In vitro and in vivo iron bioavailability of biofortified beans (Phaseolus vulgaris L.) and its effect on intestinal function and microbiota

• Ano de defesa: 2019
• Autor(a) principal: Dias, Desirrê Morais
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa
• Palavras-chave em Português: Minerais na nutrição; Biodisponibilidade; Ferro; Anemia; Intestinos - Microbiologia; Polifenóis; Células CACO-2; Bioquímica da Nutrição
• Link de acesso: https://locus.ufv.br//handle/123456789/29108

Iron (Fe) deficiency is the most prevalent nutrient deficiency, affecting around 40% of the world population, particularly women and children in developing countries. Biofortified staple food crops have become an effective tool to reduce Fe deficiency. Common bean (Phaseolus vulgaris) is one of the crops target for biofortification program since it exhibits sufficient genetic variability in iron concentration. Thus, this study aimed to evaluate the in vitro and in vivo iron bioavailability of Fe-biofortified beans compared to the Fe-standard beans and its effect on the gut microbiota and intestinal function. For this study it was used different genotypes of Fe-biofortified beans and Fe-standard beans. The beans were cooked in a conventional pressure cooker for 40 minutes using distilled water, the beans were dried in an air oven for 17 hours at 60ºC, ground by stainless steel mill 090 CFT at 3000 rpm and stored at -12 °C. Firstly, it was evaluated the effect of the prebiotics extracted from the tested beans on the intestinal brush border membrane (BBM) iron related proteins, and intestinal bacterial populations were evaluated using the Gallus gallus model and by the intra-amniotic administration procedure (Manuscript 2). Eight treatment groups [(non-injected; 18MW H 2 O; 40mg/mL Inulin; 50 mg/mL BRS Perola (carioca standard); 50 mg/mL BRS Cometa (carioca, Fe biofortified); 50 mg/mL BRS Esteio (black, standard); 50 mg/mL SMN 39 (black, Fe biofortified); 50 mg/mL BRS Artico (white, standard)] were utilized. The gene expression of the iron related proteins was performed by RT- qPCR and the abundance of bacteria was evaluated by PCR. Carioca bean groups presented an increased (p<0.05) relative abundance of bifidobacteria and lactobacilli in comparison to controls. The relative expression of zinc transprter 1 (ZnT1), ferroportin (FNP) and amino peptidase (AP) were up-regulated (p<0/05) in the BRS Cometa group (Fe- biofortified carioca beans). The second study (Manuscript 3), aimed to evaluate the in vitro iron bioavailability of different genotypes Fe-biofortified beans and Fe-standard beans by themselves and in a combination with others staple food crops. The bean genotypes used in this study were: BRS Perola; BRS Cometa; BRS Esteio and SMN39. The food proportions used were based on the Brazilian consumption. The polyphenol analysis was performed by UPLC-MS, the Fe concentration was evaluated by ICP-AES and the phytate concentration was evaluated using the Magazyme kit assay. In vitro iron bioavailability was evaluated using Caco-2 cells. Fe-biofortified beans (BRS Cometa ans SMN39) presented higher (p<0.05) iron concentration compared to Fe-standard beans (BRS Perola and BRS Esteio). Black beans (BRS Esteio and SMN39) showed higher (p<0.05) concentration of myricetin 3-glucoside and quercetin 3-glucoside compared to the carioca beans, whereas carioca beans (BRS Cometa and BRS Perola) presented higher (p<0.05) concentration of kaempferol 3-glucoside, epicatechin and catechin compared to the black beans. Also, both carioca beans presented higher (p<0.05) iron bioavailability compared to the both black beans and the combination of the beans and other staple food increased (p< 0.05) the iron bioavailability of both, carioca and black beans, except for the Fe-standard bean BRS Esteio. For the third study (Manuscript 4), it was performed a 6-week feeding trial in Gallus gallus (n=15), aimed to investigate the Fe status and the alterations in the gut microbiome following the administration of Fe-biofortified carioca bean based diet (BC) versus a Fe-standard carioca bean based diet (SC). The tested diets were designed based on the Brazilian food consumption survey. Two primary outcomes were observed: 1) a significant increase in total body Hb-Fe values in the group receiving the Fe-biofortified carioca bean based diet; and 2) changes in the gut microbiome composition and function were observed, specifically, significant changes in phylogenetic diversity between treatment groups, as there was increased abundance of bacteria linked to phenolic catabolism, and increased abundance of beneficial SCFA-producing bacteria. The BC group also presented a higher intestinal villi height compared to the SC group. Overall, our results demonstrate that Fe-biofortified beans (black and carioca) presented a higher iron concentration compared to the Fe-standard beans and the black beans presented higher content of polyphenols that can inhibit the iron absorption. Thus, carioca beans presented a higher iron bioavailability compared to the black beans (in vitro) and the combination of the beans with other staple foods increased the in vitro iron bioavailability. Our in vivo (Gallus gallus) results demonstrated that the Fe-biofortified carioca bean variety was able to moderately improve Fe status and to positively affect the intestinal functionality and bacterial populations. Overall, the carioca beans BRS Cometa presented the best results both in vitro and in vivo, improveing Fe status and to positively affecting the intestinal functionality and bacterial populations. Thus, it can be considered a promissor vehicle for the Fe biofortification.