Stomach ulcers are common in pigs, like they are in humans. Until recently, the cause of this disease was unclear. The results from this thesis show that two bacteria play a role. One of these bacteria was previously unknown and was discovered during this thesis. This paves the way for development of new methods to control the disease.
Stomach ulcers are a common problem in pigs worldwide. They cause pain, a weight loss and sometimes even sudden death. It is clear that these ulcers affect the welfare of the animal. Diet, stress and illness all may contribute to the development of stomach ulcers, but the exact cause of the disease is not yet clear. Moreover, no treatment exists that fully protects pigs against the development of stomach ulcers.
Helicobacter suis is a bacterium that is frequently found in the stomach of pigs. Humans can also be infected with this microbe. An infection with Helicobacter suis results in several problems, including stomach ulcers. Until recently, it was not clear how this bacterium induces lesion development. The results from this thesis show that Helicobacter suis affects gastric acid secretion. The effect depends on the age of the pigs. For example, in six-month old pigs, acid secretion was inhibited. This decrease in acid secretion paves the way for a new bacterium, that was discovered during this doctoral research, namely Fusobacterium gastrosuis. This bacterium may kill cells of the stomach wall. In adult pigs, the acid secretion again is increased, but at that point, it may make the already existing damage more severe.
The results of this thesis show that the concerted action of two bacteria, Helicobacter suis and Fusobacterium gastrosuis, play a role in the development of stomach ulcers in pigs. One of these bacteria, Helicobacter suis, can also cause stomach problems in people. Further studies on both bacteria are necessary, in order to develop new control measures for this disease.