Background It has been recognized that a number of mechanisms mediating the health benefits of beneficial bacterial cells do require viability. However, new terms such as paraprobiotic or postbiotic have emerged to denote that non-viable microbial cells, microbial fractions, or cell lysates might also offer physiological benefits to the host by providing additional bioactivity. Scope and approach This review provides an overview of the postbiotic concept, evidence of their health benefits and possible signaling pathways involved in their protective effects, as well as perspectives for applications in foods and pharmaceuticals. Key findings and conclusions Postbiotics refers to soluble factors (products or metabolic byproducts), secreted by live bacteria, or released after bacterial lysis, such as enzymes, peptides, teichoic acids, peptidoglycan-derived muropeptides, polysaccharides, cell surface proteins, and organic acids. These postbiotics have drawn attention because of their clear chemical structure, safety dose parameters, long shelf life and the content of various signaling molecules which may have anti-inflammatory, immunomodulatory, anti-obesogenic, antihypertensive, hypocholesterolemic, anti-proliferative, and antioxidant activities. These properties suggest that postbiotics may contribute, to the improvement of host health by improving specific physiological functions, even though the exact mechanisms have not been entirely elucidated.

Postbiotics: An evolving term within the functional foods field

Livestock and aquaculture production is under political and social pressure, especially in the European Union (EU), to decrease pollution and environmental damage arising due to animal agriculture. The EU has banned the use of antibiotics and other chemicals, which have been shown to be effective in promoting growth and reducing environment pollutants because of the risk caused to humans by chemical residues in food and by antibiotic resistance being passed on to human pathogens. As a result of this, scientists have intensified efforts in exploiting plants, plant extracts or natural plant compounds as potential natural alternatives for enhancing the livestock productivity. This paper discusses work on the effects of various phytochemicals and plant secondary metabolites in ruminant and fish species. The focus is on (i) plants such as Ananas comosus (pine apple), Momordica charantia (bitter gourd) and Azadirachta indica (neem) containing anthelmintic compounds and for their use for controlling internal parasites; (ii) plants containing polyphenols and their applications for protecting proteins from degradation in the rumen, increasing efficiency of microbial protein synthesis in rumen and decreasing methane emission; for using as antioxidants, antibacterial and antihelmintic agents; and for changing meat colour and for increasing n-3 fatty acids and conjugated linoleic acid in meat; (iii) saponin-rich plants such as quillaja, yucca and Sapindus saponaria for increasing the efficiency of rumen fermentation, decreasing methane emission and enhancing growth; for producing desired nutritional attributes such as lowering of cholesterol in monogastric animals; for increasing growth of fish (common carp and Nile tilapia) and for changing male to female ratio in tilapia; and for use as molluscicidal agents; (iv) Moringa oleifera leaves as a source of plant growth factor(s), antioxidants, beta-carotene, vitamin C, and various glucosinolates and their degraded products for possible use as antibacterial, antioxidant, anticarcinogenic and antipest agents; (v) Jatropha curcas toxic variety with high levels of various phytochemicals such as trypsin inhibitor, lectin, phytate and phorbol esters in seeds limiting the use of seed meal in fish and livestock diets; and the use of phorbol esters as bio-pesticidal agent; and (vi) lesser-known legumes such as Entada phaseoloides seeds containing high levels of trypsin inhibitor and saponins, Sesbania aculeate seeds rich in non-starch polysaccharides and Mucuna pruriens var. utilis seeds rich in l-3,4-dihydroxyphenylalanine and their potential as fish feed; Cassia fistula seeds as a source of antioxidants; and the use of Canavalia ensiformis, C. gladiata and C. virosa seeds containing high levels of trypsin inhinitor, lectins and canavanine. The paper also presents some challenges and future areas of work in this field.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/6AAFA15BAA469CAAFCEDAF37EF825F18/S1751731107000298a.pdf/div-class-title-bioactivity-of-phytochemicals-in-some-lesser-known-plants-and-their-effects-and-potential-applications-in-livestock-and-aquaculture-production-systems-div.pdf

Bioactivity of phytochemicals in some lesser-known plants and their effects and potential applications in livestock and aquaculture production systems.

Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. Most of the probiotic bacteria currently available in the market belong to the genera Lactobacillus and Bifidobacterium, and specific health-promoting activities, such as treatment of diarrhea or amelioration of gastrointestinal discomfort, have been attributed to them. In order to be able to survive the gastrointestinal transit and transiently colonize our gut, these bacteria must be able to counteract the deleterious action of bile salts, which are the main components of bile. Bile salts are detergent-like biological substances synthesized in the liver from cholesterol. Host enzymes conjugate the newly synthesized free bile acids in the liver with the amino acids glycine or taurine, generating conjugated bile salts. These compounds are stored in the gall bladder and they are released into the duodenum during digestion to perform their physiological function, which is the solubilization of fat coming from diet. These bile salts possess strong antimicrobial activity, since they are able to disorganize the structure of the cell membrane, as well as trigger DNA damage. This means that bacteria inhabiting our intestinal tract must have intrinsic resistance mechanisms to cope with bile salts. To do that, Lactobacillus and Bifidobacterium display a variety of proteins devoted to the efflux of bile salts or protons, to modify sugar metabolism or to prevent protein misfolding. In this manuscript, we review and discuss specific bile resistance mechanisms, as well as the processes responsible for the adaptation of bifidobacteria and lactobacilli to bile.

https://digital.csic.es/bitstream/10261/153135/1/Bile_resistance_mechanisms_Lactobacillus.pdf

Bile resistance mechanisms in Lactobacillus and Bifidobacterium

ICE, the electric field experiment on DEMETER

The review highlights the specific features of the Jatropha curcas plant and its potential for the production of biofuel, protein concentrates as livestock feed and value-added products that could enhance the economic viability of Jatropha seed oil-based biodiesel production. The roles of the plant in carbon capture, enhancing socio-economic conditions, food production in the tropical regions, and influencing microclimate, vegetation and soil quality are discussed. The paper also gives a comparative account of the toxic and non-toxic genotypes of J. curcas from the point of view of their physical and chemical properties and their potential for biodiesel and livestock feed production. Future areas of research are also presented.

Jatropha curcas, a promising crop for the generation of biodiesel and value-added coproducts

RNA interference (RNAi) is a naturally evolved and a conserved self-defensive mechanism triggered by double-stranded RNA (dsRNA) that limits transcript levels either by suppressing transcription or activating sequence-specific degradation of RNA. RNAi protects the host from endogenous and exogenous invading nucleic acids by regulating gene expression. RNAi is used as a promising tool in functional genomics and targeting microbial infections.

RNA Interference: A Veterinary Health Perspective

Transcriptomics or genome-wide expression analysis has always played a central role in the field of functional genomics. Simultaneous quantification of thousands of genes at genome-wide scale has revolutionized the research in livestock. It has helped in unraveling the complexity of gene regulation and providing insights into gene networks and molecular pathways relevant to functional traits. 


Highlights

Birbal Singh

Papers

RNA Interference: A Veterinary Health Perspective

Transcriptomics: Genome-Wide Expression Analysis in Livestock Research