Influence of Dietary Fiber and Polyphenols During Pre-Gestation, Gestation, or Lactation on Intestinal Gene Expression

Abstract

Background/objectives: Diet composition is important for health, especially during critical periods such as pre-gestation (P), gestation (G), or lactation (S), due to its potential impact not only on the mother but on the offspring. The Mediterranean diet includes many healthy foods rich in fiber and/or polyphenols, such as whole grains, fruits, vegetables, beans, and nuts. The present preclinical study assesses the impact of a diet rich in fiber and polyphenols (HFP diet) during one of those three periods (P, G, or S, three weeks each) on the rat gene expression of the small intestine obtained at the end of the lactation period.

Methods: This analysis was performed by the mRNA two step PCR amplification by random primers and poly-T, followed by library generation and HiSeq X-Ten Illumina sequencing (Seqplexing), and further confirmed by Real time PCR and ELISA.

Results: The results showed a broad number of genes significantly modulated after the HFP diet compared to the reference diet, with a higher number of genes modulated when the supplementing period was closer to the analysis day (S > G > P). Notably, genes involved in immune signaling, intestinal absorption, and cell growth were among those more significantly affected by the HFP dietary intervention. The HFP diet influenced the expression of key genes such as ferritin, fatty acid synthase, apelin, and complement proteins, among others. There was a unique gene modified in all the intervention periods (Family with Sequence Similarity 117 Member A, Fam117A, which codifies a protein with unknown function), indicating that this molecule may participate critically in the effects induced by fiber and polyphenols during these periods.

Conclusions: Overall, in rats, the influence of diet for a three-week period around birth is able to modulate the intestinal gene expression, and consequently, maternal health, which can eventually have an indirect impact on the offspring.

Keywords: Mediterranean diet; fiber; gene expression; gut; maternal diet; polyphenols; small intestine.

Figure 1

Heatmap of the genes significantly modified by the HFP diet, either: (A) during the three weeks prior to gestation (pre-gestation or P group), (B) during the three weeks of gestation (gestation or G group), or (C) during the three weeks of lactation (S group). The color scale indicates the log 2-fold change for all three panels. In all cases, REF animals are displayed in black (controls), and animals receiving the HFP diet are shown in blue (analysis: nutritional intervention) (n = 4–6/group). Grouping of animals based on similarity is displayed at the top of each panel.

Figure 2

Venn diagram displaying statistically significant differentially up- and downregulated genes in pre-gestation group (P group), gestation group (G group), and lactation group (S group) with respect to the REF group (n = 4–6/group).

Figure 3

Comparison of fold change in (A) Ets-1, (B) Lsd1, (C) Fam117a, (D) Fasn, (E) Apln, and (F) Hmox1 with respect to REF between the array results (black bars) and the PCR (grey bars) (n = 6), pre-gestation group (P group), gestation group (G group), and lactation group (S group). Statistical differences: * p < 0.05 vs. REF, # p < 0.1.

Figure 4

(A) Ferritin gene fold-change with respect to REF by array results. Ferritin plasma levels in (B) dams and (C) pups at the end of suckling by ELISA. (D) Correlation between plasma levels of ferritin in the mothers and in the offspring. (E) Adipsin gene fold-change with respect to REF by array results. Adipsin plasma levels in (F) dams and (G) pups at the end of suckling by ELISA. (H) Correlation between plasma levels of adipsin in the mothers and in the offspring. Data (B,C,F,G) are expressed as mean ± S.E.M. (n = 4–6 animals per group). Statistical differences: * p adj < 0.05 vs. REF.