assessed their predictive performance using logistic regression and bootstrap resampling. RESULTS: We included 128 individuals, 47 (36.7%) with bHSIL and 99 (77.3%) with human immunodeficiency virus. We detected 40 potential predictors of bHSIL. Ruminococcaceae NK4A214 group, Alloprevotella genus, Prevotella melanonigenica, and Ruminococcaceae UCG-014 were the most predictive of bHSIL. From 35 false-positive cytologic results, the combination of these 4 biomarkers with the anal cytology reclassified to true-negative 33 individuals (94%) and showed good diagnostic performance (area under the receiver operating characteristic curve, 0.805; 95% confidence interval, .728-.882). CONCLUSIONS: We found anal-associated bacteria indicative of a higher risk of precancerous anal lesions, which combination was highly specific. The microbiota could be developed as a complementary diagnostic tool to overcome the limitations of the current screening strategy for anal cancer.

Blood Bacterial Profiles Associated With Human Immunodeficiency Virus Infection and Immune Recovery.

Human immunodeficiency virus (HIV) infection impairs mucosal immunity and leads to bacterial translocation, fueling chronic inflammation and disease progression. While this is well established, questions remain about the compositional profile of the translocated bacteria, and to what extent it is influenced by antiretroviral therapy (ART). Using 16S ribosomal DNA targeted sequencing and shotgun proteomics, we showed that HIV increases bacterial translocation from the gut to the blood. HIV increased alpha diversity in the blood, which was dominated by aerobic bacteria belonging to Micrococcaceae (Actinobacteria) and Pseudomonadaceae (Proteobacteria) families, and the number of circulating bacterial proteins was also increased. Forty-eight weeks of ART attenuated this phenomenon. We found that enrichment with Lactobacillales order, and depletion of Actinobacteria class and Moraxellaceae and Corynebacteriacae families, were significantly associated with greater immune recovery and correlated with several inflammatory markers. Our findings suggest that the molecular cross talk between the host and the translocated bacterial products could influence ART-mediated immune recovery.

Interplay between dietary phenolic compound intake and the human gut microbiome in hypertension: A cross-sectional study.

In the present study, potential associations between dietary phenolic compounds (PCs), gut microbiota composition and targeted faecal metabolites were identified in a cross-sectional study including grade 1 hypertensive (HT) and normotensive (NT) subjects. We performed comprehensive quantification of PC intake, together with 16S rRNA gene sequencing of the gut microbiota, and faecal and plasma short-chain fatty acids (SCFAs) determination. The results showed multiple-way relationships between PCs from several plant-based foods and 25 bacterial taxa previously defined as discriminant biomarkers among groups. Remarkably, coffee PCs were positively associated with systolic and diastolic blood pressure, faecal SCFAs, Bacteroides plebeius and Bacteroides coprocola in HT and negatively associated with Faecalibacterium prausnitzii and Christensenellaceae R-7 in NT. Olive fruit PCs were positively associated with Ruminococcaceae UCG-010, Christensenellaceae R-7 and plasma SCFAs in NT. These interplays with discriminant bacterial taxa in HT and NT subjects highlight the potential role of specific PCs as gut microbiome modulators in either the pathogenesis or prevention of hypertension.

Effect of a Nutritional Intervention on the Intestinal Microbiota of Vertically HIV-Infected Children: The Pediabiota Study.

AIMS: The gut microbiota exerts a critical influence in the immune system. The gut microbiota of human virus immunodeficiency (HIV)-infected children remains barely explored. We aimed to characterize the fecal microbiota in vertically HIV-infected children and to explore the effects of its modulation with a symbiotic nutritional intervention. METHODS: a pilot, double blind, randomized placebo-controlled study including HIV-infected children who were randomized to receive a nutritional supplementation including prebiotics and probiotics or placebo for four weeks. HIV-uninfected siblings were recruited as controls. The V3-V4 region of the 16S rRNA gene was sequenced in fecal samples. RESULTS: 22 HIV-infected children on antiretroviral therapy (ART) and with viral load (VL) <50/mL completed the follow-up period. Mean age was 11.4 ± 3.4 years, eight (32%) were male. Their microbiota showed reduced alpha diversity compared to controls and distinct beta diversity at the genus level (Adonis p = 0.042). Patients showed decreased abundance of commensals Faecalibacterium and an increase in Prevotella, Akkermansia and Escherichia. The nutritional intervention shaped the microbiota towards the control group, without a clear directionality. CONCLUSIONS: Vertical HIV infection is characterized by changes in gut microbiota structure, distinct at the compositional level from the findings reported in adults. A short nutritional intervention attenuated bacterial dysbiosis, without clear changes at the community level. SUMMARY: In a group of 24 vertically HIV-infected children, in comparison to 11 uninfected controls, intestinal dysbiosis was observed despite effective ART. Although not fully effective to restore the microbiota, a short intervention with pre/probiotics attenuated bacterial dysbiosis.

Valorization of Persimmon and Blueberry Byproducts to Obtain Functional Powders: In Vitro Digestion and Fermentation by Gut Microbiota.

Globalization of fruit and vegetable markets generates overproduction, surpluses, and potentially valuable residues. The valorization of these byproducts constitutes a challenge, to ensure sustainability and reintroduce them into the food chain. This work focuses on blueberry and persimmon residues, rich in polyphenols and carotenoids, to obtain powders with high added value to be used as ingredients in food formulation. These powders have been characterized, and the changes in the bioactive compounds in in vitro gastrointestinal digestion have been evaluated. The results indicated that the type of residue, the drying process, as well as the content and type of fiber determine the release of antioxidants during digestion. In vitro colonic fermentations were also performed, and it was observed that the characteristics of digested powders had an effect on the composition of the growing microbial community. Thus, carotenoids and anthocyanins maintain an interplay with microbiota that could be beneficial for human health.

Gut metagenomic and short chain fatty acids signature in hypertension: a cross-sectional study.

Hypertension is an independent and preventable risk factor for the development of cardiovascular diseases, however, little is known about the impact of gut microbiota composition in its development. We carried out comprehensive gut microbiota analysis and targeted metabolomics in a cross-sectional study of 29 non-treated hypertensive (HT) and 32 normotensive (NT) subjects. We determined fecal microbiota composition by 16S rRNA gene sequencing and bacterial functions by metagenomic analysis. The microbial metabolites analysed were short chain fatty acids (SCFA) both in plasma and feces, and trimethylamine N-oxide (TMAO) in plasma. The overall bacterial composition and diversity of bacterial community in the two groups were not significantly different. However, Ruminococcaceae NK4A214, Ruminococcaceae_UCG-010, Christensenellaceae_R-7, Faecalibacterium prausnitzii and Roseburia hominis were found to be significantly enriched in NT group, whereas, Bacteroides coprocola, Bacteroides plebeius and genera of Lachnospiraceae were increased in HT patients. We found a positive correlation between the HT-associated species and systolic and diastolic blood pressure after adjusted for measured confounders. SCFA showed antagonistic results in plasma and feces, detecting in HT subjects significant higher levels in feces and lower levels in plasma, which could indicate a less efficient SCFA absorption. Overall, our results present a disease classifier based on microbiota and bacterial metabolites to discriminate HT individuals from NT controls in a first disease grade prior to drug treatment.