Effects of dietary energy levels on microorganisms and short-chain fatty acids of rumen and tight junction proteins in Honghe Yellow cattle

The Effect of Microbiome-Derived Metabolites in Inflammation-Related Cancer Prevention and Treatment

Chronic inflammation plays a crucial role in cancer development, yet the mechanisms linking the microbiome to inflammation-related carcinogenesis remain unclear. Emerging evidence suggests that microbiome-derived metabolites influence inflammatory pathways, presenting both challenges and opportunities for therapy. However, a deeper understanding of how these metabolites regulate inflammation and contribute to cancer prevention is still needed. This review explores recent advances in microbiome-derived metabolites and their roles in inflammation-related carcinogenesis. It highlights key molecular mechanisms, emerging therapies, and unresolved challenges. Synthesizing current research, including clinical trials and experimental models, bridges the gap between microbiome science and cancer therapy. Microbial metabolites such as short-chain fatty acids (SCFAs), polyamines, indoles, and bile acids play vital roles in regulating inflammation and suppressing cancer. Many metabolites exhibit potent anti-inflammatory and immunomodulatory effects, demonstrating therapeutic potential. Case studies show promising results, but challenges such as metabolite stability, bioavailability, and individual variability remain. Understanding microbiome-metabolite interactions offers novel strategies for cancer prevention and treatment. This review identifies knowledge gaps and proposes future research directions to harness microbiome-derived metabolites for innovative cancer therapies. Addressing these issues may pave the way for microbiome-targeted cancer interventions.

Effects of Feeding Reduced Protein Diets on Milk Quality, Nitrogen Balance and Rumen Microbiota in Lactating Goats

Lowering dietary protein content is one of the effective ways to reduce nitrogen (N) emissions and conserve protein feed resources. However, it is unclear how reducing dietary protein levels affects milk quality and the efficiency of N utilization in lactating goats. It is therefore difficult to determine exactly how much reduction in dietary protein levels is optimal. The objective of this study was to evaluate the effects of low-protein diets on milk quality, N balance and rumen microbiota in lactating goats. A total of 50 lactating goats were enrolled in a completely randomized design and maintained on either a diet with 15.82% protein level as the control group (CON) or reduced protein levels with 13.85% (R2 group), 11.86% (R4 group), 9.84% (R6 group) and 7.85% (R8 group), respectively. The results showed that the dry matter intake, milk yield, fecal and urinary N excretion and utilization efficiency of N of lactating goats decreased linearly with reduced dietary protein levels. Specifically, the milk yield was reduced by the R8 group (p < 0.05). Furthermore, the R8 group reduced the contents of protein, fat and lactose (p < 0.05), but R2 and R4 have no influence (p > 0.05). The R6 group decreased protein content only at the 4th week. Fecal and urinary N excretion and utilization efficiency of N reduced linearly with decreasing dietary protein levels (p < 0.05). The R8 group affected the relative abundance of rumen microbiota including Christensenellaceae_R-7_group, NK4A214_group and UCG-005 (p < 0.05). In conclusion, lowering dietary protein levels decreased milk quality and N excretion by altering rumen microbiota in goats during lactation. This phenomenon was most pronounced when the dietary protein level was reduced by 8 percentage points. Nevertheless, dietary protein levels should not be reduced by more than 6 percentage points to ensure normal performance of the goat during lactation.

Multi-Omics Insights into Rumen Microbiota and Metabolite Interactions Regulating Milk Fat Synthesis in Buffaloes

The present study was conducted to analyze the correlation between the milk fat content of Binglangjiang buffaloes and their microbial and host metabolites. The 10 buffaloes with the highest milk fat content (HF, 5.60 ± 0.61%) and the 10 with the lowest milk fat content (LF, 1.49 ± 0.13%) were selected. Their rumen fluid and plasma were collected for rumen microbiota and metabolome analysis. The results showed that the rumen bacteria abundance of Synergistota, Quinella, Selenomonas, and Fretibacterium was significantly higher in the HF buffaloes. The abundance of 14 rumen fungi, including Candida, Talaromyces, Cyrenella, and Stilbella, was significantly higher in the HF buffaloes. The analysis of the metabolites in the rumen and plasma showed that several metabolites differed between the HF and LF buffaloes. A total of 68 and 42 differential metabolites were identified in the rumen and plasma, respectively. By clustering these differential metabolites, most of those clustered in the HF group were lipid and lipid-like molecules such as secoeremopetasitolide B, lucidenic acid J LysoPE (0:0/18:2 (9Z, 12Z)), and 5-tetradecenoic acid. Spearman's rank correlations showed that Quinella, Fretibacterium, Selenomonas, Cyrenella, and Stilbella were significantly positively correlated with the metabolites of the lipids and lipid-like molecules in the rumen and plasma. The results suggest that rumen microbiota such as Quinella, Fretibacterium, Selenomonas, and Cyrenella may regulate milk fat synthesis by influencing the lipid metabolites in the rumen and plasma. In addition, the combined analysis of the rumen microbiota and host metabolites may provide a fundamental understanding of the role of the microbiota and host in regulating milk fat synthesis.

Effects of Dietary Energy Levels on Growth Performance, Nutrient Digestibility, Rumen Barrier and Microflora in Sheep

Dietary energy is crucial for ruminants' performance and health. To determine optimal dietary energy levels for growing sheep, we evaluated their growth performance, nutrient digestibility, rumen fermentation, barrier function, and microbiota under varying metabolic energy (ME) diets. Forty-five growing Yunnan semi-fine wool sheep, aged 10 months and weighing 30.8 ± 1.9 kg, were randomly allocated to five treatments, each receiving diets with ME levels of 8.0, 8.6, 9.2, 9.8 or 10.4 MJ/kg. The results showed that with increasing dietary energy, the average daily gain (ADG) as well as the digestibility of dry matter (DM) and organic matter (OM) increased (p < 0.05), while the feed conversion ratio (FCR) decreased linearly (p = 0.01). The concentration of total VFA (p = 0.03) and propionate (p = 0.01) in the rumen increased linearly, while rumen pH (p < 0.01) and the acetate-propionate ratio (p = 0.01) decreased linearly. Meanwhile, the protein contents of Claudin-4, Claudin-7, Occludin and ZO-1 as well as the relative mRNA expression of Claudin-4 and Occludin also increased (p < 0.05). In addition, rumen bacterial diversity decreased with the increase of dietary energy, and the relative abundance of some bacteria (like Saccharofermentans, Prevotella and Succiniclasticum) changed. In conclusion, increasing dietary energy levels enhanced growth performance, nutrient digestibility, rumen fermentation, and barrier function, and altered the rumen bacterial community distribution. The optimal dietary ME for these parameters in sheep at this growth stage was between 9.8 and 10.4 MJ/kg.