Announcements

We are pleased to present a selection of highly cited papers published in Metabolites (ISSN 2218-1989) from 2024 to 2026, as indexed by the Web of Science.

Below is a selection of articles that we believe will be of interest to you:

1. “Lipid Metabolism in Metabolic-Associated Steatotic Liver Disease (MASLD)”
by Majid Mufaqam Syed-Abdul
Metabolites 2024, 14(1), 12; https://doi.org/10.3390/metabo14010012
Available online: https://www.mdpi.com/2218-1989/14/1/12

2. “Polyphenols, Alkaloids, and Terpenoids Against Neurodegeneration: Evaluating the Neuroprotective Effects of Phytocompounds Through a Comprehensive Review of the Current Evidence”
by Enzo Pereira de Lima, Lucas Fornari Laurindo, Vitor Cavallari Strozze Catharin, Rosa Direito, Masaru Tanaka, Iris Jasmin Santos German, Caroline Barbalho Lamas, Elen Landgraf Guiguer, Adriano Cressoni Araújo, Adriana Maria Ragassi Fiorini et al.
Metabolites 2025, 15(2), 124; https://doi.org/10.3390/metabo15020124
Available online: https://www.mdpi.com/2218-1989/15/2/124

3. “Diverse Physiological Roles of Kynurenine Pathway Metabolites: Updated Implications for Health and Disease”
by Yuechang Wang, Yonggang Zhang, Wei Wang, Yanmin Zhang, Xueqian Dong and Yang Liu
Metabolites 2025, 15(3), 210; https://doi.org/10.3390/metabo15030210
Available online: https://www.mdpi.com/2218-1989/15/3/210

4. “Trimethylamine-N-Oxide (TMAO) as a Rising-Star Metabolite: Implications for Human Health”
by Eugenio Caradonna, Federico Abate, Elisabetta Schiano, Francesca Paparella, Fulvio Ferrara, Emilio Vanoli, Rossana Difruscolo, Vito Maria Goffredo, Bruno Amato, Carlo Setacci et al.
Metabolites 2025, 15(4), 220; https://doi.org/10.3390/metabo15040220
Available online: https://www.mdpi.com/2218-1989/15/4/220

5. “From Inflammation to Infertility: How Oxidative Stress and Infections Disrupt Male Reproductive Health”
by Anastasios Potiris, Efthalia Moustakli, Eleni Trismpioti, Eirini Drakaki, Despoina Mavrogianni, Alkis Matsas, Athanasios Zikopoulos, Antonios Sfakianakis, Ioannis Tsakiridis, Themistoklis Dagklis et al.
Metabolites 2025, 15(4), 267; https://doi.org/10.3390/metabo15040267
Available online: https://www.mdpi.com/2218-1989/15/4/267

6. “Plant Secondary Metabolites—Central Regulators Against Abiotic and Biotic Stresses”
by Ameer Khan, Farah Kanwal, Sana Ullah, Muhammad Fahad, Leeza Tariq, Muhammad Tanveer Altaf, Asad Riaz and Guoping Zhang
Metabolites 2025, 15(4), 276; https://doi.org/10.3390/metabo15040276
Available online: https://www.mdpi.com/2218-1989/15/4/276

7. “A Comprehensive Review on Medium- and Long-Chain Fatty Acid-Derived Metabolites: From Energy Sources to Metabolic Signals”
by Jin-Byung Park, Sungyun Cho and Sung-Joon Lee
Metabolites 2026, 16(1), 45; https://doi.org/10.3390/metabo16010045
Available online: https://www.mdpi.com/2218-1989/16/1/45

We had the pleasure of speaking with Mr. Asad Riaz, correspondence author of the the Editor’s Choice Article in Metabolites (ISSN 2218-1989). Below, he discusses his research focus, paper, and further reflections on study development.

“Plant Secondary Metabolites—Central Regulators Against Abiotic and Biotic Stresses”
by Ameer Khan, Farah Kanwal, Sana Ullah, Muhammad Fahad, Leeza Tariq, Muhammad Tanveer Altaf, Asad Riaz, and Guoping Zhang
Metabolites 2025, 15(4), 276; https://doi.org/10.3390/metabo15040276
Available online: https://www.mdpi.com/2218-1989/15/4/276

The following is an interview with Mr. Asad Riaz:

1. Could you briefly introduce yourself and describe your main research focus?
I am Asad Riaz, a PhD candidate at the Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, and a member of the ARC Centre of Excellence for Plant Success in Nature and Agriculture.
My primary research is in the quantitative genetics of plant architecture, particularly tillering, where I combine GWAS, haplotype analysis, transcriptomics, and field experiments across planting densities to understand how plants regulate growth and yield. Alongside this, I have a long-standing interest in plant stress metabolism. I began my research training with Prof. Guoping Zhang and have continued collaborating with his group on transcriptomics and metabolomics under abiotic stress. Working at the interface of quantitative genetics and metabolism is what shaped my perspective on this review: I am interested in the functional layer that connects genotype to stress resilience, and ultimately in translating that knowledge into climate-resilient crop varieties.

2. Could you briefly describe the main research content of your Highly Cited Paper, as well as its key innovative highlights?
Our review, “Plant Secondary Metabolites—Central Regulators Against Abiotic and Biotic Stresses”, synthesises the diverse roles of plant secondary metabolites in protecting plants against environmental and biological challenges. We examine the major groups, flavonoids, phenolics, terpenoids, alkaloids, tannins, lignins, and sulphur- and nitrogen-containing compounds and discuss their biosynthesis, regulatory networks, and stress-responsive functions.
A key innovative aspect is that we integrate findings across multiple metabolite classes and multiple stress conditions within a single conceptual framework. Rather than examining metabolite groups in isolation, we show how these compounds collectively contribute to adaptation, signalling, antioxidant defence, pathogen resistance, and stress tolerance. We also discuss emerging opportunities to harness these pathways through modern breeding, biotechnology, and genetic engineering, and identify knowledge gaps and future directions that could accelerate the development of climate-resilient crops.

3. Would you mind sharing what inspired your research?
The inspiration came from the growing pressure climate change is placing on agriculture. Crops worldwide are increasingly exposed to drought, salinity, heat, emerging diseases, and pest outbreaks. Working on plant stress responses, our team was struck by how effectively plants survive these conditions despite being unable to escape their environment.
Secondary metabolites drew our attention because they represent one of the most sophisticated defence systems in plants, functioning not only as protective molecules but also as signalling agents that regulate complex physiological responses. Although a great deal of research had been done on individual metabolite classes, we felt there was a clear need for a review that connected those discoveries within a broader framework of plant resilience. That gap is what motivated the study.

4. What were the biggest challenges you encountered during this study, and how did you overcome them?
The main challenge was the sheer volume and diversity of the literature. Secondary metabolites encompass thousands of chemically diverse compounds whose functions vary across species, stress types, and environmental conditions. A related difficulty was integrating work from very different disciplines, plant physiology, molecular biology, biochemistry, genetics, metabolomics, and crop science, since most studies focus on a single metabolite or stress, making a unified picture hard to assemble.
We addressed this through a systematic and critical review approach: evaluating recent advances carefully, identifying mechanisms common across studies, and organising the literature around functional themes such as biosynthesis, signalling, defence, and stress adaptation. That structure allowed us to offer an integrated perspective useful to readers from a range of backgrounds.

5. How do you see this research evolving or influencing future studies in the field?
I believe plant metabolism research is moving toward a systems-level understanding. Advances in metabolomics, transcriptomics, genomics, and computational biology are creating real opportunities to unravel how metabolic networks regulate stress responses, and integrating these layers with quantitative genetics is where I see much of the progress happening.
I expect increasing emphasis on identifying the key regulatory nodes controlling beneficial metabolite production, and on understanding how those pathways interact with other physiological processes. That knowledge will support precision breeding and genome-editing strategies that improve resilience without sacrificing productivity. Beyond stress tolerance, secondary metabolites also offer routes to reduce reliance on chemical pesticides and strengthen crop adaptation to climate change. I hope our review provides a useful foundation for researchers working in these directions.

6. What advice would you give to early career researchers who aim to publish impactful work in Plant Metabolism?
First, prioritise scientific rigour; lasting work is built on strong experimental design, reproducibility, and careful interpretation.
Second, take communication seriously. A well-designed study only has impact if others can follow it, so learning to write clearly, structure an argument, and present your work to audiences outside your immediate field is a skill worth deliberate practice, not an afterthought once the data are in.
Third, collaborate globally. My own experience moving between research groups in China and Australia, and working with colleagues across several countries, has shaped my thinking more than any single technique I learned. Different groups bring different tools, crops, and questions, and international collaboration exposes you to problems you would never encounter in one lab. Reach out to people whose work you admire; most are more willing to engage than early-career researchers expect.
Finally, be patient and don’t get discouraged. Research is rarely a straight path, and those who make lasting contributions tend to be the ones who stay curious and persistent.

We had the pleasure of speaking with Dr. Limin Shi, correspondence author of the Editor’s Choice Article in Metabolites (ISSN 2218-1989). Below, he discusses his research focus, paper, and further reflections on study development.

“The Functions of Major Gut Microbiota in Obesity and Type 2 Diabetes”
by Siman Liu, Zhipeng Tao, Mingyu Qiao, and Limin Shi
Metabolites 2025, 15(3), 167; https://doi.org/10.3390/metabo15030167
Available online: https://www.mdpi.com/2218-1989/15/3/167

The following is an interview with Dr. Limin Shi:

1. Could you briefly introduce yourself and describe your main research focus?
My name is Limin Shi, and I am currently a postdoctoral researcher at Duke University School of Medicine. My research broadly focuses on metabolic diseases, particularly obesity, insulin resistance, adipose tissue dysfunction, mitochondrial metabolism, and the molecular communication between metabolic organs.
I am especially interested in understanding how environmental, nutritional, and molecular factors disrupt metabolic homeostasis. My previous work examined adipose tissue remodeling, iron metabolism, mitochondrial quality control, and systemic metabolic regulation. I have also developed a strong interest in the gut microbiome because intestinal microorganisms and their metabolites can influence nutrient utilization, inflammation, glucose metabolism, adipose tissue function, and communication between the gut and other organs.

2. Could you briefly describe the main research content of your Highly Cited Paper, as well as its key innovative highlights?
Our review, entitled “The Functions of Major Gut Microbiota in Obesity and Type 2 Diabetes,” examined how major intestinal microbial groups contribute to the development or prevention of obesity and type 2 diabetes.
Rather than discussing the gut microbiome only as a single microbial community, we organized the available evidence according to major bacterial phyla and representative genera or species, including Firmicutes, Bacteroidetes, Proteobacteria, Verrucomicrobiota, Parabacteroides, and Akkermansia muciniphila. We evaluated how these microorganisms may influence energy harvest, short-chain fatty acid production, bile acid metabolism, intestinal barrier function, inflammation, glucose regulation, and insulin sensitivity. We also discussed environmental and lifestyle factors that shape the microbiome, including age, diet, eating patterns, physical activity, geography, and cultural background.
One important feature of the paper is that it presents both supportive and contradictory findings. For example, an elevated Firmicutes-to-Bacteroidetes ratio has frequently been associated with obesity, but several studies have failed to reproduce this relationship. We therefore emphasized that this ratio should not yet be regarded as a universal biomarker without considering population differences, dietary factors, analytical methods, and sample size.
Another innovative aspect was the integration of mechanistic research with translational and clinical evidence. We reviewed microbiota-targeting strategies such as dietary intervention, probiotics, prebiotics, symbiotic, and fecal microbiota transplantation. We also extended the discussion beyond classical metabolic pathways to include the gut–brain axis, through which the microbiome may influence appetite, stress responses, endocrine signaling, immune activity, and cognitive function.
Overall, the paper provides a balanced framework for understanding not only which microorganisms are associated with obesity and diabetes, but also why their effects may differ across individuals and experimental settings.

3. Would you mind sharing what inspired your research?
This research was inspired by the increasing recognition that obesity and type 2 diabetes cannot be fully explained by caloric intake, physical activity, or genetics alone. Individuals with apparently similar lifestyles can show very different metabolic outcomes, suggesting that additional biological factors contribute to disease susceptibility.
The gut microbiome is particularly interesting because it is positioned at the interface between diet and the host. Gut microorganisms process nutrients that cannot be completely digested by human enzymes and generate metabolites that can enter the circulation and influence distant tissues, including the liver, adipose tissue, skeletal muscle, immune system, and brain.
At the same time, microbiome literature contains many apparently conflicting findings. A microorganism may be beneficial in one model but harmful or neutral in another. This complexity inspired us to critically evaluate recent studies rather than simply categorize individual bacteria as “good” or “bad”. We wanted to understand the conditions under which specific microbial communities or metabolites influence obesity and type 2 diabetes and to identify the major gaps preventing microbiome discoveries from being translated into effective treatments.

4. What were the biggest challenges you encountered during this study, and how did you overcome them?
One of the greatest challenges was the enormous complexity and variability of the gut microbiome. Microbial composition differs substantially among individuals and can be influenced by age, dietary patterns, medication use, geographic location, lifestyle, genetics, and methods of sample collection and sequencing. These factors make it difficult to compare studies directly or identify universal microbial signatures.
Another challenge was distinguishing associations from causation. Many human studies report correlations between bacterial abundance and metabolic measurements, but these studies cannot always determine whether microbial changes cause obesity or arise as a consequence of obesity, altered diet, or medication use.
We addressed these issues by comparing evidence from several types of studies, including animal experiments, observational human cohorts, randomized clinical trials, dietary intervention studies, and fecal microbiota transplantation studies. We also gave particular attention to inconsistent findings rather than excluding them. For example, we highlighted both studies supporting the Firmicutes-to-Bacteroidetes ratio as a metabolic indicator, and studies showing no significant relationship with obesity.
A further challenge was evaluating microbiota-targeting therapies because clinical studies often involve small sample sizes, different treatment durations, varied bacterial strains, and heterogeneous patient populations. We therefore avoided presenting probiotics, symbiotic, or fecal microbiota transplantation as universally effective interventions. Instead, we described their potential benefits while emphasizing the need for larger, standardized, and carefully controlled clinical studies.

5. How do you see this research evolving or influencing future studies in the field?
I believe future microbiome research will move from broad taxonomic associations toward strain-level and function-based analysis. Two microorganisms belonging to the same species may have different metabolic effects because they carry different genes or produce different metabolites. Shotgun metagenomic sequencing, meta transcriptomics, metabolomics, and other multi-omics approaches will therefore be important for identifying the functional activities of microbial communities rather than simply measuring their relative abundance.
Future studies will also need to define causal mechanisms more precisely. This may involve isolating individual strains, identifying microbial metabolites, manipulating microbial genes, and testing their effects on physiologically relevant animal models and human-derived systems.
Another important direction is personalized or precision nutrition. Because microbiome composition and treatment responses vary among individuals, a single probiotic or dietary intervention is unlikely to work equally well for everyone. Integrating microbiome profiles with dietary information, host genetics, metabolic biomarkers, medication history, and lifestyle factors may allow researchers to predict which interventions are most suitable for specific patients.
Engineered probiotics are another promising area. Microorganisms could potentially be designed to produce beneficial metabolites, strengthen intestinal barrier function, reduce inflammation, or respond to specific metabolic conditions. However, their long-term safety, stability, and effectiveness will require rigorous evaluation. The review also indicates that future clinical studies should use larger cohorts, standardized protocols, longer follow-up periods, and more diverse populations.
Ultimately, I hope this research encourages the field to view the gut microbiome not as an isolated organ but as part of an interconnected metabolic network involving the intestine, adipose tissue, liver, immune system, endocrine system, and brain.

Conference: The 13th Congress of the Chinese Society for Plant Pathology
Date: 18–21 August 2026
Location: Wuhan, China

MDPI will be attending the 13th Congress of the Chinese Society for Plant Pathology as an exhibitor, welcoming researchers from diverse backgrounds to visit and share their latest ideas.

Organized by the Chinese Society for Plant Pathology and co-organized by Huazhong Agricultural University, the Hubei Society of Plant Pathology, and other supporting institutions, the meeting aims to strengthen academic exchange, promote the high-quality development of plant pathology in China, and complete the election of the Society’s new Council and Board of Supervisors.

Researchers, professionals, and graduate students in plant pathology are warmly invited to participate. We look forward to welcoming you to Wuhan in August 2026!

The following MDPI journals will be represented:

• CIMB;
• Plants;
• Agronomy;
• Horticulturae;
• Microorganisms;
• JoF;
• IJPB;
• Agriculture;
• Life;
• Metabolites;
• Seeds;
• IJMS.

If you are planning to attend this conference, please do not hesitate to start an online conversation with us. Our delegates look forward to meeting you in person and answering any questions that you may have. For more information, please visit http://www.cspp.org.cn/newsdata/202649201445.html.

Conference: The 8th International Conference on Biotic Plant Interactions (8th ICBPI)
Organization: Nanjing Agricultural University, CAS Center for Excellence in Molecular Plant Sciences, Chinese Society for Plant Biology and Chinese Society for Plant Pathology
Date: 18–21 October 2026
Location: Fengda International Hotel, Nanjing, China 

Plant–biotic interactions extensively occur in nature. Plant diseases and pests infecting crops severely limit their high yield and good quality, posing a significant risk to global food security. Meanwhile, beneficial organisms are of great importance in maintaining efficient crop production and sustainable development of agriculture and the ecosystem. In order to showcase the latest progress and achievements in global plant–biotic interaction research, and to promote exchanges and collaborations among researchers around the world, the International Conference on Biotic Plant Interactions (ICBPI) is held every two or three years and has been held seven times since 2011. The scale of the conference has also expanded drastically, with the attendees increasing from over 300 to over 1,500, and a large number of top international experts in the field of plant–biotic interactions have been attracted to participate in the conference, which has significantly strengthened the cooperation and communication among international colleagues in the field of plant–biotic interactions, making positive contributions to the food security of the world.

This conference will bring together around 800 scientists and students to share research advances covering a wide range of scientific topics. The topics include, but are not limited to, cross-kingdom signal perception, immunity receptor and effector biochemical activity/function, plant–microbe and insect symbioses, plant microbiome and microbe–microbe interactions, plant–insect–natural enemy multitrophic interactions, new technologies and frontiers: systems and spatial biology in plant–microbe interactions, plant metabolism and immunity, evolution of plant–insect/microbe interactions, emerging harmful organisms and agroecology, and plant resistance and crop molecular design, etc.    

The following MDPI journals will be represented:

• Plants;
• Horticulturae;
• International Journal of Plant Biology (IJPB);
• Antioxidants;
• Crops;
• Agriculture;
• Seeds;
• Insects;
• Metabolites;
• BioChem;
• AgriEngineering;
• Bacteria. 

Our portfolio of journals available for publishing up-to-date research in immediate open access format has been further expanded. In June 2026, eleven new journals released their inaugural issues and two transferred journals released their first issue as part of MDPI, covering the subjects of environmental & earth sciences, chemistry & materials science, public health & healthcare, engineering, medicine & pharmacology, and biology & life sciences. 

We extend our gratitude to the Editors-in-Chief, Associate Editors, and Editorial Board Members who will shape the future course of these new journals. Each journal is dedicated to upholding strong editorial standards through a thorough peer review process, enabling impactful open access scholarship. 

Please feel free to browse and discover more about the new journals below. 

We would like to thank everyone who has supported the development of open access publishing. If you would like to create a new journal, you are welcome to send an application here or contact the New Journal Committee (newjournal-committee@mdpi.com).

The Metabolites Young Investigator Award was established in 2020 to acknowledge the achievements of young investigators in the field of metabolomics, metabolic biochemistry, computational and systems biology, biotechnology, and medicine. Nominations will be accepted from April through December each year, with the winners notified by the end of March the following year.

Prize:

• CHF 2000;
• An electronic certificate;
• A voucher to waive the Article Processing Charges (APCs) for one submission in the journal (subject to peer review)—valid for one year.

Number of winners: 1.

Eligibility and requirements:

• Must have received their PhD no more than 10 years prior to 31 December 2026;
• Must have produced ground-breaking research and made a significant contribution to the advancement of metabolomics, metabolic biochemistry, computational and systems biology, biotechnology, and medicine;
• Must be nominated by senior scientists.

List of documents for nomination:

• Detailed curriculum vitae, including an updated publication list and a list of the researcher’s own research grants;
• Scanned copy of doctorate certificate;
• Signed nomination letters from two established senior scientists.

Nomination deadline: 31 December 2026;
Winner announcement: 31 March 2027.

The nominations must be submitted online at: https://www.mdpi.com/journal/metabolites/awards/3894.

Please do not hesitate to contact us at metabolites@mdpi.com if you have any questions. We look forward to receiving your nominations.

We are pleased to announce that Metabolites (ISSN 2218-1989) will be granting its annual Travel Award to junior scientists. This award provides financial support for the winners to attend an international conference in 2027 in the fields of metabolomics, metabolic biochemistry, computational and systems biology, biotechnology, or medicine, where they may present a talk, a poster, or both.

Prize:

• CHF 500;
• An electronic certificate;
• A voucher to waive the Article Processing Charges (APCs) for one submission in the journal (subject to peer review)—valid for one year.

Number of winners: 1.

Eligibility and requirements

• Postdoctoral fellows or PhD students;
• Plans to attend an international conference in 2027 (oral presentation or poster).

List of documents for application:

• Information of the conference the applicant is planning to attend and the abstract that will be submitted;
• Curriculum vitae and list of publications;
• Justification letter describing the focus of the research (max. 800 words);
• Letter of recommendation from the supervisor, research director, or department head, which also confirms the applicant’s status.

Application deadline: 31 October 2026;
Winner announcement: 31 December 2026.

For more information about the award, please visit the following link: https://www.mdpi.com/journal/metabolites/awards/3897.

Peer review is the invisible foundation of academic progress. The 2025 MDPI Top Reviewers are some of the key experts who helped build it.

We are honored to recognize 1000 individuals from our global community of 210,000 reviewers across 67 countries and territories—chosen for their commitment to rigorous, constructive peer review and the consistency of their contributions throughout 2025.

The Top Reviewers provided constructive and impartial feedback that makes research stronger and more impactful, and we are grateful for it.

The names of these reviewers are listed below in alphabetical order by first name:

(Note: we respected all privacy preferences, with part of nominees opting for limited attribution.)