Intestinal Microbiota Community and Blood Fatty Acid Profiles of Albas Cashmere Goats Fed with Flaxseed Oil and Whole Flaxseed

Abstract

The present study investigated the effects of flaxseed oil or flaxseed grain on the intestinal microbiota and blood fatty acid profiles of Albas cashmere goats. Sixty kid goats were allocated to three treatments and fed for 90 days with a control treatment, comprising a basal diet (CON, total-mixed ration with flaxseed meal), or experimental treatments, comprising a basal diet with added flaxseed oil (LNO) and a basal diet with added heated flaxseed grain (HLS). On day 90, two goats were randomly selected from each pen (eight goats per treatment) for euthanizing; then, five of the eight goats were randomly selected, and we collected their intestinal (duodenum, jejunum, ileum, cecum, and colon) digesta for analysis of the bacteria community. The results indicated that Firmicutes are the most predominant phylum in different segments of the intestinal digesta. Compared with the CON group, the relative abundance of duodenal Firmicutes, jejunal Saccharibacteria, and Verrucomicrobia significantly decreased in the LNO and HLS groups (p < 0.05), but there was no significant difference between the LNO and HLS groups. Compared with the CON and HLS groups, the RA of duodenal and jejunal Proteobacteria remarkably increased in the LNO group (p < 0.05), and there was no significant difference between the CON and HLS groups. Compared with the CON and LNO groups, the RA of Actinobacteria remarkably increased in the small intestine of the HLS group (p < 0.05), but there was no significant difference between the CON and LNO groups in the duodenum and ileum. The results of linear discriminant analysis (LDA) effect size (LEfSe) analysis showed that the HLS group was characterized by a higher RA of the [Eubacterium]_coprostanoligenes_group in the small intestine and the LNO group was represented by a higher RA of the Lachnospiraceae_NK3A20_group in the cecum and colon, while the CON group was represented by a higher RA of Solobacterium, Pseudoramibacter, and Acetitomaculum in the small intestine and a higher RA of norank_o__Bradymonadales, the Prevotellaceae_Ga6A1_group, and Ruminiclostridium_1 in the cecum and colon. In conclusion, the addition of flaxseed oil and grain rich in c18:3n3 to the diet could reduce the microbial diversity of the small intestinal segments and the microbial diversity and richness of the cecum and colon in Albas cashmere goats. And flaxseed grain is more efficient than flaxseed oil in protecting intestinal health and promoting the absorption of c18:3n3.

Keywords: bacteria; different intestinal segments; goat; grain; n-3 poly-unsaturated fatty acids.

Figure 1

The OTU rarefaction curves of the intestinal digesta bacterial communities. Curves were drawn using the least-sequenced sample as the upper limit for the rarefactions. Each color represents one treatment: the red curves represent kids fed the basal diet (CON), the green curves represent kids fed the basal diet supplemented with flaxseed oil (LNO), and the blue curves represent kids fed the basal diet supplemented with heated flaxseed grain (HLS). (A): duodenum; (B): jejunum; (C): ileum; (D): cecum; (E): colon.

Figure 2

Principal coordinate analysis (PCoA, using the weighted Unifrac similarity metric) of bacterial operational taxonomic units (OTUs) in the intestinal digesta of kid goats. Each symbol represents one treatment: The solid red circle represents kids fed with the basal diet (CON), the solid blue triangle represents kids fed with the basal diet supplemented with flaxseed oil (LNO), and the solid green rhombus represents kids fed with the basal diet supplemented with heated flaxseed grain (HLS). (A): duodenum; (B): jejunum; (C): ileum; (D): cecum; (E): colon.

Figure 3

The bar chart shows the phylum-level bacterial composition of intestinal digesta. The x-coordinate represents the samples; the Y-coordinate indicates the relative abundance of bacteria at the phylum level. (A): duodenum; (B): jejunum; (C): ileum; (D): cecum; (E): colon.

Figure 4

Linear discriminant analysis (LDA) identified distinct bacterial genera that were enriched in the CON, LNO, and HLS groups. Genera with LDA score > 2 and p < 0.05 were considered significant. Each color represents one treatment: the red represents kids fed the basal diet (CON), the blue represents kids fed the basal diet supplemented with flaxseed oil (LNO), and the green represents kids fed the basal diet supplemented with heated flaxseed grain (HLS). (A): duodenum; (B): jejunum; (C): ileum; (D): cecum; (E): colon.

Figure 5

Venn diagram analysis of shared distinct bacteria at genus level in the intestinal digesta of kid goat. Each color represents one site: the blue represents the duodenum, the red represents the jejunum, the green represents the ileum, the yellow represents the cecum, and the brown represents the colon.

Figure 6

Average relative abundance of the dominant phyla (phyla with average relative abundance ≥ 0.01 in at least one region) in 5 intestinal regions of cashmere goats. The X-coordinate represents the samples, the Y-coordinate indicates the relative abundance of bacteria at the phylum level. (A): All groups; (B): CON group; (C): LNO group; (D): HLS group).

Figure 7

Venn diagram analysis of generic level bacterial composition in the intestinal digesta of goat kids. (A): All groups (n = 75). (B): CON group. (C): LNO group. (D): HLS group. Each color represents one site: the red represents duodenum, the blue represents jejunum, the green represents ileum, the yellow represents cecum, and the purple represents colon. The bar chart shows the number of genera in each segment.

Figure 8

Principal coordinate analysis (PCoA, using the weighted Unifrac similarity metric) of bacterial operational taxonomic units in 5 intestinal segments of Albas cashmere goats. (A) All groups (n = 75). (B): CON group. (C): LNO group. (D): HLS group. Each symbol represents one site: the solid red circle represents duodenum, the solid blue triangle represents jejunum, the solid green rhombus represents ileum, the solid yellow square represents cecum, and the solid purple cross-shaped represents colon.