Stress-induced depression and anxiety (DA) are closely connected to gastrointestinal inflammation and dysbiosis, which can suppress brain-derived neurotrophic factor (BDNF) in the brain. Herein, we isolated the BDNF expression-inducing probiotics Lactobacillus casei HY2782 and Bifidobacterium lactis HY8002 in lipopolysaccharide-stimulated SH-SY5Y cells. Then, we investigated the effects of HY2782, HY8002, anti-inflammatory L-theanine, and their supplement (PfS, probiotics-fermented L-theanine-containing supplement) on DA in mice exposed to restraint stress (RS) or the fecal microbiota of patients with inflammatory bowel disease and depression (FMd). Oral administration of HY2782, HY8002, or L-theanine alleviated RS-induced DA-like behaviors. They also decreased RS-induced hippocampal interleukin (IL)-1β and IL-6 levels, as well as NF-κB-positive cell numbers, blood corticosterone level, and colonic IL-1β and IL-6 levels and NF-κB-positive cell numbers. L-theanine more potently suppressed DA-like behaviors and inflammation-related marker levels than probiotics. However, these probiotics more potently increased RS-suppressed hippocampal BDNF level and BDNF⁺NeuN⁺ cell numbers than L-theanine. Furthermore, HY2782 and HY8002 suppressed RS-increased Proteobacteria and Verrucomicrobia populations in gut microbiota. In particular, they increased Lachnospiraceae and Lactobacillacease populations, which are closely positively associated with hippocampal BDNF expression, and suppressed Sutterellaceae, Helicobacteriaceae, Akkermansiaceae, and Enterobacteriaceae populations, which are closely positively associated with hippocampal IL-1β expression. HY2782 and HY8002 potently alleviated FMd-induced DA-like behaviors and increased FMd-suppressed BDNF, serotonin levels, and BDNF-positive neuronal cell numbers in the brain. They alleviated blood corticosterone level and colonic IL-1β α and IL-6 levels. However, L-theanine weakly, but not significantly, alleviated FMd-induced DA-like behaviors and gut inflammation. BDNF expression-inducing probiotic (HY2782, HY8002, Streptococcus thermophilus, and Lactobacillus acidophilus)-fermented and anti-inflammatory L-theanine-containing supplement PfS alleviated DA-like behaviors, inflammation-related biomarker levels, and gut dysbiosis more than probiotics or L-theanine. Based on these findings, a combination of BDNF expression-inducing probiotics with anti-inflammatory L-theanine may additively or synergistically alleviate DA and gut dysbiosis by regulating gut microbiota-mediated inflammation and BDNF expression, thereby being beneficial for DA.

(1) We investigated the effects of the Lactobacillus fermentum HY7302 (HY7302) in a mouse model of benzalkonium chloride (BAC)-induced dry eye, and the possibility of using HY7302 as a food supplement for preventing dry eye. (2) The ocular surface of Balb/c mice was exposed to 0.2% BAC for 14 days to induce dry eye (n = 8), and the control group was treated with the same amount of saline (n = 8). HY7302 (1 × 10⁹ CFU/kg/day, 14 days, n = 8) was orally administered daily to the mice, and omega-3 (200 mg/kg/day) was used as a positive control. To understand the mechanisms by which HY7302 inhibits BAC-induced dry eye, we performed an in vitro study using a human conjunctival cell line (clone-1-5c-4). (3) The probiotic HY7302 improved the BAC-induced decreases in the corneal fluorescein score and tear break-up time. In addition, the lactic acid bacteria increased tear production and improved the detached epithelium. Moreover, HY7302 lowered the BAC-induced increases in reactive oxygen species production in a conjunctival cell line and regulated the expression of several apoptosis-related factors, including phosphorylated protein kinase B (AKT), B-cell lymphoma protein 2 (Bcl-2), and activated caspase 3. Also, HY7302 alleviated the expression of pro-inflammatory cytokines, such as interleukin-1β (IL-1β), IL-6, and IL-8, and also regulated the matrix metallopeptidase-9 production in the conjunctival cell line. (4) In this study, we showed that L. fermentum HY7302 helps prevent dry eye disease by regulating the expression of pro-inflammatory and apoptotic factors, and could be used as a new functional food composition to prevent dry eye disease.

Background/Objectives: Premenstrual syndrome (PMS), a clinical condition that manifests in the form of various physical and psychological symptoms, occurs periodically during the luteal phase of the menstrual cycle and reduces quality of life. Methods: Here, we conducted in vitro and in vivo experiments to investigate the effects of Lactobacillus helveticus HY7801 (HY7801) on PMS symptoms. Results: Data from the in vitro experiments showed that HY7801 inhibits prolactin secretion by estradiol-induced GH3 cells, as well as the secretion of pro-inflammatory cytokines by LPS-induced Raw 264.7 cells. Additionally, the oral administration of HY7801 (10⁹ colony-forming units/kg/day) to mice with metoclopramide-induced hyperprolactinemia reduced uterine tissue mass and endometrial thickness, both of which were increased excessively in the presence of prolactin. HY7801 also regulated the serum levels of follicle-stimulating hormone and prostaglandin E1/E2, as well as recovering the progesterone/estradiol ratio. HY7801 also downregulated the serum levels of prolactin and pro-inflammatory cytokines such as interleukin (Il)-6, tumor necrosis factor-alpha (Tnf), and IL-1β. Finally, HY7801 reduced the expression of genes encoding inflammatory cytokines (i.e., Tnf and Il-6), cyclooxygenase-2 (Cox-2), and inducible nitric oxide synthase (iNOS) in mice with hyperprolactinemia. Conclusion: In summary, HY7801 may be a functional bacterium that alleviates PMS symptoms by modulating hormones and inflammatory markers.

Chronic kidney disease (CKD) causes a variety of health problems including renal dysfunction and cardiovascular disease. This study aimed to investigate whether the probiotic strain Lactiplantibacillus plantarum HY7718 (HY7718) can protect against CKD using HK2 cells and a CKD mouse model, generated by feeding mice a diet containing 0.15% adenine. In vitro tests showed that HY7718 was anti-inflammatory in H₂O₂-treated HK2 cells and reduced apoptosis of tumor necrosis factor-α/cycloheximide-induced HK2 cells. In the adenine-induced CKD model, markers of renal dysfunction (blood urea nitrogen (BUN) and creatinine (Crea)) and inorganic calcium and phosphorus were markedly increased. However, oral administration of HY7718 (10⁸ colony-forming units/kg/day) significantly attenuated these increases. HY7718 also reduced the kidney histopathological score, including tubular necrosis, cast formation, and tubular dilatation, as well as the mononuclear cell infiltration score in kidney tissue, suggesting that it could reverse the progression of CKD. Additionally, HY7718 downregulated the renal expression of pro-inflammatory cytokine genes and members of the TLR/NF-κB signaling pathway. Furthermore, HY7718 reduced tubule apoptotic cells and expression of apoptosis-related genes, indicating that it is potentially renoprotective. These results demonstrate that supplementation with the probiotic HY7718 can ameliorate CKD symptoms by improving renal function and reducing kidney injury.

This study investigated the therapeutic potential of Codonopsis lanceolata peel extract (CPE) for premenstrual syndrome (PMS). The focus was on hormonal, immune, and microbial pathways. In vitro, CPE reduced nitric oxide production and suppressed IL-6 and TNF-α expression in LPS-stimulated macrophages. In pituitary GH3 cells stimulated with estradiol, CPE inhibited prolactin secretion. In a metoclopramide (MCP)-induced hyperprolactinemia mouse model, CPE decreased serum prolactin, PGE2, and inflammatory cytokines, while increasing PGE1 and FSH levels. Microbiome analysis showed that CPE enriched beneficial genera such as Lactobacillus and Bifidobacterium and reduced pro-inflammatory taxa including Oscillibacter and Desulfovibrionaceae . These microbial shifts were associated with improved inflammatory and hormonal markers. Overall, these findings suggest that CPE alleviates PMS symptoms by modulating endocrine function and regulating gut microbiota.

Chronic kidney disease (CKD), a progressive disorder leading to renal dysfunction, remains a significant global health issue. This study investigated whether Lactiplantibacillus plantarum HY7718 modulates gut–kidney axis-associated inflammatory, gastrointestinal, and microbial alterations in a mouse model of adenine-induced chronic kidney disease. We examined fibrosis- and inflammation-related gene expression in mouse tissues and analyzed the gut microbiota via next-generation sequencing. HY7718 supplementation was associated with reduced expression of genes related to renal fibrosis (Col1a1, Acta2) and vascular inflammation (Icam-1, Vcam-1). Further, HY7718 suppressed intestinal inflammatory responses, including downregulation of pro-inflammatory cytokines (Tnf, Il-1β, Il-6) and TLR4/MyD88/NF-κB signaling pathway genes in the colon tissues. Gastrointestinal function was also improved, with significant upregulation of gastric motility-related genes and increased digestive enzyme activity. The gut microbiota composition was altered by HY7718, with reduced abundance of pro-inflammatory taxa such as Mucispirillum and Deferribacterota, whereas beneficial genera like Lactiplantibacillus were enriched. These microbial shifts were associated with reduced intestinal inflammatory and renal fibrosis-related markers. Overall, the findings indicate that HY7718 supplementation modulates gut–kidney axis-associated inflammatory, gastrointestinal, and microbial alterations in adenine-induced CKD mice and supports further investigation of this strain in CKD-related settings.