Metabolic syndrome (MS) is a growing disorder affecting thousands of people worldwide, especially in industrialised countries, increasing mortality. Oxidative stress, hyperglycaemia, insulin resistance, inflammation, dysbiosis, abdominal obesity, atherogenic dyslipidaemia and hypertension are important factors linked to MS clusters of different pathologies, such as diabesity, cardiovascular diseases and neurological disorders. All biochemical changes observed in MS, such as dysregulation in the glucose and lipid metabolism, immune response, endothelial cell function and intestinal microbiota, promote pathological bridges between metabolic syndrome, diabesity and cardiovascular and neurodegenerative disorders. This review aims to summarise metabolic syndrome’s involvement in diabesity and highlight the link between MS and cardiovascular and neurological diseases. A better understanding of MS could promote a novel strategic approach to reduce MS comorbidities.

Two experiments were conducted to investigate the chemical and fermentative characteristics of by-product-mixed silages consisting of wheat straw (WS), grape pomace (GP), olive mill wastewater (OMWW) and cheese whey (CW) at 7, 30 and 90 days. The silage formulations were based on a ratio of 60% solids (WS + GP) and 40% liquids (CW + OMWW), with the addition of water (W) where necessary to achieve 40% of liquids. In experiment 1, the effects of the inclusion of GP or CW in a mixture of WS and OMWW were studied according to two silage formulations: SIL-A, WS40% + OMWW5% + GP20% + W35%; SIL-B, WS60% + OMWW5% + CW35%. In experiment 2, the effects of two levels of CW and the inclusion of OMWW in mixed silages based on WS, GP, and CW were studied according to four silage formulations: SIL-C, WS40% + GP20% + CW20% + W20%; SIL-D, WS40% + GP20% + CW20% + OMWW5% + W15%; SIL-E, WS40% + GP20% + CW35% + W5%; SIL-F, WS40% + GP20% + CW35% + OMWW5%. In experiment 1, the silage formulation affected the chemical composition showing a greater (p < 0.05) content of DM in SIL-B; crude protein, ether extract and ADL contents were higher (p < 0.05) in SIL-A. In experiment 2, no differences (p > 0.05) in the chemical characteristics of the silages were found. In both of the experiments, the chemical composition and total phenol content did not change (p > 0.05) during the ensiling period. Fermentative characteristics were not affected (p > 0.05) by the by-product combination nor the ensiling period and proved to be adequate for good-quality silages. The Flieg’s scores at D30 and D90 were greater than a 100 score in all the experimental silages, leading to the conclusion that WS, GP, OMWW and CW can be effective for producing silage.

This study aimed to evaluate the effects of a mixture of olive, laurel, and rosemary leaf powders, on the oxidative state, biochemical, immune, intestinal morphophysiological parameters, and egg quality of laying hens. One hundred Lohmann Brown hens (28 weeks old) were equally assigned to two groups (n. 50) corresponding to a basal control diet (CON) or the diet supplemented with 6 g/kg feed of leaf powder mixture (LPM) containing olive, laurel, and rosemary leaves (1:1:1), for 60 days. Oxidative status, biochemical indices, immune response, cecal short chain fatty acids (SCFAs), intestinal morphological characteristics, and some egg traits were evaluated at the end of the experiment. The results indicated that LPM improved (P < 0.05) the oxidative status (TOS, ROMs), the immune system (IL-6, IL-1β, and TNF-α), the total protein and HDL cholesterol content, whereas it decreased (P < 0.05) total cholesterol and LDL cholesterol. Aspartate aminotransferase (AST), alkaline phosphatase (ALP), and alanine aminotransferase were significantly (P < 0.05) lower in the LPM than in the CON group. A significant increase (P < 0.05) in SCFA content in the caecum, as well as in villi height and crypt depth in both duodenum and ileum of LPM-treated hens, was observed. Egg quality parameters were not influenced (P > 0.05) by LPM. These findings indicate that LPM can be considered a candidate as an antioxidant ingredient for functional food in laying hens.

This study investigated the chemical composition, fermentation dynamics, fatty-acid profile, and polyphenolic evolution of two mixed silages designed to valorize agro-industrial by-products for ruminant feeding. Silages were produced by co-ensiling wheat straw, cheese-whey, and molasses with grape pomace (SIL-1) or olive mill wastewater (SIL-2), and were monitored over a 150-day ensiling period. The two formulations exhibited distinct compositional characteristics and fermentation kinetics. SIL-1 showed higher crude protein content and a more favorable fatty-acid profile, with greater levels of selected long-chain fatty acids, whereas SIL-2 had higher dry matter and structural fiber fractions. Both silages achieved effective fermentation, reaching stable acidic conditions (pH < 4.0), although SIL-1 consistently maintained lower pH and higher buffering capacity. Fermentation end-products differed between silages, with higher concentrations of short-chain fatty acids in SIL-1 and greater lactic acid accumulation in SIL-2, under significant treatment × time interactions. Bioactive compound analysis revealed higher total phenolic content and antioxidant capacity in SIL-1, whereas SIL-2 showed marked degradation of phenolic compounds, including the loss of characteristic secoiridoids. Polyphenolic profiles displayed compound-specific temporal dynamics during ensiling. Overall, both silages were well preserved; however, SIL-1 demonstrated superior nutritional quality and bioactive stability, supporting its potential as a functional feed ingredient for ruminant nutrition.