Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (763 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
A functional system which includes the organisms of a natural community together with their environment. (McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Ecologic System; System, Ecologic; Systems, Ecologic; Ecosystems; Ecological System; Ecological Systems; System, Ecological; Systems, Ecological.
Where it fits in the MeSH classification
- Broader topics
- Environment
- Narrower topics
- Biodiversity; Biomass; Coral Reefs; Ecological Systems, Closed; Food Chain; Forests; Grassland; Rhizosphere; Seashore; Tundra; Wetlands
- See also
- Ecology
Research landscape
PubMed indexes 399,087 records tagged with the MeSH heading “Ecosystem” (counts retrieved 2026-10-31). 202,435 of them (50.7%) were published from 2020 onward, and the busiest period so far is 2020 onward with 202,435 records.
Reviews account for 51,202 records (12.8%) and meta-analyses for 2,502. Randomized controlled trials number 2,623 (0.7%) as a share of all records on the topic. Randomized trials make up only a small share of this literature, so much of what is known comes from laboratory, observational or descriptive work.
Show the data
| Period | Records |
|---|---|
| through 1999 | 0 |
| 2000-2009 | 43,423 |
| 2010-2019 | 153,717 |
| 2020 onward | 202,435 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 51,202 | 12.8% |
| Meta-analyses | 2,502 | 0.6% |
| Randomized controlled trials | 2,623 | 0.7% |
Method: PubMed query "Ecosystem"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-31.
Reading the evidence in public health and nutrition
Population and nutrition studies mostly observe what people eat, breathe or are exposed to and then look for links with health, which shows association and not proof of cause. Self-reported diet is imprecise, people who eat or live differently also differ in other ways, and effects measured across a population may not apply to one person. Check the study design, how exposure was measured, what else was accounted for and the size of the effect, not only whether it was statistically significant.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| Fear of humans mediates spatiotemporal interactions between endangered large Asian felids | 2026 | Research article Design not recorded in structured metadata | 1 | cc by PMID 42838563 · DOI · PMC13641897 |
| Harnessing macrogenomics to study changing marine ecosystems under global climate change | 2026 | Review article Design not recorded in structured metadata | 1 | cc by PMID 42838558 · DOI · PMC13641918 |
| Subverting colonization resistance: Salmonella pathogenesis at the interface of microbiota, metabolism and inflammasome | 2026 | Review article Design not recorded in structured metadata | 0 | cc by PMID 42885908 · DOI · PMC13682399 |
| Effects of xylooligosaccharide supplementation on methane emissions, rumen microbiome, and serum metabolome in lactating Jersey cows | 2027 | Research article Design not recorded in structured metadata | 0 | cc by PMID 42908331 · DOI · PMC13715329 |
Fear of humans mediates spatiotemporal interactions between endangered large Asian felids [1]
Abstract reading summary — source excerpts
- Opening excerpt
- Species competitive interactions influence carnivore demography.
- Closing excerpt
- Furthermore, we highlight the importance of considering the pervasive risk introduced by a dynamic human presence to better understand the adaptive strategies used by competing top predators to mitigate threats.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (283 words)
Species competitive interactions influence carnivore demography. Humans, as global 'super predators,' may mediate interactions among sympatric carnivores, although the effects of ecological fear on these interactions remain less understood. We used two years of camera trap data from more than 300 sites in northeast China to fit two-species, dynamic occupancy models. We then assessed how direct human passage affects spatial and temporal interactions between tigers and leopards, and the consequences for predator‒prey overlap in a temperate forest. We found evidence that median site occupancy, colonization and detection of leopards were lower at sites where tigers were present than at sites where tigers were absent. The effect of tigers on leopards in both space and time varied with disturbances. Leopards and tigers co-occurred less often than would be expected by chance at sites where human activity was greater. Tigers, but not leopards, significantly shifted their activity towards increased nocturnality in response to predominantly diurnal humans. This resulted in a decrease in temporal overlap among the two top predators and predator-ungulate prey at more disturbed sites, most notably between the tiger and prey (but no decrease in spatial overlap). Leopards appear to avoid tigers through time or space in areas where encounter risks are increased; in particular, leopards shift their core activity range as a main strategy to cope with dominant tiger and human activity across the sites. These results reveal that the human-induced landscape of fear may modify the strength of intraguild interactions between apex felids and structure food webs in a shared ecosystem. Furthermore, we highlight the importance of considering the pervasive risk introduced by a dynamic human presence to better understand the adaptive strategies used by competing top predators to mitigate threats.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42838563 · DOI · PMC13641897
Harnessing macrogenomics to study changing marine ecosystems under global climate change [2]
Abstract reading summary — source excerpts
- Opening excerpt
- Climate change is reshaping marine ecosystems at an accelerating pace.
- Closing excerpt
- Ultimately, coupling empirical and prediction data offers a powerful approach for ecosystem-based management, improving our ability to predict adaptive responses and extinction risks at relevant scales, and equipping managers and policymakers with actionable insights to prioritize biodiversity conservation strategies.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (199 words)
Climate change is reshaping marine ecosystems at an accelerating pace. Predicting its impacts on biodiversity and ecosystem functions is therefore crucial to developing effective conservation strategies. Integration of genomic tools, habitat modelling and simulations offers a transformative approach to forecast these impacts. Yet, current frameworks remain limited to single-species analyses. In this review, we discuss future directions in the emerging field of macrogenomics, the analysis of large-scale genomic data across species and time, and show how its integration with environmental data can be applied to understand past and predict future climate-driven ecological shifts across entire marine communities. We demonstrate how applying a macrogenomic framework can provide insights into future responses of marine ecosystems under global climate change by integrating multi-species demographic analyses, metagenomics and signatures of adaptation associated with past climate fluctuations. We also show how macrogenomics combined with predictive approaches can be used to forecast cascading effects of species fluctuations on ecosystem structure and potentially identify ecosystem tipping points. Ultimately, coupling empirical and prediction data offers a powerful approach for ecosystem-based management, improving our ability to predict adaptive responses and extinction risks at relevant scales, and equipping managers and policymakers with actionable insights to prioritize biodiversity conservation strategies.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42838558 · DOI · PMC13641918
Subverting colonization resistance: Salmonella pathogenesis at the interface of microbiota, metabolism and inflammasome [3]
Abstract reading summary — source excerpts
- Opening excerpt
- The intestinal tract is a key immune organ and microecological system, where colonization resistance (CR) mediated by gut microbiota prevents pathogen invasion.
- Closing excerpt
- We also highlight microbiota-based countermeasures, including probiotics, natural antimicrobials, and phage therapy, as promising strategies to restore gut homeostasis.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (97 words)
The intestinal tract is a key immune organ and microecological system, where colonization resistance (CR) mediated by gut microbiota prevents pathogen invasion. Salmonella disrupts CR via type VI and type III secretion systems (T6SS/T3SS), inducing dysbiosis, inflammasome-driven inflammation, and intestinal barrier damage. This creates a self-reinforcing cycle:dysbiosis alters microbial metabolites, sustains inflammation, and enhances pathogen fitness, favoring chronic infection. This review integrates molecular mechanisms of microbiota disruption, inflammasome activation, and metabolic imbalance to explain how Salmonella overcomes CR. We also highlight microbiota-based countermeasures, including probiotics, natural antimicrobials, and phage therapy, as promising strategies to restore gut homeostasis.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42885908 · DOI · PMC13682399
Effects of xylooligosaccharide supplementation on methane emissions, rumen microbiome, and serum metabolome in lactating Jersey cows [4]
Abstract reading summary — source excerpts
- Opening excerpt
- Xylooligosaccharides (XOS) are recognized as effective prebiotics that can mitigate methane (CH4) emissions.
- Closing excerpt
- The study suggests that XOS may regulate ruminant CH4 emissions by influencing the microbiota, thereby providing a rationale for CH4 control.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (184 words)
Xylooligosaccharides (XOS) are recognized as effective prebiotics that can mitigate methane (CH4) emissions. However, the specific relationship between the effects of XOS on CH4 emissions and alterations in the ruminal microbiota and their metabolites remains unclear. To investigate the relationship between XOS and CH4 emissions, 48 Jersey cows were randomly divided into two groups: the XOS group (group T) and the control group (group C). Group T received 25 g/d of XOS, while group C received 0 g/d of XOS added to the basal diet. Three randomly selected cows from each group, exhibiting consistent milk production and lactation stage, were analyzed for CH4 emissions detection, 16S rRNA sequencing, and untargeted metabolomics analysis. The addition of XOS significantly reduced CH4 emissions and increased both the number of observed species and the abundance-based coverage estimator (ACE) index of ruminal microbiota compared to group C. Sixteen differential metabolites were identified between the two groups; these differential metabolites were correlated with microbiota, including Chloroflexi, Acidobacteriota, and Succiniclasticum. The study suggests that XOS may regulate ruminant CH4 emissions by influencing the microbiota, thereby providing a rationale for CH4 control.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42908331 · DOI · PMC13715329
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Host genetic regulation of human gut microbial structural variation [5]
- Research article A gut microbial signature for combination immune checkpoint blockade across cancer types [6]
- Research article A meta-analysis on global change drivers and the risk of infectious disease [7]
- Research article Global meta-analysis shows action is needed to halt genetic diversity loss [8]
- Research article Climate change extinctions [9]
- Research article Effects of Exercise on Gut Microbiota of Adults: A Systematic Review and Meta-Analysis [10]
References
- Feng J, Wang D, Li Z, Wei X, Ge J, Wang T. Fear of humans mediates spatiotemporal interactions between endangered large Asian felids. . 2026. PMID 42838563 · DOI · PMC13641897
- Dussex N, Andersson L, Bergström U, Johannesson K, Wallberg A. Harnessing macrogenomics to study changing marine ecosystems under global climate change. . 2026. PMID 42838558 · DOI · PMC13641918
- Gao Z, Li Z, Cui J, Zhang Q, Jia Y, Ding K, et al.. Subverting colonization resistance: Salmonella pathogenesis at the interface of microbiota, metabolism and inflammasome. . 2026. PMID 42885908 · DOI · PMC13682399
- Zhou X, Zhao Z, Zhao L, Diao Q, Dong L, Kang X. Effects of xylooligosaccharide supplementation on methane emissions, rumen microbiome, and serum metabolome in lactating Jersey cows. . 2027. PMID 42908331 · DOI · PMC13715329
- Zhernakova DV, Wang D, Liu L, Andreu-Sánchez S, Zhang Y, Ruiz-Moreno AJ, et al.. Host genetic regulation of human gut microbial structural variation. Nature. 2024. PMID 38172637 · DOI · PMC10808065
- Gunjur A, Shao Y, Rozday T, Klein O, Mu A, Haak BW, et al.. A gut microbial signature for combination immune checkpoint blockade across cancer types. Nat Med. 2024. PMID 38429524 · DOI · PMC10957475
- Mahon MB, Sack A, Aleuy OA, Barbera C, Brown E, Buelow H, et al.. A meta-analysis on global change drivers and the risk of infectious disease. Nature. 2024. PMID 38720068 · DOI
- Shaw RE, Farquharson KA, Bruford MW, Coates DJ, Elliott CP, Mergeay J, et al.. Global meta-analysis shows action is needed to halt genetic diversity loss. Nature. 2025. PMID 39880948 · DOI · PMC11839457
- Urban MC. Climate change extinctions. Science. 2024. PMID 39636977 · DOI
- Min L, Ablitip A, Wang R, Luciana T, Wei M, Ma X. Effects of Exercise on Gut Microbiota of Adults: A Systematic Review and Meta-Analysis. Nutrients. 2024. PMID 38613103 · DOI · PMC11013040
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-11-04; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-11-04.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.