Probiotics have been rapidly developed for health promotion, but clinical validation of the effects on exercise physiology has been limited. In a previous study, Lactobacillus plantarum TWK10 (TWK10), isolated from Taiwanese pickled cabbage as a probiotic, was demonstrated to improve exercise performance in an animal model. Thus, in the current study, we attempted to further validate the physiological function and benefits through clinical trials for the purpose of translational research. The study was designed as a double-blind placebo-controlled experiment. A total of 54 healthy participants (27 men and 27 women) aged 20–30 years without professional athletic training were enrolled and randomly allocated to the placebo, low (3 × 10¹⁰ colony forming units (CFU)), and high dose (9 × 10¹⁰ CFU) TWK10 administration groups (n = 18 per group, with equal sexes). The functional and physiological assessments were conducted by exhaustive treadmill exercise measurements (85% VO_2max), and related biochemical indices were measured before and after six weeks of administration. Fatigue-associated indices, including lactic acid, blood ammonia, blood glucose, and creatinine kinase, were continuously monitored during 30 min of exercise and a 90 min rest period using fixed intensity exercise challenges (60% VO_2max) to understand the physiological adaptation. The systemic inflammation and body compositions were also acquired and analyzed during the experimental process. The results showed that TWK10 significantly elevated the exercise performance in a dose-dependent manner and improved the fatigue-associated features correlated with better physiological adaptation. The change in body composition shifted in the healthy direction for TWK10 administration groups, especially for the high TWK10 dose group, which showed that body fat significantly decreased and muscle mass significantly increased. Taken together, our results suggest that TWK10 has the potential to be an ergogenic aid to improve aerobic endurance performance via physiological adaptation effects.

Sarcopenia is a condition in which there is a loss of muscle caused by aging and it is one of the most significant factors that affects physical fragility. In recent years, the role of the gut–muscle axis has garnered attention as, along with the gut microbiota, it potentially plays a significant role in muscle regeneration, in addition to nutritional supplements and exercise training. Past studies have found that supplementation with Lactobacillus plantarum TWK10 could effectively increase the muscle mass of animals or adult humans. Therefore, in this study, we investigated whether the supplementation of L. plantarum TWK10 produces increased muscle mass and improves the functional performance of elderly persons with mild fragility. A total of 68 elderly subjects were recruited, of which 13 subjects were excluded or withdrew from the study. We adopted a double-blind design, and the 55 subjects were randomly divided into three groups: the placebo group, the TWK10 low-dose group (2 × 10¹⁰ CFU/day) (TWK10-L), and the TWK10 high-dose group (6 × 10¹⁰ colony-forming unit (CFU)/day) (TWK10-H). For 18 weeks, all subjects were required to regularly take experimental samples, perform functional activity testing, and have their body composition analyzed before the study and every six weeks after the intervention. Finally, 17 subjects in the placebo group, 12 subjects in the TWK10-L group, and 13 subjects in the TWK10-H group finished the study. It was found that supplementation with TWK10 had a tendency to increase and improve muscle mass, left hand grip strength, lower limb muscle strength, and gait speed and balance after the sixth week, especially in the TWK10-H group, and, as the supplement time was longer up to the 18th week, it had an even greater effect (p < 0.05). In conclusion, consecutive supplementation of L. plantarum TWK10 for more than six weeks could effectively improve the muscle strength and endurance of the elderly, reducing sarcopenia and physical fragility. This trial was registered as NCT04893746.

Lactiplantibacillus plantarum TWK10, a probiotic strain, has been demonstrated to improve exercise performance, regulate body composition, and ameliorate age-related declines. Here, we performed a comparative analysis of viable and heat-killed TWK10 in the regulation of exercise performance, body composition, and gut microbiota in humans. Healthy adults (n = 53) were randomly divided into three groups: Control, TWK10 (viable TWK10, 3 × 10¹¹ colony forming units/day), and TWK10-hk (heat-killed TWK10, 3 × 10¹¹ cells/day) groups. After six-week administration, both the TWK10 and TWK10-hk groups had significantly improved exercise performance and fatigue-associated features and reduced exercise-induced inflammation, compared with controls. Viable TWK10 significantly promoted improved body composition, by increasing muscle mass proportion and reducing fat mass. Gut microbiota analysis demonstrated significantly increasing trends in the relative abundances of Akkermansiaceae and Prevotellaceae in subjects receiving viable TWK10. Predictive metagenomic profiling revealed that heat-killed TWK10 administration significantly enhanced the signaling pathways involved in amino acid metabolisms, while glutathione metabolism, and ubiquinone and other terpenoid-quinone biosynthesis pathways were enriched by viable TWK10. In conclusion, viable and heat-killed TWK10 had similar effects in improving exercise performance and attenuating exercise-induced inflammatory responses as probiotics and postbiotics, respectively. Viable TWK10 was also highly effective in regulating body composition. The differences in efficacy between viable and heat-killed TWK10 may be due to differential impacts in shaping gut microbiota.

Lactiplantibacillus plantarum TWK10 (TWK10), isolated from Taiwanese pickled cabbage, has been demonstrated to exert beneficial probiotic effects in both mice and humans. Here, we comprehensively assessed the safety of TWK10 using both in vivo and in vitro approaches, including whole-genome sequence analysis, an assessment of hemolytic activity, and performing an antimicrobial susceptibility test, the Ames bacterial reverse mutation assay, the chromosomal aberration test, a rodent peripheral blood micronucleus test, and the 28-day subacute oral toxicity assay. The results showed that there was no significant increase in the incidence of reverse mutations or chromosomal aberrations following exposure to TWK10. Moreover, no significant changes were detected either in the number of reticulocytes or the incidence of micronuclei in ICR mice, and no subacute toxicity was recorded in SD rats at the oral TWK10 dosage of 2000 mg/kg body weight/day repeated for 28 days. Additionally, TWK10 exhibited no hemolytic activity and was susceptible to all the antibiotics tested, except kanamycin. However, no antimicrobial resistance genes, virulence factors, or genes involved in biogenic amine synthesis were found in the genome of TWK10. Our findings demonstrated that TWK10 has high potential of being safe for human consumption as a probiotic.

Kefir is an acidic, carbonated, and fermented dairy product produced by fermenting milk with kefir grains. The Lactobacillus species constitutes an important part of kefir grains. In a previous animal study, kefir effectively improved exercise performance and had anti-fatigue effects. The purpose of this research was to explore the benefits of applying kefir to improve exercise performance, reduce fatigue, and improve physiological adaptability in humans. The test used a double-blind crossover design and supplementation for 28 days. Sixteen 20–30 year-old subjects were divided into two groups in a balanced order according to each individual’s initial maximal oxygen uptake and were assigned to receive a placebo (equal flavor, equal calories, 20 g/day) or SYNKEFIR™ (20 g/day) every morning. After the intervention, there were 28 days of wash-out, during which time the subjects did not receive further interventions. After supplementation with SYNKEFIR™, the exercise time to exhaustion was significantly greater than that before ingestion (p = 0.0001) and higher than that in the Placebo group by 1.29-fold (p = 0.0004). In addition, compared with the Placebo group, the SYNKEFIR™ administration group had significantly lower lactate levels in the exercise and recovery (p < 0.05). However, no significant difference was observed in the changes in the gut microbiota. Although no significant changes in body composition were found, SYNKEFIR™ did not cause adverse reactions or harm to the participants’ bodies. In summary, 28 days of supplementation with SYNKEFIR™ significantly improved exercise performance, reduced the production of lactic acid after exercise, and accelerated recovery while also not causing any adverse reactions.

Background: Osteoarthritis (OA) is a chronic condition characterized by joint pain and disability, driven by excessive oxidative stress and inflammatory cytokine production in chondrocytes, resulting in cell death and cartilage matrix breakdown. Our previous study showed that in monosodium iodoacetate (MIA)-induced OA rats, oral administration of heat-killed Lactobacillus delbrueckii subsp. lactis 557 (LDL557) could significantly decrease OA progression. Methods: Accordingly, we designed an in vitro cell culture study aimed at investigating the effects of heat-killed LDL557 extracts on chondrocytes using SW1353 cells (a human chondrosarcoma cell line) challenged with 5 μM MIA to mimic OA conditions. Results: The results showed that the 10 μg/mL LDL557 extracts protected SW1353 cells from MIA-induced death and reduced extracellular matrix (ECM) loss, as evaluated by toluidine blue O staining and extracellular matrix component synthesis with RT-qPCR measurement. This was achieved by decreasing the expression of MIA-induced pro-inflammatory cytokines, including IL-1β, IL-6, and TNF-α, while slightly increasing the MIA-suppressed expression of the anti-inflammatory cytokine IL-10, which were evidenced by RT-qPCR analysis. Moreover, the RT-qPCR evaluation also indicated that the LDL557 extracts slightly reduced the expression of COX-2 compared with the control, while it did not reduce the MIA-increased expression of microsomal prostaglandin E synthase-1 (mPGES-1). In addition, the LDL557 extracts influenced neither the matrix-degrading protease expressions measured via RT-qPCR nor the oxidative stress measured via fluorescence flow cytometry in the cells with or without the MIA challenge. Conclusions: This study demonstrates that LDL557 extracts may protect chondrocytes from OA damage by reducing inflammation-related factors and thus mitigating cartilage matrix loss, suggesting LDL557 extracts are attractive alternatives for OA applications.