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Aims: To evaluate a mixture of selected lactic acid bacteria (LAB) (a riboflavin‐producer, a folate‐producer and an immunomodulatory strain) as co‐adjuvant for 5‐fluorouracil (5‐FU) chemotherapy in cell culture and using a 4T1 cell animal model of breast cancer. Methods and results: The viability of Caco‐2 cells exposed to 5‐FU and/or LAB was analysed. Mice bearing breast tumour were treated with 5‐FU and/or LAB. Tumour growth was measured. Intestinal mucositis (IM) was evaluated in small intestine; haematological parameters and plasma cytokines were determined. The bacterial mixture did not negatively affect the cytotoxic activity of 5‐FU on Caco‐2 cells. The LAB mixture attenuated the IM and prevented blood cell decreases associated with 5‐FU treatment. Mice that received 5‐FU and LAB mixture decreased tumour growth and showed modulation of systemic cytokines modified by both tumour growth and 5‐FU treatment. The LAB mixture by itself delayed tumour growth. Conclusions: The mixture of selected LAB was able to reduce the side‐effects associated with chemotherapy without affecting its primary anti‐tumour activity. Significance and Impact of the Study: This bacterial mixture could prevent the interruption of conventional oncologic therapies by reducing undesirable side‐effects. In addition, this blend would provide essential nutrients (vitamins) to oncology patients. [ABSTRACT FROM AUTHOR]

Aim: To evaluate two folate‐producing strains, Streptococcus (Strep.) thermophilus CRL 808 and Strep. thermophilus CRL 415, against chemically induced mucositis in mice. Methods and Results: In vitro assays with Caco‐2 cells were performed to evaluate the effect of the bacteria in the presence of 5‐fluorouracil (5‐FU). For in vivo studies, mice were daily injected with 5‐FU to induce intestinal mucositis (IM) and orally administered with folate‐producing strains during 6 days. Clinical symptoms, histological parameters and cytokine profiles were assessed. The results showed that Strep. thermophilus CRL 808 increased the cytotoxicity of 5‐FU against Caco‐2 cells. Administration of this strain in mice with chemically induced IM resulted in a reduction in diarrhoea score and restoration of the intestinal architecture. Cytokine analysis showed that the anti‐inflammatory effect by the bacterium is not associated with an immune mechanism. Regarding Strep. thermophilus CRL 415, no improvements were observed in any of the parameters evaluated. Conclusion: The administration of the folate‐producing Strep. thermophilus CRL 808 has the potential to prevent IM induced by 5‐FU in mice. Significance and Impact of the Study: Folate‐producing LAB could be used in chemotherapy patients to reduce the symptoms of IM, improve their nutritional status and increase the effectiveness of 5‐FU. [ABSTRACT FROM AUTHOR]

Aim To assess the anti-inflammatory effect associated with individual probiotic suspensions of riboflavin-producing lactic acid bacteria ( LAB) in a colitis murine model. Methods and Results Mice intrarectally inoculated with trinitrobenzene sulfonic acid ( TNBS) were orally administered with individual suspensions of riboflavin-producing strains: Lactobacillus (Lact.) plantarum CRL2130, Lact. paracasei CRL76, Lact. bulgaricus CRL871 and Streptococcus thermophilus CRL803; and a nonriboflavin-producing strain or commercial riboflavin. The extent of colonic damage and inflammation and microbial translocation to liver were evaluated. iNOs enzyme was analysed in the intestinal tissues and cytokine concentrations in the intestinal fluids. Animals given either one of the four riboflavin-producing strains showed lower macroscopic and histologic damage scores, lower microbial translocation to liver, significant decreases of iNOs+ cells in their large intestines and decreased proinflammatory cytokines, compared with mice without treatment. The administration of pure riboflavin showed similar benefits. Lact. paracasei CRL76 accompanied its anti-inflammatory effect with increased IL-10 levels demonstrating other beneficial properties in addition to the vitamin production. Conclusion Administration of riboflavin-producing strains prevented the intestinal damage induced by TNBS in mice. Significance and Impact of the Study Riboflavin-producing phenotype in LAB represents a potent tool to select them for preventing/treating IBD. [ABSTRACT FROM AUTHOR]