RESUMO
The diversity and delicate balance of the oral microbiome contribute to oral health, with its disruption leading to oral and systemic diseases. Toothpaste includes elements like traditional additives such as sodium lauryl sulfate (SLS) as well as novel postbiotics derived from probiotics, which are commonly employed for maintaining oral hygiene and a healthy oral cavity. However, the response of the oral microbiota to these treatments remains poorly understood. In this study, we systematically investigated the impact of SLS, and toothpaste containing postbiotics (hereafter, postbiotic toothpaste) across three systems: biofilms, animal models, and clinical populations. SLS was found to kill bacteria in both preformed biofilms (mature biofilms) and developing biofilms (immature biofilms), and disturbed the microbial community structure by increasing the number of pathogenic bacteria. SLS also destroyed periodontal tissue, promoted alveolar bone resorption, and enhanced the extent of inflammatory response level. The postbiotic toothpaste favored bacterial homeostasis and the normal development of the two types of biofilms in vitro, and attenuated periodontitis and gingivitis in vivo via modulation of oral microecology. Importantly, the postbiotic toothpaste mitigated the adverse effects of SLS when used in combination, both in vitro and in vivo. Overall, the findings of this study describe the impact of toothpaste components on oral microflora and stress the necessity for obtaining a comprehensive understanding of oral microbial ecology by considering multiple aspects.
RESUMO
Exposure to titanium dioxide nanoparticles (TiO2 NPs) and bisphenol A (BPA) is ubiquitous, especially through dietary and other environmental pathways. In the present study, adult C57BL/6J mice were exposed to TiO2 NPs (100 mg/kg), BPA (0, 5, and 50 mg/kg), or their binary mixtures for 13 weeks. The 16S rDNA amplification sequence analysis revealed that co-exposure to TiO2 NPs and BPA altered the intestinal microbiota; however, this alteration was mainly caused by TiO2 NPs. Faecal metabolomics analysis revealed that 28 metabolites and 3 metabolic pathways were altered in the co-exposed group. This study is the first to reveal the combined effects of TiO2 NPs and BPA on the mammalian gut microbial community and metabolism dynamics, which is of great value to human health. The coexistence of TiO2 NPs and BPA in the gut poses a potential health risk due to their interaction with the gut microbiota.
RESUMO
We investigated if the self-assembled micelles of rebaudioside A (RA) could potentially be utilized as an ocular drug-delivery system in this investigation. RA self-assembled into micelles with ultra-small particle sizes (<4â¯nm) in a homogeneous distribution state (polydispersity indexâ¯<â¯0.3). RA had good cellular tolerance and no cytotoxicity was observed at concentrationsâ¯≤â¯18.5â¯mg/ml at 72â¯h of incubation. RA also did not cause cell apoptosis at concentrationâ¯≤â¯12â¯mg/ml. Coumarin-6 (Cou6)-loaded RA micelles had good cellular tolerance and in vivo non-irritants to the rabbit eyes. RA micelles dramatically improved the cellular uptake of Cou6 (compared to free-Cou6 Pâ¯<â¯0.05); an energy-independent, active, intracellular endocytosis pathway was apparently involved, and cellular organelles such as lysosomes, endoplasmic reticuli, and mitochondria were observed with a high distribution of Cou6, while a much more sophisticated endocytosis pathway was apparently involved in the ex vivo corneal endocytosis mechanism tests. The use of RA micelles significantly improved in vivo corneal permeation of the encapsulated Cou6 when compared to free-Cou6 eye drops (Pâ¯<â¯0.05). These findings indicate that RA micelle formulations have great potential as a novel ocular drug-delivery system to improve the bioavailability of hydrophobic drugs.