As weaning exposes piglets to significant nutritional, environmental and social stresses, preparing the gut — the main organ affected by stress — for potential challenges early on is key.
Supplementing sow and piglet diets with yeast has been shown to help manipulate bacteria in the gut at a critical time in offspring development. By encouraging beneficial bacteria to colonise the gut pre-weaning, it ensures piglets are better prepared to manage stresses during that period and prepares them for healthy and productive lives.
As a leading developer of yeast probiotics, Phileo by Lesaffre has been driving research into the role the gut microbiota plays in piglet development and productivity. Here Tadele Kiros, Phileo by Lesaffre’s research and development manager, tells Feedinfo why early steps to manage piglet gut health are so important. Phileo by Lesaffre also refers to a 2018 Scientific Reports article: “Effect of live yeast Saccharomyces cerevisiae (Actisaf Sc 47) supplementation on the performance and hindgut microbiota composition of weanling pigs”, which you can read at the bottom of this interview.
|[Feedinfo] During the first few weeks of life, the gut microbiota of piglets is reported to be unstable and prone to modification. What is Phileo by Lesaffre’s understanding of this “obscure” period?
[Tadele Kiros] In most mammals, including pigs, this period covers the time between the first microbiota colonisation, until the host develops stable, adult-like microbiota.
It’s generally accepted that the uterus of mammals is sterile, and colonisation of newborns starts at birth. However, recent research has suggested that bacteria exist in the amniotic fluid, making it possible that gut microbiota colonisation can start in the foetus before birth. Regardless of the way the first colonisation begins, the newborn is exposed to a variety of microbes from the mother’s amniotic fluid, faeces, vagina, skin, milk and the environment, which try to establish themselves and shape the future of the offspring.
While the microbiota establishes itself — which can take 5-6 weeks in pigs — the immune response of the piglet isn’t well developed, and any bacteria that come into contact with the gut will try to establish itself by displacing other bacterial communities. This can lead to a highly unstable or ‘chaotic’ gut environment.
During this period, the microbiota is highly prone to genetic, environmental and nutritional changes, making it a window of opportunity for microbial modulation using probiotics. It’s important that any modification during this period has a lasting effect on the pig’s health and performance.
[Feedinfo] Can you talk more specifically about the importance of hindgut microbiota?
[Tadele Kiros] Gut microbiota plays a major role in the normal physiological function and health of the host. In terms of metabolic function, host microbiota produce vitamins, amino acids and improve nutrient utilisation. Most importantly, hindgut microbiota in pigs improve fibre fermentation and short chain fatty acids (SCFA) production. SCFA play essential role in pig health and performance, including as energy sources that can cover up to 30% of the maintenance energy in adults.
Gut microbiota also play a major role in protecting the host from pathogens through competition with pathogenic bacteria for nutrient and space, production of antimicrobial peptides and stimulation of both adaptive and innate immunity. Compared to conventional animals, animals with no gut microbiota have less developed immune response both structurally and functionally. In terms of structural function, metabolites produced by gut microbiota, such as SCFA, are also an import source of energy for the growth and development of mucus and epithelial cells in the gut, thereby improving gut health and barrier function.
The gut microbiota needs to be in hemostasis and under stable condition to perform all of these physiological roles. Any disturbance to the gut ecosystem due to antibiotic treatment, host stress, nutritional or environmental factors can upset the equilibrium (dysbiosis), leading to metabolic and health disorders. Probiotics like yeast may decrease dysbiosis by creating more stable and resilient microbiota.
[Feedinfo] Do you see big differences between the various yeast supplementation regimens used in trials?
[Tadele Kiros] Even though the positive effect of yeast in ruminants is well established, we sometimes see discrepancies on the effect of yeast on animal health and performance among different animal trials — especially in monogastric animals which use different yeast supplementations regimens.
This could be because the impact yeast probiotics has on animal health is a result of different factors such as breed, the physiological status of the animal, the strain and formulation of the yeast, and environmental conditions during the trials.
At Phileo, we believe the main effect of yeast probiotics is its ability to improve feed digestibility and nutrient availability for absorption, either directly or indirectly through the modification of the microbiota. Therefore, finding the right feed composition for each age group of pigs is very important to obtain a consistent and positive impact of yeast probiotics on animal health and performance.
[Feedinfo] Live yeast has been proven to be a useful alternative to antibiotic growth promoters in reducing weaning stress and improving performance of piglets. What similar roles to AGPs can live yeast play for piglets?
[Tadele Kiros] To answer this question, it’s important to understand the real mode of action of AGPs. The absence of the growth promoting effect of AGP in germ-free animals, and reduced growth of these germ-free animals upon inoculation with gut microbes, suggests that the mode of action of AGP is directly or indirectly related to their effect on the gut microbiota. Even though AGP are reported to modify gut microbiota by selectively inhibiting growth of pathogenic bacteria as well as improve nutrient absorption, their main role, is their anti-inflammatory effect that inhibits the low-grade inflammation induced by microbiota, and hence divert energy from the immune system to growth.
Reports show that AGP may accumulate inside macrophages and induce the production of anti-inflammatory cytokines to inhibit inflammation and innate immune stimulation, which has been referred to as the “non-antibiotic anti-inflammatory effect of antibiotics.”
Therefore, products can be used as alternatives to antibiotics if they have similar mode of action to AGP.
Several of our own studies on yeast and yeast cell wall products have shown that improved performance is associated with the anti-inflammatory effect of products, including modification of gut microbiota, inhibition of unnecessary inflammation induced by gut microbiota, improving gut health and enhancing nutrient digestibility and absorption.
We have in vitro and in vivo data showing that yeast and yeast cell wall products work on macrophages to inhibit inflammation under steady state condition while training the innate immunity during infection to enhance immune protection against pathogens, a term known as immunomodulation.
[Feedinfo] Why is pre-weaning yeast supplementation the most critical? What is your advice for farmers who consider yeasts for the post-weaning period only?
[Tadele Kiros] As piglet microbiota during pre-weaning is highly unstable and prone to change, this period is the window of opportunity to modulate gut microbiota towards beneficial bacteria. It’s also been shown that microbiota established during this time will have a lasting effect on pig health and performance. During this period, it’s of paramount importance to modify gut microbiota using interventions such as probiotics and prebiotics so that a stable and resilient microbiota will be established.
Our studies have shown that piglet gut microbiota can be modified towards beneficial bacteria by supplementing yeast probiotics to suckling piglets. That’s why we recommend farmers include probiotics in the creep feed whenever possible. However, in areas where creep feeding isn’t common practice, an alternative is to supplement sows with probiotics during gestation and lactation period. This approach is believed to have dual function where it can modify sow gut microbiota, and hence the piglets will get modified gut microbiota directly from the sow through vertical transmission.
In addition to this, supplementing sows with probiotics is believed to be an important source of the probiotics for the newborn as they can get it through sow faeces. Our own study has shown that piglets borne from sows supplemented with yeast probiotics during gestation and lactation were shedding 104 cfu/g faeces of the same yeast in their faeces, suggesting that they were able to get enough dose of probiotics from the sows.
Supplementing piglets with yeast during the post-weaning period only also has benefits, particularly in helping create stable microbiota and improved gut health during the weaning transition. However, our published studies show that starting yeast supplementation in the farrowing room — either by direct supplementation through creep feed or indirectly through the sows — has a better effect in establishing beneficial microbiota with better health and performance of pigs in the post weaning period.
Published in association with Phileo by Lesaffre
T. G. Kiros, H. Derakhshani, E. Pinloche, R. D’Inca, Jason Marshall, E. Auclair, E. Khafipour, & A. Van Kessel
As an alternative to antibiotic growth promoters, live yeast supplementation has proven useful in reducing weaning stress and improving performance parameters of piglets. Here, we compared the performance and hindgut microbiota of weanling piglets subjected to different pre- and post-weaning yeast supplementation regimens using a live strain of Saccharomyces cerevisiae (Actisaf Sc 47). Average feed intake and average daily weight gain of piglets within Yeast-Control and Yeast-Yeast groups were higher than those in the Control-Control group. Yeast supplementation resulted in development of microbial communities that were phylogenetically more homogenous and less dispersed compared to the microbiota of control piglets. Key bacterial taxa overrepresented in the microbiota of yeast supplemented piglets included phylum Actinobacteria, specifically family Coriobacteriaceae, as well as Firmicutes families Ruminococcaceae, Clostridiaceae, Peptostreptococcaceae, and Peptococcaceae. Correlation network analysis revealed that yeast supplementation was associated with enrichment of positive correlations among proportions of different bacterial genera within the hindgut ecosystem. In particular, within the cecal microbiota of supplemented piglets, higher numbers of positive correlations were observed among potentially beneficial genera of the phyla Actinobacteria and Firmicutes, suggesting a mechanism by which yeast supplementation may contribute to regulation of intestinal homeostasis and improved performance of piglets.
SCientiFiC REPOrts | (2018) 8:5315 | DOI:10.1038/s41598-018-23373-8