The associations between sarcopenia and metabolic syndrome (MetS) in non-obese middle-aged and older adults remain controversial. Thus, this meta-analysis aimed to evaluate the overall prevalence of MetS and the correlations between sarcopenia and MetS in middle-aged and older non-obese adults. We performed a systematic searched strategy using PUBMED, EMBASE and Web of Science databases for relevant observational studies investigating sarcopenia and MetS up to 11 May 2017. The polled prevalence of MetS and odds ratios with 95% confidence intervals (CI), as well as subgroup analyses were calculated using a random effects model. Twelve articles with a total of 35,581 participants were included. The overall prevalence of MetS was 36.45% (95% CI, 28.28–45.48%) in middle-aged and older non-obese adults with sarcopenia. Our analysis demonstrated a positive association between sarcopenia and MetS (OR = 2.01, 95% CI, 1.63–2.47). The subgroup analysis showed that both larger cohort size and the use of dual-energy X-ray absorptiometry to measure body composition can enhance the relationship. Our study revealed that a higher proportion of MetS in middle-aged and older non-obese people with sarcopenia. Moreover, sarcopenia was positively associated with MetS in this population. Further large-scale prospective cohort studies are needed to investigate the causality between sarcopenia and MetS.

Polyvinyl alcohol (PVA) hydrogel and stem cell therapy have been widely used in wound healing. However, the lack of bioactivity for PVA and security of stem therapy limited their application. In this study, an adipose-derived stem cells (ADSCs)-seeded PVA dressing (ADSCs/PVA) was prepared for wound healing. One side of the PVA dressing was modified with photo-reactive gelatin (Az-Gel) via ultraviolet (UV) irradiation (Az-Gel@PVA), and thus ADSCs could adhere, proliferate on the PVA dressings and keep the other side of the dressings without adhering to the wound. The structure and mechanics of Az-Gel@PVA were determined by scanning electron microscopy (SEM) and material testing instruments. Then, the adhesion and proliferation of ADSCs were observed via cell counts and live-dead staining. Finally, in vitro and in vivo experiments were utilized to confirm the effect of ADSCs/PVA dressing for wound healing. The results showed that Az-Gel was immobilized on the PVA and showed little effect on the mechanical properties of PVA hydrogels. The surface-modified PVA could facilitate ADSCs adhesion and proliferation. Protein released tests indicated that the bioactive factors secreted from ADSCs could penetrated to the wound. Finally, in vitro and in vivo experiments both suggested the ADSCs/PVA could promote the wound healing via secreting bioactive factors from ADSCs. It was speculated that the ADSCs/PVA dressing could not only promote the wound healing, but also provide a new way for the safe application of stem cells, which would be of great potential for skin tissue engineering.

The adverse effects of anti-tuberculosis (TB) drugs in the intestines were related to alteration of the intestinal microbiota. However, there was less information about microbial metabolism on the adverse reactions. This study aimed to explore whether Lactobacillus casei could regulate gut microbiota or short-chain fatty acids (SCFAs) disorders to protect intestinal adverse reactions induced by isoniazid (H) and rifampicin (R). Male Wistar rats were given low and high doses of Lactobacillus casei two hours before daily administration of anti-TB drugs. After 42 days, colon tissue and blood were collected for analysis. The feces at two-week and six-week were collected to analyze the microbial composition and the content of SCFAs in colon contents was determined. Supplementation of Lactobacillus casei increased the proportion of intestinal goblet cells induced by H and R (p < 0.05). In addition, HR also reduced the level of mucin-2 (p < 0.05), and supplementation of Lactobacillus casei restored. After two weeks of HR intervention, a decrease in OTUs, diversity index, the abundance of Bacteroides, Akkermansia, and Blautia, and an increase of the abundance of Lacetospiraceae NK4A136 group and Rumencoccus UCG-005, were observed compared with the control group (p all < 0.05). These indices in Lactobacillus casei intervention groups were similar to the HR group. Six-week intervention resulted in a dramatic reduction of Lacetospiraceae NK4A136 group, butyric acid, valeric acid and hexanoic acid, while an increase of Bacteroides and Blautia (p all < 0.05). Pretreatment with Lactobacillus casei significantly increased the content of hexanoic acid compared with HR group (p < 0.05). Lactobacillus casei might prevent intestinal injury induced by anti-tuberculosis drugs by regulating gut microbiota and SCFAs metabolism.

The influence of air pollution on human health has sparked widespread concerns across the world. Previously, we found that exposure to ambient fine particulate matter (PM2.5) in our "real-ambient exposure" system can result in reduced lung function. However, the mechanism of organ-specific toxicity is still not fully elucidated. The balance of the microbiome contributes to maintaining lung and gut health, but the changes in the microbiome under PM2.5 exposure are not fully understood. Recently, crosstalk between nuclear factor E2-related factor 2 (Nrf2) and the microbiome was reported. However, it is unclear whether Nrf2 affects the lung and gut microbiomes under PM2.5 exposure. In this study, wild-type (WT) and Nrf2^-/- (KO) mice were exposed to filtered air (FA) and real ambient PM2.5 (PM) in the " real-ambient exposure" system to examine changes in the lung and gut microbiomes. Here, our data suggested microbiome dysbiosis in lung and gut of KO mice under PM2.5 exposure, and Nrf2 ameliorated the microbiome disorder. Our study demonstrated the detrimental impacts of PM2.5 on the lung and gut microbiome by inhaled exposure to air pollution and supported the protective role of Nrf2 in maintaining microbiome homeostasis under PM2.5 exposure.

Studies have shown that blue mussel lipid extract (BMLE) can improve the glycemic traits, inflammatory cytokines, and lipid profile of patients with type 2 diabetes mellitus (T2DM) in China. Gut microbiota is closely related to T2DM. This study aims to explore whether BMLE can improve the glycemic status of T2DM patients by regulating gut microbiota in a 60-day double-blind randomized controlled trial. A total of 133 T2DM subjects were randomized into BMLE (n = 44), fish oil (FO) (n = 44), and corn oil (CO) (n = 45) groups. The participants were asked to take two corresponding oil capsules (0.8 g per capsule each) every day. The faecal microbiota, glycemic traits, and other cardiometabolic factors were analyzed at baseline and endpoint. The α diversity estimators of Ace and Chao1 decreased significantly in all three groups, but there was no significant difference between the groups. Eight bacteria decreased significantly in the BMLE group but not in the FO and CO groups: unclassified_Clostridia_UCG_014, unclassified_Bacteroidia, Erysipelotrichaceae, and uncultured_Ruminococcaceae_bacterium at the family level and unclassified_Bacteroidia, uncultured_Ruminococcaceae_bacterium, unclassified_Clostridia_UCG_014, and Turicibacter at genus level. In the BMLE group, the change in the relative abundance of Erysipelotrichaceae was positively correlated with the changes in the homeostatic model assessment of insulin resistance (HOMA-IR) (r = 0.454, p < 0.01) and fasting insulin (r = 0.414, p < 0.01). The change in the relative abundance of Turicibacter was positively correlated with the changes in HOMA-IR (r = 0.431, p < 0.01), fasting insulin (r = 0.414, p < 0.01), total cholesterol (TC) (r = 0.358, p < 0.05), and triacylglycerol (TG) (r = 0.393 p = 0.013). In conclusion, BMLE might improve glycemic traits by modulating gut microbiota in T2DM patients.

Aims: This meta-analysis and systematic review aimed to comprehensively investigate the effects of vitamin K supplementation on bone mineral density (BMD) at various sites and bone metabolism in middle-aged and older adults.Methods: The databases of PubMed, Web of Science, and Cochrane Library were thoroughly searched from inception to July 2023.Results: The results revealed that vitamin K supplementation increased BMD at the lumbar spine (p = 0.035). Moreover, the pooled effects demonstrated a notable increase in carboxylated osteocalcin (cOC) (p = 0.004), a decrease in uncarboxylated osteocalcin (ucOC) (p < 0.001), and no significant effect on total osteocalcin (tOC) (p = 0.076). Accordingly, the ratio of cOC to ucOC (p = 0.002) significantly increased, while the ratio of ucOC to tOC decreased (p = 0.043). However, there was no significant effect of vitamin K supplementation on other bone metabolism markers, such as cross-linked telopeptide of type 1 collagen (NTx), bone alkaline phosphatase (BAP), and procollagen I N-terminal propeptide (PINP). Subgroup analysis revealed that vitamin K notably enhanced bone health in females by increasing lumbar spine BMD (p = 0.028) and decreasing ucOC (p < 0.001). Vitamin K, especially vitamin K2, exhibited effects on maintaining or increasing lumbar spine BMD, and influencing the balance of cOC and ucOC.Conclusion: This review suggests that the beneficial effects of vitamin K supplementation on bone health primarily involve enhancing the carboxylation of OC rather than altering the total amount of OC.Cite this article: Bone Joint Res 2024;13(12):750–763.