Effect of fructo-oligosaccharides and transgalacto-oligosaccharides on microbial populations and microbial activity in the gastrointestinal tract of piglets post-weaning

An in vivo experiment was conducted with newly weaned piglets to study the effect of fructo-oligosaccharides (FOS) and transgalacto-oligosaccharides (TOS) on microbial populations and activity in the gastrointestinal tract. Thirty 28-day-old piglets were fed a semi-synthetic control diet or the control diet supplemented with 40 g FOS or TOS per kg (n = 10). After 4 weeks, the piglets were slaughtered and the gastrointestinal contents were removed for analysis. s demonstrated that the number of yeast was significantly increased in the distal small intestine, caecum and colon of piglets fed the FOS diet (P < 0.05) and throughout the gastrointestinal tract of piglets fed the TOS diet (P < 0.01). Bifidobacteria were isolated from 24 out of 27 piglets investigated. The density of bifidobacteria was not significantly affected by the experimental diets. Bifidobacteria were identified as Bifidobacterium boum (0.71), B. suis (0.15), B. pseudolongum (0.10) and B. choerinum (0.03) based on 16S rRNA gene sequencing. The population of culturable anaerobic bacteria, lactobacilli and enterobacteria were not affected by the experimental diets. The FOS diet affected fermentation patterns in the caecum and proximal colon with significantly higher molar proportions of butyric acid (P < 0.05) and lower molar proportions of acetic acid (P < 0.05). It is concluded that FOS, and especially TOS, strongly stimulate the population of yeast throughout the gastrointestinal tract, and FOS change the fermentation patterns in the caecum and proximal colon of piglets. However, neither FOS or TOS have any strong prebiotic effect on the population of bifidobacteria in the gastrointestinal tract of piglets.