title: Raw meat based diet influences faecal microbiome and end products of fermentation in healthy dogs.
abstract: BACKGROUND
  Dietary intervention studies are required to deeper understand the variability of gut microbial ecosystem in healthy dogs under different feeding conditions and to improve diet formulations. The aim of the study was to investigate in dogs the influence of a raw based diet supplemented with vegetable foods on faecal microbiome in comparison with extruded food.
  
  
  METHODS
  Eight healthy adult Boxer dogs were recruited and randomly divided in two experimental blocks of 4 individuals. Dogs were regularly fed a commercial extruded diet (RD) and starting from the beginning of the trial, one group received the raw based diet (MD) and the other group continued to be fed with the RD diet (CD) for a fortnight. After 14 days, the two groups were inverted, the CD group shifted to the MD and the MD shifted to the CD, for the next 14 days. Faeces were collected at the beginning of the study (T0), after 14 days (T14) before the change of diet and at the end of experimental period (T28) for DNA extraction and analysis of metagenome by sequencing 16SrRNA V3 and V4 regions, short chain fatty acids (SCFA), lactate and faecal score.
  
  
  RESULTS
  A decreased proportion of Lactobacillus, Paralactobacillus (P < 0.01) and Prevotella (P < 0.05) genera was observed in the MD group while Shannon biodiversity Index significantly increased (3.31 ± 0.15) in comparison to the RD group (2.92 ± 0.31; P < 0.05). The MD diet significantly (P < 0.05) decreased the Faecal Score and increased the lactic acid concentration in the feces in comparison to the RD treatment (P < 0.01). Faecal acetate was negatively correlated with Escherichia/Shigella and Megamonas (P < 0.01), whilst butyrate was positively correlated with Blautia and Peptococcus (P < 0.05). Positive correlations were found between lactate and Megamonas (P < 0.05), Escherichia/Shigella (P < 0.01) and Lactococcus (P < 0.01).
  
  
  CONCLUSIONS
  These results suggest that the diet composition modifies faecal microbial composition and end products of fermentation. The administration of MD diet promoted a more balanced growth of bacterial communities and a positive change in the readouts of healthy gut functions in comparison to RD diet.
authors.affiliation: Department of AgroFood, Environmental and Animal Sciences, University of Udine, Via delle Scienze 2908, 33100, Udine, Italy. misa.sandri@uniud.it.
authors.forename: Misa
authors.identifier: http://orcid.org/0000-0002-2240-5573
authors.initials: M
authors.lastname: Sandri
authors.affiliation: Cluster in Biomedicine, CBM S.c.r.l., Bioinformatic Services, Area Science Park, I‑34149, Basovizza, Italy.
authors.forename: Simeone
authors.initials: S
authors.lastname: Dal Monego
authors.affiliation: Department of Agricultural, Food and Agro-Environmental Sciences, University of Pisa, Via del Borghetto 80, 56124, Pisa, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Conte
authors.affiliation: Department of AgroFood, Environmental and Animal Sciences, University of Udine, Via delle Scienze 2908, 33100, Udine, Italy.
authors.forename: Sandy
authors.initials: S
authors.lastname: Sgorlon
authors.affiliation: Department of AgroFood, Environmental and Animal Sciences, University of Udine, Via delle Scienze 2908, 33100, Udine, Italy.
authors.forename: Bruno
authors.initials: B
authors.lastname: Stefanon
mesh_terms: D000821:Animal Feed; D000818:Animals; D004032:Diet / Q000662:veterinary*; D004285:Dogs / Q000382:microbiology*; D005243:Feces / Q000382:microbiology*; D005260:Female; D005285:Fermentation; D008297:Male; D008460:Meat; D064307:Microbiota; D066256:Raw Foods; D014675:Vegetables
keywords: Diet; Dog; Feces; Lactic acid; Microbiome; Raw meat; Short chain fatty acids