Probiotics is already a very popular technology especially nowadays when we are looking for alternatives to antibiotics to manage gut flora balance. Still, we have

to learn more on the way probiotics are acting in order to optimize their use and maximize their positive impact on livestock and aquaculture production. There are a lot of different probiotics available on the market and it is often believed that bacterias that hold the same name should claim the same benefits. It is actually important to understand that there is a lot of variability between bacteria, even inside the same family.

Vietnamese Version

When there are only 3% of DNA differences between a man and a gorilla, there are actually 30% of differences between 2 different sub-strains of Bacillus Subtilis. To really identify a bacterial type, it is necessary to define the sub-strain. If I make a comparison between bacteria classification and mammals, the bacillus group would be equivalent to Suis Group, bacillus subtilis would be equivalent to Suis Domesticus and each sub-strain would then be equivalent to a Swine breed as Danbreed, Landrace or Large White.

As we would select carefully your Swine breed depending on the benefits we are looking for, it is important to select the proper sub-strain of bacteria depending on your feed strategy. There are 6 main elements to take into consideration when selecting a probiotic sub-strain.

1 – PRODUCTION OF ENZYMES Over years of evolution, bacterias adapted themselves to their environment to survive. To do so, some bacterias acquired the capacities to produce several sort of enzymes, to digest protein, energy, lipids and even fibers. This capacity is very valuable in feed production as it equips the animal with the ability to value better the energy portion from the diet. Some suppliers are even able to provide you a matrix to value in your formulation software the amount of digestible energy gained from the addition of probiotics. 2 – E-COLI ANTI-ADHESIVE EFFECT Some bacteria have the ability to prevent the development of E-Coli by inhibiting their adhesion to gut cells. Such properties have been demonstrated in-vitro in cell culture.


Bacterias are exchanging information between each other to avoid growing in the same area. When a strain is alone in its environment, it will grow without limitations. When a strain is sharing the space with another strain, they will inhibit each other and avoid growing in the direction of each other. We call that the exclusive growth inhibition. But some bacteria developed a strong inhibition capacity than other against a wider range of competitors. When adding in the environment such bacteria will conquer a larger space and most importantly avoid that another bacteria take too much space. Such ability helps to regulate gut flora.

4 – SUB-STRAIN PURITY Like for Swine or Poultry genetic, the difficulty in

selection, is to obtain pure breed. Particularly in the case of bacteria selection as contamination is frequent, coming from everywhere. It is critical when we are purchasing a probiotic, we get sure that it is exactly what is on the label, not less and mostly not more. If it is out of control, it could be damageable for the gut balance.

5 – SUB-STRAIN THERMOSTABILITY In feed manufacturing, thermo stability is an important constraint when we want to mix probiotics in the feed, either to resist pelleting for Swine, Poultry and Shrimp feed or extrusion for Fish. Live bacteria will not survive through these processes and such probiotics (lactobacillus and enterococcus) will have to be sprayed on the pellets after pelleting or extrusion. Only Bacillus family have the ability to hibernate as spores to resist such temperature. Once in the gut, they will then germinate to act as live organism. To confirm probiotics thermo-stability, it needs to grow.

6 – ANTIBIOTIC SURVIVAL The effect of probiotics is under the threat of antibiotics as any other bacteria. The use of antibiotic in the feed will annihilate their action. Only the probiotics that are under the forms of spores will survive the presence of antibiotic. Only some sub-strain of Bacillus probiotics will get their spores to germinate at different moment in the gut to repopulate the gut every time that the presence of antibiotic will disrupt the flora. It is an endless cycle between the antibacterial effect of feed antibiotic and the germination of new spores. Like for Swine and Poultry genetics, probiotics suppliers spend years and a lot of money to select, multiply and cross-breed bacteria with the best combination of claims. Bacteria probiotics are becoming an important tool for feed manufacturer to optimize feed performance both in Swine, Poultry, Shrimp and Fish and I expect such interest to grow tremendously in the coming years. It is important for nutritionists and purchasers to be educated on the questions to ask probiotics suppliers to select the best options.