title: Deep Illumina-based shotgun sequencing reveals dietary effects on the structure and function of the fecal microbiome of growing kittens.
abstract: BACKGROUND
  Previously, we demonstrated that dietary protein:carbohydrate ratio dramatically affects the fecal microbial taxonomic structure of kittens using targeted 16S gene sequencing. The present study, using the same fecal samples, applied deep Illumina shotgun sequencing to identify the diet-associated functional potential and analyze taxonomic changes of the feline fecal microbiome.
  
  
  RESULTS
  Fecal samples from kittens fed one of two diets differing in protein and carbohydrate content (high-protein, low-carbohydrate, HPLC; and moderate-protein, moderate-carbohydrate, MPMC) were collected at 8, 12 and 16 weeks of age (n = 6 per group). A total of 345.3 gigabases of sequence were generated from 36 samples, with 99.75% of annotated sequences identified as bacterial. At the genus level, 26% and 39% of reads were annotated for HPLC- and MPMC-fed kittens, with HPLC-fed cats showing greater species richness and microbial diversity. Two phyla, ten families and fifteen genera were responsible for more than 80% of the sequences at each taxonomic level for both diet groups, consistent with the previous taxonomic study. Significantly different abundances between diet groups were observed for 324 genera (56% of all genera identified) demonstrating widespread diet-induced changes in microbial taxonomic structure. Diversity was not affected over time. Functional analysis identified 2,013 putative enzyme function groups were different (p<0.000007) between the two dietary groups and were associated to 194 pathways, which formed five discrete clusters based on average relative abundance. Of those, ten contained more (p<0.022) enzyme functions with significant diet effects than expected by chance. Six pathways were related to amino acid biosynthesis and metabolism linking changes in dietary protein with functional differences of the gut microbiome.
  
  
  CONCLUSIONS
  These data indicate that feline feces-derived microbiomes have large structural and functional differences relating to the dietary protein:carbohydrate ratio and highlight the impact of diet early in life.
authors.affiliation: WALTHAM Centre for Pet Nutrition, Waltham-on-the-Wolds, Leicestershire, United Kingdom.
authors.forename: Oliver
authors.initials: O
authors.lastname: Deusch
authors.affiliation: WALTHAM Centre for Pet Nutrition, Waltham-on-the-Wolds, Leicestershire, United Kingdom.
authors.forename: Ciaran
authors.initials: C
authors.lastname: O'Flynn
authors.affiliation: WALTHAM Centre for Pet Nutrition, Waltham-on-the-Wolds, Leicestershire, United Kingdom.
authors.forename: Alison
authors.initials: A
authors.lastname: Colyer
authors.affiliation: WALTHAM Centre for Pet Nutrition, Waltham-on-the-Wolds, Leicestershire, United Kingdom.
authors.forename: Penelope
authors.initials: P
authors.lastname: Morris
authors.affiliation: WALTHAM Centre for Pet Nutrition, Waltham-on-the-Wolds, Leicestershire, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Allaway
authors.affiliation: WALTHAM Centre for Pet Nutrition, Waltham-on-the-Wolds, Leicestershire, United Kingdom.
authors.forename: Paul G
authors.initials: PG
authors.lastname: Jones
authors.affiliation: Department of Animal Sciences, University of Illinois, Urbana, Illinois, United States of America; Division of Nutritional Sciences, University of Illinois, Urbana, Illinois, United States of America; Department of Veterinary Clinical Medicine, University of Illinois, Urbana, Illinois, United States of America.
authors.forename: Kelly S
authors.initials: KS
authors.lastname: Swanson
mesh_terms: D000818:Animals; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D002415:Cats; D004032:Diet; D004040:Dietary Carbohydrates / Q000494:pharmacology; D004044:Dietary Proteins / Q000494:pharmacology; D005243:Feces / Q000382:microbiology*; D005260:Female; D059014:High-Throughput Nucleotide Sequencing; D007422:Intestines / Q000382:microbiology; D064307:Microbiota / Q000187:drug effects; D012689:Sequence Homology, Nucleic Acid; D013997:Time Factors
chemical_list: D004040:Dietary Carbohydrates; D004044:Dietary Proteins