Effect of Plant-Based Diets on Gut Microbiota: A Systematic Review of Interventional Studies

The association between Planetary Health Diet Index and the risk of colorectal cancer: a case-control study

Background Despite the beneficial effects of a plant-based diet on colorectal cancer (CRC), no study has yet investigated the relationship between a Planetary Health Diet Index (PHDI) and CRC in the Iranian population. Therefore, the present case-control study aimed to assess the relationship between this index and CRC. Methods The current research was conducted on 71 patients with CRC (case group) and 142 (control group) admitted to hospitals in Tehran, Iran. The PHDI (0-150 points) was calculated based on a semi-quantitative food frequency questionnaire. Conditional logistic regression was applied to evaluate the association between CRC and PHDI and its sub-scores. Results After adjusting for the role of potential confounders, lower odds of CRC were observed in the second tertile of the total ratio score (odds ratio (OR) = 0.334; 95% confidence interval (CI): 0.127-0.878, P = 0.026) and the last tertile of PHDI (OR = 0.407; 95% CI: 0.183-0.907, P = 0.028), total adequacy score (OR = 0.261; 95% CI: 0.110-0.622, P = 0.002), and total moderation score (OR = 0.380; 95% CI: 0.162-0.891, P = 0.026) in comparison to the first tertile of each index. Conclusions The current study's findings indicated a reverse relationship between PHDI, total adequacy, moderation, and ratio scores with the CRC odds. However, it is suggested that more research be performed in this field in the future to confirm the results of this study.

Increasing plant protein in the diet induces changes in the plasma metabolome that may be beneficial for metabolic health. A randomized crossover study in males

BACKGROUND & AIM

Dietary shifts replacing animal protein (AP) with plant protein (PP) sources have been associated with lowering cardiometabolic risk (CMR), but underlying mechanisms are poorly characterized. This nutritional intervention aims to characterize the metabolic changes induced by diets containing different proportions of AP and PP sources in males at CMR.

DESIGN

This study is a 4-week, crossover, randomized, controlled-feeding trial in which 19 males with CMR followed two diets providing either 36 % for the control diet (CON-D) or 64 % for the flexitarian diet (FLEX-D) of total protein intake from PP sources. Plasma nontargeted metabolomes (LC-MS method) were measured in the fasted state and after a high-fat challenge meal at the end of each intervention arm. Lipogenesis and protein synthesis fluxes, flow-mediated dilatation (FMD) and gluco-lipidic responses were assessed after the challenge meal. Data were analyzed with mixed models, and univariate and multivariate models for metabolomics data.

RESULTS

In both arms CMR improved with time, with decreased body weight (-0.9 %), insulin resistant (-34 %, HOMA-IR, Homeostatic Model Assessment for Insulin Resistance) and low-density lipoproteins (LDL)-cholesterol (-11 %). Diet had no effect on FMD or metabolic fluxes, but a trend (0.05

CONCLUSIONS

Despite little changes in risk factors after 4 wk, this study evidenced subtle metabolic adaptations in amino acids and lipid metabolism and gut microbiota activity occurring after higher PP source intake that may be beneficial to CMR.

CLINICALTRIALS

GOV STUDY IDENTIFIER

NCT04236518.

CLINICAL TRIAL REGISTRY

NCT04236518 on ClinicalTrials.gov.

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Key Words

• Branched-chain amino acids
• Hypertriglyceridemic waist phenotype
• Plant proteins
• Plant-based diet
• Postprandial response
• Trimethylamine-oxide

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Affiliation(s)

Gaïa Lépine Université Clermont Auvergne, INRAE, UNH, 63000, Clermont-Ferrand, France; Université Paris-Saclay, AgroParisTech, INRAE, UMR PNCA, 91120, Palaiseau, France
François Mariotti Université Paris-Saclay, AgroParisTech, INRAE, UMR PNCA, 91120, Palaiseau, France
Marie Tremblay-Franco Toxalim - Research Centre in Food Toxicology, Toulouse University, INRAE, ENVT, INP-Purpan, UT3, F-31300, Toulouse, France; MetaboHUB-MetaToul, National Infrastructure of Metabolomics and Fluxomics, Toulouse, 31077, France
Marion Courrent CHU Clermont-Ferrand, Inserm CIC 1405, France
Marie-Anne Verny Université Clermont Auvergne, INRAE, UNH, 63000, Clermont-Ferrand, France
Jérémie David Université Clermont Auvergne, INRAE, UNH, 63000, Clermont-Ferrand, France
Véronique Mathé Université Paris-Saclay, AgroParisTech, INRAE, UMR PNCA, 91120, Palaiseau, France
Patrick Jame Universite Claude Bernard Lyon 1, CNRS, ISA, UMR5280, 5 rue de la Doua, F-69100 Villeurbanne, France
Anthony Anchisi Universite Claude Bernard Lyon 1, CNRS, ISA, UMR5280, 5 rue de la Doua, F-69100 Villeurbanne, France
Catherine Lefranc-Millot Roquette Frères, Lestrem, France
Caroline Perreau Roquette Frères, Lestrem, France
Laetitia Guérin-Deremaux Roquette Frères, Lestrem, France
Céline Chollet CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), MetaboHUB, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
Florence Castelli CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), MetaboHUB, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
Emeline Chu-Van CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), MetaboHUB, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
Jean-François Huneau Université Paris-Saclay, AgroParisTech, INRAE, UMR PNCA, 91120, Palaiseau, France
Didier Rémond Université Clermont Auvergne, INRAE, UNH, 63000, Clermont-Ferrand, France
Gisèle Pickering CHU Clermont-Ferrand, Inserm CIC 1405, France
Hélène Fouillet Université Paris-Saclay, AgroParisTech, INRAE, UMR PNCA, 91120, Palaiseau, France.
Sergio Polakof Université Clermont Auvergne, INRAE, UNH, 63000, Clermont-Ferrand, France.

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The Effect of Dietary Types on Gut Microbiota Composition and Development of Non-Communicable Diseases: A Narrative Review

INTRODUCTION

The importance of diet in shaping the gut microbiota is well established and may help improve an individual's overall health. Many other factors, such as genetics, age, exercise, antibiotic therapy, or tobacco use, also play a role in influencing gut microbiota.

AIM

This narrative review summarizes how three distinct dietary types (plant-based, Mediterranean, and Western) affect the composition of gut microbiota and the development of non-communicable diseases (NCDs).

METHODS

A comprehensive literature search was conducted using the PubMed, Web of Science, and Scopus databases, focusing on the keywords "dietary pattern", "gut microbiota" and "dysbiosis".

RESULTS

Both plant-based and Mediterranean diets have been shown to promote the production of beneficial bacterial metabolites, such as short-chain fatty acids (SCFAs), while simultaneously lowering concentrations of trimethylamine-N-oxide (TMAO), a molecule associated with negative health outcomes. Additionally, they have a positive impact on microbial diversity and therefore are generally considered healthy dietary types. On the other hand, the Western diet is a typical example of an unhealthy nutritional approach leading to an overgrowth of pathogenic bacteria, where TMAO levels rise and SCFA production drops due to gut dysbiosis.

CONCLUSION

The current scientific literature consistently highlights the superiority of plant-based and Mediterranean dietary types over the Western diet in promoting gut health and preventing NCDs. Understanding the influence of diet on gut microbiota modulation may pave the way for novel therapeutic strategies.

The interplay between gut microbiome and physical exercise in athletes

PURPOSE OF REVIEW

The gut microbiome regulates several health and disease-related processes. However, the potential bidirectional relationship between the gut microbiome and physical exercise remains uncertain. Here, we review the evidence related to the gut microbiome in athletes.

RECENT FINDINGS

The effect of physical exercise on the intestinal microbiome and intestinal epithelial cells depends on the type, volume, and intensity of the activity. Strenuous exercise negatively impacts the intestinal microbiome, but adequate training and dietary planning could mitigate these effects. An increase in short-chain fatty acids (SCFAs) concentrations can modulate signaling pathways in skeletal muscle, contributing to greater metabolic efficiency, preserving muscle glycogen, and consequently optimizing physical performance and recovery. Furthermore, higher SCFAs concentrations appear to lower inflammatory response, consequently preventing an exacerbated immune response and reducing the risk of infections among athletes. Regarding dietary interventions, the optimal diet composition for targeting the athlete's microbiome is not yet known. Likewise, the benefits or harms of using probiotics, synbiotics, and postbiotics are not well established, whereas prebiotics appear to optimize SCFAs production.

SUMMARY

The intestinal microbiome plays an important role in modulating health, performance, and recovery in athletes. SCFAs appear to be the main intestinal metabolite related to these effects. Nutritional strategies focusing on the intestinal microbiome need to be developed and tested in well controlled clinical trials.

Health Benefits of a Plant-Based Dietary Pattern and Implementation in Healthcare and Clinical Practice

The American College of Lifestyle Medicine recommends eating a predominantly plant-based diet with a variety of minimally processed vegetables, fruits, whole grains, legumes, nuts and seeds. At any level, adoption of a plant-based diet can improve one's health through a variety of mechanisms. Increasing intake of plant-based foods often results in increases in fiber intake, decreases in saturated fat intake, and increased intake of essential vitamins and minerals, among other healthful benefits. Despite such potential benefits, many individuals are reluctant or resistant to change their usual dietary behaviors or unable to sustain diet changes over time. This is largely because an individual's decision to adopt a plant-based diet is influenced by a diverse array of motivating factors, priorities, and/or misconceptions about nutrient adequacy of plant-based diets. Here, we discuss key points from a session at the American College of Lifestyle Medicine's annual conference LM2023. Specifically, we review common preconceptions about plant-based diets, provide guidance on removing the barriers to adopting and adhering to plant-based diets, and highlight key literature findings supporting the health benefits of plant-based diets. Last, we discuss how plant-based diets are increasingly being implemented within health care and clinical practice to support Food is/as Medicine approaches.

Impact of Novel Foods on the Human Gut Microbiome: Current Status

The microbiome is a complex ecosystem of microorganisms that inhabit a specific environment. It plays a significant role in human health, from food digestion to immune system strengthening. The "Novel Foods" refer to foods or ingredients that have not been consumed by humans in the European Union before 1997. Currently, there is growing interest in understanding how "Novel Foods" affect the microbiome and human health. The aim of this review was to assess the effects of "Novel Foods" on the human gut microbiome. Research was conducted using scientific databases, focusing on the literature published since 2000, with an emphasis on the past decade. In general, the benefits derived from this type of diet are due to the interaction between polyphenols, oligosaccharides, prebiotics, probiotics, fibre content, and the gut microbiome, which selectively promotes specific microbial species and increases microbial diversity. More research is being conducted on the consumption of novel foods to demonstrate how they affect the microbiome and, thus, human health. Consumption of novel foods with health-promoting properties should be further explored to maintain the diversity and functionality of the gut microbiome as a potential tool to prevent the onset and progression of chronic diseases.

The role of fiber in modulating plant protein-induced metabolic responses

The rising consumption of plant protein foods and the emergence of meat alternatives have prompted interest in the health benefits of such products, which contain fiber in addition to protein. This review investigates the effect of fiber on plant-based protein metabolism and evaluates its contribution to gut-derived health impacts. Plant proteins, which often come with added fiber, can have varying health outcomes. Factors such as processing and the presence of fiber and starch influence the digestibility of plant proteins, potentially leading to increased proteolytic fermentation in the gut and the production of harmful metabolites. However, fermentable fiber can counteract this effect by serving as a primary substrate for gut microbes, decreasing proteolytic activity. The increased amount of fiber, rather than the protein source itself, plays a significant role in the observed health benefits of plant-based diets in human studies. Differences between extrinsic and intrinsic fiber in the food matrix further impact protein fermentation and digestibility. Thus, in novel protein products without naturally occurring fiber, the health impact may differ from conventional plant protein sources. The influence of various fibers on plant-based protein metabolism throughout the gastrointestinal tract is not fully understood, necessitating further research.

From Garden to Pillow: Understanding the Relationship between Plant-Based Nutrition and Quality of Sleep

The effect of diet on sleep quality has been addressed in many studies; however, whether/how plant-based diets (PBDs) impact sleep-related parameters has not been explored in detail. This review aims to give an overview of the components of PBDs and the possible mechanisms through which PBDs may improve sleep quality. Studies have indicated that diets such as PBDs, which are typically high in fruits, vegetables, nuts, seeds, whole grains, and fiber, are associated with better sleep outcomes, including less fragmented sleep and improved sleep duration. Several mechanisms may explain how PBDs impact and/or improve sleep outcomes. Firstly, PBDs are characteristically rich in certain nutrients, such as magnesium and vitamin B6, which have been associated with improved sleep patterns. Secondly, PBDs are often lower in saturated fats and higher in fiber, which may contribute to better overall health, including sleep quality. Additionally, plant bioactive compounds like phytochemicals and antioxidants in fruits, vegetables, and herbs may have sleep-promoting effects. According to available data, PBD and Mediterranean diet elements promise to enhance sleep quality; however, it is crucial to note that diets should be customized based on each person's needs.

Impact of Substituting Meats with Plant-Based Analogues on Health-Related Markers: A Systematic Review of Human Intervention Studies

The growing drive towards more sustainable dietary patterns has led to an increased demand for and availability of plant-based meat analogues (PBMAs). This systematic review aims to summarize the currently available evidence from human intervention studies investigating the impact of substituting animal meat (AM) with PBMAs in adults. A total of 19 studies were included. Overall, an increase in satiety following PBMA intake was reported, albeit to different extents and not always accompanied by changes in leptin and ghrelin. PBMAs generally resulted in lower protein bioavailability and a smaller increase in plasma essential amino acids in comparison to AM. However, muscle protein synthesis and physical performance were not affected. Finally, conflicting results have been reported for other outcomes, such as pancreatic and gastrointestinal hormones, oxidative stress and inflammation, vascular function, and microbiota composition. In conclusion, we documented that the impact of substituting AM with PBMA products has been scarcely investigated. In addition, the heterogeneity found in terms of study design, population, outcomes, and findings suggests the need for additional high-quality intervention trials, particularly long-term ones, to better clarify the advantages and potential critical issues of such substitutions within sustainable healthy diets.

Foodomics-based metabolites profiling of the Greek yogurt incorporated with unripened papaya peel powder

The food waste of the fruit processing industry is rich in many bio-active components such as polysaccharides, polyphenols, peptides, etc. that own multifaceted health benefits. The valorization of this waste is an intriguing optimization method for various dairy products. Meanwhile, LC-MS-based foodomics has been an emerging approach for the quantitative and qualitative analysis of dairy foods. Untargeted metabolomics has been done of the optimized functional yogurt that contains different levels of unripened papaya peel powder (UPPP) using high-resolution mass spectroscopy for analysis of added bio-active components in the matrix. UPPP comprises a high content of phytochemicals which could give functionality and therapeutic effect to the Greek yogurt. A total of 36 functional metabolites have been identified which have various health-beneficial attributes. Kaempferol, ostruthin, putative carpaine derivatives, etc. are some of the metabolites of high importance with a wide area coverage in the metabolome. This work highlights the bioactivity of the UPPP and its prebiotic properties added to the functional yogurt as an independent ingredient. The incorporated plant-based ingredients like UPPP can effectively enhance the functional attributes of Greek yogurt, which is a potential synbiotic food.

Plant-based and Early Time-restricted Eating for Prevention and Treatment of Type 2 Diabetes in Adults: A Narrative Review

Type 2 diabetes (T2D) is a significant public health challenge for which effective lifestyle interventions are needed. A growing body of evidence supports the use of both plant-based eating patterns and early time-restricted eating (eTRE) for the prevention and treatment of T2D, but research has not yet explored the potential of these dietary strategies in combination. In this narrative review, we assessed the evidence by which plant-based diets, in conjunction with eTRE, could support T2D care. The electronic databases MEDLINE and the Web of Science were searched for relevant articles published throughout the last decade. Observational research has shown that healthy plant-based eating patterns and eTRE are associated with reductions in T2D risk. Interventional trials demonstrated that plant-based diets promote improvements in glycated hemoglobin, insulin resistance, glycemic management, and cardiometabolic risk factors. These changes may be mediated, in part, by reductions in oxidative stress, dietary acid load, and hepatocellular and intramyocellular lipids. The eTRE strategies were also shown to improve insulin resistance and glycemic management, and mechanisms of action included enhanced regulation of circadian rhythm and increased metabolic flexibility. Integrating these dietary strategies may produce additive benefits, mediated by reduced visceral adiposity and beneficial shifts in gut microbiota composition. However, potential barriers to concurrent implementation of these interventions may exist, including social challenges, scheduling constraints, and tolerance. Prospective trials are needed to examine their acceptability and clinical effects.

Modulation of the gut microbiota by processed food and natural food: evidence from the Siniperca chuatsi microbiome

Habitual dietary changes have the potential to induce alterations in the host's gut microbiota. Mandarin fish (Siniperca chuatsi), an aquatic vertebrate species with distinct feeding habits, were fed with natural feeds (NF) and artificial feeds (AF) to simulate the effects of natural and processed food consumption on host gut microbiota assemblages. The results showed that the alpha diversity index was reduced in the AF diet treatment, as lower abundance and diversity of the gut microbiota were observed, which could be attributed to the colonized microorganisms of the diet itself and the incorporation of plant-derived proteins or carbohydrates. The β-diversity analysis indicated that the two dietary treatments were associated with distinct bacterial communities. The AF diet had a significantly higher abundance of Bacteroidota and a lower abundance of Actinomycetota, Acidobacteriota, and Chloroflexota compared to the NF group. In addition, Bacteroidota was the biomarker in the gut of mandarin fish from the AF treatment, while Acidobacteriota was distinguished in the NF treatments. Additionally, the increased abundance of Bacteroidota in the AF diet group contributed to the improved fermentation and nutrient assimilation, as supported by the metabolic functional prediction and transcriptome verification. Overall, the present work used the mandarin fish as a vertebrate model to uncover the effects of habitual dietary changes on the evolution of the host microbiota, which may provide potential insights for the substitution of natural foods by processed foods in mammals.

Unveiling the dynamics of gut microbial interactions: a review of dietary impact and precision nutrition in gastrointestinal health

The human microbiome, a dynamic ecosystem within the gastrointestinal tract, plays a pivotal role in shaping overall health. This review delves into six interconnected sections, unraveling the intricate relationship between diet, gut microbiota, and their profound impact on human health. The dance of nutrients in the gut orchestrates a complex symphony, influencing digestive processes and susceptibility to gastrointestinal disorders. Emphasizing the bidirectional communication between the gut and the brain, the Brain-Gut Axis section highlights the crucial role of dietary choices in physical, mental, and emotional well-being. Autoimmune diseases, particularly those manifesting in the gastrointestinal tract, reveal the delicate balance disrupted by gut microbiome imbalances. Strategies for reconciling gut microbes through diets, precision nutrition, and clinical indications showcase promising avenues for managing gastrointestinal distress and revolutionizing healthcare. From the Low-FODMAP diet to neuro-gut interventions, these strategies provide a holistic understanding of the gut's dynamic world. Precision nutrition, as a groundbreaking discipline, holds transformative potential by tailoring dietary recommendations to individual gut microbiota compositions, reshaping the landscape of gastrointestinal health. Recent advancements in clinical indications, including exact probiotics, fecal microbiota transplantation, and neuro-gut interventions, signify a new era where the gut microbiome actively participates in therapeutic strategies. As the microbiome takes center stage in healthcare, a paradigm shift toward personalized and effective treatments for gastrointestinal disorders emerges, reflecting the symbiotic relationship between the human body and its microbial companions.

Exploring Australian News Media Portrayals of Sustainable and Plant-Based Diets

(1) Background: Dietary behaviour transformation is imperative for the attainment of more sustainable food systems, including an increased intake of plant-based foods and lower consumption of red meat and highly processed foods. The influence of news media coverage on public opinion regarding dietary behaviours is significant. Therefore, this study aimed to explore how sustainable/plant-based diets have been portrayed in Australian news media. (2) Methods: The Factiva global news database was used to search news articles published in Australia between 2018 and 2020. Relevant news articles were selected if they included keywords relating to sustainable diets, plant-based diets, and meat alternatives. We used a coding protocol to extract key information, such as date of publication, article topic, and any health, environmental and economic impacts. Then, we performed a framing and thematic analysis of the data. (3) Results: From 357 included articles, more than half of the articles encouraged increasing the intake of plant-based foods (53.5%) and reducing animal-derived food intake (55.2%). Several reasons for such shift from animal protein centric Australian diets were identified throughout the articles such as health benefits (15.4%), environmental impacts (11.2%), animal welfare (4.8%), seasonality and local food intake (5.3%), avoiding overconsumption (4.5%) and food wastage (4.5%). (4) Conclusions: The predominant frame in Australian news coverage about sustainable diets has been about consumption, more plant- and less animal-based products, with little nuance about the complex interplay of diet quality and environment in influencing food choices. Australian news media should broaden its coverage of sustainable diets to include health, environmental, and economic factors to improve public understanding and facilitate informed and sustainable food choices. Further research is needed to enhance comprehension of how the audience perceives media coverage on this topic, which will provide a more thorough understanding.

Planting the Seed for Blood Pressure Control: The Role of Plant-Based Nutrition in the Management of Hypertension

PURPOSE OF REVIEW

Hypertension results in significant morbidity, mortality, and healthcare expenditures. Fortunately, it is largely preventable and treatable by implementing dietary interventions, though these remain underutilized. Here, we aim to explore the role of healthy dietary patterns in hypertension management and describe approaches for busy clinicians to address nutrition effectively and efficiently with patients.

RECENT FINDINGS

DASH, Mediterranean, vegetarian, and vegan diets that include minimally processed, plant-based foods as core elements have consistently shown positive effects on hypertension. Recommendations that distill the most healthful components of these diets can significantly impact patient outcomes. Clinicians can harness evidence-based dietary assessment and counseling tools to implement and support behavioral changes, even during brief office visits. Healthful plant-based dietary patterns can often effectively prevent and treat hypertension. Clinicians may help improve patient outcomes by discussing evidence-based nutrition with their patients. Future work to promote infrastructural change that supports incorporating evidence-based nutrition into medical education, clinical care, and society at large can support these efforts.

Microbiota Implications in Endocrine-Related Diseases: From Development to Novel Therapeutic Approaches

This comprehensive review article delves into the critical role of the human microbiota in the development and management of endocrine-related diseases. We explore the complex interactions between the microbiota and the endocrine system, emphasizing the implications of microbiota dysbiosis for the onset and progression of various endocrine disorders. The review aims to synthesize current knowledge, highlighting recent advancements and the potential of novel therapeutic approaches targeting microbiota-endocrine interactions. Key topics include the impact of microbiota on hormone regulation, its role in endocrine pathologies, and the promising avenues of microbiota modulation through diet, probiotics, prebiotics, and fecal microbiota transplantation. We underscore the importance of this research in advancing personalized medicine, offering insights for more tailored and effective treatments for endocrine-related diseases.

Vegan diet: nutritional components, implementation, and effects on adults' health

Vegan diet has emerged as a popular dietary choice for people worldwide in recent times, due to concerns such as health issues, animal rights and welfare, and the sustainability of the environment. The purpose of this literature review was to explain how a vegan diet may affect the health of adults and to point out beneficial components found in it as well as any difficulties associated with its implementation. Evidence supports that a vegan diet can reduce the risk of chronic diseases, such as type 2 diabetes, hypertension, and certain types of cancer. A well-planned vegan diet must include adequate calories and nutrients, as well as the necessary supplements, such as vitamin B12, vitamin D and EPA/DHA. Given the current growing interest in plant-based diets among the general population, it is crucial to understand both the barriers, risks, and benefits of the vegan diet among physicians, policy makers, and the general population.

Towards the characterisation of sustainable diet's gut microbiota composition and functions: A narrative review

The gut microbiome is a key element for health preservation and disease prevention. Nevertheless, defining a healthy gut microbiome is complex since it is modulated by several factors, such as host genetics, sex, age, geographical zone, drug use, and, especially, diet. Although a healthy diet has proven to increase microbial alpha and beta diversity and to promote the proliferation of health-related bacteria, considering the current environmental and nutritional crisis, such as climate change, water shortage, loss of diversity, and the obesity pandemic, it should be highlighted that a healthy diet is not always sustainable. Sustainable diets are dietary patterns that promote all dimensions of people's health and well-being while exerting low pressure on the environment, and being accessible, affordable, safe, equitable, and culturally acceptable. Examples of diets that tend to be sustainable are the Planetary Health Diet of the EAT-Lancet Commission or territorial diets such as the Mediterranean and the Traditional Mexican diet (milpa diet), adapted to specific contexts. These diets are principally plant-based but include small or moderate amounts of animal-based foods. Characterising the effects of sustainable diets on gut microbiota is urgent to ensure that the benefits for human health are aligned with environmental preservation and respect the sociocultural aspects of individuals.

Obesity, Gut Microbiota, and Metabolome: From Pathophysiology to Nutritional Interventions

Obesity is a disorder identified by an inappropriate increase in weight in relation to height and is considered by many international health institutions to be a major pandemic of the 21st century. The gut microbial ecosystem impacts obesity in multiple ways that yield downstream metabolic consequences, such as affecting systemic inflammation, immune response, and energy harvest, but also the gut-host interface. Metabolomics, a systematized study of low-molecular-weight molecules that take part in metabolic pathways, represents a serviceable method for elucidation of the crosstalk between hosts' metabolism and gut microbiota. In the present review, we confer about clinical and preclinical studies exploring the association of obesity and related metabolic disorders with various gut microbiome profiles, and the effects of several dietary interventions on gut microbiome composition and the metabolome. It is well established that various nutritional interventions may serve as an efficient therapeutic approach to support weight loss in obese individuals, yet no agreement exists in regard to the most effective dietary protocol, both in the short and long term. However, metabolite profiling and the gut microbiota composition might represent an opportunity to methodically establish predictors for obesity control that are relatively simple to measure in comparison to traditional approaches, and it may also present a tool to determine the optimal nutritional intervention to ameliorate obesity in an individual. Nevertheless, a lack of adequately powered randomized trials impedes the application of observations to clinical practice.