The genome of Bifidobacterium pseudocatenulatum IPLA 36007, a human intestinal strain with isoflavone-activation activity

Background: Bifidobacterium species, including Bifidobacterium pseudocatenulatum, are among the dominant microbial populations of the human gastrointestinal tract. They are also major components of many commercial probiotic products. Resident and transient bifidobacteria are thought to have several beneficial health effects. However, our knowledge of how these bacteria interact and communicate with host cells remains poor. This knowledge is essential for scientific support of their purported health benefits and their rational inclusion in functional foods. Results: This work describes the draft genome sequence of Bifidobacterium pseudocatenulatum IPLA 36007, a strain isolated as dominant from the feces of a healthy human. Besides several properties of probiosis, IPLA 36007 exhibited the capability of releasing aglycones from soy isoflavone glycosides. The genome contains 1,851 predicted genes, including 54 genes for tRNAs and fie copies of unique 16S, 23S and 5S rRNA genes. As key attributes of the IPLA 36007 genome we can mention the presence of a lysogenic phage, a cluster encoding type IV fimbriae, and a locus encoding a clustered, regularly interspaced, short, palindromic repeat (CRISPR)-Cas system. Four open reading frames (orfs) encoding \u3b2-glucosidases belonging to the glycosyl hydrolase family 3, which may act on isoflavone glycosides, were encountered. Additionally, one gene was found to code for a glycosyl hydrolase of family 1 that might also have \u3b2-glucosidase activity. Conclusion: The availability of the B. pseudocatenulatum IPLA 36007 genome should allow the enzyme system involved in the release of soy isoflavone aglycones from isoflavone glycosides, and the molecular mechanisms underlying the strain's probiotic properties, to be more easily understood

Impact of curative pelvic radiotherapy on the gut environment of prostate cancer patients

Trabajo presentado en el 10th Workshop on Probiotics and Prebiotics, de la Sociedad Española de Probióticos y Prebióticos (SEPyP), celebrado en Las Palmas de Gran Canarias, del 6 al 8 de febrero de 2019[Background] Gastrointestinal symptoms are frequent after pelvic radiotherapy and can greatly affect the quality of life of cancer survivors. The effect of radiation on the intestinal microbiome, and the implications of a radiotherapy-induced dysbiosis and the derived intestinal inflammation have received very little attention. [Aim] To perform a follow-up study in patients with prostate cancer for investigating alterations in gut microbiota and metabolites induced by pelvic radiotherapy and associations with inflammation and dietary changes. [Methods] Fourteen patients with prostate cancer undergoing pelvic radiotherapy were recruited and followed during the anti-cancer treatment until two months after finishing. Four stool samples were collected from each patient and changes in the bacterial communities were investigated by sequencing the V3-V4 region of the 16S rRNA gene with Illumina Technology (Miseq PE250), meanwhile short chain fatty acids (SCFAs) were analysed by gas chromatography. Additionally, calprotectin levels were determined using an ELISA kit and, evaluation of dietary intake was recorded by means of semi quantitative food frequency questionnaires. [Results] The composition of the gut communities changes along the radiation treatment, being the Bacteroidetes, the group more affected (p= 0.008, Wilcoxon test). Total SCFAs in feces was reduced with pelvic radiation. In particular, statistical differences were observed for butyrate and acetate excretion with respect to basal time. On the contrary, fecal calprotectin increased significantly during radiotherapy (p= 0.016). In addition, statistical differences in the energy intake were observed before and after two months of radiotherapy. Conclusions: An impact of pelvic radiotherapy on gut microbiota composition and metabolites was observed in prostate cancer patients. Intestinal inflammation occurs at the same time that the microbiome shifts. The effect of radiation was partially, but not completely, restored after two months of finishing the anti-cancer therapy, with changes in the food ingestion patterns still noticeable at this time point