Amino acids might be a tool to transform animals from a pro- to an anti-inflammatory phenotype through the downregulation of several genes (TLR-4, NF-κB, TNFa, IL-1β, IL-2, IL-6, IL-8, CCL-5 and CXCL-16) whose expression increases during inflammation. To examine this possibility, each of sixty Chios dairy sheep was assigned to one of the following five dietary treatments: A: basal diet (control group); B: basal diet +6.0 g/head rumen-protected methionine (MetaSmart ); C: basal diet +5.0 g/head rumen-protected lysine (LysiGEM ); D: basal diet +6.0 g/head MetaSmart + 5.0 g/head LysiGEM ; and E: basal diet +12.0 g/head MetaSmart + 5.0 g/head LysiGEM. The results showed a significant downregulation in the expression of the TLR-4 gene in both the macrophages and the neutrophils of ewes fed rumen-protected amino acids. Significantly lower mRNA transcript accumulation was also observed for the TNFa, IL-1β and CXCL-16 genes in the macrophages and for the IL-1β gene in the neutrophils of ewes supplemented with amino acids. The ewes that received dietary supplementation with rumen-protected lysine alone (C) had significantly lower CCL-5 transcript levels in their macrophages than the ewes fed the other supplemented diets. Diet D enhanced the mRNA expression of the IL-2 gene in ewe neutrophils. Negative correlations were found between: a. TLR-4, TNFa, IL-1β and CXCL-16 gene expression in macrophages and the milk fat and total solids content; b. CCL-5 gene expression in neutrophils and the milk yield and FCM ; and c. CXCL-16 gene expression and the milk protein content. Moreover, positive correlations were found between the BHBA concentration and the expression of the TLR-4 and CXCL-16 genes in macrophages. In conclusion, the rumen-protected amino acids improved sheep metabolism (as indicated by reduced blood BHBA and urea concentrations), milk chemical composition and immune system function.

Microalgae might be considered as an alternative source of fat and/or protein for ruminant's diets. However, changes in populations of ruminal micro-organisms associated with biohydrogenation process, methane and ammonia production in response to microalgae dietary supplementation have not been well characterized. Thus, 16 cross-bred goats were divided into two groups. Each goat of both groups was fed individually with alfalfa hay and concentrates separately. The concentrates of the control group had no microalgae while those of the treated group were supplemented with 10 g lyophilized Chlorella vulgaris/kg concentrate (chlor). On the 30th experimental day, samples of rumen fluid were collected for microbial DNA extraction, fatty acid profile and enzyme activity analyses. The results showed that the chlor diet compared with the control increased significantly the populations of Methanosphaera stadtmanae, Methanobrevibacter ruminantium and Methanogens bacteria and protozoa in the rumen of goats. A significant reduction in the cellulase activity and in the abundance of Ruminococcus albus, and a significant increase in the protease activity and in the abundance of Clostridium sticklandii in the rumen liquid of goats fed with the chlor diet, compared with the control, were found. Chlorella vulgaris supplementation promoted the formation of trans C , trans-11 C and monounsaturated fatty acids (MUFA), while the proportions of C and long-chain fatty acids (LCFA) reduced significantly in the rumen liquid of goats. This shift in ruminal biohydrogenation pathway was accompanied by a significant increase in Butyrivibrio fibrisolvens trans C -producing bacteria. In conclusion, the supplementation of diets with microalgae needs further investigation because it enhances the populations of methane-producing bacteria and protozoa.

Fat rich microorganisms, such as microalgae Schizochytrium spp., are potential biotechnological tools in the modulation of rumen microbiome towards ecofriendly and high nutritional value end-products. However, limited in vivo trials have been reported on the topic. The aim of this study was to contribute to the knowledge on the effect of fat rich microalgae on the methanogenic and feed degrading particle-associated microbes in goats’ rumen content. For the trial, twenty-four goats were divided into four homogenous clusters (six goats/treatment) according to their fat corrected (4%) milk yield, body weight and age and individually were fed with alfalfa hay and concentrate feeds (F/C = 50/50). The concentrate of the control group (CON) contained no microalgae, while those of the treated groups were supplemented daily with 20 (ALG20), 40 (ALG40), and 60 (ALG60) g of Schizochytrium spp./goat. The relative abundances of total Archaea, methanogens, Methanomassiliicoccales, Methanobrevibacter spp., Methanosphaera stadmanae and Methanobacterium formicicum were significantly (p < 0.05) decreased in microalgae-fed goats compared to the CON ones. Moreover, a significant decline in the relative abundances of Firmicutes, Ruminococcus flavefaciens, Butyrivibrio fibrosolvents, and Neocallimastigales in the rumen particle-associated microbiota of microalgae supplemented goats were observed. In conclusion, goats’ diets supplementation with Schizochytrium spp., could be considered a sustainable nutritional strategy for methanogens inhibition in their rumen particle-associated microbiota.

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The airway epithelium is the primary site where inhaled and resident microbiota interacts between themselves and the host, potentially playing an important role on allergic asthma development and pathophysiology. With the advent of culture independent molecular techniques and high throughput technologies, the complex composition and diversity of bacterial communities of the airways has been well-documented and the notion of the lungs' sterility definitively rejected. Recent studies indicate that the microbial composition of the asthmatic airways across the spectrum of disease severity, differ significantly compared with healthy individuals. In parallel, a growing body of evidence suggests that bacterial viruses (bacteriophages or simply phages), regulating bacterial populations, are present in almost every niche of the human body and can also interact directly with the eukaryotic cells. The triptych of airway epithelial cells, bacterial symbionts and resident phages should be considered as a functional and interdependent unit with direct implications on the respiratory and overall homeostasis. While the role of epithelial cells in asthma pathophysiology is well-established, the tripartite interactions between epithelial cells, bacteria and phages should be scrutinized, both to better understand asthma as a system disorder and to explore potential interventions.