Review: Are there indigenous Saccharomyces in the digestive tract of livestock animal species? Implications for health, nutrition and productivity traits

Abstract

All livestock animal species harbour complex microbial communities throughout their digestive tract that support vital biochemical processes, thus sustaining health and productivity. In part as a consequence of the strong and ancient alliance between the host and its associated microbes, the gut microbiota is also closely related to productivity traits such as feed efficiency. This phenomenon can help researchers and producers develop new and more effective microbiome-based interventions using probiotics, also known as direct-fed microbials (DFMs), in Animal Science. Here, we focus on one type of such beneficial microorganisms, the yeast Saccharomyces. Saccharomyces is one of the most widely used microorganisms as a DFM in livestock operations. Numerous studies have investigated the effects of dietary supplementation with different species, strains and doses of Saccharomyces (mostly Saccharomyces cerevisiae) on gut microbial ecology, health, nutrition and productivity traits of several livestock species. However, the possible existence of Saccharomyces which are indigenous to the animals’ digestive tract has received little attention and has never been the subject of a review. We for the first time provide a comprehensive review, with the objective of shedding light into the possible existence of indigenous Saccharomyces of the digestive tract of livestock. Saccharomyces cerevisiae is a nomadic yeast able to survive in a broad range of environments including soil, grass and silages. Therefore, it is very likely that cattle and other animals have been in direct contact with this and other types of Saccharomyces throughout their entire existence. However, to date, the majority of animal scientists seem to agree that the presence of Saccharomyces in any section of the gut only reflects dietary contamination; in other words, these are foreign organisms that are only transiently present in the gut. Importantly, this belief (i.e. that Saccharomyces come solely from the diet) is often not well grounded and does not necessarily hold for all the many other groups of microbes in the gut. In addition to summarizing the current body of literature involving Saccharomyces in the digestive tract, we discuss whether the beneficial effects associated with the consumption of Saccharomyces may be related to its foreign origin, though this concept may not necessarily satisfy the theories that have been proposed to explain probiotic efficacy in vivo. This novel review may prove useful for biomedical scientists and others wishing to improve health and productivity using Saccharomyces and other beneficial microorganisms.

Colonic Mucosa-associated Mycobiota in Individuals With Normal Colons

“…Saccharomyces cerevisiae was not detected in our samples. Because Saccharomyces is a yeast that is most abundant in foods, our observation supported the notion that foodborne Saccharomyces cerevisiae is likely not a mucosa-associated fungus and is only transiently present in the human GI tract [47]. A Saccharomyces-free diet has been shown to eliminate its presence in the stool [15].…”

Understanding the Mechanism of Action of Indigenous Target Probiotic Yeast: Linking the Manipulation of Gut Microbiota and Performance in Animals

“…The main target of the PY used in new born ruminate diet are; (a) improvement in the rumen maturation; (b) stop the pathogenic bacterial growth; (c) establishment of the normal growing animals like microbial flora [26][27][28]. Microbial based feed can improve the rumen development during the growing phase of the dairy animals.…”

The Influence of β-1,3-1,6-Glucans on Rabies Vaccination Titers in Cats

“…Though both species are carnivores, capable of eating meat and plants, the narrow food requirements of cats as obligate carnivores require more precision in the formulation of its diets, relative to the more omnivorous dogs [ 27 ]. It was postulated that Saccharomyces is not an indigenous organism in any species’ intestinal microbiota, but rather, is found only after nutritional consumption [ 28 ]. Saccharomyces species are, however, found in large quantities in the intestinal microbiome of cats, and this may be an indication as to why the β-1,3-1,6-glucans, derived from the yeast cell wall of Saccharomyces cerevisiae , have had a different effect compared to what is seen in other animal species.…”