Age-induced osteoporosis is a global problem. Essential amino acids (EAAs) work as an energy source and a molecular pathway modulator in bone, but their functions have not been systematically reviewed in aging bone. This study aimed to discuss the contribution of EAAs on aging bone from in vitro, in vivo, and human investigations. In aged people with osteoporosis, serum EAAs were detected changing up and down, without a well-established conclusion. The supply of EAAs in aged people either rescued or did not affect bone mineral density (BMD) and bone volume. In most signaling studies, EAAs were proven to increase bone mass. Lysine, threonine, methionine, tryptophan, and isoleucine can increase osteoblast proliferation, activation, and differentiation, and decrease osteoclast activity. Oxidized L-tryptophan promotes bone marrow stem cells (BMSCs) differentiating into osteoblasts. However, the oxidation product of tryptophan called kynurenine increases osteoclast activity, and enhances the differentiation of adipocytes from BMSCs. Taken together, in terms of bone minerals and volume, more views consider EAAs to have a positive effect on aging bone, but the function of EAAs in bone metabolism has not been fully demonstrated and more studies are needed in this area in the future.

Antimicrobial resistance (AMR) is a global health challenge. The gut microbiome, a major reservoir for AMR, is influenced by dietary habits. However, the specific impact of dietary patterns on gut resistome remains poorly understood. This study aimed to assess the effects of high-fat/low-fiber and high-fiber/low-fat diets on the development of AMR in the gut microbiome. The shift from a normal diet to a high-fat/low-fiber or a high-fiber/low-fat diet in mice resulted in corresponding increases and decreases in the relative abundance of the resistome (0.14 to 0.25, p < 0.001 vs. 0.14 to 0.09 p < 0.05), virulence genes (VGs) (0.56 to 0.91, p < 0.001 vs. 0.58 to 0.50, p < 0.05), and mobile genetic elements (MGEs) (0.20 to 1.66, p < 0.001 vs. 0.22 to 0.13, p < 0.05), respectively. Network analyses identified bacteria such as Bacteroides, Parabacteroides, and Alistipes as hosts of ARGs and VGs, with changes in their abundance closely associated with shifts in ARG and VG levels. Mobile genetic elements such as Tn916, ISBf10, IS91, and intl1 were linked to these variations, including genes conferring resistance to vancomycin and capsule-related VGs. In humans, a similar trend was observed, with high-fat diets correlating with higher resistome levels, while high-fiber diets were associated with lower resistome levels compared to a normal diet group. ARGs were more prevalent in pathogenic genera such as Enterococcus spp., Klebsiella spp., Pseudomonas spp., and Staphylococcus spp. The high-fat/low-fiber diet increased the bacterial resistome and VG abundance compared to a high-fiber/low-fat diet. Therefore, adopting a high-fiber/low-fat diet may be an effective strategy to reduce the AMR burden in the human gut, providing a valuable insight for public health recommendations.

Background: The emergence of optrA, which can confer resistance to phenicols and oxazolidinones in Enterococcus spp., poses a growing public health threat.Methods: 102 optrA-positive enterococci (OPEs) including various species were isolated from feces of 719 healthy volunteers in a Shenzhen community, China. Antimicrobial susceptibility of these isolates was tested. Whole-genome sequencing and bioinformatics analysis were performed to characterize molecular epidemiology of OPEs.Results: Compared to optrA-negative enterococci (ONEs), antimicrobial resistance (linezolid, florfenicol, doxycycline, erythromycin and ciprofloxacin) and presence of antimicrobial resistance genes (ARGs) (fexA, cat, tet(M), erm(A), erm(B) and etc) were higher in OPEs. Phylogenetic analysis revealed that high similarly (19–338 SNPs) was observed between the optrA-positive E. faecalis from community and the strains from patients, animals, and environment. In 102 OPEs, the optrA gene was detected on the chromosome (n = 36), on plasmids (n = 62), or both (n = 4). A diverse range of optrA-carrying plasmid types was identified. The rep9-plasmid replicons were widely detected in E. faecalis (44/66), whereas repUS1-plasmid replicons were widely identified in other enterococcal species (7/66). Most of all ARGs harbored by isolates were co-existed on optrA-carrying plasmids, suggesting that the acquisition of optrA-carrying plasmids will pose a greater threat to public health. Notably, the pAD1 (rep9 family) + DOp1-type plasmids should receive more attention for the transfer of optrA given their high prevalence (36.36%), high number of co-located ARGs with optrA (83.87% of total ARGs) and presence in multiple sources. Tn6674, IS1216E, ISEnfa1 and ISEnfa5 are related to the transfer of chromosomal and plasmids-derived optrA, respectively. The bcrABDR gene cluster, fexA, and erm(A) were frequently identified surrounding optrA and may be transferred with optrA via IS1216E or ISEnfa1.Conclusion: The transfer of optrA gene is related to a variety of mobile elements (including plasmids, insertion sequences, transposons), which will promote the horizontal transfer of optrA. Moreover, many ARGs co-exist with optrA and could co-transfer with optrA. The acquisition of OPEs and optrA-carrying plasmids will pose a greater threat to public health and should be obtained more attention, especially optrA-positive E. faecalis and pAD1 + DOp1-type plasmids.

Neonicotinoid insecticides (NEOs), one of the most widely used pesticide classes worldwide, have raised concerns due to potential neurotoxic effects. Yet evidence on human exposure and health outcomes, particularly in preschool children, remains limited. In this study, 506 children aged 3–6 years from Shenzhen, China, were assessed. Neurobehavioral development was evaluated with the Strengths and Difficulties Questionnaire (SDQ), and urinary concentrations of 11 NEOs were measured, including imidacloprid (IMI), clothianidin (CLO), thiamethoxam (THM), dinotefuran (DNT), nitenpyram (NIT), sulfoxaflor (SFX), acetamiprid (ACE), thiacloprid (THD), flonicamid (FLO), 6-chloronicotinic acid (6-CINA), N-desmethyl-acetamiprid (NACE), and N-desmethyl-thiamethoxam (NTHM). Seven compounds showed high detection rates, including IMI (97.4%), CLO (100%), THM (100%), DNT (99.8%), NIT (99.8%), NACE (100%), and NTHM (99.8%). The mean urinary concentration was 234.145 μg/g creatinine, exceeding levels in earlier studies and indicating widespread exposure. IMI, NTHM, and NACE showed significant positive dose–response relationships with emotional symptoms, hyperactivity, and total difficulties and were major contributors in mixture models; sex-stratified analyses suggested effect modification for NTHM and NACE. These findings provide new epidemiological evidence to inform public health risk assessment and regulatory action on NEOs.