生物谷報(bào)道：長久以來人們就知道土豆對腸道健康有好處,，但一項(xiàng)最新研究證實(shí)，土豆或許還對整個免疫系統(tǒng)有利,，特別是食用土豆沙拉,。結(jié)果發(fā)表在《化學(xué)與工業(yè)》（Chemistry & Industry）上。
西班牙科學(xué)家發(fā)現(xiàn),，用大量生馬鈴薯淀粉（RPS）喂養(yǎng)的豬有更健康的腸道,，這并不意外。但是他們同時(shí)發(fā)現(xiàn)RPS能降低豬血液中白血球數(shù)量,，例如白細(xì)胞和淋巴細(xì)胞,。白血球是炎癥和其它疾病產(chǎn)生的，它們表明身體存在一定問題,。
來自瑞典Goteborg大學(xué)的免疫學(xué)家Lena Ohman表示,，這種現(xiàn)象表明整個身體都處于更健康的狀態(tài)。RPS喂養(yǎng)的豬白細(xì)胞數(shù)量降低了15%左右,。但Ohman也認(rèn)為,，同時(shí)觀察到白細(xì)胞和淋巴細(xì)胞降低是令人吃驚的。
實(shí)驗(yàn)中,，科學(xué)家用RPS喂養(yǎng)豬14周,，以分析它們對腸道健康的作用。研究項(xiàng)目負(fù)責(zé)人 José Francisco Pérez 說：“用RPS的目的是模擬高抗性淀粉的飲食,。”
人類不會食用生土豆,，但是會食用大量含有抗性淀粉的食物,，例如冷煮土豆、豆莢,、綠香蕉,、意大利面和谷類。大約10%的人類食用淀粉是抗性淀粉,，它們不會在小腸中消化,，因此最終會進(jìn)入大腸中發(fā)酵。
淀粉攝入能降低大腸癌風(fēng)險(xiǎn),，而且對腸易激綜合癥（IBS）有利,。Ohman小組之前研究發(fā)現(xiàn)，對IBS病人而言淋巴細(xì)胞數(shù)量不會變化,，但淋巴細(xì)胞會從周圍血液聚集到腸道,，這意味著IBS至少是部分炎癥反應(yīng)。因此她認(rèn)為觀察到淋巴細(xì)胞下降很有意思,，或許含有抗性淀粉的食物對IBS病人有利,。 （引自教育部科技發(fā)展中心）
英文原文鏈接：http://www.physorg.com/news101952367.html
原始出處:
Journal of the Science of Food and Agriculture
Published Online: 21 Jun 2007
Research Article
Long-term effects on the digestive tract of feeding large amounts of resistant starch: A study in pigs
Daniel Martínez-Puig 1, Marisol Castillo 1, Miquel Nofrarias 2, Eva Creus 1, Dr José F Pérez 1 *
1Animal Nutrition, Management and Welfare Research Group, Departament de Ciència Animal i dels Aliments, 08193 Bellaterra, Barcelona, Spain
2Centre de Recerca en Sanitat Animal (CReSA), Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
email: José F Pérez ([email protected])
*Correspondence to José F Pérez, Animal Nutrition, Management and Welfare Research Group, Departament de Ciència Animal i dels Aliments, 08193 Bellaterra, Barcelona, Spain
Funded by:
CICYT; Grant Number: AGL2001-2621-CO2-01
resistant starch ?large bowel fermentation ?short-chain fatty acids ?growing pigs
Abstract
The present study aimed to assess the digestive consequences of the long-term intake of two starches providing different amounts of resistant starch. Growing pigs were used as the animal model and meal-fed for 14 weeks on a diet containing a high amount of either raw potato starch (RPS) or corn starch (CS). Digestive adaptation was chronologically evaluated by measuring organic matter (OM), crude protein (CP), neutral detergent fibre (NDF) and starch digestibility. After 97 days, whole-tract digestibility of OM, CP and NDF was lower for RPS- compared to CS-fed pigs, whereas no differences were observed in faecal starch digestibility. In contrast, starch digestibility was reduced in the proximal compartments (ileum, caecum and proximal colon) of animals fed the RPS diet. The concentration of short-chain fatty acids (SCFAs; P < 0.05), and purine bases (PBs; P < 0.01) was also higher in distal colon and rectum of animals fed the RPS diet. Changes in bacterial community structure (dendogram analyses) were seen in the rectum. Biodiversity tends to increase more in RPS compared to CS fed animals (34.1 vs. 28.8; P = 0.07). Among SCFAs, the proportion of butyrate was two-fold higher in proximal colon digesta of RPS compared to CS fed pigs (0.20 vs. 0.11; P < 0.05). Increased butyrate formation in the colon reduced the number of apoptosis per crypt in the proximal colonic mucosa (0.38 vs. 0.62; P < 0.05). RPS fermentation reduced indices associated with damage to intestinal epithelial cells, such as crypt cell hyperproliferation and magnesium excretion. Long-term ingestion of RPS induces pronounced changes of the digestive tract and their microflora, modifying mineral absorption and colonic morphology for which health benefits are likely to be associated. Copyright © 2007 Society of Chemical Industry
