Influence of Lonicera japonica and Radix Puerariae Crude Extracts on the Fecal Microbiome and Nutrient Apparent Digestibility of Finishing Pigs

Abstract

This study aims to investigate the influence of adding Lonicera japonica (L. japonica) and Radix Puerariae crude extracts and their mixture to the diet of finishing pigs on their fecal microbes and nutrient apparent digestibility. A total of 72 healthy Duroc × Landrace × Yorkshire crossbred barrows without significant differences in body weight (93 ± 2 kg) were selected and randomly divided into four groups (18 in each group). Three replicate pens per group (six pigs per pen) were used, and two pigs were evaluated for each pen. The groups were fed the following diets: control group (CON), basic diet; chlorogenic acid group (CGA group), basic diet + 1 kg/ton L. japonica crude extract; Pueraria flavonoid group (PF group), basic diet + 1 kg/ton Radix Puerariae crude extract; and mix group (Mix group), basic diet + 0.5 kg/ton L. japonica crude extract + 0.5 kg/ton Radix Puerariae crude extract. The following results were obtained: (1) At the phylum level, Bacteroidetes, Firmicutes, Spirochaetes, Proteobacteria, Fibrobaeteres, and Kiritimatiellaeota were the main components of the fecal microbiota (top 5); the relative abundance of bacteria from phyla Firmicutes significantly increased in the Mix group than in the CON group (p < 0.05). At the genus level, Treponema_2, Rikenellaceae_RC9_gut_group, uncultured_bacterium_f_Lachnospiraceae, uncultured_bacterium_f_Prevotellaceae, and Prevotellaceae_NK3B31_group were the main components of the fecal microbiota (top 5); the relative abundance of bacteria from genus Lactobacillus significantly increased in the Mix group than in the CON group (p < 0.05). Chao1 and Ace counts were significantly higher in group CGA than in the CON group and group Mix (p < 0.05). The alpha and beta diversities and the relative abundance of fecal microbes were higher in all test groups than in the CON group. (2) The protein digestibility was significantly higher in the CGA and PF groups than in the CON group, and the TP digestibility was significantly higher in the CGA than in the CON and Mix groups (p < 0.05). In conclusion, Lonicera japonica and Radix Puerariae crude extract supplementation in the diet significantly changed fecal microbiota and improved the protein and TP digestibility of finishing pigs.

Keywords: Lonicera japonica crude extracts; Radix Puerariae crude extracts; feces microbiota; finishing pigs; nutrient apparent digestibility.

Figure 1

Rarefaction curves. The horizontal coordinate is the number of randomly selected sequencing strips, and the vertical coordinate is the number of features obtained based on the number of sequencing strips. Each curve represents one sample, marked with different colors.

Figure 2

Rarefaction curve of the Shannon index. The horizontal coordinate is the number of sequencing strips randomly selected from a sample, and the vertical coordinate is the Shannon index. As the number of sequencing increased, more species were discovered until the species were saturated, and increasing the number of sampling strips did not reveal new features.

Figure 3

OTU Venn diagram of rectal microbes in finishing pigs. The overlapping numbers between multiple color graphs are the number of features shared between multiple samples, and the non-overlapping part is the number of unique features of each sample.

Figure 4

α diversity analysis of rectal microbes in finishing pigs. (a) Chao1 index, (b) Ace index, (c) Simpson index, and (d) Shannon index. All bar charts show means ± SD, * = p < 0.05, n = 9 in each group.

Figure 5

UPGMA clustering analysis of rectal microbe sin finishing pigs. The figure on the right represents the top 10 species according to the species abundance; the others are classified as Others, and those not annotated are classified as Unclassified.

Figure 6

NMDS analysis of rectal microbes in finishing pigs.

Figure 7

Annotation and taxonomic analysis of rectal species in finishing pigs. (a) Histogram of species distribution of phylum-level abundance (b) Histogram of species distribution of genus -level abundance. The horizontal coordinate is the sample name, and the vertical coordinate is the relative abundance (%).

Figure 8

LDA distribution histogram and LEfSe cladogram. The radial circles of the cladogram represent the taxonomic levels from phylum to species. Each small circle at a different taxonomic level represents a taxon at that level, and the diameter of the small circles is proportional to the relative abundance. The coloring principle is to color the species with no significant difference in yellow, whereas the other species with differences are colored according to the group with the highest abundance. Different colors indicate different groups, and nodes with different colors indicate microbiotas that play an important role in the group represented by that color.

Figure 9

Composition and differential analysis of KEGG metabolic pathways. (a) Composition and differential analysis of the CON-CGA KEGG metabolic pathway. (b) Composition and differential analysis of the CON-PF KEGG metabolic pathway. (c) Composition and differential analysis of the CON-Mix KEGG metabolic pathway. All bar charts show means ± SD, * = p < 0.05; ** = p < 0.01.

Figure 9

Composition and differential analysis of KEGG metabolic pathways. (a) Composition and differential analysis of the CON-CGA KEGG metabolic pathway. (b) Composition and differential analysis of the CON-PF KEGG metabolic pathway. (c) Composition and differential analysis of the CON-Mix KEGG metabolic pathway. All bar charts show means ± SD, * = p < 0.05; ** = p < 0.01.

Figure 10

Prediction of BugBase phenotypes. The horizontal coordinate in the figure is the group name, the vertical coordinate is the relative abundance (%), and the three lines from bottom to top are the lower quartile, the mean, and the upper quartile, respectively, showing nine phenotypes: (a) aerobic, (b) anaerobic, (c) contains mobile elements, (d) facultatively anaerobic, (e) biofilms forms, (f) Gram-negative, (g) Gram-positive, (h) potentially pathogenic, and (i) stress tolerant.