Rice straw is not easy to decompose, it takes a long time to compost, and the anaerobic bacteria involved in the decomposition process produce a large amount of carbon dioxide (CO₂), indicating that applications for rice straw need to be developed. Recycling rice straw in agricultural crops is an opportunity to increase the sustainability of grain production. Several studies have shown that the probiotic population gradually decreases in the soil, leading to an increased risk of plant diseases and decreased biomass yield. Because the microorganisms in the soil are related to the growth of plants, when the soil microbial community is imbalanced it seriously affects plant growth. We investigated the feasibility of using composted rice stalks to artificially cultivate microorganisms obtained from the Oryza sativa-planted environment for analyzing the mycobiota and evaluating applications for sustainable agriculture. Microbes obtained from the water-submerged part (group-A) and soil part (group-B) of O. sativa were cultured in an artificial medium, and the microbial diversity was analyzed with internal transcribed spacer sequencing. Paddy field soil was mixed with fermented paddy straw compost, and the microbes obtained from the soil used for O. sativa planting were designated as group-C. The paddy fields transplanted with artificially cultured microbes from group-A were designated as group-D and those from group-B were designated as group-E. We found that fungi and yeasts can be cultured in groups-A and -B. These microbes altered the soil mycobiota in the paddy fields after transplantation in groups-D and -E compared to groups-A and -B. Development in O. sativa post treatment with microbial transplantation was observed in the groups-D and -E compared to group-C. These results showed that artificially cultured microorganisms could be efficiently transplanted into the soil and improve the mycobiota. Phytohormones were involved in improving O. sativa growth and rice yield via the submerged part-derived microbial medium (group-D) or the soil part-derived microbial medium (group-E) treatments. Collectively, these fungi and yeasts may be applied in microbial transplantation via rice straw fermentation to repair soil mycobiota imbalances, facilitating plant growth and sustainable agriculture. These fungi and yeasts may be applied in microbial transplantation to repair soil mycobiota imbalances and sustainable agriculture.

Dietary trimethylamine (TMA) underwent gut microbiota-mediated catabolism and subsequent hepatic oxidation to generate trimethylamine N-oxide (TMAO), a key metabolic factor linked to vascular and colorectal diseases. While the systemic effects of circulating TMAO were heavily investigated, the direct localized cellular interactions of its precursor, TMA, at the intestinal epithelial level required further elucidation. This study characterized extracellular vesicles isolated from Lactobacillus rhamnosus (Lr-EVs) and evaluated their cytoprotective potential in an in vitro human intestinal Caco-2 cell model under TMA-induced stress. Exposure to a high concentration of TMA (20 mM) significantly reduced Caco-2 viability to 78.8%, triggered intracellular reactive oxygen species (ROS) accumulation, and compromised tight junction integrity as observed via the disruption of Zonula Occludens-1 (ZO-1) alignment. Co-treatment with Lr-EVs (100-300 μg/mL) counteracted this cellular toxicity, enhancing cell survival up to 172%. Quantitative PCR analysis revealed that Lr-EVs suppressed the transcriptional upregulation of the pro-inflammatory gene IL-1β, restored the expression of the metabolic regulator SIRT1, and stabilized transcript levels of key mitochondrial-encoded electron transport chain genes (ND6, CYTB, CO1, and ATP6). Additionally, Lr-EVs exhibited intrinsic radical scavenging activities in cell-free ABTS and DPPH assays. These preliminary in vitro findings demonstrated that Lr-EVs mitigated TMA-induced cellular injury, oxidative stress, and junctional disruption at the transcriptomic level, supporting further investigation of probiotic-derived EVs as prospective cell-free functional ingredients.