When piglets are weaned from milk to solid food, their intestinal flora change, with a steep rise in the numbers of potentially harmful streptococci.
This finding has come out of research done by Odette Pérez Gutiérrez, who developed a micro-array called the PIT (pig intestinal tract) chip with which she can quickly scan six hundred different types of bacteria on a glass slide in the lab. The chip makes it possible to analyse the composition of the bacteria over time, from three days before weaning until fifteen days after it. Pérez Gutiérrez saw significant changes, with a big decrease in healthy Lactobacillus bacteria in favour of the potentially unhealthy streptococci.
The research is part of the EU project Feed for Pig Health, in which researchers are looking for alternatives to antibiotic use in pig farming. Recently weaned piglets frequently fall sick and are given preventive doses of antibiotics in their feed. This is no longer allowed, however. For this reason, research is now going on into feed additives such as organic acids and oils which have a beneficial effect on the balance of the gut flora. The research shows that certain lactobacillus species stimulate the immune system and with it the piglets' resistance to disease.
Researchers can use the PIT chip developed by Pérez Gutiérrez to assess the impact of feed additives on the gut flora. There are forty to fifty candidates, including garlic oil and an oregano extract, explains her colleague Wilbert Pellikaan of the Animal Nutrition chair group. The impact of these additives is now being screened with the chip and Pellikaan then wants to test them on animals. 'We test the end products of the bacteria, while Microbiology checks what the gut bacteria are doing in the gut and how you can influence the numbers of bacteria.'
Pérez Gutiérrez was awarded her PhD last week by microbiologists Willem de Vos and Hauke Smidt, and professor of Animal Nutrition Martin Verstegen.