Eggshell membrane modulates gut microbiota to prevent murine pre-cachexia through suppression of T helper cell differentiation

Influence of Gut Microbiota-Mediated Immune Regulation on Response to Chemotherapy

The involvement of the gut microbiota in anti-cancer treatment has gained increasing attention. Alterations to the structure and function of the gut bacteria are important factors in the development of cancer as well as the efficacy of chemotherapy. Recent studies have confirmed that the gut microbiota and related metabolites influence the pharmacological activity of chemotherapeutic agents through interactions with the immune system. This review aims to summarize the current knowledge of how malignant tumor and chemotherapy affect the gut microbiota, how the gut microbiota regulates host immune response, and how interactions between the gut microbiota and host immune response influence the efficacy of chemotherapy. Recent advances in strategies for increasing the efficiency of chemotherapy based on the gut microbiota are also described. Deciphering the complex homeostasis maintained by the gut microbiota and host immunity provides a solid scientific basis for bacterial intervention in chemotherapy.

Targeting the gut microbiota-related metabolites for osteoporosis: The inextricable connection of gut-bone axis

Osteoporosis is a systemic skeletal disease characterized by decreased bone mass, destruction of bone microstructure, raised bone fragility, and enhanced risk of fractures. The correlation between gut microbiota and bone metabolism has gradually become a widespread research hotspot in recent years, and successive studies have revealed that the alterations of gut microbiota and its-related metabolites are related to the occurrence and progression of osteoporosis. Moreover, several emerging studies on the relationship between gut microbiota-related metabolites and bone metabolism are also underway, and extensive research evidence has indicated an inseparable connection between them. Combined with latest literatures and based on inextricable connection of gut-bone axis, this review is aimed to summarize the relation, potential mechanisms, application strategies, clinical application prospects, and existing challenges of gut microbiota and its-related metabolites on osteoporosis, thus updating the knowledge in this research field and providing certain reference for future researches.

Dietary intake of micronized avian eggshell membrane in aged mice reduces circulating inflammatory markers, increases microbiota diversity, and attenuates skeletal muscle aging

Introduction

Avian eggshell membrane (ESM) is a complex extracellular matrix comprising collagens, glycoproteins, proteoglycans, and hyaluronic acid. We have previously demonstrated that ESM possesses anti-inflammatory properties in vitro and regulates wound healing processes in vivo. The present study aimed to investigate if oral intake of micronized ESM could attenuate skeletal muscle aging associated with beneficial alterations in gut microbiota profile and reduced inflammation.

Methods

Elderly male C57BL/6 mice were fed an AIN93G diet supplemented with 0, 0.1, 1, or 8% ESM. Young mice were used as reference. The digestibility of ESM was investigated using the static in vitro digestion model INFOGEST for older people and adults, and the gut microbiota profile was analyzed in mice. In addition, we performed a small-scale pre-clinical human study with healthy home-dwelling elderly (>70 years) who received capsules with a placebo or 500 mg ESM every day for 4 weeks and studied the effect on circulating inflammatory markers.

Results and discussion

Intake of ESM in elderly mice impacted and attenuated several well-known hallmarks of aging, such as a reduction in the number of skeletal muscle fibers, the appearance of centronucleated fibers, a decrease in type IIa/IIx fiber type proportion, reduced gene expression of satellite cell markers Sdc3 and Pax7 and increased gene expression of the muscle atrophy marker Fbxo32. Similarly, a transition toward the phenotypic characteristics of young mice was observed for several proteins involved in cellular processes and metabolism. The digestibility of ESM was poor, especially for the elderly condition. Furthermore, our experiments showed that mice fed with 8% ESM had increased gut microbiota diversity and altered microbiota composition compared with the other groups. ESM in the diet also lowered the expression of the inflammation marker TNFA in mice and in vitro in THP-1 macrophages. In the human study, intake of ESM capsules significantly reduced the inflammatory marker CRP. Altogether, our results suggest that ESM, a natural extracellular biomaterial, may be attractive as a nutraceutical candidate with a possible effect on skeletal muscle aging possibly through its immunomodulating effect or gut microbiota.

The role of chicken eggs in modulating sarcopenic obesity and gut microbiota in db/db mice

Background

Sarcopenia obesity, in which loss of muscle mass and fat accumulation occur simultaneously, is the pathological basis of type 2 diabetes mellitus. The usefulness of chicken eggs in sarcopenia prevention has been reported in several previous studies. The purpose of this study was to determine the beneficial effects of chicken eggs in the prevention of sarcopenic obesity in db/db mice.

Methods

We raised 8-week-old db/db male mice, a model of sarcopenia obesity, for 8 weeks and fed them a diet mixed with dried whole eggs. The fecal microbiota transplant (FMT) group was treated with antibiotics for 2 weeks, starting at 6 weeks of age, followed by FMT twice a week until 16 weeks of age.

Results

Eggs administered to db/db mice showed increased grip strength (p = 0.022) and muscle mass (p = 0.013), decreased visceral fat mass (p = 0.005), and significantly increased physical activity (p < 0.001). The FMT group of egg-fed mice showed a significant improvement in glucose intolerance and sarcopenic obesity. Sequencing of gene expression in the small intestine showed that the gene expression of amino acid transporters such as Slc6a18, Slc6a19, and Slc38a6 was increased in egg-fed mice. 16S rRNA sequencing of the gut microbiota showed an increase in the genus Vampirovibrio in both the egg-fed and FMT groups compared to that in egg-fed mice.

Conclusion

The results of this study indicate that egg consumption not only increases the intake of amino acids and other nutrients but also alters the intestinal microbiota and increases amino acid absorption from the intestinal tract, suggesting that eggs might contribute to the ameliorative mechanism of sarcopenic obesity.

Gut microbiota in muscular atrophy development, progression, and treatment: New therapeutic targets and opportunities

Skeletal muscle atrophy is a debilitating condition that significantly affects quality of life and often lacks effective treatment options. Muscle atrophy can have various causes, including myogenic, neurogenic, and other factors. Recent investigation has underscored a compelling link between the gut microbiota and skeletal muscle. Discerning the potential differences in the gut microbiota associated with muscle atrophy-related diseases, understanding their influence on disease development, and recognizing their potential as intervention targets are of paramount importance. This review aims to provide a comprehensive overview of the role of the gut microbiota in muscle atrophy-related diseases. We summarize clinical and pre-clinical studies that investigate the potential for gut microbiota modulation to enhance muscle performance and promote disease recovery. Furthermore, we delve into the intricate interplay between the gut microbiota and muscle atrophy-related diseases, drawing from an array of studies. Emerging evidence suggests significant differences in gut microbiota composition in individuals with muscle atrophy-related diseases compared with healthy individuals. It is conceivable that these alterations in the microbiota contribute to the pathogenesis of these disorders through bacterium-related metabolites or inflammatory signals. Additionally, interventions targeting the gut microbiota have demonstrated promising results for mitigating disease progression in animal models, underscoring the therapeutic potential of modulating the gut microbiota in these conditions. By analyzing the available literature, this review sheds light on the involvement of the gut microbiota in muscle atrophy-related diseases. The findings contribute to our understanding of the underlying mechanisms and open avenues for development of novel therapeutic strategies targeting the gut-muscle axis.

The ionome and proteome landscape of aging in laying hens and relation to egg white quality

The ionome is essential for maintaining body function and health status by participating in diverse key biological processes. Nevertheless, the distribution and utilization of ionome among different organs and how aging impacts the ionome leading to a decline in egg white quality remain unknown. Thus, we used inductively coupled plasma mass spectrometry (ICP-MS) to analyze 35 elements and their isotopic contents in eight organs of laying hens at 35, 72, and 100 weeks. Moreover, the magnum proteome, amino acids in egg white, and egg white quality were analyzed in laying hens at three different ages using 4D proteomics techniques, an amino acid analyzer, and an egg quality analyzer. Across the organs, we identified varying distribution patterns among macroelements (Mg24, Ca43/44, K39, and P31), transition metals (Zn64/66, Cu63/65, Fe56/57, and Mn55), and toxic elements (Pb208, Ba137, and Sr86). We observed an organ-specific aging pattern characterized by the accumulation of toxic elements (Pb208, Ba137, and Sr86) and calcification in the small intestine. Additionally, a decrease in the utilization of essential trace elements selenium (Se78/82) and manganese (Mn55) was noted in the oviduct. By analyzing ionome in tandem with egg quality, egg white amino acids, and proteome, we unveiled that the reduction of selenium and manganese concentrations in the magnum during the aging process affected amino acid metabolism, particularly tryptophan metabolism, thereby inhibiting the amino acid synthesis in the magnum. Furthermore, it accelerated the senescence of magnum cells through necroptosis activation, leading to a decline in the albumen secretion function of the magnum and subsequently reducing egg white quality. Overall, this study provides insights into the evolution of 35 elements and their isotopes across 8 organs of laying hens with age. It also reveals the elemental composition, interactions, and utilization patterns of these organs, as well as their correlation with egg white quality. The present study highlights the significance of ionome and offers a comprehensive perspective on the selection of ionome for regulating the aging of laying hens.

The Loss of YTHDC1 in Gut Macrophages Exacerbates Inflammatory Bowel Disease

The nuclear N⁶ -methyladenosine (m⁶ A) reader YT521-B homology-domain-containing protein 1 (YTHDC1) is required to maintain embryonic stem cell identity. However, little is known about its biological functions in intestinal-resident macrophages and inflammatory bowel disease (IBD). Herein, it is demonstrated that macrophage-specific depletion or insufficiency of YTHDC1 accelerates IBD development in animal models. On the molecular basis, YTHDC1 reduction in IBD-derived macrophages is attributed to Zinc finger protein 36 (ZFP36)-induced mRNA degradation. Importantly, transcriptome profiling and mechanistic assays unveil that YTHDC1 in macrophages regulates Ras homolog family member H (RHOH) to suppress inflammatory responses and fine-tunes NME nucleoside diphosphate kinase 1 (NME1) to enhance the integrity of colonic epithelial barrier, respectively. Collectively, this study identifies YTHDC1 as an important factor for the resolution of inflammatory responses and restoration of colonic epithelial barrier in the setting of IBD.

Abnormal lipid metabolism in cancer-associated cachexia and potential therapy strategy

Cancer-associated cachexia (CAC) is a major characteristic of advanced cancer, associates with almost all types of cancer. Recent studies have found that lipopenia is an important feature of CAC, and it even occurs earlier than sarcopenia. Different types of adipose tissue are all important in the process of CAC. In CAC patients, the catabolism of white adipose tissue (WAT) is increased, leading to an increase in circulating free fatty acids (FFAs), resulting in " lipotoxic". At the same time, WAT also is induced by a variety of mechanisms, browning into brown adipose tissue (BAT). BAT is activated in CAC and greatly increases energy expenditure in patients. In addition, the production of lipid is reduced in CAC, and the cross-talk between adipose tissue and other systems, such as muscle tissue and immune system, also aggravates the progression of CAC. The treatment of CAC is still a vital clinical problem, and the abnormal lipid metabolism in CAC provides a new way for the treatment of CAC. In this article, we will review the mechanism of metabolic abnormalities of adipose tissue in CAC and its role in treatment.

From Mouth to Muscle: Exploring the Potential Relationship between the Oral Microbiome and Cancer-Related Cachexia

Cancer cachexia is a multifactorial wasting syndrome associated with skeletal muscle and adipose tissue loss, as well as decreased appetite. It affects approximately half of all cancer patients and leads to a decrease in treatment efficacy, quality of life, and survival. The human microbiota has been implicated in the onset and propagation of cancer cachexia. Dysbiosis, or the imbalance of the microbial communities, may lead to chronic systemic inflammation and contribute to the clinical phenotype of cachexia. Though the relationship between the gut microbiome, inflammation, and cachexia has been previously studied, the oral microbiome remains largely unexplored. As the initial point of digestion, the oral microbiome plays an important role in regulating systemic health. Oral dysbiosis leads to the upregulation of pro-inflammatory cytokines and an imbalance in natural flora, which in turn may contribute to muscle wasting associated with cachexia. Reinstating this equilibrium with the use of prebiotics and probiotics has the potential to improve the quality of life for patients suffering from cancer-related cachexia.