While it is know that the level of iron in our diet can directly influence the composition of our gut microbiota, there has been little study of how our gut ecosystem itself affects iron status and regulation, according to the team of French researchers.
Writing in The FASEB Journal, the authors of the new research used a mouse model to test how the microbiota affects iron uptake and regulation – finding that the bacteria in our gut are an important regulator of intestinal status and storage and play a role in regulating intestinal intake and absorption or iron by gut epithelial cells.
“This study is the first to demonstrate that gut microbes induce a specific iron-related protein signature, highlighting new aspects of the crosstalk between the microbiota and the intestinal epithelium,” wrote the French researchers – led by senior author Dr Gaël Nicolas of Inserm.
“Our data suggest that the intestinal cells of GF [germ free] mice are depleted of iron and that following colonization, the epithelial cells favour iron storage,” they added.
The researchers from INRA and Inserm compared the iron status and uptake of mice devoid of intestinal microbiota (germ-free) with other mice that had a controlled microbiota is controlled and in germ free mice that were then colonised.
Nicolas and his team found that in the absence of microbiota, intestinal cells have very low iron stores and transportation systems to the body are very scarce.
By contrast, provided that the microbiota settles in the intestine, intestinal cells acquire a high iron storage capacity (in the form of ferritin) and facilitate its transport to the body (increased ferroportin), said the team.
Indeed, they found that commensal organisms (Bacteroides thetaiotaomicron VPI-5482 and Faecalibacterium prausnitzii A2-165) and a probiotic strain (Streptococcus thermophilus LMD-9) led to up to 12-fold induction of ferritin in colon.
Therefore, the team concluded that the presence of the microbiota leads to an adaptation of intestinal cells, and induces their ability to distribute and store iron – adding that the identification of this new metabolic control could lead to better control iron intake and may help to better understand the anomalies of iron status in people with gut bacteria imbalances.
Source: The FASEB Journal
Published online ahead of print, doi: 10.1096 / fj.15-276840
“The microbiota shifts the iron sensing of intestinal cells”
Authors: Jean-Christophe Deschemin, et al