Effects of dietary fiber on intestinal iron absorption, and physiological status: a systematic review of in vivo and clinical studies

Abstract

The benefits of dietary fiber on intestinal health have been well established. However, there is no consensus on the dietary fiber effects on mineral absorption. The objective of this systematic review is to discuss the evidence on the dietary fiber effects on iron absorption and iron status-related biomarkers. A comprehensive search of 3 databases: PubMed, Scopus and Web of Science was carried out. We followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, and a total of 32 studies were included with 9 of them clinical studies and 23 in vivo. The studies included assessment of dietary fiber in the form of fructo-oligosaccharides, galacto-oligosaccharides, inulin, pectin, guar gum, oligofructose, xylo-oligosaccharides, and mannan-oligosaccharide. Hemoglobin (n = 21) and fractional iron absorption (n = 6) were the most frequently reported outcomes. The results showed no significant correlations between consumption of dietary fiber to iron absorption/status-related biomarkers. However, the current evidence may not be substantial to invalidate the recommendation of dietary fiber as an agent to improve dietary iron bioavailability, and absorption. In conclusion, there is a need to conduct further clinical trials with long dietary fiber intervention focusing on population at high risk for iron deficiency.

Keywords:

• Fructo-oligosaccharides
• inulin
• iron bioavailability
• iron deficiency
• microbiome
• prebiotic

Disclosure statement

The authors report there are no competing interests to declare.

Acknowledgments

The authors would like to thank the Coordination for the Improvement of Higher Educational Personnel (CAPES), Brazil, for the doctor’s scholarship support in the Capes-Print Program (process number 88887.569929/2020-00), and the National Counsel of Technological and Scientific Development (CNPq, Brazil) for scholarship support (process number 310910/2020-0).

Data availability statement

The data analyzed in this study are openly available within the following references [and/or] its supplementary materials: Kobayashi et al. (2011); Lobo et al. (2011); Freitas, Amancio, and de Morais (2012); Petry et al. (2012); Tako and Glahn (2012); Laparra et al. (2014); Lobo et al. (2014); Marciano et al. (2015); Tiengtam et al. (2015); Lepczyński et al. (2016); Maawia et al. (2016); Carvalho et al. (2017); Pacifici et al. (2017); Paganini, Uyoga, Cercamondi, et al. (2017); Paganini, Uyoga, Kortman, et al. (2017); Weinborn et al. (2017); de Lima Correia Silva et al. (2018); Jaramillo et al. (2018); da Silva et al. (2019); Dias et al. (2019); Jeroense et al. (2019); Samolińska et al. (2019); Wang et al. (2019); Carboni et al. (2020); Jeroense et al. (2020); Martino, Kolba, and Tako (2020); Gomes et al. (2021); Husmann et al. (2022); Mahmoud et al. (2021); Mikulic et al. (2021); Mohammed et al. (2021), and Zhang, Yung, and KongYeung (2021).