Jules Tournut Award 2014: probiotics to play a role in sustainable animal production

On November 12th 2014, at EUROTIER in Hanover, Germany, the European Probiotic Association (EPA) awarded the Jules Tournut Probiotics Prize 2014 to Dr Steven Frese, for his innovative research project on the evolution of the host-microflora interaction. At this occasion, industry members and Scientific Committee of the EPA, FEFANA, and journalists discussed the potential of probiotics for sustainable animal production, with benefits beyond zootechnical performance, in animal health and welfare.

Dr Gérard Bertin, Secretary General of EPA, and Professor Joaquim Brufau, member of the association’s Scientific Committee gave an overview of the applications received for the Jules Tournut Probiotic Award, offering a peek at the scope and diversity of probiotic research going on around the world, as applications came from ten different countries across the five continents. Research projects concerned major animal species (swine, beef and dairy cattle, aquaculture, poultry…). Interestingly, the end-points of the studies presented addressed a vast array of potential benefits for probiotics, with a shift from performance enhancement (ADG, FCR, etc.) towards health and welfare issues: immuno-modulation, heat stress, animal behaviour (stress reduction), quality of food products, reduction of pathogens carriage…

As explained by Professor Brufau, this is in line with the bigger picture of probiotic research. He showed how probiotic research grows especially in the areas of immunity, mucosa integrity, gastrointestinal tract functionality, health status, while performance enhancement is still addressed by scientists, with a better understanding of mechanisms of action.

We know that the digestive microflora plays a key role in nutrition, but also in health and overall well-being. It is a rich and complex ecosystem which is increasingly recognised as an organ in itself. But how did evolution shaped the symbiotic relationship between bacteria and animal?

 Dr Frese’s winning project, conducted at the University of Nebraska, Lincoln (USA), and titled: “The evaluation of the specificity in the vertebrate gut symbiont Lactobacillus reuteri”, tried to address this issue, looking at the mechanisms by which the host-microflora relationships are established and maintained. His work was praised for its high scientific value.

Lactobacillus reuteri is a digestive commensal bacteria which was used as a model of microflora-host relationships in this project. First of all, it was shown that L. reuteri were host specific (only L. reuteri strains isolated from rodent were able to colonize rodent gut). Looking at the molecular basis undelaying this host specificity, the young researcher found out that L. reuteri strains isolated from different animal species expressed host-specific genes, some of which were responsible for microbe attachment to the host gut surface. This was the first time that host-specificity of a vertebrate gut symbiont and associated genomics features were demonstrated (1). These findings were then harnessed to screen probiotic strains with optimal persistence and colonization features in human. S. Frese also showed how different strains from the same species exhibited different probiotic features; for example the potential to produce antimicrobial compound reuterin varies greatly between strains. All these characteristics should be taken into account when searching for novel probiotics: host origin, as well as biological activities and features.

This fundamental research work illustrates the importance of strain specificity, and could help select tailored probiotic strains able to colonize and persist in the host gut with desired outcomes (antimicrobial, anti-inflammatory…): the next generation of probiotics.

In his introduction, Professor Brufau had questioned how probiotics could help answer some of the major issues of sustainable animal production: animal welfare, reduction of antibiotic usage... By discussing the perspectives and practical implications of S. Frese project, Dr Eric Auclair, Treasurer of EPA, brought some answers in his wrap up of the meeting: anti-inflammatory property of L. reuteri could improve resistance to disease, strains producing high level of reuterin (antimicrobial) could also help reducing antibiotics usage, both leading to better animal welfare.

Combined with adapted economical approach, this can participate in a sustainable approach of animal nutrition and health. Altogether, the experts present agreed that probiotics can help address the three pillars of sustainability, with great scope for discoveries and innovation:

-   Societal concern (animal welfare, food quality, antibiotic reduction)

-   Economic (profitability)

-   Environment (carbon footprint, methane emissions)

Based on such potential for probiotics, it seems that their definition should be updated. As exposed by Laurent Dussert, President of EPA, the definition of probiotics has evolved over time, shaped by regulation: “In 1989, Roy Fuller defined probiotics for animal production as ‘live microbial feed supplement which beneficially affects the host animal by improving its intestinal microbial balance’. Today, in Europe, registered probiotics are classified as zootechnical feed additives: well identified and safe strains officially recognized for their beneficial functions of either gut flora stabilizer or digestibility enhancer. And tomorrow? Shouldn’t this definition be revised in the light of new functions described, beyond performance? Scientists, industrials and the regulatory authorities should come together to agree on a functional definition which encompasses the diversity of probiotics benefits on animal health and welfare.”

1)    Frese SA et al.  The evolution of host specialization in the vertebrate gut symbiont Lactobacillus reuteri. PLoS Genetics. 7(2): e1001314 (2011).