Probiotics: an update / Probióticos: informações atualizadas

OBJECTIVE: Triggered by the growing knowledge on the link between the intestinal microbiome and human health, the interest in probiotics is ever increasing. The authors aimed to review the recent literature on probiotics, from definitions to clinical benefits, with emphasis on children. SOURCES: Relevant literature from searches of PubMed, CINAHL, and recent consensus statements were reviewed. SUMMARY OF THE FINDINGS: While a balanced microbiome is related to health, an imbalanced microbiome or dysbiosis is related to many health problems both within the gastro-intestinal tract, such as diarrhea and inflammatory bowel disease, and outside the gastro-intestinal tract such as obesity and allergy. In this context, a strict regulation of probiotics with health claims is urgent, because the vast majority of these products are commercialized as food (supplements), claiming health benefits that are often not substantiated with clinically relevant evidence. The major indications of probiotics are in the area of the prevention and treatment of gastro-intestinal related disorders, but more data has become available on extra-intestinal indications. At least two published randomized controlled trials with the commercialized probiotic product in the claimed indication are a minimal condition before a claim can be sustained. Today, Lactobacillus rhamnosus GG and Saccharomyces boulardii are the best-studied strains. Although adverse effects have sporadically been reported, these probiotics can be considered as safe. CONCLUSIONS: Although regulation is improving, more stringent definitions are still required. Evidence of clinical benefit is accumulating, although still missing in many areas. Misuse and use of products that have not been validated constitute potential drawbacks. .

OBJETIVO: Motivado pelo conhecimento cada vez maior da associação entre o microbioma intestinal e a saúde humana, o interesse nos probióticos vem crescendo cada vez mais. Os autores visaram analisar a última literatura a respeito dos probióticos, de definições a benefícios clínicos com ênfase nas crianças. FONTES DOS DADOS: Foi analisada a literatura relevante de pesquisas do PubMed, do CINAHL e dos últimos consensos. SÍNTESE DOS DADOS: Apesar de um equilíbrio no microbioma estar relacionado à saúde, um desequilíbrio no microbioma ou disbiose está relacionado a vários problemas de saúde no trato gastrointestinal, como diarreia e doença inflamatória intestinal, e fora do trato gastrointestinal, como obesidade e alergia. Nesse contexto, a regulamentação rigorosa dos probióticos a alegações de saúde é urgente, pois a grande maioria desses produtos é comercializada como alimentação (suplementos), alegando benefícios à saúde que frequentemente não são comprovados com evidências clinicamente relevantes. As principais indicações de probióticos são feitas na área da prevenção e tratamento de doenças gastrointestinais, porém mais dados têm sido disponibilizados a respeito de indicações extraintestinais. Pelo menos dois ensaios clínicos controlados e randomizados publicados com o probiótico comercializado na indicação declarada são a condição mínima antes de uma afirmação poder ser mantida. Atualmente, o Lactobacillus rhamnosus GG e Saccharomyces boulardii são as melhores cepas estudadas. Apesar de efeitos adversos terem sido esporadicamente relatados, os probióticos podem ser considerados seguros. CONCLUSÕES: Apesar de a regulamentação estar aumentando, ainda são necessárias definições mais rigorosas. As evidências de benefícios clínicos estão aumentando, apesar de ainda ausentes em várias áreas. O uso inadequado e a utilização de produtos não validados constituem possíveis desvantagens. .

Microencapsulation of Bifidobacterium animalis subsp. lactis and Lactobacillus acidophilus in cocoa butter using spray chilling technology

In the present study, the cells of Bifidobacterium animalis subsp. lactis (BI-01) and Lactobacillus acidophilus (LAC-04) were encapsulated in cocoa butter using spray-chilling technology. Survival assays were conducted to evaluate the resistance of the probiotics to the spray-chilling process, their resistance to the simulated gastric and intestinal fluids (SGF and SIF), and their stability during 90 days of storage. The viability of the cells was not affected by microencapsulation. The free and encapsulated cells of B. animalis subsp. lactis were resistant to both SGF and SIF. The micro-encapsulated cells of L. acidophilus were more resistant to SGF and SIF than the free cells; the viability of the encapsulated cells was enhanced by 67%, while the free cells reached the detection limit of the method (10³ CFU/g). The encapsulated probiotics were unstable when they were stored at 20 °C. The population of encapsulated L. acidophilus decreased drastically when they were stored at 7 °C; only 20% of cells were viable after 90 days of storage. The percentage of viable cells of the encapsulated B. animalis subsp.lactis, however, was 72% after the same period of storage. Promising results were obtained when the microparticles were stored at -18 °C; the freeze granted 90 days of shelf life to the encapsulated cells. These results suggest that the spray-chilling process using cocoa butter as carrier protects L. acidophilus from gastrointestinal fluids. However, the viability of the cells during storage must be improved.

Effect of probiotics on the development of dimethylhydrazine-induced preneoplastic lesions in the mice colon

PURPOSE: To determine the effect of probiotics on the development of chemically induced (1, 2-dimethylhydrazine) colonic preneoplastic lesions, in mice. METHODS: The animals were divided into five groups. The control group was injected with carcinogen alone and the other groups also received probiotics (1- Lactobacillus delbrueckii UFV-H2b20; 2- Bifidobacterium animalis var. lactis Bb12; 3- L. delbrueckii UFV-H2b20 plus B. animalis var. lactis Bb12; and 4- Saccharomyces boulardii) administered orally in drinking water throughout fourteen weeks. RESULTS: Consumption of lactobacilli and bifidobacteria alone resulted in a significant reduction of the total number of aberrant crypt foci (55.7% and 45.1%, respectively). Significant reduction in the number of these small foci (<3 aberrant crypts) was only observed in the group treated with lactobacilli (52.2%) in comparison to control group. The number of larger foci (>3 aberrant crypts) crypts had no significant reduction. CONCLUSION: L. delbrueckii UFV-H2b20 and B. animalis var. lactis Bb12 administered alone protect colonic preneoplastic lesions in mice, while the combined treatment of these bacteria and the administration of S.boulardii were not effective in reducing such colonic lesions.

Efeito bifidogênico do frutooligossacarídeo na microbiota intestinal de pacientes com neoplasia hematológica / Bifidogenic effect of fructooligosaccharides in the intestinal flora of patients with hematological neoplasia

OBJETIVO: Verificar o efeito bifidogênico do frutooligossacarídeo nos pacientes com neoplasias hematológicas submetidos a quimioterapia. MÉTODOS: Trata-se de um estudo clínico randomizado duplo cego, desenvolvido na Unidade de Transplante de Medula Óssea do Centro de Pesquisas Oncológicas de Florianópolis, o qual envolve 25 pacientes divididos em 2 grupos que receberam, por 15 dias, 12g de frutooligossacarídeo (n=14) ou placebo (maltodextrina) (n=11). Foram avaliados a quantidade de bifidobactérias e os valores de pH fecal antes e após a suplementação. RESULTADOS: Observou-se na população estudada o predomínio do sexo masculino (72 por cento) e a idade média de 34 anos. O grupo suplementado apresentou um aumento significante na quantidade de bifidobactérias (p<0,05) e o pH fecal não foi alterado em nenhum dos grupos. CONCLUSÃO: Verificou-se que a suplementação aumentou a quantidade de bifidobactérias, interferindo na composição da microbiota intestinal, e que não houve alteração do pH fecal.

OBJECTIVE: To verify the bifidogenic effect of fructooligosaccharides in patients with hematological neoplasia submitted to chemotherapy. METHODS: This is a clinical, randomized, double-blind study done in the Bone Marrow Transplant Unit of the Oncology Research Center of Florianopolis. It involved 25 patients divided into 2 groups who received 12g of fructooligosaccharides (n=14) for 15 days or placebo (maltodextrin) (n=11). The amount of bifidobacteria and the values of fecal pH before and after supplementation were investigated. RESULTS: Most of the studied population was male (72 percent) and the mean age was 34 years. The group that received supplementation presented a significant increase in the amount of bifidobacteria (p<0.05) and fecal pH remained unchanged in both groups. CONCLUSION: Supplementation increased the amount of bifidobacteria, interfering in the composition of the intestinal flora, but fecal pH was not affected.

The role of probiotics and prebiotics in pediatric practice

OBJETIVO: Revisar os efeitos dos probióticos e prebióticos em situações clínicas da prática pediátrica. FONTES DOS DADOS: MEDLINE, preferencialmente os artigos que abordavam aspectos de aplicabilidade prática, na forma de revisões, ensaios clínicos e meta-análises. Artigos que já eram do conhecimento dos autores também foram utilizados. SíNTESE DOS DADOS: A literatura científica sobre probióticos e prebióticos apresentou crescimento expressivo nos últimos 10 anos. Seus mecanismos de ação vêm sendo investigados experimentalmente. Os estudos indicam que os probióticos podem exercer seus efeitos competindo com patógenos, modificando o ambiente intestinal pela redução do pH, em conseqüência dos produtos da fermentação, interagindo e modulando a resposta inflamatória e imunológica local e sistêmica, entre outros. Ensaios clínicos e meta-análises mostram que os probióticos parecem contribuir para a prevenção da diarréia aguda e da diarréia associada ao uso de antibióticos, além de encurtar a duração da diarréia aguda. No entanto, existem dados contraditórios, além de não existirem ainda estudos confirmando sua efetividade do ponto de vista da relação custo-benefício. Estudos preliminares mostram que probióticos no início da vida podem reduzir a ocorrência de dermatite atópica. A adição de prebióticos em fórmulas para lactentes associa-se com mudança do perfil da microbiota intestinal em relação aos lactentes que recebem fórmula láctea sem prebióticos. CONCLUSÕES: As evidências indicam que novos estudos devem ser realizados sobre probióticos, prebióticos e simbióticos. Um aspecto que deve ser reforçado é a especificidade dos efeitos que cada probiótico ou prebiótico pode apresentar do ponto de vista clínico.

OBJECTIVE: To review the effects of probiotics and prebiotics in clinical pediatric practice. SOURCES: MEDLINE was searched, especially for articles that addressed their practical application, in the form of reviews, clinical trials and meta-analyses. Articles that had already been analyzed by the authors were also included. SUMMARY OF THE FINDINGS: Scientific literature on probiotics and prebiotics has remarkably increased in the last 10 years. Their mechanisms of action have been experimentally investigated. Studies indicate that probiotics can act by competing with pathogens, modifying the intestinal environment by reduction in pH, as a result of fermentation products, interacting and modulating local and systemic inflammatory and immune response, among others. Clinical trials and meta-analyses show that probiotics seem to contribute towards the prevention of acute diarrhea and of antibiotic-associated diarrhea, in addition to shortening the duration of acute diarrhea. However, the data are inconsistent and there are no studies confirming their efficacy in terms of cost-benefit ratio. Preliminary studies show that probiotics in early life can reduce the occurrence of atopic dermatitis. The addition of prebiotics to infant formulas is associated with the change in the profile of the intestinal microbiota compared to infants fed milk formulas without prebiotics. CONCLUSIONS: Evidence indicates that new studies should be carried out about probiotics, prebiotics and symbiotics. The specific clinical effects that each probiotic or prebiotic may cause must be considered.