Postbióticos: un nuevo miembro en la familia de los bióticos / Postbiotics: A new member in the biotics family

Los postbióticos fueron definidos en 2021 por la Asociación Científica Internacional de Probióticos y Prebióticos (ISAPP) como "una preparación de microorganismos inanimados y/o sus componentes celulares capaces de conferir un efecto benéfico al hospedador". El campo de los postbióticos es un área nueva dentro de la familia de los bióticos; se han desarrollado ya numerosos productos con aplicaciones clínicas, como la estimulación inmunológica, el manejo de diarreas en niños y adultos, el abordaje del intestino irritable, además de tres fórmulas infantiles. En particular, las fórmulas infantiles con postbióticos obtenidos a partir de la fermentación de la leche con Bifidobacterium breve C50 y Streptococcus thermophilus O65, y sus metabolitos, incluido el oligosacárido 3'-GL, han demostrado seguridad y contribución al desarrollo de la microbiota intestinal y el sistema inmune asociado al intestino. Estas modificaciones contribuyen a la prevención y el manejo de los trastornos funcionales digestivos del lactante.

Postbiotics were defined in 2021 by the International Scientific Association for Probiotics and Prebiotics (ISAPP) as a "preparation of inanimate microorganisms and/or their cellular components that confers a health benefit to the host." The field of postbiotics is a new area within the biotics family; numerous products have already been developed for clinical applications, such as immune stimulation, the management of diarrhea in children and adults, the management of irritable bowel syndrome, and 3 infant formulas. In particular, infant formulas with postbiotics obtained from milk fermented with Bifidobacterium breve C50 and Streptococcus thermophilus O65 ­and their metabolites­, including the oligosaccharide 3'-GL, have demonstrated to be safe and to contribute to the development of the gut microbiota and the gutassociated immune system. These modifications help to prevent and manage functional gastrointestinal disorders in infants.

Arabinoxylan from Argentinian whole wheat flour promote the growth of Lactobacillus reuteri and Bifidobacterium breve.

Arabinoxylans are part of dietary fibre and have received attention given their emergent prebiotic character. Four arabinoxylans extracts were obtained from Argentinian soft and hard wheat. In vitro assays were performed to describe the extent to which the extracts from whole wheat flour support selective growth of Bifidobacterium breve and probiotic Lactobacillus reuteri ATCC23272 in a defined media. The prebiotic effect was evaluated by three quantitative scores: relative growth, prebiotic activity score and prebiotic index. For prebiotic index equation the growth of Bacteroides and Clostridium strains was compared to that of bifidobacteria and lactic acid bacteria. All the arabinoxylans extracts supported the growth of Lactobacillus and Bifidobacterium, reaching higher prebiotic activity score values than inulin (0·37 and 0·36 for Lactobacillus and Bifidobacterium respectively). AX2 from soft wheat and AX4 from hard showed similar prebiotic index value to commercial inulin (2·64, 2·52 and 2·22 respectively), and AX3 extract presented higher prebiotic index value (4·09) than the positive control and other prebiotic index reported for arabinoxylans. These extracts could be used as prebiotic, synbiotic compositions or novel food prototypes to treat dysbiosis associated with many diseases. SIGNIFICANCE AND IMPACT OF THE STUDY: The present work demonstrates that AX extracts from Argentinian soft and hard wheat promote efficiently the growth of probiotic strain L. reuteri ATCC23272 and B. breve 286, validated with three different parameters that consider the growth of representative strains of Bacteria genera found in the gut. The evaluation of AX extracts as a food supplement in a murine model could confirm their ability to modulate the microbiome. Novel food prototypes including AX and probiotics could relieve local symptoms and may act as psychobiotics with a beneficial effect on microbiome-brain axis.

Evaluation of Potential Probiotics Isolated from Human Milk and Colostrum.

Several studies have demonstrated a diversity of bacterial species in human milk, even in aseptically collected samples. The present study evaluated potential probiotic bacteria isolated from human milk and associated maternal variables. Milk samples were collected from 47 healthy women and cultured on selective and universal agar media under aerobic and anaerobic conditions. Bacterial isolates were counted and identified by Biotyper Matrix-Assisted Laser Desorption Ionization-Time of Flight mass spectrometry and then tested for probiotic properties. Total bacteria in human milk ranged from 1.5 to 4.0 log10 CFU/mL. The higher bacterial counts were found in colostrum (mean = 3.9 log10 CFU/mL, 95% CI 3.14-4.22, p = 0.00001). The most abundant species was Staphylococcus epidermidis (n = 76). The potential probiotic candidates were Lactobacillus gasseri (n = 4), Bifidobacterium breve (n = 1), and Streptococcus salivarius (n = 4). Despite the small sample size, L. gasseri was isolated only in breast milk from mothers classified into a normal weight range and after a vaginally delivered partum. No potential probiotics showed antagonism against pathogens, but all of them agglutinated different pathogens. Nine bacterial isolates belonging to the species L. gasseri, B. breve, and S. salivarius were selected as potential probiotics. The present study confirms the presence in breast milk of a bacterial microbiota that could be the source of potential probiotic candidates to be used in the formula of simulated maternal milk.