ABSTRACT:

The intestinal microbiota has an important role in animal health. Therefore, prebiotics have gained interest in the scientific community for their role in manipulating populations of intestinal microorganisms. Among prebiotics, there is Smallanthus sonchifolius Poepp. Endl (yacon) root, which can be ingested in natura or in different forms, such as flours and extracts. This prebiotic has been associated with beneficial effects in different diseases, including metabolic (like type 2 diabetes) and immunological disorders. Thus, mouse models of human diseases caused by immunological factors have been used to better understand the prebiotic effects of yacon. Since prebiotics interfere with animal microbiota, it is important to take into consideration the quality level of mouse facilities. In this way, the beneficial effects of a yacon root pulp were tested in a mouse model of allergic asthma and, considering how animal facility conditions could affect those results, we performed experiments both in conventional facilities and specific pathogen-free (SPF) ones. Our results showed that better prebiotic effects were observed in a SPF facility than in a conventional one and, in some cases, evidence of yacon beneficial effects was observed exclusively in a SPF facility. For example, there were reductions of 63.6% and 58.0% in IgE and eosinophils, respectively, in immunized/yacon-treated animals compared to immunized mice only. Taken together, our results not only showed the beneficial effects of yacon root pulp in an asthma model but also demonstrated the relevance of performing experiments with prebiotics in SPF facilities.

Key words:
Smallanthus sonchifolius; IgE; eosinophils; allergy; lactobacilli.