Probiotics, as defined by the World Health Organization, are live microorganisms that, when consumed in sufficient quantities, provide health benefits to the host. Although some countries have approved specific probiotic species for use in food, safety concerns may still arise with individual strains. Lacticaseibacillus paracasei subsp. paracasei NTU 101 (NTU 101), isolated from the gut of healthy infants, has demonstrated various probiotic effects and shown safety in a prior 28-day animal feeding study. To further verify its safety and mitigate potential risks, we performed a comprehensive genotypic and phenotypic safety evaluation in accordance with the European Food Safety Authority guidelines for safety assessment through whole genome sequencing and related literature. In this research, minimum inhibitory concentration testing identified NTU 101’s resistance to chloramphenicol; however, subsequent gene analysis confirmed no associated risk of resistance. Assessments of safety, including biogenic amine content, hemolytic activity, mucin degradation, and D-lactic acid production, indicated a low level of risk. Additionally, a repeated-dose 90-day oral toxicity study in Sprague-Dawley rats revealed no toxicity at a dose of 2000 mg/kg body weight, further supporting the strain’s safety for consumption. Based on these comprehensive analyses, NTU 101 is considered safe for regular consumption as a health supplement.

Atopic dermatitis (AD) is a recurrent allergic disease characterized by symptoms such as itching, redness, swelling, dryness, scaling skin, inflammation, and tissue damage. The underlying pathogenesis of AD remains unclear. Steroid drugs are commonly used in the clinical treatment of AD; however, their long-term use may lead to associated complications. Numerous studies have indicated that probiotics could modulate the immune system, enhance immune function, or suppress excessive immune responses. In this study, Lactobacillus paracasei subsp. paracasei NTU 101 (NTU 101) was orally administered for a duration of 4 weeks, followed by the induction of AD using ovalbumin (OVA) in a mouse model. The skin condition of the stimulated site was observed during the induction period. Subsequently, the serum immunoglobulin E (IgE) content, splenocyte T cell typing, and skin histological interpretation were examined to evaluate the efficacy of NTU 101 in alleviating AD symptoms in allergen-exposed animals. The findings indicated that administering NTU 101 beforehand effectively alleviated skin symptoms in animals with AD. It reduced the infiltration of inflammatory cells in skin tissue sections, and compared to the OVA group, there was a significant reduction in the thickening of the epidermal cell layer (decreased from 89.0 ± 20.2 µM to 48.6 ± 16.0 µM) and dermis layer (decreased from 310.3 ± 69.0 µM to 209.7 ± 55.5 µM). Moreover, the proportion of regulatory T (Treg) cells and T helper 2 (Th2) cells in splenocytes significantly increased, while the proportions of T helper 1 (Th1) and T helper 17 (Th17) cells did not differ. It is speculated that the potential mechanism by which NTU 101 prevents AD involves increasing the expression of Forkhead box protein P3 (FOXP3) and promoting Treg cell maturation, thereby alleviating allergic reaction symptoms associated with AD.

Chronic allergic skin conditions, including atopic dermatitis (AD), are characterized by pruritus, erythema, xerosis, desquamation, and inflammation, significantly impacting quality of life. Long-term steroid use, while common in treatment, carries the risk of adverse effects. Previous studies have demonstrated the potential of Lactobacillus paracasei subsp. paracasei NTU 101 (NTU 101) in alleviating AD symptoms from a preventive perspective. This study, however, focuses on exploring NTU 101’s therapeutic potential by investigating its effects on regulatory T cell (Treg) maturation and Th1/Th2 balance. The results revealed that NTU 101 administration effectively reduced serum IgE levels and inflammatory cell infiltration in the skin, leading to a significant improvement in both epidermal and dermal thickness in the AD model. Additionally, NTU 101 modulated the immune response by increasing the proportion of CD4+/IL-4+ (Th2) cells in the spleen and concurrently enhancing FOXP3 expression in CD4+/CD25+ cells, which is critical for Treg cell development. This immune modulation was further associated with a rebalancing of the Th1/Th2 ratio, achieved by increasing the proportion of CD4+/IFN-γ+ (Th1) cells. Moreover, NTU 101 influenced the proportion of CD4+IL-17+ (Th17) cells, thereby supporting neutrophil maturation and promoting allergen clearance, ultimately mitigating AD symptoms. These findings underscore the potential of NTU 101 not only in managing AD symptoms but also in modulating key immune pathways involved in the pathogenesis of the disease, offering a promising alternative or adjunct to conventional steroid therapies.

Gut microbiota dysbiosis is increasingly being recognized as a major contributor to host metabolic imbalance, immune dysfunction, and neurophysiological disorders. Probiotics are known to modulate intestinal metabolism and exert systemic effects through the gut–brain axis. Herein, we evaluated the safety and probiotic potential of Pediococcus acidilactici SWP-CGPA01 (SWP-CGPA01) under antibiotic-induced microbiota dysbiosis. Genomic and phenotypic analyses verified its safety profile, supporting its suitability for use in food and nutritional applications. In a mouse model of antibiotic-induced dysbiosis, SWP-CGPA01 supplementation alleviated diarrhea and restored hippocampal brain-derived neurotrophic factor expression. These findings demonstrate that SWP-CGPA01 is a safe and functionally active probiotic with the potential to maintain gastrointestinal and neurotrophic homeostasis under gut microbiota dysbiosis.

Probiotics, as defined by the World Health Organization, are live microorganisms that, when consumed in sufficient quantities, provide health benefits to the host. Although some countries have approved specific probiotic species for use in food, safety concerns may still arise with individual strains. Lacticaseibacillus paracasei subsp. paracasei NTU 101 (NTU 101), isolated from the gut of healthy infants, has demonstrated various probiotic effects and shown safety in prior 28-day animal feeding study. To further verify its safety and mitigate potential risks, we performed a comprehensive genotypic and phenotypic safety evaluation in accordance with European Food Safety Authority guidelines for safety assessment through whole genome sequencing and related literature. In this research, minimum inhibitory concentration testing identified NTU 101's resistance to chloramphenicol; however, subsequent gene analysis confirmed no associated risk of resistance. Assessments of safety, including biogenic amine content, hemolytic activity, mucin degradation, and D-lactic acid production, indicated a low level of risk. Additionally, a repeated dose 90-day oral toxicity study in Sprague-Dawley rats revealed no toxicity at a dose of 2000 mg/kg body weight, further supporting the strain's safety for consumption. Based on these comprehensive analyses, NTU 101 is considered safe for regular consumption as a health supplement.