Great gut health enables successful antibiotic reduction

Poultry producers deserve practical solutions to successfully transition from preventative antibiotic use while maintaining poultry performance and boosting return on investment. Superior quality yeast postbiotic is well known to bolster bird gut health and reduce pathogen pressure, thus facilitating progress into the post-antibiotic era.

Alain Riggi
Global Species Manager – Poultry
Phileo by Lesaffre
Elen Rondel
Poultry Manager – Western Europe
Phileo by Lesaffre
Lin Wang
Global Program Manager – Poultry
Phileo by Lesaffre

Effectively reducing antibiotics requires a holistic approach, from optimised farm management and biosecurity measures to minimise pathogen penetration, to stimulating poultry immune systems bolstered by comprehensive complete vaccination strategies to improve infection resistance, to high-quality nutritional approaches for healthy growth, to enhancing gut health for improved pathogen resistance and feed efficiency.

Hippocrates—the father of modern medicine—proclaimed that “All disease begins in the gut”. Not surprisingly then, promoting robust gut health is an essential first step for poultry producers to successfully phase out antibiotic use and succeed in transitioning to a post-antibiotic era.

Improving poultry gut health and production performance without relying on antibiotics requires the following core elements:
• Protecting epithelial cells by increasing goblet cell number and modulating mucus secretion
• Avoiding leaky gut by strengthening tight junctions
• Decreasing disease outbreaks by reducing pathogen pressure in the gut

To help poultry producers address each of these specific areas, Phileo by Lesaffre has developed a premium-quality yeast postbiotic, Safmannan, (here after called “the reference postbiotic” characterised by consistently high mannan and (1,3-1,6) beta-glucan levels. It improves poultry health and yield by optimising intestinal microbiota, reducing pathogen pressure, supporting gut function, and boosting natural defences. Multiple real-world trials have demonstrated that the reference postbiotic is able to improve both poultry growth and feed conversion ratios (FCR) to the same extent as antimicrobial growth promoters, and under a variety of conditions such as heat stress or challenge with the ubiquitous Clostridium perfringens pathogen.

Figure 1. At the completion of the 44-day trial, the feed conversion ratio (FCR) was significantly improved in Ross 308 birds supplemented with the reference postbiotic (p < 0.01), adapted from Pascual et al. (2020).

Yeast postbiotic supplements added to poultry feed can reduce pathogenic bacterial load, prevent diseases caused by pro-inflammatory responses, and modulate gut microbiota composition. Recent evidence further supports the positive effect of nutritional supplementation, where in a 2020 trial, Pascual et al. found that adding the reference postbiotic to broiler diets improved gut health and immune status, as well as promoted differences in gut gene expression in 576 Ross 308 male chickens1. Half of the birds were fed a standardised corn soya control diet, and the remaining birds were supplemented with 250, 500, and 250 g/t the reference postbiotic at 1-14, 15-28, and 29-44 days, respectively. Significantly improved feed conversion ratio was observed in the reference postbiotic group, compared to the control group (p < 0.01, Figure 1). At 21 and 42 days, the jejunum portion of the gut was stained and analysed to investigate the gut health status of 12 chickens from each feed group. The number and density of mucin-producing goblet cells significantly increased (p<0.001, Figure 2), which would aid gut pathogen resistance. In addition, the density of gut immune cells (CD45+ and CD3+ intraepithelial leukocytes) was reduced in nutritionally supplemented birds (p < 0.001 and p = 0.08, respectively, Table 1), demonstrating a reduction the inflammatory status of the gut. Gut gene expression analysis was performed at 42 days and demonstrated differences between the two groups. A gene set related to viral infection responses was upregulated in the control group, and a gene set implicated in nutrient absorption was increased in the the reference postbiotic group.

Figure 2. The density of goblet cells was significantly (P ≤ 0.001) higher (47.0 vs. 21.7 cells/500 μm) and the area of the same cells lower (14.4 vs. 39.2 μm2) in chickens fed diet supplemented with the reference postbiotic (b) compared to chickens fed control diet (a). Bar = 50 μm. adapted from Pascual et al. (2020).


The tight junction is one of the first gastrointestinal gut constituents to be damaged by inflammatory processes. The loss of tight junction proteins degrades the integrity of the epithelial cell wall. Too much liquid can enter the lumen and pathogens now translocate across this barrier, resulting in a leaky gut which is highly harmful to animal health. A recent trial conducted in Japan demonstrated that supplementing bird diets with the reference postbiotic reinforced tight junctions and prevented leaky gut. Birds were challenged with an acute heat stress throughout the 21-day trial. Compared to the control group, birds in the reference postbiotic group had significantly increased quantities of two key tight junction proteins, ZO-1 and Claudin 5 (p<0.05, Figure 3). Strengthening the tight junctions resulted in birds with robust gut integrity, enabling them to avoid pathogen translocation and a leaky gut.

Figure 3. Following a 21-day trial, birds exposed to heat stress and supplemented with the reference postbiotic had significantly higher levels of ZO-1 and Claudin 5 (p<0.05), two key tight junction proteins, when compared to the unsupplemented control diet.


A trial conducted in the US in 2017 demonstrated how the reference postbiotic can provide superior protection to a Clostridium challenge when compared to a standard antibiotic growth promoter2. Birds were fed either a control diet, or the control diet supplemented with either 10% bacitracin methylene disalicylate (BMD) at 500 g/t of feed or 250 g/t the reference postbiotic. Birds received a daily gavage of 109 CFU Clostridium perfringens (C. perfringens) from days 16 to 18. The feed was prepared with no enzyme and 8 to 12% DDGS, to enhance the impact of Clostridium challenge. Outcome measures up to 42 days included mortality, FCR, and bodyweight. At the completion of the trial, FCR increased to 2.1 in the Clostridium-challenged group on a control diet, but remained at 1.91 for both Clostridium-challenged groups supplemented with either BMD or the reference postbiotic (p<0.01). Bodyweight at 42 days in the BMD- and the reference postbiotic groups challenged with Clostridium was similar to the unchallenged control group (1.89 and 1.90 kg versus 1.92 kg in controls, respectively, p<0.01). The postbiotic therefore reduces the negative effects of a C. perfringens challenge and helps birds maintain similar levels of performance to unchallenged control birds. Importantly, compared to the control diet C. perfringens-challenged group, the reference postbiotic supplementation also reduced mortality to the same level as the antibiotic treatment group (p<0.01).

Nutritional yeast postbiotic supplements can vary widely in their effectiveness due to various mannan and beta-glucan fractions influenced by their fermentation conditions and cultivation methods. The reference postbiotic is carefully produced and controlled to contain the consistent ideal ratios of mannans and beta-glucans to promote great gut health.

Furthermore, multiple R&D studies and field trials have consistently demonstrated that the reference postbiotic improves broiler growth performance, that it modulates gut mucosal secretion improving infection resistance, and strengthens tight junctions to avoid leaky gut and pathogen translocation. Together with the changes observed in gut gene expression, these outcomes are vital to improving poultry welfare and health under the challenging conditions of intensive rearing without antibiotics.

Moreover, this advanced yeast postbiotic improves poultry FCR and bodyweight and significantly reduces mortality rates in birds subject to a Clostridium challenge, eliminating the need to rely on antibiotics. Adding the reference postbiotic to a holistic approach towards antibiotic reduction will enable poultry producers to confidently transition away from antibiotics while maintaining excellent returns.

1Pascual, A., et al., 2020. Effect of dietary supplementation with yeast cell wall extracts on performance and gut response in broiler chickens. J Anim Sci Biotechnol 11, 40.
2Sims, D.M., et al., USA, 2017. Perfomance of Broilers Fed Diets with BMD or Safmannan® in the Presence of a Moderate Clostridium perfringens Challenge in a 42-Day Floor Pen Trial. Internal Report.

About Dr. Alain Riggi
Dr Alain Riggi has rich field working experiences as Chief Veterinarian with different poultry production companies before joining MSD animal health in 2010 where he held different positions including Poultry Technical Director for Europe and North & West Africa. Currently, Dr Riggi is Global species manager – Poultry at Phileo by Lesaffre. As poultry veterinarian, one of Dr Riggi’s core missions at Phileo by Lesaffre is to help large poultry producers in the world (US, China, EU, Brazil, Thailand, etc.) to identify the issues in their farms and provide solutions.

About Elen Rondel
Graduated from AgroParisTech, French National Institute of Technology for Life, food and environmental sciences, in 2009, Ms Rondel started working in feed formulation in all species, for a French premix company. In 2014, Ms Rondel joined Biomin as poultry sales manager for France, before working for Elanco as poultry nutrition technical support. Since 2018, Ms Rondel joined Phileo by Lesaffre as poultry manager for Europe-Russia, and then Western Europe.

About Lin Wang
With more than 10 years working experiences in animal nutrition and health including 7 years specializing in poultry sector, Mrs Wang is passionate about quality protein to better feed the global population and contributes, via her missions at Phileo by Lesaffre, to develop sustainable animal production for both producer and animal welfare.