Biology subjects

Park, E.-J.

Publications and source records attributed to Park, E.-J..

4 recordsLinked to original sources

bioRxiv2026

Seasonal dynamics in lettuce phyllosphere microbiota and potential transmission to the human gut

The surface of fresh vegetable leaves harbors diverse microorganisms with the potential to influence human health through the microbiome-food-gut axis. We investigated the ecology of the bacterial and fungal microbiota on green and red lettuces (n=143) for a 12-month period using high-throughput amplicon sequencing, and assessed the potential transfer of these microbiota to the human gut. Lettuce-associated fungal and bacterial microbiota exhibited substantial temporal variation, converging into two distinct seasonal cycles: early-season (S1) and late-season (S2). Seasonal progression from S1 to S2 increased species richness in season-specific fungal and bacterial taxa, while inducing abundance shifts in persistent fungal taxa and compositional shifts in persistent bacterial taxa. These seasonal dynamics resulted in more complex and stable microbial networks, in which potentially pathogenic fungi were less frequently enriched. Comparative analyses with gut microbiota datasets from 2,831 (fungal) and 3,254 (bacterial) individuals revealed that lettuce-associated fungi and bacteria were widely detected in the human gut, with bacteria detected more frequently than fungi. Season-specific taxa were detected more frequently than persistent taxa, and microbial assembly in the gut was shaped by both neutral and deterministic processes. Notably, lettuce-associated bacteria predominantly co-occurred with non-plant glycan-degrading commensal bacteria in a season-dependent manner, and enrichment of these co-occurring taxa correlated positively with gut microbiota richness and composition. Our findings provide insights into the ecological linkages between fresh vegetable microbiota and the human gut microbiota through the food-gut axis.

microbiology↗

bioRxiv2024

The food-gut axis: the phyllosphere virome of fresh vegetables is diverse, abundant, and transmitted to the human gut virome

Fresh vegetables harbor diverse microorganisms on leaf surfaces, yet their viral communities remain unexplored. We investigated the diversity and ecology of phyllosphere viromes of six leafy green vegetables using virus-like particle (VLP) enrichment and shotgun metagenome sequencing. On average, 9.2 x 107 viruses were present per gram of leaf tissue. The majority (93.1 {+/-} 6.2%) of these viruses were taxonomically unclassified. Virome compositions were distinct among vegetable types and exhibited temporal variations. Virulent phages with replication-enhancing auxiliary metabolic genes (AMGs) were more dominant than temperate phages with host fitness-benefiting AMGs. Analysis of 1,498 human fecal VLP metagenomes revealed that approximately 10% of vegetable viruses were present in the human gut virome, including viruses commonly observed in multiple studies. These gut-associated vegetable viruses were enriched with short-term vegetable intake, and depleted in individuals with metabolic and immunologic disorders. Overall, this study elucidates the ecological contribution of the fresh vegetable virome to human gut virome diversity.

microbiology↗

bioRxiv2020

Improvement of glymphatic-lymphatic drainage of beta-amyloid by focused ultrasound in Alzheimer's disease model

Drainage of parenchymal waste through the lymphatic system maintains brain homeostasis. Age-related changes of glymphatic-lymphatic clearance lead to the accumulation beta-amyloid (A{beta}) in dementia models. In this study, focused ultrasound treatment in combination with microbubbles (FUS-MB) improved A{beta} drainage in early dementia model mice, 5XFAD. FUS-MB enhanced solute A{beta} clearance from brain, but not plaques, to cerebrospinal fluid (CSF) space and then deep cervical lymph node (dCLN). dCLN ligation exaggerated memory impairment and progress of plaque formation and also the beneficial effects of FUS-MB upon A{beta} removal through CSF-lymphatic routes. In this ligation model, FUS-MB improved memory despite accumulation of A{beta} in CSF. In conclusion, FUS-MB enhances glymphatic-lymphatic clearance of A{beta} mainly by increasing brain-to-CSF A{beta} drainage. We suggest that FUS-MB can delay dementia progress in early period and benefits of FUS-MB depend on the effect of A{beta} disposal through CSF-lymphatics.

neuroscience↗

bioRxiv2019

Evidence for widespread selection in shaping the genomic landscape during speciation of Populus

Increasing our understanding of how various evolutionary processes drive the genomic landscape of variation is fundamental to a better understanding of the genomic consequences of speciation. However, the genome-wide patterns of within- and between-species variation have not been fully investigated in most forest tree species despite their global ecological and economic importance. Here, we use whole-genome resequencing data from four Populus species spanning the speciation continuum to reconstruct their demographic histories, investigate patterns of diversity and divergence, infer their genealogical relationships and estimate the extent of ancient introgression across the genome. Our results show substantial variation in these patterns along the genomes although this variation is not randomly distributed but is strongly predicted by the local recombination rates and the density of functional elements. This implies that the interaction between recurrent selection and intrinsic genomic features has dramatically sculpted the genomic landscape over long periods of time. In addition, our findings provide evidence that, apart from background selection, recent positive selection and long-term balancing selection are also crucial components in shaping patterns of genome-wide variation during the speciation process.

evolutionary biology↗