Chemistry Reference
In-Depth Information
bacterial populations may be due to the fundamentals of the two procedures. Plating
measures those bacterial species that are alive at the time of plating, whereas qPCR
measures bacterial DNA, thereby measuring those bacteria from dead as well as liv-
ing organisms. scFOS is rapidly fermented in the proximal colon, and that is the area
where bacterial cells utilizing these substrates will proliferate. It is possible that these
cells die prior to reaching the distal colon and, therefore, qPCR likely results in a
more accurate representation of the number of bacteria in the proximal large bowel.
Finally, two novel carbohydrates were evaluated in dogs by Spears et al.
13
High-
molecular-weight pullulan is a slowly hydrolyzed carbohydrate, while γ-cyclodextrin
is a cyclic oligosaccharide in which a portion is able to escape enzymatic diges-
tion and thereby become available for fermentation. Increasing concentrations of
pullulan and γ-cyclodextrin tended to increase ileal bifidobacteria and lactobacilli.
Increasing concentrations of γ-cyclodextrin resulted in a quadratic decrease in fecal
C. perfringens
concentrations. These novel carbohydrates responded similarly to
other prebiotic oligosaccharides fed to dogs.
Although several novel outcomes were reported in the studies discussed previ-
ously, it is clear that the trends noted by Swanson and Fahey
2
were consistent with
those reported here. These new experiments add ever-growing evidence of the ben-
eficial effects of feeding prebiotics to pets. They also begin to fill in the gaps in the
research, most notably, measuring the effects of prebiotics in immunocompromised
animals. These studies, however, by no means complete the research needed on
prebiotic supplementation. As mentioned previously, work in cats is lacking com-
pared to other species and more research is warranted. Despite the more extensive
research in dogs, little is known regarding optimal dosage, and/or the effects on
immune characteristics. Although some research has evaluated blends of prebiot-
ics,
11
more research in this area is warranted, especially in cats that have unique
nutritional needs.
17.4 EvAluATIoN oF ProbIoTICs IN Dogs AND CATs
The most common microbial species evaluated and utilized as probiotics in
the pet include
L. acidophilus
and
Enterococcus faecium
.
Three studies evalu-
ated the effects of probiotics
in vitro
.
14 -16
In vivo
work includes 5 studies evaluating
Enteroccoccus
spp.,
17-21
10 studies evaluating
Lactobacillus
spp.,
22-31
and 1 study
evaluating
Bacillus
spp.
32
Of these, only 2 studies evaluated the use of probiotics
in cats.
21,27
These studies are described in detail in Table 17.2 and are summarized
briefly in the following paragraphs.
Because probiotic usage in pet nutrition is still a relatively new concept (litera-
ture dates to 1998), many studies reported only the ability of the probiotic to sur-
vive in the gastrointestinal tract of dogs and cats. Furthermore, many of them were
prospective studies to determine if a bacterial strain had probiotic effects. Because
of this, very little information is available regarding the dosage that is most appro-
priate. A difficulty with pet foods containing probiotic strains is the fact that most
ingredients are extruded, using high heat and pressure for short periods of time.
