Byung Wook Yoo

Background: Despite substantial improvements in maternal health indicators and near-universal institutional delivery coverage in El Salvador, limited evidence is available regarding maternal health literacy and health-seeking behaviors among women residing in socioeconomically vulnerable and geographically isolated communities. This study aimed to establish baseline evidence on knowledge, attitudes, and practices related to antenatal care and maternal health among women living in high-risk municipalities of El Salvador.Methods: A cross-sectional baseline survey was conducted between June 2 and June 26, 2025, among 304 pregnant and postpartum women receiving care from five family community health units (UCSFs) located in high-risk municipalities of El Salvador. Data were collected using a structured 75-item questionnaire administered through KoBoToolbox. Descriptive statistics, Mann-Whitney U-tests, Pearson’s chi-square tests, and Spearman correlation analyses were performed.Results: Although antenatal care utilization was high (96.4%) and institutional delivery was nearly universal among multiparous women (97.5%), substantial gaps in technical maternal health knowledge were identified. Only 25.0% of participants demonstrated adequate knowledge regarding essential prenatal tests, and only 18.1% correctly identified the benefits of both iron and folic acid supplementation. Educational attainment was significantly associated with knowledge of prenatal tests and contraception (both P<0.001), whereas age was not associated with any knowledge indicator. Significant knowledge–practice gaps were observed, particularly regarding contraception (χ2=14.6, P=0.002) and tetanus vaccination (P=0.847), suggesting the presence of structural barriers beyond individual awareness. Territorial disparities of up to 25 percentage points were observed across participating facilities.Conclusions: High coverage of antenatal care services does not necessarily translate into adequate maternal health knowledge or optimal preventive practices. The findings identify priority areas for maternal health education and service-delivery strengthening and provide important baseline evidence for future monitoring and evaluation of maternal health interventions in vulnerable communities of El Salvador.

Sangmin Park, Byungwook Lee, Hwayeon Sun, Wangyoon Shin, Ji-ye Mok, Jeonghyun Seo, Hak-jong Choi, Ga Hee Choi, Ju Yeon Son, and Byungwook Yoo. J. Microbiol. Biotechnol. 2026;36:1-10. https://doi.org/10.4014/jmb.2606.06054

Background: This study aimed to evaluate whether Bioelectrical Impedance Analysis (BIA) can serve as a practical alternative to Dual- Energy X-ray Absorptiometry (DEXA) for measuring body composition in clinical settings.Methods: BIA (InBody970, InBody770, InBody770C, and InBody270C) and DEXA were repeatedly used for measurements on the same day (n=100). Participants fasted for at least 4 hours and stood upright for 10 minutes before the measurements to stabilize body water composition.Results: All four BIA devices (InBody970, InBody770, InBody770C, and InBody270C) showed a high correlation with DEXA, with Pearson correlation coefficients (r) of ≥0.97 for both muscle mass and body fat mass. Among them, the InBody770C demonstrated a slightly higher correlation in body fat mass measurements (P<0.05). However, Lin’s Concordance Correlation Coefficient ranged from 0.939 to 0.941, indicating only moderate agreement. In addition, Bland–Altman analysis revealed statistically significant mean biases and wide limits of agreement across all devices, suggesting that strong correlation does not necessarily imply measurement equivalence.Conclusions: Given the high correlation between BIA and DEXA, BIA may serve as a useful tool for tracking body composition. However, moderate agreement levels suggest that caution is warranted when interpreting BIA as a substitute for DEXA in clinical practice.

Objectives: This study aims to evaluate the efficacy and safety of probiotics for body fat reduction in obese individuals. Methods: A total of 106 participants with a body mass index between 25 and 30 kg/m² were randomly assigned to either the experimental group treating with Lactobacillus plantarum LMT1-48 or the placebo group in the placebo-controlled clinical trial. Body composition was assessed by dual-energy X-ray absorptiometry and computed tomography. Fecal samples between the groups were contrasted via DNA sequencing for evaluation of the microbiota and its diversity. Results: After 12 weeks of follow-up period, the body fat mass decreased significantly, from 30.0 ± 4.4 to 28.3 ± 4.1 kg in the experimental group (p = 0.009). The percentage of body fat in the two groups showed a similar trend (p = 0.004). Conclusions: LMT1-48 also positively influenced the microbial taxa linked to obesity analyzed by gut microbiome sequencing. LMT1-48 is a safe and collaborative agent to reduce obesity.

Alcohol-related hangovers impact both physical and mental wellness, largely due to acetaldehyde levels produced through alcohol metabolism. The present study investigated the efficacy and safety of the Wilac L probiotic complex (Levilactobacillus brevis WiKim0168 and Leuconostoc mesenteroides WiKim0172 isolated from kimchi) in improving hangovers post-alcohol consumption. This study was conducted as a randomized, double-blind, crossover placebo-controlled clinical trial from August 2023 to February 2024. Subjects (n = 26) were randomized into six test groups consuming three products, the Wilac L probiotic complex, Wilac L35 (Wilac L probiotic complex with Pyrus pyrifolia Nakai), or placebo, in different orders with crossover after a wash-out interval of 7–10 days. Blood alcohol and acetaldehyde concentrations were measured 0, 0.25, 0.5, 1, 2, 4, 6, and 15 h after alcohol consumption. The blood acetaldehyde levels measured with Wilac L probiotic complex supplementation were significantly lower than the control at 0.25 (p = 0.0381), 0.5 (p = 0.0498), and 1 h (p = 0.0260) post-consumption. The blood acetaldehyde levels after Wilac L35 consumption compared to the control are significant at 0.25 (p = 0.0115), 0.5 (p = 0.0054), 1 (p = 0.0285), 2 (p = 0.0113), and 6 h (p = 0.0287) post-consumption. No significant adverse events were reported. The Wilac L probiotic complex is associated with decreased blood acetaldehyde levels and improved subjective hangover symptoms.

Background: WCFA19 (Weissella confusa WIKIM51), found during the fermentation of kimchi, is known for its inhibitory effects on body weight and body fat. This study looked at the impact of WCFA19 isolated from dandelion kimchi on weight loss in overweight and obese adults that are otherwise healthy. Methods: This study was conducted as a multicenter, double-blind, randomized, placebo-controlled study with 104 overweight and obese subjects. Subjects were randomized evenly into the test group (WCFA19, 500 mg, n = 40) or control group (n = 34) for 12 weeks from 14 June 2021 to 24 December 2021. Effects were based on DEXA to measure changes in body fat mass and percentage. Results: Among the 74 subjects analyzed, WCFA19 oral supplementation for 12 weeks resulted in a significant decrease in body fat mass of 633.38 ± 1396.17 g (p = 0.0066) in overweight and obese individuals in the experimental group. The control group showed an increase of 59.10 ± 1120.57 g (p = 0.7604), indicating a statistically significant difference between the two groups. There was also a statistically significant difference (p = 0.0448) in the change in body fat percentage, with a decrease of 0.41 ± 1.22% (p = 0.0424) in the experimental group and an increase of 0.17 ± 1.21% (p = 0.4078) in the control group. No significant adverse events were reported. Conclusions: Oral supplementation of 500 mg of WCFA19 for 12 weeks is associated with a decrease in body weight, particularly in body fat mass and percentage.

Background: Vitamin D deficiency is a common challenge its consequences are studied to be related to diversity of other health concerns. The efficacy and safety in longevity of vitamin D3 B.O.N. 200,000 IU Intramuscular Injection were examined through investigator-initiated clinical trial.Methods: One-hundred and eight subjects between ages of 19 and 65 who showed vitamin D deficiency (serum 25(OH)D<20 ng/mL) were initially injected once and were checked every 3 months for the next 12 months for serum 25(OH)D and 1,25(OH)2D levels for the drug’s efficacy, and for other safety observations. The percentage of participants maintaining within the normal serum 25(OH)D range were analyzed. Participants who reduced in the serum level below 30 ng/mL during the regular visits were given additional injections.Results: All the subjects showed similar patterns of statistically significant improvements at all times. The percentage of participants remaining in the normal range was higher in the better compliance group. No serious adverse events or severe adverse reactions occurred.Conclusions: Treatment of the vitamin D-deficient subjects with the injection of 200,000 IU vitamin D3 B.O.N. Intramuscular Injection induced a statistically significant increase in blood vitamin D concentration for 12 months demonstrating the clinical efficacy of the intervention. The higher percentage of the better compliance group being within normal ranges strengthens the evidence of the efficacy. No new adverse events or severe adverse events were associated with the injection, demonstrating its safety. Further studies to facilitate development of appropriate guidelines for interventions using vitamin D3 intramuscular injections will be desirable.

Background: The quick and easy nature of point-of-care (POC) testing devices allows regular monitoring of serum lipid levels to increase efficiency. The purpose of this study was to assess a POC lipid analyzer, Barozen Lipid Plus (MICO Biomed Co., Ltd.), which uses capillary blood to measure total cholesterol (TC), triglycerides (TGs), and high-density lipoprotein cholesterol (HDL-C). Methods: Capillary and venous blood samples were collected from 110 participants at a single center in Korea between June 10 and June 26, 2021. TC, TG, and HDL-C measurements using Barozen Lipid Plus were compared with measurements using our reference device, the Roche-Hitachi Cobas 8000 c702 (Hitachi High-Technologies Corporation). This study followed the guidelines of the Clinical and Laboratory Standards Institute and the Clinical Laboratory Improvement Amendments. We surveyed participants regarding the convenience of the POC device using a questionnaire following the completion of blood collection. Results: When compared to the reference equipment, the measurements obtained using Barozen Lipid Plus were more than 95% satisfactory within TC±10%, TG±25%, and HDL-C±30%. The coefficient of variation in the repeatability testing was within 5% for TC, 5% for TGs, and 7% for HDL-C. The survey results indicated high levels of satisfaction. No adverse events were reported.Conclusion: These findings suggest that Barozen Lipid Plus is reliable for measuring lipid profiles and can therefore be used to monitor lipid levels at the time and place of patient care.

This study aimed to examine international students’ perceptions, characteristics, use of public medical services, and satisfaction with the National Health Insurance System, and compared the results with the Health Insurance System Perception Survey conducted on Korean population to understand the differences between the two groups’ perceptions of the health insurance system and their use of medical services.A survey was conducted from May 23, 2022 to June 21, 2022 to measure various data of international students related to the National Health Insurance System and analyzed the results.Most international students were in their 20s (the average age was 23±2.06 years), which showed that they were less likely to use medical services compared to Korean population in their 20s. Both Korean population and international students viewed their subjective health as generally good. Regarding the perceptions of the National Health Insurance System, 75.6% of the Korean population responded positively, while only 16% of international students responded positively. The biggest reason for the negative responses was the higher contributions compared to private health insurance, showing that financial hardship played a large role in the negative perceptions. The insurance contribution calculation methods by the Government showed differences. International students receive the same insurance contributions regardless of their nationality, age, income, or assets.Through this study, it has been confirmed that further research and examination are needed regarding the application of Korean health insurance to foreign residents and the appropriate calculation of insurance contributions.

Sun-Jong Kang, Jung-Eun Oh, Yong-Jin Cho, Hwang-Sik Shin, Byung-Wook Yoo, Sung-Ho Hong, Hyun Joe, Doo-Yong Son, Kyung-Suk Shin. Korean J Fam Pract 2023;13:165-70. https://doi.org/10.21215/kjfp.2023.13.3.165