Antibiotics: Mainly used for gastro-intestinal issues

Dr. Maarten De Gussem is the MD of Vetworks, an independent global consultancy agency to the animal production and veterinary pharmaceutical industries, based in Belgium. According to De Gussem, about 70-80% of the therapeutic antibiotics are currently used for enteric disorders. However antibiotics can also disrupt the microbiota in the gastro-intestinal tract so they do not always have a positive impact.

Various phases of acceptance

De Gussem has a global experience in managing poultry health and in dealing with the antibiotic issue in many different countries. He has found that there are various phases in acceptance and use of antibiotics. Initially people may deny there is a problem and then move onto acceptance and implementation of a programme. “In North West Europe a lot of farmers are trying to increase profits with an antibiotic reduction plan. They all realize though, that it is not easy and for a while it will be a big investment to have everything in the whole system working better. There are more and more people who believe that you do not need to use antibiotics to have an optimal performance. Of course there will always be a group of people who believe that the use of antibiotics can do something extra to performance”, says De Gussem.

Dr. Maarten De Gussem, the MD of Vetworks: “There are more and more people who believe that you do not need to use antibiotics to have an optimal performance.”

Gastro-intestinal health issues

An important factor in the reduction of antibiotics is to control gastro-intestinal health issues as these accounts for 70-80% of antibiotic use. De Gussem: “Fortunately today we have more knowledge and tools available to efficiently control enteric health issues than ever before”. He further explains that frequently in enteric health problems Clostridium species are involved. This is related to disruption of normal gastro-intestinal tract function by various triggers which could be mycotoxins, viruses or Clostridial species. The damage to the gastro-intestinal tract impacts upon the immune system and that causes the tight junctions in the cells of the gastro-intestinal tract to open more.

The opened tight junctions can cause a release of plasma proteins into the lumen of the gastro-intestinal tract and these plasma proteins are an excellent source of nutrients for Clostridial bacteria. There is also increased mucus production in gastro-intestinal tract and again mucus is a very good source of nutrients for bacteria. A third effect is that damage to the gastro-intestinal tract reduces its functionality. This means that more unabsorbed nutrients remain in the gastro-intestinal tract and these, especially proteins, are a very good source for growth of Clostridial species. The net effect is that enteric damage gives an advantage to Clostridial species of bacteria and they will compete with the so called good bacteria such as Lactobacilli. In reality it is far more complicated than this because the bacteria are communicating with each other and they can also communicate with the gastro-intestinal tract. The whole area of microflora and their interactions in the gastro-intestinal tract is a rapidly developing research area.

Antibiotics can be sledgehammer

De Gussem emphasized that use of antibiotics will always bring some collateral damage, particularly as we still do not understand well enough the interactions between the different bacteria. Sometimes the use of antibiotics can be like using a sledgehammer to crack a nut. “Therefore we need to use less drastic tools in terms of modulating the Clostridial overgrowth which will certainly lead to better, longer lasting solutions. Frequently if a therapeutic treatment is stopped there is a relapse of the problem. That means that the core problem has not been solved, only covered up”, he addresses. To conclude Dr. De Gussem indicated that various products such as probiotics could be useful in managing enteric disorders in poultry.