In vitro digestion and microbial fermentation of dried food residues, a potential “new” component for pet food, and different non-digestible carbohydrate sources

Food residues are often fed to dogs in private households and might also be a potential “new” ingredient for pet food in the future. As food residues might contain not only digestible, but also fermentable substrates, an effect on the intestinal microbiota can be assumed. In the present study, two batches of dried food residues (DFR) collected from hotels in Crete were microbially fermented in an in vitro batch culture system with canine fecal inoculum: non-sterile DFR including meat (DFRm), sterile DFR including meat (DFRms) and sterile DFR without meat (DFRwms). Different non-digestible carbohydrate sources (beet pulp, wheat bran, inulin, carrot pomace, brewer´s spent grains, cellulose and lignocellulose) were included for comparison. Inulin, cellulose and lignocellulose were only used as raw materials, while the other test substrates were incubated as raw and enzymatically pre-digested substrates. After incubation for 24 hours, the raw food residues markedly increased the concentrations of bacterial metabolites in the fermenters, although smaller effects were observed for the DFRwms. When the enzymatically pre-digested food residues were incubated, the effects were more pronounced for the DFRms and DFRwms. In general, when compared with the other test substrates, the food residues were microbially fermented to a comparable or partly higher extent. Interestingly, high n-butyrate concentrations were measured in the inocula, both after incubation of the raw and pre-digested food residues. In conclusion, the food residues contained enzymatically digestible and microbially fermentable substrates. If considered as a potential future ingredient for pet food, a standardization of the collection and processing of food residues might be necessary in order to reduce compositional variability and varying effects on the intestinal microbiota.

Assessment of Carbohydrate Availability, Fermentability, and Food Energy Value in Humans Using Measurements of Breath Hydrogen

Measurements in humans of their breath hydrogen is sometimes used to assess the availability, fermentability, and food energy value of carbohydrates that, to an unknown extent, resists small intestinal digestion and fermentation in the large intestine. Here I outline that the method is utterly flawed and conclude that it is unsuitable for making claims as to the availability, fermentability, and food energy value of carbohydrates. More traditional methods, although more demanding of time and effort, can be used. Otherwise further development of methodology is essential to avoid undue risk of bias.

Synthesis of novel α-glucans with potential health benefits through controlled glucose release in the human gastrointestinal tract

The glycemic carbohydrates we consume are currently viewed in an unfavorable light in both the consumer and medical research worlds. In significant part, these carbohydrates, mainly starch and sucrose, are looked upon negatively due to their rapid and abrupt glucose delivery to the body which causes a high glycemic response. However, dietary carbohydrates which are digested and release glucose in a slow manner are recognized as providing health benefits. Slow digestion of glycemic carbohydrates can be caused by several factors, including food matrix effect which impedes α-amylase access to substrate, or partial inhibition by plant secondary metabolites such as phenolic compounds. Differences in digestion rate of these carbohydrates may also be due to their specific structures (e.g. variations in degree of branching and/or glycosidic linkages present). In recent years, much has been learned about the synthesis and digestion kinetics of novel α-glucans (i.e. small oligosaccharides or larger polysaccharides based on glucose units linked in different positions by α-bonds). It is the synthesis and digestion of such structures that is the subject of this review.

Associations between gastric dilatation-volvulus in Great Danes and specific alleles of the canine immune-system genes DLA88, DRB1, and TLR5

OBJECTIVE To determine whether specific alleles of candidate genes of the major histocompatibility complex (MHC) and innate immune system were associated with gastric dilatation-volvulus (GDV) in Great Danes. ANIMALS 42 healthy Great Danes (control group) and 39 Great Danes with ≥ 1 GDV episode. PROCEDURES Variable regions of the 2 most polymorphic MHC genes (DLA88 and DRB1) were amplified and sequenced from the dogs in each group. Similarly, regions of 3 genes associated with the innate immune system (TLR5, NOD2, and ATG16L1), which have been linked to inflammatory bowel disease, were amplified and sequenced. Alleles were evaluated for associations with GDV, controlling for age and dog family. RESULTS Specific alleles of genes DLA88, DRB1, and TLR5 were significantly associated with GDV. One allele of each gene had an OR > 2 in the unadjusted univariate analyses and retained a hazard ratio > 2 after controlling for temperament, age, and familial association in the multivariate analysis. CONCLUSIONS AND CLINICAL RELEVANCE The 3 GDV-associated alleles identified in this study may serve as diagnostic markers for identification of Great Danes at risk for GDV. Additional research is needed to determine whether other dog breeds have the same genetic associations. These findings also provided a new target for research into the etiology of, and potential treatments for, GDV in dogs.