Yixuan Li

This study explored the combined anti-inflammatory potential of lactoferrin (LF) and osteopontin (OPN) using both in vitro (LPS-challenged macrophages) and in vivo (LPS-induced intestinal injury) models. The LF-OPN combination demonstrated superior efficacy over monotherapies in suppressing pro-inflammatory mediator expression in macrophages. In vivo, co-administration markedly attenuated intestinal-barrier disruption and preserved mucosal architecture, evidenced by increased villus height, crypt depth, and goblet-cell counts, surpassing the effects of OPN alone. This structural protection was accompanied by significant immunomodulation; the combination treatment elevated systemic and local anti-inflammatory cytokines while reducing pro-inflammatory ones more effectively than either single protein. Notably, at LF:OPN ratios of 1:1, 5:1, and 10:1, murine intestinal Il10 concentrations rose by 44.25%, 54.46%, and 60.02%, respectively, relative to LF group; Tnfα concentrations fell by 33.73%, 52.27%, and 37.80% at the same three ratios when benchmarked against the OPN group (all p < 0.05). These data reveal a potent combined effect of LF and OPN against acute inflammatory insults, suggesting a promising therapeutic combined effect. Future work should focus on elucidating the underlying signaling mechanisms and evaluating efficacy in chronic disease models.

The neuroprotective properties of edible bird's nest (EBN) are well established; however, its effects on neuronal growth remain unclear. In this study, we investigated the effects of enzyme‐digested EBN (EBND) on neurogenesis in the PC12 neuronal cell line. Although treatment with EBND alone did not significantly promote the differentiation of PC12 cells, it increased neurite outgrowth and neurofilament expression when co‐administered with nerve growth factor (NGF). Moreover, EBND significantly augmented the NGF‐induced phosphorylation of TrkA and ERK1/2, which in turn activated CREB and increased brain‐derived neurotrophic factor (BDNF) expression. Notably, these effects of EBND were diminished by the TrkA inhibitor GW441756. Taken together, these findings suggest that combined treatment with EBND and NGF enhances neurogenesis in PC12 cells by activating the TrkA‐ERK‐CREB‐BDNF signaling pathway.

Background: Plasmalogens (PLS) are a distinctive class of glycerophospholipids with reported neuroprotective properties; however, the mechanisms underlying their potential benefits for age-related cognitive decline remain incompletely understood. Methods: A D-galactose-induced mouse model of aging was used to evaluate the effects of PLS on cognitive performance. Hippocampal synaptic remodeling was assessed by examining the expression of synaptic proteins and receptors. An in vitro BBB model was used to evaluate the transport of PE-PLS 18:0/20:4. Molecular interaction analyses were conducted to investigate the potential binding of PE-PLS 18:0/20:4 to the brain-derived neurotrophic factor (BDNF) and its association with BDNF/TrkB signaling activation. Results: High-dose PLS supplementation significantly improved spatial memory and novel object recognition in D-galactose-treated mice. Molecular interaction analysis indicated that PE-PLS 18:0/20:4 could interact with BDNF through multiple hydrogen bonds. This interaction was associated with activation of the BDNF/TrkB signaling pathway, increased synaptic protein expression, and neuroprotective effects. Conclusions: PLS may mitigate age-related cognitive dysfunction by promoting hippocampal synaptic remodeling. PE-PLS 18:0/20:4 may contribute to these effects through BBB transport and modulation of BDNF/TrkB signaling, supporting the potential of plasmalogens as a nutritional strategy for promoting healthy brain aging.

Age‐related pulmonary fibrosis (PF) imposes a growing global burden with limited therapies. This study explored the role of Lactobacillus paracasei L9 (L9) in alleviating PF in C57BL/6J mice and its mechanisms. Nine‐month oral administration of L9 (4 × 10 ⁹ CFU/mL) suppressed collagen (Col‐) I deposition in aged mice, with no significant effect on Col‐III. Mechanistically, L9 inhibited the JNK‐HSF1 signaling pathway, thereby resulting in a 61% decrease in HSP47 expression, which is crucial for Col‐I synthesis. L9 reshaped the gut microbiota by increasing short‐chain fatty acid (SCFA)‐producing bacteria (e.g., Blautia), leading to a 97% increase in serum propionic acid and 193% increase in butyric acid; notably, the levels of SCFAs in the lungs were below the limit of detection. In L9‐treated mice, pulmonary IL‐17A levels and Th17 cell populations were reduced. In vitro, SCFAs directly inhibited Th17 cell differentiation and IL‐17A secretion, and IL‐17A was confirmed to promote Col‐I synthesis via the JNK‐HSF1 pathway in pulmonary fibroblasts. Consequently, L9 modulates the gut microbiota to produce SCFAs, which regulate naïve CD4 ⁺ T cell differentiation and migration via the gut‐lung axis. This reduces pulmonary Th17 cells and IL‐17A, thereby suppressing Col‐I synthesis in pulmonary fibroblasts and ultimately alleviating age‐related PF. In conclusion, this study highlights L9 as a microbiome‐targeted precision nutrition strategy for the adjuvant therapy of age‐related PF via the novel gut‐lung axis mechanism.

Background: Aging is frequently accompanied by disrupted amino acid homeostasis, contributing to malnutrition and physical function decline in elderly individuals. However, age-related impairment of intestinal absorptive capacity limits the efficacy of protein supplementation alone to improve nutritional status. Gut microflora diversity is regarded as a key factor for nutrient absorption. Lactobacillus paracasei L9 (L9) has recently been shown to improve gut health, but its effects on intestinal amino acid absorption remain unclear. Methods: In this study, 15-month-old male C57BL/6J mice (n = 4 per group) were administered L9 (4 × 10¹⁰ CFU in 100 μL) via daily gavage for 9 months to investigate the effect of L9 on amino acid absorption. Results: After L9 intervention, both plasma amino acid levels and the expression of large neutral amino acid transporter 2 (LAT2), a key transporter associated with neutral amino acid absorption, were significantly increased. Subsequently, microbiota composition analysis revealed that L9 modulated the gut microbiota, increasing the abundance of multiple beneficial bacteria in aged mice. Targeted metabolomics then revealed that plasma concentrations of butyric acid significantly elevated in aged mice after L9 intervention. Furthermore, IEC-6 cells experiments were conducted, demonstrating that butyric acid can enhance LAT2 expression via activating the Akt/mTOR pathway. Conclusions: Overall, these results suggested that L9 significantly enhanced amino acid absorption capacity in aged mice via the butyric acid-Akt/mTOR-LAT2 axis, and this identifies potential targets for improving age-related malnutrition and providing a promising strategy to maintain amino acid homeostasis in the elderly.

Chronic fatigue syndrome (CFS) is a debilitating disorder characterized by persistent fatigue with an unclear pathophysiology. Increasing evidence suggests that neuroinflammation plays an important role in the development of CFS; however, the underlying mechanisms remain poorly defined. In this study, we evaluated the effects of edible bird's nest (EBN) in a sleep‐deprivation–induced CFS‐like mouse model. EBN treatment improved motor and cognitive performance, reduced neuronal necrosis, and preserved synaptic structure in the prefrontal cortex. Blood metabolomic profiling revealed elevated levels of the dipeptide valyl‐tryptophan (Val‐Trp) following EBN administration. Functional assays showed that Val‐Trp attenuates neuroinflammation by suppressing nuclear factor kappa‐B signaling, thereby shifting microglia from a pro‐inflammatory to a homeostatic state. These findings implicate Val‐Trp as a candidate bioactive metabolite associated with the neuroprotective effects of EBN, providing preclinical evidence to support exploration of natural‐product‐derived interventions for CFS.

Background/Objectives: Sarcopenia is an age-related condition marked by a progressive decline in muscle mass, weakened strength, and decreased physical performance in the elderly. Methods: In this research, we used D-galactose (D-gal)-induced 8-week-old male C57BL/6J mice to establish a sarcopenia model. This model was utilized to investigate the effect and potential mechanism of α-ketoglutaric acid (AKG), a key intermediate of the tricarboxylic acid cycle, on sarcopenia. Results: Our findings demonstrated that AKG significantly ameliorated muscle mass, exercise endurance, grip strength, and cold tolerance in D-gal-induced aging mice. AKG could regulate protein homeostasis, thereby enhancing the protein composition and size of myofibers in D-gal-induced aging mice. Additionally, AKG enhanced SOD activity in the skeletal muscle of D-gal-induced aging mice and scavenged reactive oxygen species (ROS) by activating the SIRT1/PGC-1α/Nrf2 pathway, thereby improving mitochondrial function. Conclusions: In conclusion, AKG combated sarcopenia by regulating protein homeostasis and optimizing mitochondrial function in skeletal muscle. This study provides a scientific foundation for developing therapeutic interventions using AKG to target muscle aging.

Background/Objectives: Early life is crucial for infant gut development and intestinal homeostasis. Lactoferrin (LF) and osteopontin (OPN) are bioactive breast milk proteins that are supplemented into infant formula to promote gut development. However, the combined effect of LF and OPN (LOP) on in vivo gut maturation has not been fully elucidated. This study investigated the effects of LF, OPN, and LOP on intestinal epithelium maturation in C57BL/6N mice from postnatal days 7 to 21. Methods: 3-day-old pups were assigned to four groups: Control group, LF group: 300 mg/kg LF; OPN group: 300 mg/kg OPN, LOP group: 300 mg/kg of a 1:5 (w/w) mixture of LF and OPN. Results: Compared to controls, LOP reduced plasma Diamine Oxidase (DAO) activity by 1.54-fold and D-lactate levels by 1.41-fold, demonstrating greater efficacy than LF or OPN alone in reducing intestinal permeability. LOP also significantly increased intestinal absorptive cells versus controls or single proteins. Mechanistically, LOP promoted directional intestinal stem cell differentiation, increasing jejunal transit-amplifying cells by 1.40-fold in 21-day-old mice. LOP upregulated expression of the Notch pathway target Hes1 by 1.70-fold. Further investigations revealed LOP activated Notch signaling via the transcription factor Brg1. Validation using intestinal organoids and IEC-6 cells confirmed intact OPN within LOP mediates increased Brg1 expression, activating the Notch pathway to direct intestinal stem cell differentiation into absorptive cells. Conclusions: Collectively, these findings in neonatal mice suggest that LOP cooperatively enhances intestinal barrier maturation and directs stem cell differentiation via Brg1-Notch signaling, offering potential insights for future research on bioactive protein supplementation in infant nutrition.

The spoilage of dairy products and foodborne diseases caused by Bacillus spp. are important public concerns. The objective of this study was to estimate the global prevalence of Bacillus spp. in a range of milk and dairy products by using a meta-analysis of literature data published between 2001 and 2023. A total of 3624 publications were collected from Web of Science and PubMed databases. Following the principles of systematic review, 417 sets of prevalence data were extracted from 142 eligible publications. Estimated by the random-effects model, the overall prevalence of Bacillus spp. in milk and dairy products was 11.8% (95% CI: 10.1–13.7%), with highly severe heterogeneity (94.8%). Subgroup analyses revealed substantial heterogeneity in Bacillus spp. prevalence according to geographical continents, sources of sampling, types of dairy products, microbial species, and detection methods. The prevalence of Bacillus spp. was highest in Asia (15.4%, 95% CI: 12.3–19.1%), lowest in Oceania (3.5%, 95% CI: 3.3–3.7%) and generally higher in developing versus developed countries. The prevalence of Bacillus spp. isolated from retail markets (16.1%, 95% CI: 13.0–19.7%) was higher than from farms (10.3%, 95% CI: 6.9–15.0%) or dairy plants (9.2%, 95% CI: 7.1–12.0%). This finding is likely attributable to its inherent characteristic of the resistant endospores and ubiquitous presence in the environment—Bacillus spp. can potentially cyclically contaminate farms, dairy products and human markets. Regarding the species distribution, Bacillus cereus presented a cosmopolitan distribution across all continents. The epidemic patterns of different Bacillus species vary depending on the sample sources. In addition, the detection method utilized also affected the reported prevalence of Bacillus spp. It is recommended to use molecular-based rapid detection methods to obtain a more accurate prevalence of Bacillus contamination. Therefore, a better understanding of variations in Bacillus spp. prevalence across different factors will enable competent authorities, industries, and other relevant stakeholders to tailor their interventions for effectively controlling Bacillus spp. in milk and dairy products.

Breast milk is the best source of nutrition for infants. Simulating breast milk, which maximizes the restoration of composition and proportion in breast milk protein, is the ultimate goal of upgrading powdered infant milk products. Although products upgraded with protein, including lactoferrin and osteopontin, have been sold on the market, their effect on intestinal health is not yet well-defined. This study evaluated the effect of protein-upgraded infant formula on the intestinal barrier of piglets. Seven-day-old piglets were used as a model and fed normal and upgraded powdered milk formula for 28 d. The results showed that the upgraded formula increased villus height in the ileum and duodenum by approximately 15% and promoted the expression of tight junction proteins ZO-1, claudin-1, and occludin by 1.5 to 3 times compared with the normal formula group. Intestinal flora were detected to analyze the mechanism by which the upgraded formula improved intestinal mechanical barrier function. The results showed that the upgraded formula promoted the development of beneficial bacteria like Bifidobacterium by 1.5 to 2 times compared with the normal formula. Overall, this study demonstrated that an infant formula mimicking breast milk protein promoted intestinal development effectively and established good intestinal microbiota, which provides a robust scientific foundation for the precise and informed formulation of infant formulas to better meet their nutritional and health requirements.