Description:
<jats:sec><jats:title>Scope</jats:title><jats:p>2´‐Fucosyllactose (2´FL) is an abundant oligosaccharide in human milk. It is hypothesized that its brain enrichment is associated with improved learning. Accumulation of 2´FL in organs, biological fluids, and feces is assessed in wild‐type and germ‐free mice.</jats:p></jats:sec><jats:sec><jats:title>Methods and results</jats:title><jats:p><jats:sup>13</jats:sup>C‐labelled 2´FL is applied to NMRI wild‐type mice intravenously (0.2 g kg<jats:sup>−1</jats:sup>) or orally (1 g kg<jats:sup>−1</jats:sup>), while controls receive saline. Biological samples are collected (0.5–15 h) and <jats:sup>13</jats:sup>C‐enrichment is measured by elemental analysis isotope ratio mass spectrometry (EA‐IRMS). After oral application, 2´FL is primarily eliminated in the feces. <jats:sup>13</jats:sup>C‐enrichment in organs including the brain follows the same pattern as in plasma with a maximum peak after 5 h. However, <jats:sup>13</jats:sup>C‐enrichment is only detected when the <jats:sup>13</jats:sup>C‐2´FL bolus reaches the colon. In contrast, in germ‐free mice, the <jats:sup>13</jats:sup>C‐bolus remains in the intestinal content and is expelled via the feces. Furthermore, intravenously applied <jats:sup>13</jats:sup>C‐2´FL is eliminated via urine; no <jats:sup>13</jats:sup>C‐enrichment of organs is observed, suggesting that intact 2´FL is not retained.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p><jats:sup>13</jats:sup>C‐enrichment in brain and other organs after oral application of <jats:sup>13</jats:sup>C‐2´FL in wild‐type mice indicates cleaved fucose or other gut microbial 2´FL metabolites may be incorporated, as opposed to intact 2´FL.</jats:p></jats:sec>