Maternal Roughage Sources Influence the Gastrointestinal Development of Goat Kids by Modulating the Colonization of Gastrointestinal Microbiota

Abstract

During pregnancy and lactation, maternal nutrition is linked to the full development of offspring and may have long-term or lifelong effects. However, the influence of the doe's diet on the gastrointestinal (GI) tract of young kids remains largely unexplored. Therefore, we investigated the effects of doe roughage sources (alfalfa hay, AH, or corn straw, CS) during pregnancy and lactation on kid growth, GI morphology, barrier function, metabolism, immunity, and microbiome composition. The results indicate that, compared with the CS group, does fed an AH diet had significantly higher feed intake (p < 0.01). However, CS-fed does exhibited higher neutral detergent fiber (NDF) digestibility (p < 0.05). There were no significant differences in animal (doe or kid) weight among the groups (p > 0.05). In the rumen of goat kids, the AH group exhibited a higher papillae width and increased levels of interleukin-10 (IL-10) compared with the CS group (p < 0.05). In the jejunum of goat kids, the AH group showed a higher villus-height-to-crypt-depth (VH/CD) ratio, as well as elevated levels of secretory immunoglobulin A (SIgA), immunoglobulin G (IgG), IL-10, acetate, and total volatile fatty acids (TVFAs), when compared with the CS group (p < 0.05). Transcriptome analysis revealed that the source of roughage in does was associated with changes in the GI transcriptome of the kids. Differentially expressed genes (DEGs) in the rumen were mainly associated with tissue development and immune regulation, while the DEGs in the jejunum were mainly associated with the regulation of transferase activity. Spearman correlation analyses indicated significant associations between GI DEGs and phenotypic indicators related to GI development, immunity, and metabolism. LEfSe analysis identified 14 rumen microbial biomarkers and 6 jejunum microbial biomarkers. Notably, these microorganisms were also enriched in the rumen or day 28 milk of the does. Further microbial composition analysis revealed significant correlations between the rumen and milk microbiomes of does and the rumen or jejunum microbiomes of kids. Association analyses indicated that microbial biomarkers interact with host genes, thereby affecting the development and function of the GI system. Additionally, correlation analyses revealed significant association between milk metabolites and the rumen and jejunum microbiomes of kids. This study demonstrated that maternal diet significantly influences the development of microbial ecosystems in offspring by modulating microbial communities and metabolite composition. The early colonization of GI microorganisms is crucial for the structural development, barrier function, immune capacity, and microbial metabolic activity of the GI system.

Keywords: gastrointestinal development; goats; immune function; maternal diet; metabolome; microbiome; transcriptome; vertical transmission.

Figure 5

Effect of the maternal diet on offspring gastrointestinal epithelial barrier integrity. Immunofluorescence images showing protein expression of rumen claudin-1 (A) and ZO-1 (B). Immunofluorescence images showing protein expression of jejunum claudin-1 (C) and ZO-1 (D) and MUC2 (E). Red, target proteins. Blue, DAPI-stained nuclei. CS, corn straw group. AH, alfalfa hay group. Data are shown as mean ± STDEV. ** p  <  0.01. On the left is the CS group picture, on the right is the AH group picture. n = 6/group.

Figure 6

Effect of the maternal diet on offspring gastrointestinal transcriptome. (A) Histogram of differentially expressed genes (DEGs). (B) Plot shows the significantly enriched GO biological process terms in the rumen and jejunum (Padj < 0.1). (C) Scatter diagram shows the significantly enriched KEGG pathways in kid jejunum (Padj < 0.05). Characterization of DEGs involved in significantly enriched pathways in the rumen (D) and jejunum (E). CS, corn straw group. AH, alfalfa hay group. n = 6/group.

Figure 1

Effect of the maternal diet on offspring growth. (A) The doe daily feed intake on days 105 and 140 of gestion and days 0 and 28 of lactation. n = 18/group. (B) The doe weight on days 60, 75 and 105 of gestation and days 0 and 28 of lactation. n = 18/group. (C) The kid weight on days 0, 7, 14, 21 and 28 of lactation. n = 36. CS, corn straw group. AH, Alfalfa hay group. Data are shown as mean ± STDEV. ** p  <  0.01.

Figure 2

Effect of the maternal diet on offspring gastrointestinal morphology. Comparisons of the rumen (A,B,E) and jejunum (C,D,F) morphology between the two groups. VH, villus height. CD, crypt depth. Data are shown as mean ± STDEV. * p  <  0.05. n = 6/group.

Figure 3

Effect of the maternal diet on offspring gastrointestinal immunity. (A) Comparison of the differences in intestinal immunoglobulin between the two groups. (B) Comparison of the differences in immune factors in the rumen and jejunum between the groups. CS, corn straw group. AH, alfalfa hay group. Data are shown as mean ± STDEV. * p  <  0.05, ** p  <  0.01. n = 6/group.

Figure 4

Effect of the maternal diet on offspring gastrointestinal volatile fatty acids. (A) Comparison of the differences in VFAs in the rumen (A) and jejunum (B) between the groups. TVFA, total volatile fatty acids. CS, corn straw group. AH, alfalfa hay group. Data are shown as mean ± STDEV. ** p  <  0.01. n = 6/group.

Figure 7

Effect of the maternal diet on offspring gastrointestinal microbiota. NMDS analysis of rumen (A) and jejunum (B) microbiome composition was performed using Bray–Curtis distance, and statistical analysis using ANOSIM analysis. (C) α diversity-Chao1 indexes of the rumen and jejunum microbiota. Rumen microbial composition at the level of phylum (D) and genus (E). Jejunum microbial composition at the level of phylum (F) and genus (G). LEfSe analyses were used to identify the rumen (H) and jejunum (I) microbial community structure (LDA > 2.5). CS, corn straw group. AH, alfalfa hay group. Red and blue circles, 95% confidence interval. * p  <  0.05, ** p  <  0.01. n = 6/group.

Figure 8

The vertical mother-to-infant microbial transmission. (A) SourceTracker was used to estimate the proportions of microbes in the kid rumen from the doe rumen. (B) Source of the milk proportions of microbes in the kid jejunum estimated using SourceTracker. (C) NMDS analysis compared the β diversity of the microbiota of does and kids. Circles, 95% confidence interval. CS, corn straw group. AH, alfalfa hay group. n = 12/group.

Figure 9

The host microbiota is correlated with the host genes and gastrointestinal phenotype data. Spearman correlations between DEGs and phenotype data in the rumen (A) and jejunum (B). Spearman correlations between DEGs and microbial markers in the rumen (C) and jejunum (D). Significant correlation was defined as |r| > 0.8 and p < 0.05. * p  <  0.05, ** p  <  0.01. *** p  <  0.001. Red, positive correlation; blue, negative correlation. n = 6/group.

Figure 10

Effect of the maternal diet on doe’s milk metabolome. (A) PLS-DA plot of milk metabolites. (B) Differential metabolite quantity statistic. Classification of upregulated metabolites in CS group (C) and AH group (D) based on HMDB database annotation. (E) KEGG functional enrichment map of differential metabolites. CS, corn straw group. AH, alfalfa hay group. Circles, 95% confidence interval. n = 6/group.

Figure 11

Maternal diet reshaped offspring gastrointestinal microbial composition via altered milk metabolites. Procrustes analysis for correlations between differential metabolites and rumen (A) and jejunum (B) microbiota in kids. (C) Spearman correlation analysis of differential milk metabolites in does and rumen and jejunum microbiota in kids. * p  <  0.05, ** p  <  0.01. *** p  <  0.001. n = 12/group.