Iron-saturated bovine lactoferrin preserves microbiota diversity and healthy ageing-associated taxa in an in vitro colon model of elderly gut microbiota (Iron-saturated bovine lactoferrin impact on elderly gut microbiota)

Lactoferrin is a multifunctional milk protein receiving increased interest in recent years because of its potential as a functional food ingredient to reduce the prevalence of iron deficiency, while providing additional health benefits including gut microbiota modulation. Iron deficiency represents one of the most prevalent micronutrient deficiencies globally. As such, the aims of this study were (1) to assess the effect of lactoferrin, with different states of iron saturation, on the growth of a simple consortium of gut bacteria, and (2) to evaluate the impact of iron-saturated lactoferrin on the whole gut microbiome of elderly (healthy and frail) donors in an in vitro colon model. We report that iron-depleted and native lactoferrin inhibited consortium growth, while the iron-saturated form resulted in changes in consortium composition by enhancing the growth of Alistipes putredinis. Fermentation experiments with whole faecal microbiomes showed that the elderly microbiota composition was modified by iron-saturated lactoferrin, mainly in the case of healthy subjects, by altering beta diversity through the modulation of healthy-aging associated taxa including Coprococcus, Alistipes and Bifidobacterium. These findings indicate the positive role that iron saturated lactoferrin may provide in modulating the microbiota of the elderly in vitro, increasing the α-diversity with the modulation of groups that are normally abundant in healthy individuals and that are typically lost in the transition from a healthy to frail microbiota profile.