ASSESSMENT OF THE EFFECTS OF EDIBLE MICROALGAE IN A CANINE GUT MODEL

Gut microbiota plays a fundamental role in maintaining host health and metabolism and is considered a potential target of novel therapeutics. Microalgae represent an interesting source of bioactive compounds such as protein, fatty acids, fibre, and minerals for nutritional supplementation in humans and animals. Nevertheless, there is a lack of information on the effect of microalgae on canine gut microbiota. The aim of the study was to evaluate in a in vitro canine gut model the effects of four microalgae Arthrospira platensis (AP), Haematococcus pluvialis (HP), Phaeodactylum tricornutum (PT), Chlorella vulgaris (CV), on some faecal microbial populations and metabolites. Following the in vitro fermentation, chemical and microbiological analysis displayed significant differences between the control and microalgae groups. In particular, after 6h of incubation, microalgae increased propionate (+36% for CV; p=0.001) and butyrate (+24% for CV p=0,013), and decreased total BCFA (-47% for both PT and CV; p=0.006), isobutyrate (-52% for CV; p=0.022) and isovalerate (-43% for AP, CV, PT; p=0.009) and C. hiranonis (-0.46 log10 copies/75 ng DNA for CV; p=0.052); after 24h microphytes increased propionate (+21% for CV; p=0.001) and isovalerate (+10% for CV; p=0.041), and decreased the abundance of Turicibacter spp. (7.18 vs. 6.69 and 6.56 log10 copies/75 ng DNA for CTRL vs HP and CV, respectively; p=0.018), C. leptum (-1.12 log10 copies/75 ng DNA for PT; p=0.008) and Enterococcus spp. (-0.37 log10 copies/75 ng DNA for PT; p=0.044). These findings suggest a potential modulatory effect of microalgae on metabolism of canine faecal microbiota.