Probiotic for infantile colic

A method for screening and isolating novel Pediococcus pentosaceus cells, comprising the following steps:

• (I) assaying new Pediococcus pentosaceus cells from a pool of Pediococcus pentosaceus cells for their ability to induce the production of interleukin-10 by the following steps;
• (a) differentiating THP-1 monocytes into macrophages by growing the THP-1 monocyte cell line obtained from the cell collection of the Public Health England, catalogue number 88081201, in Roswell Park Memorial Institute (RPMI) 1640 medium with 10% Fetal Bovine Serum (FBS), and with phorbol 12-myristate 13-acetate (PMA) to a final concentration of 0.16 μM;
• (b) growing the THP-1 macrophages in RPMI 1640 medium with 10% FBS in 24-wells ELISA plates to a final concentration of 106 macrophages/well;
• (c) incubating for 2.5 hours the THP-1 macrophages with lipopolysaccharide (LPS) at a final concentration of 10 ng/ml, and washing the THP-1 macrophages with Dulbecco's Phosphate Buffered Saline medium (D-PBS);
• (d) getting a culture of Pediococcus pentosaceus cells ready by having grown it overnight in Man, Rogosa and Sharpe medium (MRS) at 37° C. in a 5% CO2 atmosphere;
• (e) adding to each ELISA-well 500 μl of RPMI 1640 medium with 10% FBS and an appropriate amount of a dilution of Pediococcus pentosaceus cells to obtain a final ratio of 25:1, i.e. 2.5×107 cfu of Pediococcus pentosaceus cells:
• 106 THP-1 macrophages;
• (f) incubating the THP-1 macrophages with the Pediococcus pentosaceus cells for 2.5 hours at 37° C. or without the Pediococcus pentosaceus cells in the same conditions as negative control;
• (g) washing the THP-1 macrophages with D-PBS medium to remove the Pediococcus pentosaceus cells, subsequently adding to the THP-1 macrophages RPMI 1640 medium with 10% FBS supplemented with 50 μg/ml gentamicin, 10 μg/ml ampicillin and 12 μg/ml chloramphenicol, incubating at 37° C. at 5-7% CO2, and taking aliquots at 5 and 24 hours;
• (h) centrifuging the aliquots and assaying the supernatants for interleukin-10 quantification by flow cytometry;
• and
• (i) calculating the normalized increase of interleukin-10 concentration, with the formula (IL1024 h−IL105 h)/IL105 h;
• wherein IL105 h and IL1024 h is the concentration of interleukin-10 in pg/ml at 5 and 24 hours, respectively;
• (II) selecting and isolating the new Pediococcus pentosaceus cells from the pool that induces a production of interleukin-10, expressed as normalized increase, higher than the production of interleukin-10 by the negative control, wherein said normalized increase is determined as defined in step(I).