This invention provides novel methods and compositions for modulating and
stimulating the immune system of animals to withstand microbial
infections and the lethality of endotoxic shock by feeding or injecting
bacteria-free oligoribonucleotides (ORNs) released by either harmless or
pathogenic bacteria. The invention also describes the molecular mode of
action of the health benefits derived from consuming fermented dairy
products and probiotic bacteria.