Probiotic from human breast milk, Lactobacillus fermentum , promotes growth in animal model of chronic malnutrition

Background Chronic undernutrition leads to growth hormone resistance and poor growth in children, which has been shown to be modulated by microbiota. We studied whether Lactobacillus fermentum CECT5716 ( Lf CECT5716 ), isolated from mother’s breast milk, could promote juvenile growth through the modulation of lipid absorption in a model of starvation. Methods Germ-free (GF) Drosophila melanogaster larvae were inoculated with Lf CECT5716 in conditions of undernutrition with and without infant formula. The impact of Lf CECT5716 on larval growth was assessed 7 days after egg laying (AED) by measuring the larval size and on maturation by measuring the emergence of pupae during 21 days AED. For lipid absorption test, Caco2/TC7 intestinal cells were incubated with Lf CECT5716 and challenged with mixed lipid micelles. Results The mono-associated larvae with Lf CECT5716 were significantly longer than GF larvae (3.7 vs 2.5 mm; p < 0.0001). The effect was maintained when Lf CECT5716 was added to the infant formula. The maturation time of larvae was accelerated by Lf CECT5716 (12 vs 13.2 days; p = 0.01). Lf CECT5716 did not have significant impact on lipid absorption in Caco2/TC7 cells. Conclusions Lf CECT5716 is a growth-promoting strain upon undernutrition in Drosophila, with a maintained effect when added to an infant formula but without effect on lipid absorption in vitro.