It is evident that quantitative
information on different microbial groups and their contribution
in terms of activity
in the gastro
intest
inal (GI) tract of humans and animals is required
in order to formulate functional diets target
ing improved gut function and host health. In this work, quantitative
information on levels and spatial distributions of
Bacteroides spp,
Eubacterium spp,
Clostridium spp,
Escherichia coli,
Bifidobacterium spp and
Lactobacillus/Enterococcus spp. along the porc
ine large
intest
ine was
investigated us
ing 16S rRNA targeted probes and
fluorescent in situ hybridisation (FISH). Caecum, ascend
ing colon (AC) and rectum lum
inal digesta from three groups of
individually housed grow
ing pigs fed either a corn–soybean basal diet (CON diet) or a prebiotic diet conta
ining 10 g/kg oligofructose (FOS diet) or
trans-galactooligosaccharides (TOS diet) at the expense of cornstarch were analysed. DAPI sta
ining was used to enumerate total number of cells
in the samples. Populations of total cells,
Bacteroides,
Eubacterium,
Clostridium and
Bifidobacterium decl
ined significantly (
P<0.05) from caecum to rectum, and were not affected by dietary treatments. Populations of
Lactobacillus/Enterococcus and
E. coli did not differ throughout the large
intest
ine. The relative percent (%) contribution of each bacterial group to the total cell count did not differ between caecum and rectum, with the exception of
Eubacterium that was higher
in the AC digesta. FISH analysis showed that the sum of all bacterial groups made up a small percentage of the total cells, which was 12.4%, 21.8%and 10.3%
in caecum, AC and rectum, respectively. This supports the view that
in sw
ine, the diversity of GI microflora might be higher compared to other species. In terms of microflora metabolic activity, the substantially higher numerical trends seen
in FOS and TOS treatments regard
ing total volatile fatty acid, acetate concentrations and glycolytic activities, it could be postulated that FOS and TOS promoted saccharolytic activities
in the porc
ine colon.