Functional properties of chia (Salvia hispanica L.) flour, its hydrolyzed protein and phenolic extract on microbiota and gut health in vivo
Authors:   , Mishima Marcella Duarte Villas 
Published: March 2024

Chia has a composition with potential to promote changes in the intestinal tissue that favor its functionality, morphology, and microbiota. Objective: evaluate the functional properties of chia flour, its hydrolyzed protein and phenolics on intestinal microbiota and gut health in vivo. Methodology: four experimental trials were conducted. First experiment: 32 male Wistar rats received the following diets (5 weeks): standard (SD), SD+chia, high-fat diet (HFD), or HFD+chia. Second experiment: 64 female Wistar rats fed either SD or HFD (7 weeks). Then, 32 rats underwent ovariectomy (OVX) while 32 rats underwent surgery without removal of the ovary (SHAM). After a 3-week recovery period, the rats were divided into eight groups and received the following diets (8 weeks): SD, SD+chia, HFD, or HFD+chia, for both OVX and SHAM groups. Intestinal microbiota, short-chain fatty acids (SCFA), IgA production, intestinal pH, histomorphometry, and brush border membrane functionality were analyzed. Then, a systematic review was conducted according to PRISMA guidelines, to answer the question: “How does food derived bioactive peptides can impact on gut health and inflammatory mediators in vivo?”. The third and fourth experiments were conducted in ovo. Third experiment: 45 fertile eggs (Gallus gallus) were divided into five groups receiving different treatments: not injected; 18MΩH20; 10mg/mL of hydrolyzed chia protein (1%); 10mg/mL hydrolyzed chia protein+106 CFU Lacticaseibacillus paracasei or 106 CFU Lacticaseibacillus paracasei. Fourth experiment: 27 eggs divided into three groups: not injected; 18MΩH 20; 10mg/mL (1%) of chia phenolic extract. Upon hatching, the animals were euthanized for analysis of intestinal microbiota composition, morphology, and gene expression related to functionality, inflammation, and intestinal barrier proteins. Results: Paper 1: chia flour consumption in male rats increased SCFA production and improved the circular muscle layer. Diversity and abundance of intestinal bacteria were not affected, but richness increased. Proteins associated with intestinal functionality were downregulated. Paper 2: In OVX female rats, chia flour intake increased production of acetic and butyric acids and decreased the cecum content pH, improved muscle layers and crypt thickness, improved richness and decreased microbiota diversity, and improved the expression of Ap and Si. Paper 3: In SHAM female rats, chia consumption increased the production of acetic and butyric acids in the SD group and propionic acid in the HFD group and decreased the pH of cecal content, while reducing IgA concentration in the HFD+chia group. Nevertheless, it increased microbial richness and diversity. The SD+chia group increased Si and Ap gene expression and decreased Sglt1 and Pept1. Paper 4: The systematic review highlighted the potential positive effects of bioactive peptides on inflammation and gut health. Paper 5: The hydrolyzed chia protein downregulated the gene expression of Tnf-α, increased Ocln, Muc2, and Ap, reduced Bifidobacterium, increased Lactobacillus and improved the intestinal morphology. Paper 6: Chia phenolic extract reduced Tnf-α and increased Si gene expression, reduced the Bifidobacterium, E. coli populations and Paneth cell diameter, increased depth crypt, and maintained villus height. Conclusion: chia can be considered a food with biological potential to improve intestinal health. The effects were demonstrated in different fractions of the seed. Key words: Intestinal Microbiota; Intestinal Morphology; Short Chain Fatty Acids; Intestinal Functionality; Intra-Amniotic Administration; Lacticaseibacillus paracasei; Brush Border Membrane; Ovariectomy.