Synbiotic Effect of Saccharomyces boulardii and Fructans from Agave salmiana on the Modulation of Intestinal Microbiota in Children Under Antibiotics.

Upper respiratory tract infections (URTI) in children are a problem with a remarkably diverse etiology. In most cases, the treatment requires oral antibiotics that will alter the intestinal microbiota, causing dysbiosis and diarrhea associated with such prescription. Ingesting probiotics during the therapy is recommendable to aid in modulating the microbiota. Prebiotics enhance these beneficial microorganisms. We evaluated the synbiotic effect between the probiotic yeast Saccharomyces boulardii CNCM I-745 and fructans from Agave salmiana of proven prebiotic activity on 3- to 10-year-old children diagnosed with URTI and treated with amoxicillin/clavulanic acid. First, we extracted fructans from A. salmiana, completed food safety and inflammatory response analyses, and evaluated their effect in vitro on S. boulardii under anaerobic conditions. Then, we formulated a synbiotic that was (a) included in the diet of children with URTI and taking the antibiotic, (b) excluded in a control group with URTI and under antibiotic, and (c) included in a reference group of healthy children. The extracted fructans from A. salmiana were safe for human consumption and stimulated the growth in vitro of S. boulardii, with parameters, biomass yields, and short-chain fatty acids (SCFA) comparable with inulin. The children consuming the synbiotic ingested it once daily for 1 week and tolerated it well. They had higher concentrations of beneficial microorganisms and secretory immunoglobulin A (sIgA) in stool samples with more acidic pH. Compared to those without the synbiotic, these positive effects were significant in children taking the antibiotic and the synbiotic, contributing to their favorable evolution without diarrhea.