Assessment of the prebiotic potential of globe artichoke by-product through in vitro fermentation by human faecal microbiota

Abstract

In vitro fermentability of artichoke by-product by pure cultures of lactic bacteria was previously observed. Therefore, prebiotic potential of globe artichoke by-product (Cynara cardunculus L.) was evaluated by in vitro fermentation with human faecal microbiota. Inulin, a well-known prebiotic compound, and sucrose were used as fermentation controls. The inoculated batches were incubated at 37 °C over 72h. Fermentability was evaluated by monitoring bacterial growth, pH, short chain fatty acids (SCFAs) release, lactic acid production and substrate consumption. The most representative gut bacteria were evaluated. Growth of beneficial lactic acid bacteria and bifidobacteria on artichoke by-product was higher than on inulin and similar to sucrose control. Counts of potentially pathogenic bacteria such as coliforms and sulphite-reducing clostridia, where up to 2 log UFC/mL lower than those of beneficial bacteria. After an initial adaptation period, they decreased on inulin and sucrose controls but remained on artichoke by-product. Release of SCFAs was observed on artichoke substrate which showed the highest levels of individual acetic, propionic and butyric acids at 24h or 72h of fermentation, respectively. The lactic acid produced was significantly lower on artichoke substrate than on controls. Human faecal bacteria consumed the 54.6% of artichoke by-product substrate. Therefore, artichoke by-product showed a potential prebiotic effect under the assayed conditions. Further analysis by molecular biology techniques and in vivo studies are needed to determine the specific compounds involved and health-promoting effects in humans. In addition, the possible use of artichoke waste as prebiotic ingredient could contribute to minimize food waste and environmental impact.