Susana Marta Isay Saad

Probióticos e prebióticos: o estado da arte

The gut microbiota plays an important role in both human health and disease, and the supplementation of the diet with probiotics and prebiotics may ensure an appropriate equilibrium of this microbiota. Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. Prebiotics are nondigestible carbohydrates that beneficially affect the host by selectively stimulating the growth and/or activity of a limited number of bacteria present in the colon. A product referred as symbiotic is one in which probiotics and prebiotics are combined. This article presents the state of the art about probiotics and prebiotics, reporting new concepts, the benefits these food ingredients provide for the human health, and the possible mechanisms involved, discussing health claims attributed to them, and pointing out recent findings reported, based on experimental scientific evidence. Other aspects, such as selection and applications of probiotics and prebiotics are also discussed.

Viability of Lactobacillus acidophilus in synbiotic guava mousses and its survival under in vitro simulated gastrointestinal conditions

The effects of refrigeration, freezing and substitution of milk fat by inulin and whey protein concentrate (WPC) on Lactobacillus acidophilus La-5 viability and resistance to gastric and enteric simulated conditions in synbiotic guava mousses effects were investigated. Refrigerated mousses supplemented with WPC presented the best probiotic viability, ranging from 7.77 to 6.24 log cfu/g during 28 days of storage. The highest probiotic populations, above 7.45 log cfu/g, were observed for all frozen mousses during 112 days of storage. Decreased L. acidophilus survival during the in vitro gastrointestinal simulation was observed both for refrigerated and frozen mousses. Nonetheless, for the refrigerated mousses, the addition of inulin enhanced the probiotic survival during the in vitro assays in the first week of storage. L. acidophilus survival in simulated gastrointestinal fluids was also improved through freezing. The frozen storage may be used to provide increased shelf-life for synbiotic guava mousses. Even though the protective effect of inulin and WPC on the probiotic microorganism tested was shown to be more specific for the refrigerated products, the partial replacement of milk fat by these ingredients may also help, as it improves the nutritional value of mousses in both storage conditions.

Aspectos tecnológicos de alimentos funcionais contendo probióticos

Functional food science is being considered priority of research nowadays and studies are directed towards attempts to elucidate their proprieties and effects in promoting health. Probiotics are viable microbial dietary supplements that have beneficial effects over the health of the host by means of modulation of the intestinal microflora. Some beneficial properties attributed to probiotic microorganisms still need more controlled studies to be definitely established. This article deals with technology aspects related to probiotics, the effects associated with the consumption of food products containing these microorganisms and the main strains employed for that purpose. Experimental data are also presented in order to illustrate technological aspects of the manufacture of food products containing probiotics, intending to describe their limitations and alternatives.Functional food science is being considered priority of research nowadays and studies are directed towards attempts to elucidate their proprieties and effects in promoting health. Probiotics are viable microbial dietary supplements that have beneficial effects over the health of the host by means of modulation of the intestinal microflora. Some beneficial properties attributed to probiotic microorganisms still need more controlled studies to be definitely established. This article deals with technology aspects related to probiotics, the effects associated with the consumption of food products containing these microorganisms and the main strains employed for that purpose. Experimental data are also presented in order to illustrate technological aspects of the manufacture of food products containing probiotics, intending to describe their limitations and alternatives.

Scientific evidence for health effects attributed to the consumption of probiotics and prebiotics: an update for current perspectives and future challenges.

Probiotics and prebiotics, mainly commercialised as food ingredients and also as supplements, are considered highly profitable niche markets. However, in recent years, the food industry has suffered from a series of health claim restrictions on probiotics and prebiotics in many parts of the world, including those made by the European Food Safety Authority. Therefore, we reviewed the core benefits of probiotic and prebiotic consumption on health. A number of studies have examined the prevention and/or management of intestinal infections, respiratory tract infections, CVD, osteoporosis, urogenital infections, cavities, periodontal disease and halitosis, allergic reactions, inflammatory bowel disease and irritable bowel syndrome and Helicobacter pylori gastric infections. In fact, a deeper understanding of the mechanisms involved in human microbiota and immune system modulation by probiotics and prebiotics relies on continuous efforts to establish suitable biomarkers of health and diseases risk factors for the design of clinical trials required for health claim approval. In spite of the promising results, the performance of large, long-term, well-planned, well-aligned clinical studies is crucial to provide more reliability and a more solid basis for the outcomes achieved and to support the potential use of probiotics and prebiotics in clinical practice.

Potential beneficial properties of bacteriocin‐producing lactic acid bacteria isolated from smoked salmon

Aims:  To evaluate the probiotic properties of strains isolated from smoked salmon and previously identified as bacteriocin producers.

Textura instrumental de queijo petit-suisse potencialmente probiótico: influência de diferentes combinações de gomas

The effect of different combinations of gums over texture parameters of probiotic petit-suisse cheese was evaluated. Petit-suisse cheeses were produced using Quark cheese-base prepared with the starter Streptococcus thermophilus and the probiotics Lactobacillus acidophilus and Bifidobacterium longum. Three formulations of petit-suisse were prepared, using the quark cheese-base added of 0.75% of the final product of the mixture of the hydrocolloids xanthan gum (X), carrageenan gum (C), guar gum (G), pectin (P): F1 = 2,5X:2,5C:5G; F2 = 2X:3C:5P; F3 = 5C:5G. Parameters evaluated after 1, 7, 14, and 21 days of storage of the product at 4±1oC included microbial counts of probiotic microorganisms, instrumental texture parameters, pH and moisture. Probiotic counts were always above 6.40 log CFU/g for L. acidophilus and above 7.30 log CFU/g for B. longum. The formulations were significantly different (p<0.05) for all the texture parameters, except for firmness of F1. The pH and the moisture were similar for the three formulations. F1 was considered the best formulation, due to its more stable firmness during storage.

Biopreservation by Lactobacillus paracasei in coculture with Streptococcus thermophilus in potentially probiotic and synbiotic fresh cream cheeses

The viability of Lactobacillus paracasei and its effect on growth of the microbiota in potentially probiotic and synbiotic fresh cheeses during storage at 4 +/- 1 degree C was investigated. Three cheese-making trials (T1, T2, and T3) were prepared in quadruplicate, all supplemented with a Streptococcus thermophilus culture. L. paracasei subsp. paracasei was added to cheeses in T1 and T2, and inulin was added to cheeses in T2. Counts of L. paracasei, S. thermophilus, coliforms, Escherichia coli, Staphylococcus spp., DNase-positive Staphylococcus, and yeasts and molds were monitored during storage for up to 21 days. Viable counts of L. paracasei in probiotic (T1) and synbiotic (T2) cheeses remained above 7 log CFU/g during the entire storage period, whereas counts of S. thermophilus remained above 9.5 log CFU/g for cheeses from TI, T2, and T3. Populations of coliforms, Staphylococcus spp., and DNase-positive Staphylococcus were higher in T3 cheese and differed significantly from those in cheeses from T1 and T2 (P < 0.05). Inhibition of contaminants prevailed when both L. paracasei and S. thermophilus were present in fresh cream cheese and probably was due to acid production by both strains; bacteriocin production was not found. Addition of inulin in T2 did not impact microbial viability (P > 0.05). L. paracasei subsp. paracasei in coculture with S. thermophilus was inhibitory against microbial contaminants in fresh cream cheese with or without the addition of inulin, indicating the potential use of this combination in a probiotic and synbiotic product.

Condições de processamento e comercialização de queijo-de-minas frescal

Microbial contamination of minas fresh cheese during its shelf-life and general aspects of quality and standardization of seven different trademarks (A to G), purchased in grocery stores in Sao Paulo, were investigated. For this purpose, counts of Staphylococcus spp., coliforms, Escherichia coli, and lactic acid bacteria, besides pH, moisture, and instrumental measurement of hardness were determined 7, 14 and 21 days after cheese production. The variation of coliforms and E. coli counts during the production of cheeses from pasteurized and raw milk was also evaluated. The highest counts of Staphylococcus spp., coliforms and E. coli were, respectively, 7.83 (B), 8.02 (B), and 7.83 log CFU/g (C). Except for trademark F, all others presented contamination levels above those recommended by the Brazilian legislation. Cheeses from six out of seven trademarks were already unsuitable for consumption 7 days after production. The counts of total coliforms and E. coli in cheeses prepared in the laboratory increased 2.5 log cycles during their manufacture using pasteurized milk, and 4.5 log cycles (coliforms) and 5 log cycles (E. coli) when prepared with raw milk. Conditions of production, distribution, and expiration date of commercial minas fresh cheese need improvement.

In vitro evaluation of gastrointestinal survival of Lactobacillus amylovorus DSM 16698 alone and combined with galactooligosaccharides, milk and/or Bifidobacterium animalis subsp. lactis Bb-12

Probiotic properties of Lactobacillus amylovorus DSM 16698 were previously demonstrated in piglets. Here, its potential as a human probiotic was studied in vitro, using the TIM-1 system, which is fully validated to simulate the human upper gastrointestinal tract. To evaluate the effect of the food matrix composition on the survival of L. amylovorus DSM 16698 in TIM-1, the microorganism was inoculated alone or with prebiotic galactooligosaccharides (GOS), partially skimmed milk (PSM) and/or commercial probiotic Bifidobacterium animalis subsp. lactis Bb-12 (Bb-12). Samples were collected from TIM-1 for six hours, at one-hour intervals and L. amylovorus populations were enumerated on MRS agar plates with confirmation of identity of selected isolates by randomly amplified polymorphic DNA (RAPD) fingerprinting. The cumulative survival for L. amylovorus alone (control) was 30% at the end of the experiment (t=6h). Co-administration of L. amylovorus with GOS, PSM and/or Bb-12 increased its survival in comparison with the control significantly from the 4th hour after ingestion onwards (P<0.05). Furthermore, by the use of High Performance Anion Exchange Chromatography, both L. amylovorus and Bb-12 were observed to promptly degrade GOS compounds in samples collected from TIM-1, as assessed at t=2h. Hence, food matrix composition interfered with survival and growth of L. amylovorus during passage through TIM-1, providing leads towards optimization of probiotic properties in vivo.

Activity of passion fruit (Passiflora edulis) and guava (Psidium guajava) pulps on Lactobacillus acidophilus in refrigerated mousses

Five pilot-scale mousse-making trials were produced and supplemented with Lactobacillus acidophilus La-5 probiotic culture: M1 with passion fruit concentrated juice (PJ); M2 with PJ and prebiotic fibre inulin; M3 with frozen passion fruit pulp (PP); M4 with frozen guava pulp (GP); M5 with GP and lactic acid. The products were stored refrigerated (4oC) and M2 and M5 were also stored frozen (-18oC). Viability of L. acidophilus decreased up to 4.7 log cfu.g-1 in the 21st day for refrigerated mousses containing passion fruit (M1, M2 and M3), whereas the probiotic population remained above 6 log cfu.g-1 in the mousses containing guava (M4 and M5). Inhibition due to acidity was discharged. The addition of fruits to probiotic products should be carefully planned because inhibition of probiotic strains might occur.