The Absorption of Iron from the Human Large Intestine

Ohkawara, Yasuo; Bamba, Michio; Nakai, I; Kinka, Shigeyuki; Masuda, Masasuke

doi:10.1016/s0016-5085(63)80031-1

Cited by 26 publications

(11 citation statements)

References 4 publications

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“…It has been suggested that PA exerts a positive impact in the colon by binding free unabsorbed iron, and thus preventing the formation of iron generated free radicals, and also by the direct up-regulation of tumor suppressor genes [ 162 , 165 , 166 ]. However, most information on PA as a therapeutic compound has been derived from cell studies and observational human studies [ 167 ] and, although the potential for PA to bind iron in the colon exists, iron is mostly insoluble at colonic pH [ 168 , 169 ].…”

Section: Resultsmentioning

confidence: 99%

Review: The Potential of the Common Bean (Phaseolus vulgaris) as a Vehicle for Iron Biofortification

Petry¹,

Boy

Wirth³

et al. 2015

Nutrients

243

192

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Common beans are a staple food and the major source of iron for populations in Eastern Africa and Latin America. Bean iron concentration is high and can be further increased by biofortification. A major constraint to bean iron biofortification is low iron absorption, attributed to inhibitory compounds such as phytic acid (PA) and polyphenol(s) (PP). We have evaluated the usefulness of the common bean as a vehicle for iron biofortification. High iron concentrations and wide genetic variability have enabled plant breeders to develop high iron bean varieties (up to 10 mg/100 g). PA concentrations in beans are high and tend to increase with iron biofortification. Short-term human isotope studies indicate that iron absorption from beans is low, PA is the major inhibitor, and bean PP play a minor role. Multiple composite meal studies indicate that decreasing the PA level in the biofortified varieties substantially increases iron absorption. Fractional iron absorption from composite meals was 4%–7% in iron deficient women; thus the consumption of 100 g biofortified beans/day would provide about 30%–50% of their daily iron requirement. Beans are a good vehicle for iron biofortification, and regular high consumption would be expected to help combat iron deficiency (ID).

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Section: Resultsmentioning

confidence: 99%

Review: The Potential of the Common Bean (Phaseolus vulgaris) as a Vehicle for Iron Biofortification

Petry¹,

Boy

Wirth³

et al. 2015

Nutrients

243

192

View full text Add to dashboard Cite

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“…Together, these observations strongly indicate that the enterocoated capsules with 55 Fe disintegrated and released their content of 55 Fe in the ileum, and 55 Fe thereby acted as a tracer for Fe absorption in the ileum and colon. Very little is known about the mechanisms of Fe absorption in the large intestine, but there seems to be a preference for ferrous Fe 35 as in the proximal small intestine, and as the expression of the apical ferric reductase, duodenal cytochrome B (DcytB), involved in reduction of ferric to ferrous Fe in the duodenum is significantly reduced with a downward gradient along the length of the gut 8 , the uptake is dependent on other factors, such as lowering of luminal pH by fermentation 13 . It is however uncertain whether both oxidation states of Fe are absorbable in the colon.…”

Section: Discussionmentioning

confidence: 99%

Viable, lyophilized lactobacilli do not increase iron absorption from a lactic acid-fermented meal in healthy young women, and no iron absorption occurs in the distal intestine

et al. 2007

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Lactic acid-fermented foods have been shown to increase Fe absorption in human subjects, possibly by lowering pH, activation of phytases, production of organic acids, or by the viable lactic acid bacteria. In this study the effect of a heat-inactivated lactic acid-fermented oat gruel with and without added viable, lyophilized Lactobacillus plantarum 299v on non-haem Fe absorption was investigated. Furthermore, Fe absorption in the distal intestine was determined. In a randomized, double-blinded crossover trial eighteen healthy young women aged 22 (SD 3) years with low Fe status (serum ferritin ,30 mg/l) were served the two test gruels, extrinsically labelled with 59 Fe and served with two enterocoated capsules (containing 55 Fe(II) and 55 Fe(III), respectively) designed to disintegrate in the ileum. The meals were consumed on two consecutive days, e.g. in the order AA followed by BB in a second period. Non-haem Fe absorption was determined from 59 Fe whole-body retention and isotope activities in blood samples. The concentrations of Fe, lactate, phytate, and polyphenols, and the pH were similar in the heat-inactivated lactic acid-fermented oat gruels with and without added L. plantarum 299v, and no difference in Fe absorption was observed between the test gruels (1·4 and 1·3 %, respectively). Furthermore, no absorption of Fe in the distal intestine was observed. In conclusion, addition of viable, lyophilized lactobacillus to a heat-inactivated lactic acid-fermented oat gruel does not affect Fe absorption, and no absorption seems to occur in the distal part of the intestine from low Fe bioavailability meals in these women.

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“…In humans, iron is mainly absorbed in the duodenum, but to a small extent also in the colon. Ferrous iron infused into the colon is much better absorbed than ferric iron, which is in line with findings in the duodenum where iron needs to be in the ferrous state for uptake by enterocytes (Ohkawara et al ., ). It can be envisaged that the effect of iron speciation on iron uptake is larger in the colon compared with the duodenum as the iron within the food matrix has travelled a longer route to the colon with many changes in environmental conditions, allowing the formation of many different iron complexes that possibly affect host iron uptake (see sections and ).…”

Section: Effect Of Host Iron Intake On Gut Physiology and Immunologymentioning

confidence: 97%

Nutritional iron turned inside out: intestinal stress from a gut microbial perspective

et al. 2014

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Iron is abundantly present on earth, essential for most microorganisms and crucial for human health. Human iron deficiency that is nevertheless highly prevalent in developing regions of the world can be effectively treated by oral iron administration. Accumulating evidence indicates that excess of unabsorbed iron that enters the colonic lumen causes unwanted side effects at the intestinal host-microbiota interface. The chemical properties of iron, the luminal environment and host iron withdrawal mechanisms, especially during inflammation, can turn the intestine in a rather stressful milieu. Certain pathogenic enteric bacteria can, however, deal with this stress at the expense of other members of the gut microbiota, while their virulence also seems to be stimulated in an iron-rich intestinal environment. This review covers the multifaceted aspects of nutritional iron stress with respect to growth, composition, metabolism and pathogenicity of the gut microbiota in relation to human health. We aim to present an unpreceded view on the dynamic effects and impact of oral iron administration on intestinal host-microbiota interactions to provide leads for future research and other applications.

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The Absorption of Iron from the Human Large Intestine

Cited by 26 publications

References 4 publications

Review: The Potential of the Common Bean (Phaseolus vulgaris) as a Vehicle for Iron Biofortification

Review: The Potential of the Common Bean (Phaseolus vulgaris) as a Vehicle for Iron Biofortification

Viable, lyophilized lactobacilli do not increase iron absorption from a lactic acid-fermented meal in healthy young women, and no iron absorption occurs in the distal intestine

Nutritional iron turned inside out: intestinal stress from a gut microbial perspective

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