Microbiology of the Digestive Tract

3. Microbiology of the Digestive Tract

Microbial colonization of the gastrointestinal tract starts directly after birth, and the composition of the intestinal microflora approaches the spectrum of adult cats during the first weeks of life (Osbaldiston & Stowe, 1971). The development of the microflora in kittens is comparable to other species: Clostridium perfringens, Escherichia coli and Streptococci are among the first organisms to colonize the alimentary tract of kittens. The gut flora of cats is characterized by relatively high numbers of Clostridium perfringens and lecithinase negative clostridia, probably reflecting the carnivorous type of diet. Normally, the intestinal microflora maintains a self stabilizing symbiotic balance with the host organism (Strombeck, 1996a). The bacterial concentration in all parts of the gastrointestinal tract of healthy cats is high and bacterial densities of 1012/g feces, mainly anerobic bacteria, are normal.

The intestinal microflora may contribute to the health and well-being of the host, supporting the digestive process, but it may also be a significant factor in the pathogenesis of intestinal diseases. Its composition and metabolic activity is subjected to influences by the individual and interfering diseases. Diet composition, protein quantity and quality, feed processing (Backus et al., 1994), dietary fiber and digestible carbohydrates (Fahey, 2003) and feed additives such as probiotics (Rastall, 2004; Marshall Jones et al., 2006) also affect the composition of the microbiota.