A specific blend of prebiotics and postbiotics improved gut microbiome of dogs with soft stools in the in vitro Simulator of the Canine Intestinal Microbial Ecosystem (SCIME)

Abstract

The Simulator of the Canine Intestinal Microbial Ecosystem (SCIME) allows for the study of long-term effects of food, supplements, or ingredients on the canine gut microbiome in a simulated proximal and distal colon. This model has been used to evaluate the impact of repeated administration of a test product blend composed of a mixture of baobab fruit pulp, acacia gum, heat-killed Lactobacillus helveticus HA-122, and specific fractions of selected inactivated yeast strains (including Saccharomyces cerevisiae AQP 12260 and AQP 12988 and Cyberlindnera jadinii AQP 12549), on the activity and composition of the gut microbiome of canine donors with soft stools. The SCIME colonic reactors were inoculated with fecal material from 3 different canine donors. After two days of stabilization, the 8-day parallel control/treatment period was initiated; reactors were fed with SCIME nutritional medium with or without test product. Changes in microbial metabolic activity were assessed by measuring levels of acetate, propionate, butyrate, lactate, branched short-chain fatty acids, and ammonium. Changes in microbial community composition were assessed using 16S-targeted Illumina sequencing. Overall, test product supplementation resulted in increased saccharolytic fermentation, as evidenced by increases in the health-promoting bacterial metabolites as propionate (donor-dependent), acetate and butyrate (donor-dependent) as well as increased abundances of several saccharolytic fermenting microbes, including Bifidobacterium. Conversely, proteolytic bacteria like Proteobacteria were reduced with test product compared to control. Repeated supplementation with the test product was therefore able to induce - in vitro - a positive modulation of the microbiome originated from dogs with soft stools.