Short-Term Probiotic Administration Increases Fecal-Anti Candida Activity in Healthy Subjects.

BACKGROUND: Candida albicans' ability to evade host immune responses represents a serious threat for vulnerable patients. OBJECTIVES: To investigate if (1) feces from healthy subjects exert anti-Candida activity; (2) fecal anti-Candida activity is modified by probiotic administration and (3) different probiotic differently modulate anti-Candida activity. PATIENTS AND METHODS: Feces from healthy donors were analyzed before and after seven days of dietary supplementation with two different probiotic formulations (VSL#3®; Vivomixx®). Candida albicans was cultured with decreasing concentrations of diluted feces, obtained before and after the treatment period. The relationship between anti-Candida activity of feces, interferon-α, anti-interferon-α antibodies and the expression of MxA, ISG15 and IFNAR1 was also evaluated. RESULTS: Feces obtained prior to probiotic intake and feces collected after supplementation with VSL#3® did not affect Candida albicans growth. On the contrary, a 3log10 inhibition of Candida development was observed after Vivomixx® intake. Interferon-α played a role in the inhibition of Candida growth. CONCLUSION: Fecal anti-Candida activity was not observed prior to probiotic supplementation. Seven days of administration of Vivomixx® increased fecal anti-Candida activity, the same effect was not observed after intake of VSL#3®. The probiotic-induced anti-Candida activity seems to be related to an increased local production and release of interferon-α. Clinical trials are needed to determine if a short pretreatment with specific probiotic formulations may increase anti-Candida defenses in patients at risk.