Keon Heo

Urinary tract infections (UTIs) are common bacterial infections that are predominantly caused by uropathogenic Escherichia coli. Chronic recurrence of UTIs, particularly in women, seriously affects the quality of life of infected individuals. Antibiotics are still the first-line treatment for UTIs; however, side effects and increasing antibiotic resistance emphasize the need for alternative therapies. In this study, we explored the in vitro and in vivo anti-E. coli effects of heat-inactivated Lactobacillus helveticus GUT10, L. salivarius HHuMin-U, and their combination. In lipopolysaccharide (LPS)-induced human urinary bladder cancer T24 cells, all probiotic treatments suppressed the expression of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6), cyclooxygenase 2 (COX2), and prostaglandin E2 (PGE2) by inhibiting the upregulation of NF-κB signaling and the production of reactive oxygen species (ROS). In an E. coli-induced UTI rat model, a significant alleviation of damage to the bladder and urethral mucosa by the two Lactobacillus strains in protective and treatment studies was accompanied by a decrease in the E. coli load in the bladder and urine and an increase in lactobacilli in the bladder. Thus, the probiotic mixture has potent protective and therapeutic effects and shows promise as a nonantibiotic approach for UTI treatment.

Atopic dermatitis (AD) is a chronic inflammatory disorder with immune imbalance, including elevated IgE levels and mast cell activation mediated by Th2 cytokines, leading to allergic inflammation and impaired skin barrier function. Current treatment limitations highlight the need for safer and more effective AD alternatives. We aimed to evaluate the therapeutic effects of multi-strain probiotics, BCL-2 (comprising Lactiplantibacillus plantarum LRCC5264 and Bifidobacterium longum RAPO), in alleviating AD clinical signs and elucidate its underlying immunomodulatory mechanisms. In vitro, BCL-2 treatment significantly reduced IL-4 secretion in RBL-2H3 cells, with higher inhibitory effects than single-strain treatment. In vivo, BCL-2 (10⁶–10⁸ CFU/day) was orally administered for 28 days to AD-induced Nc/Nga mice. BCL-2 treatment improved the clinical signs and histopathological features of AD, including epidermal hypertrophy, hyperkeratosis, and mast cell infiltration (p < 0.05). It also reduced neutrophil and eosinophil counts and modulated cytokine and chemokine profiles, notably decreasing IL-17, IL-5, IL-6, TNF-α, IL-1β, TARC, and eotaxin, while increasing IL-10, IFN-γ, and IL-12 (p < 0.05). Among the tested concentrations, 10⁷ CFU exhibited the most effective immune modulation with no adverse effects on body weight. These findings demonstrate the therapeutic potential of BCL-2 in AD; however, further studies are required to validate its clinical relevance.

Halitosis, or bad breath, is associated with oral microbial imbalances and the production of volatile sulfur compounds (VSCs). While existing treatments target pathogenic bacteria or oral health indicators, they may not address the underlying systemic complexity. This study explored the efficacy of Complex OK oral probiotics containing Lactobacillus gasseri HHuMIN D and L. paracasei OK in mitigating halitosis by evaluating VSC levels and metabolic markers. A 12-week, randomized, double-blind, placebo-controlled clinical trial was conducted involving 80 participants, 70 of whom completed the study in South Korea (KCT0009894). The participants were selected based on the presence of 2 of 3 pathogenic oral bacteria ( F. nucleatum , P. gingivalis , and P. intermedia ) and baseline VSCs > 2.0 ng/10 mL. Exclusion criteria included systemic diseases, recent antibiotic/probiotic use, and severe dental conditions. Oral health, VSCs, and metabolic markers were assessed using paired t -tests, ANCOVA, and Wilcoxon rank-sum tests. Despite unchanged oral health indicators and levels of harmful bacteria, probiotic supplementation showed efficacy in maintaining microbial balance. Significant reductions in H₂S and total VSCs were observed in the experimental group compared to the placebo ( P < 0.05). No significant changes were observed in oral health indices or levels of harmful oral bacteria, but the experimental group showed a significant decrease in blood glucose ( P = 0.009) and an increase in phosphorus levels ( P < 0.05). This study provides the first published evidence linking systemic metabolic regulation to halitosis reduction, suggesting that probiotics mitigate bad breath through glucose and phosphorus metabolism rather than by direct bacterial inhibition. Further research is needed to confirm these findings and to explore the underlying mechanisms.

Maintaining probiotic viability during storage, freeze-drying, and gastrointestinal transit is essential to ensure efficacy. The present study evaluated VitaShield Coating® (VSC), an innovative stabilization technology incorporating vitamins A, C, and E, for enhancing the viability of Bifidobacterium strains. VSC-coated B. bifidum BGN4 exhibited a significantly higher freeze-drying recovery rate (43.91±4.69%) compared to that of the uncoated group (15.31±6.53%, p<0.0001), with scanning electron microscopy (SEM) confirming preservation of structural integrity. Gastrointestinal stability also improved, as coated cells retained 26.21±2.41% viability in simulated gastric fluid, significantly outperforming uncoated cells (3.20±2.30%, p<0.0001). Gas chromatography-mass spectrometry (GC-MS) revealed a significant increase in polyunsaturated fatty acids (PUFAs) in coated cells, indicating enhanced membrane stability. Furthermore, storage stability of four Bifidobacterium strains (AD011, BORI, BGN4, and RAPO) was evaluated over 16 weeks at 25°C and 30°C. The findings indicate that the VSC coating effectively protects probiotic strains under harsh storage conditions, mitigating viability loss over time. Overall, this study showed that the VSC coating serves as a multifunctional stabilization technology that provides mechanical, osmotic, and oxidative stress protection. Its ability to improve probiotic survival under harsh conditions enables its practical and scalable use in formulations and enhances stability.

Bacterial vaginosis (BV) is caused by a microbial imbalance in the vaginal ecosystem, which causes genital discomfort and a variety of potential complications in women. This study validated the potential of Lactobacillus helveticus HY7801 as a probiotic to benefit vaginal health. In vivo, HY7801 reduced the number of Gardnerella vaginalis (GV) and pro-inflammatory cytokines in the vagina of GV-induced BV mice and ameliorated vaginal histological changes. In vitro, HY7801 exhibited positive resistance to simulated gastrointestinal conditions, showed excellent adherence ability to the female genital epithelium, and had high lactic acid and H₂O₂ production capacity. Furthermore, it was found that HY7801 can alleviate BV because it can suppress the expression of virulence factor genes of GV involved in epithelial cell adhesion and biofilm formation along with antibacterial activity against GV. These results indicate that HY7801 can be used as a promising probiotic strain for the maintenance of a healthy vaginal physiological state.

Journal of Animal Science and Technology (JAST) is a peer-reviewed, open access journal publishing original research, review articles and notes in all fields of animal science. Topics covered by the journal include: genetics and breeding, physiology, nutrition of monogastric animals, nutrition of ruminants, animal products (milk, meat, eggs and their by-products) and their processing, grasslands and roughages, livestock environment, animal biotechnology, animal behavior and welfare.

This study assessed the improvements yielded by Lactobacillus curvatus HY7602-fermented antlers (FA) in dexamethasone-induced muscle atrophy and the effects of bioactive compounds increased by fermentation. Dexamethasone-treated C2C12 myoblast cells were treated with FA and non-fermented antlers (NFA). FA showed inhibitory effects on muscle protein degradation in the C2C12 cells. Hsb:ICR mice were orally administered saline (control(CON) and dexamethasone only (DEX)), oxymetholone (DEX+OXY), NFA (DEX+NFA), and FA (DEX+FA) via gavage. Before the end of the experiment, dexamethasone was intraperitoneally (IP) injected into the mice, except in the control group, to induce muscle atrophy. Compared with the DEX group, the DEX+FA group exhibited a significant prevention in the reduction of hindlimb strength, calf thickness, calf muscle weight, and the cross-sectional area of muscle fibers (p < 0.05). The FA-induced improvements in muscle atrophy were associated with a decreased gene expression of protein degradation and growth inhibition, and an increased gene expression of protein synthesis and growth factors. Sialic acid, a bioactive compound associated with muscles, was increased by 51.41% after fermentation and suppressed the expression of protein degradation genes in the C2C12 cells. L. curvatus HY7602-fermented antlers with increased sialic acid after fermentation may therefore be useful for preventing and improving muscle atrophy.

Beyond probiotics, the interest in the application of postbiotics to various fields has been growing. We aimed to develop a novel postbiotic complex (PC) with antibacterial and anti-inflammatory properties. Through antibacterial activity testing against Staphylococcus aureus or Cutibacterium acnes, a PC [a mixture of cell-free supernatants (postbiotics) from probiotic Lactobacillus helveticus (HY7801) and Lactococcus lactis (HY449)] was developed. Anti-inflammatory activity of the PC was investigated using HaCaT keratinocytes treated with S. aureus or C. acnes. PC significantly decreased IL-8 levels and increased hyaluronic acid levels in HaCaT cells cultured with S. aureus or C. acnes. GC–MS based metabolic profiling suggested 2-hydroxyisocaproic acid, hypoxanthine, succinic acid, ornithine, and γ-aminobutyric acid as potential contributing metabolites for the antibacterial and anti-inflammatory effects of PC. The PC developed in this study could be utilized in food, cosmetics, and pharmaceutical products as an alternative or complementary resources of probiotics.

Intestinal microbiota mediate the development and regulation of the intestinal immune system either directly or indirectly. Particularly, Bifidobacterium spp. play an important role in regulating the intestinal immunity and intestinal barrier. We demonstrated that Bifidobacterium animalis ssp. lactis HY8002, selected from eight Bifidobacterium strains by in vitro experimentation, had exceptional resistance to digestive tract conditions and high adhesion to intestinal epithelial cells and a positive effect on immunoglobulin A (IgA) secretion by Peyer’s patch cells. Moreover, HY8002 restored the expression of tight junction-related genes, initially reduced by lipopolysaccharide treatment, to normal levels in human intestinal epithelial cells. Notably, HY8002 restored kanamycin-induced reduction in Peyer’s patch cell numbers, serum and fecal IgA levels, and zonula occludens 1 and Toll-like receptor 2 levels in the mouse small intestine. In addition, HY8002 restores microbiome composition disturbed by kanamycin, and these microbiome changes have been found to correlate with TLR2 levels in the small intestine. Moreover, the ability of HY8002 to enhance IgA in Peyer’s patch cells and ZO-1 levels in intestinal epithelial cells was significantly inhibited by a TLR2 blocking antibody, which suggests that the HY8002 improve intestinal barrier function via TLR2. Finally, whole-genome sequencing of HY8002 revealed that it did not possess any known virulence factors. Therefore, HY8002 is a promising, functional probiotic supplement to improve intestinal barrier function by improving intestinal immunity and microbiota balance.