Substitution of a commercial diet with raw meat complemented with vegetable foods containing chickpeas or peas affects faecal microbiome in healthy dogs

Figures & data

Table 1. Chemical composition of the completed extruded food used as reference diet (RD), of raw beef meat and of the complementary foods formulated with chickpeas (CCP) or peas (CPE).

Item (on a dry matter basis)	Beef meat	RD	CCP	CPE
Dry matter, %	35.5	92	93	94
Metabolizable energy, kcal/kg	5980	3930	3470	3490
Crude protein, %	49.60	23.90	11.90	10.10
Crude fat, %	41.40	15.20	4.10	4.00
Crude fibre, %	–	2.20	1.20	1.30
Ash, %	2.30	7.30	5.50	4.80
Nitrogen free extracts, %	–	43.40	70.30	73.80
Ca, %	0.04	1.10	1.16	1.21
P, %	0.48	0.80	0.31	0.31

RD, extruded: Beef meat, corn, rice, animal fats, hydrolyzed animal protein, beet pulp, linseed, mineral and vitamin complex. CCP: Rice flour, chickpeas flour, oat flakes, dried grounded carrots, algae-derived omega 3 fatty acids, mineral and vitamin complex. CPE: Rice flour, peas flour, oat flakes, dried grounded carrots, algae-derived omega 3 fatty acids, mineral and vitamin complex.

Table 2. Daily intakes of foods and nutrients and chemical composition of the reference diet (RD), the chickpeas based diet (CP) and the peas (PE) based diet administered to the dogs.

Item	Diet
	RD	CP	PE
Intakes (as fed)
RD extruded, g/d	210
CCP, g/d		128
CPE , g/d			128
Raw beef meat, g/d		210	210
Water, g/d		100	100
Total, g/d	210	438	438
Nutrient intakes
Metabolizable energy, kcal/d	759	832	839
Crude protein, g/d	46.2	52.6	50.6
Crude fat, g/d	29.4	37.1	37.1
Crude fibre, g/d	4.2	1.4	1.5
Ash, g/d	14.1	8.1	7.4
Nitrogen free extract, g/d	99.3	95.2	99.0
Ca, g/d	2.1	1.4	1.5
P, g/d	1.5	0.7	0.7
Diet composition
Metabolizable energy, Kcal/DM	3929	4298	4305
Crude protein, %/DM	23.9	27.2	26.0
Crude fat, %/DM	15.2	19.2	19.0
Crude fibre, %/DM	2.2	0.7	0.8
Ash, %/DM	7.3	4.2	3.8
Nitrogen free extract, %/DM	51.4	49.2	50.8
Ca, %/DM	1.1	0.7	0.8
P, %/DM	0.8	0.4	0.4

RD, extruded: Beef meat, corn, rice, animal fats, hydrolyzed animal protein, beet pulp, linseed, mineral and vitamin complex. CP: Complementary food with rice flour, chickpeas flour, oat flakes, dried grounded carrots, algae-derived omega 3 fatty acids, mineral and vitamin complex. CPE: Complementary food with rice flour, peas flour, oat flakes, dried grounded carrots, algae-derived omega 3 fatty acids, mineral and vitamin complex, beef meat.

Table 3. Faecal score and pH, short chain volatile fatty acids (SCFA), and lactate contents in the faeces of dog fed reference diet (RD), chickpeas based diet (CP) and peas based diet (PE).

	RD		CP		PE		Effects
	Mean	SD	Mean	SD	Mean	SD	Diet	Time	D × T
Faecal score, Score	3.0	0.8	2.4	0.4	2.6	0.5	ns	ns	ns
Faecal pH, Unit	6.7	0.2	6.6	0.3	6.7	0.4	ns	ns	ns
Lactate, μmol/g	23.3	12.2	19.1	8.1	18.3	13.7	ns	ns	ns
Acetate, μmol/g	80.4	27.0	67.7	19.6	67.6	18.8	ns	ns	ns
Propionate, μmol/g	52.8	20.4	47.4	11.4	66.1	39.4	ns	ns	ns
Isobutyrate, μmol/g	3.2	3.1	3.8	2.3	3.7	2.0	ns	ns	ns
Butyrate, μmol/g	16.4	5.3	15.2	3.0	16.0	5.9	ns	*	ns
Isovalerate, μmol/g	4.8	1.9^b	7.8	3.1^a	6.5	1.6^a	*	*	ns
Valerate, μmol/g	1.3	0.6	1.5	1.0	1.0	0.7	ns	*	ns
Total SCFA and lactate, μmol/g	182.1	47.5	162.6	34.6	179.3	43.7	ns	ns	ns

RD: Beef meat, corn, rice, animal fats, hydrolyzed animal protein, beet pulp, linseed, mineral and vitamin complex. CP: Rice flour, chickpeas flour, oat flakes, dried grounded carrots, algae-derived omega 3 fatty acids, mineral and vitamin complex, beef meat. PE: Rice flour, peas flour, oat flakes, dried grounded carrots, algae-derived omega 3 fatty acids, mineral and vitamin complex, beef meat. SCFA = sum of molar content of acetate, propionate, isobutyrate, butyrate, isovalerate and valerate. Faecal score: is a 5-point visual scale ranging from 1 (hard and dry faeces) to 5 (liquid diarrhoea).

*p < .05; ns = not significant.

Figure 1. Relative abundance of bacterial groups at the phylum level. The figure shows column charts of the relative abundance of 16S rRNA sequences at the phylum level of samples organized based on the diets and dogs. The x-axis contains the names of the diet (RD, CP and PE) and the numbers imply the number of the animal. For example, RD-1 implies diet RD and dog 1 and CP-1 diet CP and dog 1. No significant effects for diet, time of sampling and interaction were observed. RD, Reference diet: beef meat, corn, rice, animal fats, hydrolyzed animal protein, beet pulp, linseed, mineral and vitamin complex. CP, Chickpeas based diet: Rice flour, chickpeas flour, oat flakes, dried grounded carrots, algae-derived omega 3 fatty acids, mineral and vitamin complex, beef meat. PE, peas based diet: rice flour, peas flour, oat flakes, dried grounded carrots, algae-derived omega 3 fatty acids, mineral and vitamin complex, beef meat.

Figure 2. Principal coordinates analysis (PCoA) of microbial communities for the fecal samples of dogs fed RD, CP and PE diets. The figure shows a PCoA plot based on Bray Kurtis dissimilarity matrix. Analysis of similarity (ANOSIM) between the three groups was significant (p < .05). RD, reference diet: beef meat, corn, rice, animal fats, hydrolyzed animal protein, beet pulp, linseed, mineral and vitamin complex. CP, chickpeas based diet: rice flour, chickpeas flour, oat flakes, dried grounded carrots, algae-derived omega 3 fatty acids, mineral and vitamin complex, beef meat. PE, peas based diet: rice flour, peas flour, oat flakes, dried grounded carrots, algae-derived omega 3 fatty acids, mineral and vitamin complex, beef meat.

Table 4. Shannon biodiversity index (H’), evenness (J’), and relative abundance (annotated reads/1000 reads) at genus taxonomic level in the faeces of dogs fed reference diet (RD), chickpeas based diet (CP), or peas based diet (PE).

	RD		CP		PE			Effects		Contrast
	mean	SE	mean	SE	mean	SE	Diet	Time	D × T	CP vs. RD	PE vs. RD
Biodiversity, H’	2.55	0.22	2.49	0.14	2.46	0.18	ns	ns	ns	ns	ns
Evenness, J'	0.72	0.04	0.71	0.06	0.70	0.05	ns	ns	ns	ns	ns
Clostridium XI	133.70	17.90	160.30	22.60	150.80	28.40	ns	ns	ns	ns	ns
Streptococcus	84.80	20.20	9.60	4.30	10.00	4.90	ns	ns	ns	ns	ns
Blautia	60.90	15.00	68.90	16.20	51.80	10.40	ns	ns	ns	ns	ns
Prevotella	56.40	15.60	15.70	6.50	32.30	12.00	*	ns	ns	*	ns
Turicibacter	55.00	8.80	88.90	30.20	64.10	22.50	ns	ns	ns	ns	ns
Bacteroides	50.50	9.00	37.70	15.60	58.10	20.30	ns	ns	ns	ns	ns
Fusobacterium	50.50	6.80	37.70	9.80	63.00	19.30	ns	ns	ns	ns	ns
Allobaculum	46.10	12.40	59.50	27.80	71.10	36.50	ns	ns	ns	ns	ns
Lactobacillus	39.00	21.60	50.40	24.10	7.50	4.50	*	ns	ns	ns	*
Alloprevotella	27.40	6.20	10.20	2.90	22.80	8.10	*	ns	ns	*	ns
Megamonas	26.00	7.50	58.90	21.60	78.10	22.40	*	ns	ns	ns	*
Faecalibacterium	23.20	5.30	20.60	3.70	20.40	5.90	ns	ns	ns	ns	ns
Clostridium sensu stricto	18.20	7.30	86.70	21.10	76.60	15.00	ns	ns	ns	ns	ns
Collinsella	17.10	6.60	20.50	12.20	16.00	6.20	ns	*	ns	ns	ns
Sporacetigenium	16.70	2.30	18.70	2.10	20.20	3.10	ns	ns	*	ns	ns
Erysipelotrichaceae is	15.90	4.10	5.00	1.60	4.30	1.00	*	*	ns	*	**
Ruminococcus2	15.00	2.10	17.00	5.10	9.30	1.60	ns	ns	ns	ns	ns
Clostridium XIX	14.10	1.60	11.00	2.30	18.40	5.40	ns	ns	ns	ns	ns
Lachnospiracea is	11.70	3.40	10.60	2.80	9.40	2.60	ns	ns	ns	ns	ns
Paraprevotella	11.30	2.90	3.30	1.40	4.70	2.50	ns	ns	ns	ns	ns
Peptostreptococcus	10.40	6.30	9.80	5.20	15.20	14.40	ns	ns	ns	ns	ns
Peptococcus	8.70	1.40	12.30	2.80	9.70	2.30	ns	ns	ns	ns	ns
Eubacterium	8.30	1.70	3.80	1.10	2.40	0.90	*	*	ns	*	**
Paralactobacillus	7.80	3.90	9.30	4.30	2.10	0.90	ns	ns	ns	ns	ns
Cetobacterium	7.60	2.10	10.30	3.40	19.50	8.10	ns	ns	ns	ns	ns
Tannerella	5.90	1.40	5.40	2.50	6.50	3.20	ns	ns	ns	ns	ns
Escherichia/Shigella	6.60	3.80	5.00	1.20	8.20	4.90	ns	ns	ns	ns	ns
Sutterella	4.90	1.70	1.30	0.50	5.50	1.70	*	*	ns	*	ns
Phascolarctobacterium	4.80	1.60	5.40	2.00	10.20	3.00	ns	ns	ns	ns	ns
Clostridium XlVa	4.40	1.30	8.90	2.50	6.60	2.10	ns	ns	ns	ns	ns
Anaerobacter	4.40	1.50	13.30	2.70	13.10	1.90	*	*	*	**	*
Fusicatenibacter	4.00	1.10	4.30	1.00	4.40	1.70	ns	ns	ns	ns	ns
Bifidobacterium	3.40	1.30	9.60	5.30	6.60	3.40	ns	*	ns	ns	ns
Sarcina	2.20	0.90	12.80	2.90	9.60	2.10	*	*	ns	**	*

RD, extruded: Beef meat, corn, rice, animal fats, hydrolyzed animal protein, beet pulp, linseed, mineral and vitamin complex. CP: Rice flour, chickpeas flour, oat flakes, dried grounded carrots, algae-derived omega 3 fatty acids, mineral and vitamin complex, beef meat. PE: Rice flour, peas flour, oat flakes, dried grounded carrots, algae-derived omega 3 fatty acids, mineral and vitamin complex, beef meat. ns = not significant.

*p < .05; **p < .01.

Availability of data and materials

The data that support the findings of this study are available in the Sequence Read Archive repository (https://www.ncbi.nlm.nih.gov/sra/SRP150679) and not restrictions apply to the availability of these data.