Background: Modulation of the gut–brain axis using probiotics present a promising approach for enhancing cognitive function in mild cognitive impairment (MCI). In prior non-clinical research, Lactobacillus delbrueckii subsp. lactis CKDB001 (LL) exhibited potential to enhance cognitive function. We therefore conducted a clinical trial to assess the efficacy and safety of LL supplementation in MCI. Methods: A 12-week, randomized, double-blind, placebo-controlled, multi-center trial was performed in 100 participants aged 55–80 years. Subjects were randomly assigned to receive LL (n = 50, 5.0 × 10⁹ CFU/day) or placebo (n = 50). Efficacy and safety were evaluated at baseline and after 12 weeks. Results: LL supplementation resulted in significantly greater improvements than placebo in the Alzheimer’s Disease Assessment Scale–Cognition 13 total score, the memory sub-score, reaction time for Part A of the Trail Making Test, and word/color reaction times on the Stroop test. Taxonomic and metabolomic profiling of fecal samples showed significantly greater changes in the relative abundance of beneficial microorganisms in the LL group, with the most pronounced shifts at the family (Lactobacillaceae, Bifidobacteriaceae) and genus (Lactobacillus) levels. In addition, the LL group exhibited significantly higher fecal levels of indole-derived metabolites, including 5-hydroxyindole-3-acetic acid, indole-3-lactic acid, and indole-3-glycol. Safety assessments indicated LL was safe and well-tolerated, with no clinically relevant changes in laboratory findings or adverse events. Conclusions: These findings suggest that LL supplementation may enhance cognitive function in MCI by modulating the gut–brain axis through effects on gut microbiota and related metabolites, and could serve as a safe functional food to support cognitive health.

The increased global prevalence of chronic respiratory diseases in recent years has caused a substantial public health burden. Lactiplantibacillus plantarum KC3 and Leonurus japonicus Houtt. (LJH) extracts can alleviate respiratory symptoms and improve lung function in vitro and in vivo. However, the clinical efficacy and safety profile of this combination in patients with respiratory diseases remain unclear. Therefore, this multicenter, randomized, double-blind, placebo-controlled clinical trial aimed to evaluate the efficacy and safety of L. plantarum KC3 and LJH extracts in adults with respiratory discomfort. This mixture was termed ‘CKDB-315’. Participants, randomly assigned to the CKDB-315 or placebo groups, were treated for 12 weeks. Assessments included the St. George’s Respiratory Questionnaire (SGRQ) and the Chronic Obstructive Pulmonary Disease Assessment Test (CAT). The CKDB-315 group showed considerably improved SGRQ and CAT scores compared with the placebo group. Secondary outcomes, including dyspnea, pulmonary function, total antioxidant status, and inflammatory cytokine levels, were consistent with the primary outcomes. Exploratory analyses of the gut microbiota and short-chain fatty acid contents revealed the potential mechanisms underlying the effects of CKDB-315. Finally, safety analysis indicated that CKDB-315 was well tolerated and caused few adverse events. Our findings indicate that CKDB-315 is a promising therapeutic option for respiratory discomfort in adults.

Background: CKDB-322, a combination of Lactiplantibacillus plantarum Q180 and Phaeodactylum tricornutum, has shown anti-obesity potential in preclinical models, although human evidence is still limited. This randomized, double-blind, placebo-controlled, 12-week trial evaluated the efficacy and safety of CKDB-322 in overweight adults. Methods: Participants were aged 19–65 years; had a body mass index (BMI) of 25–30 kg/m², and a waist circumference of ≥90 cm for men or ≥85 cm for women. They were randomly assigned to receive either CKDB-322, which provided 1.0 × 10⁹ CFU of L. plantarum Q180 and 200 mg of P. tricornutum daily (n = 50), or a placebo (n = 50). Results: CKDB-322 supplementation resulted in statistically significant reductions in body fat mass and body fat percentage, as measured by dual-energy X-ray absorptiometry (DEXA), compared to the placebo group (p < 0.05). Computed tomography (CT) analyses also revealed significant reductions in abdominal fat area in the CKDB-322 group (p < 0.05). Additional improvements were observed in body weight and anthropometric parameters. Among metabolic biomarkers, serum triglycerides and leptin levels decreased significantly in the CKDB-322 group compared to the placebo. Exploratory microbiome analyses indicated an increase in the relative abundance of Lactobacillus, suggesting potential modulation of the gut–adipose axis. CKDB-322 was well tolerated, with no clinically significant adverse events or laboratory abnormalities. Conclusions: Collectively, CKDB-322 demonstrated a favorable safety profile and produced statistically significant improvements in multiple adiposity-related outcomes, including reductions in body fat mass, abdominal adiposity, and key anthropometric measures, supporting its potential as a functional ingredient for body fat reduction and metabolic health.