Effect of dietary inclusion of Bacillus-based probiotics on performance, egg quality, and the faecal microbiota of laying hen.

OBJECTIVE: Our study examined the impact of propriety blends of Bacillus strain probiotics on the performance, egg quality, and faecal microflora of laying hens. METHODS: A total of 183 Institut de selection Animale (ISA) brown laying hens aged 23 weeks with an average body weight of 1,894±72 g were randomly allocated into 3 groups as control (corn-soybean meal based diet, CON), 0.5 g/kg Enterosure probiotics (ET1, 3×108 colony-forming unit [CFU]/kg feed), and 5 g/kg Enterosure probiotics (ET2, 3×109 CFU/kg feed) administered in mashed form. At the completion of each phase hen day egg production (HDEP), average egg weight (AEW), feed intake, and faecal microbiota were evaluated. RESULTS: HDEP and AEW were higher (p<0.05) in the ET2-supplemented diet in phase 3 (week 9 to 12) compared with CON. Egg mass (EM) was higher (p<0.05) in phase 2 at ET2, and also higher (p<0.05) in phase 3 at the ET1 and ET2-supplemented diets compared with CON. Feed conversion ratio was lower (p<0.05) in phase 3 at the ET1 and ET2-supplemented diets, with ET2 being the lowest compared with ET1 and CON. Yolk colour was higher (p<0.05) in the ET-supplemented diets at phase 3 compared with CON. Bifidobacterium spp. was higher (p<0.05) in the ET2- supplemented diet compared with CON in phase 2, while in In phase 3, Lactobacillus spp. and Bifidobacterium spp. were higher (p<0.05) in the ET-supplemented diets compared with CON. Coliforms were lower (p<0.05) in the ETsupplemented diets compared with CON in phase 3. CONCLUSION: The propriety blends of Bacillus strain probiotics supplements at 0.5 g/kg and 5 g/kg could improve the production and quality of eggs with more significance at 5 g/kg for HDEP, AEW and EM, which was achieved via the increase of beneficial microbiomes such as Lactobacillus spp., Bifidobacterium spp., and the decrease of pathogenic microbiomes like Escherichia coli and Coliforms which was speculated to improve gut barrier function and the reproductive hormone.

Supplemental Clostridium butyricum modulates skeletal muscle development and meat quality by shaping the gut microbiota of lambs.

This study evaluated the contributions of Clostridium butyricum on skeletal muscle development, gastrointestinal flora and meat quality of lambs. Eighteen Dorper (♂) × Small Tailed Han sheep (♀) crossed ewe lambs of similar weight (27.43 ± 1.94 kg; age, 88 ± 5 days) were divided into two dietary treatments. The control group was fed the basal diet (C group), and the probiotic group was supplemented with C. butyricum on the basis of the C group (2.5 × 108 cfu/g, 5 g/day/lamb; P group) for 90 d. The results showed that dietary C. butyricum elevated growth performance, muscle mass, muscle fiber diameter and cross-sectional area, and decreased the shear force value of meat (P < 0.05). Moreover, C. butyricum supplementation accelerated protein synthesis by regulating the gene expression of IGF-1/Akt/mTOR pathway. We identified 54 differentially expressed proteins that regulated skeletal muscle development through different mechanisms by quantitative proteomics. These proteins were associated with ubiquitin-protease, apoptosis, muscle structure, energy metabolism, heat shock, and oxidative stress. The metagenomics sequencing results showed that Petrimonas at the genus level and Prevotella brevis at the species level in the rumen, while Lachnoclostridium, Alloprevotella and Prevotella at the genus level in the feces, were significantly enriched in the P group. Also, butyric acid and valeric acid levels were elevated in both rumen and feces of the P group. Overall, our results support the idea that C. butyricum could change gastrointestinal flora, and affect skeletal muscle development and meat quality of lambs by modulating gut-muscle axis.

Progress of Research on Gastrointestinal Flora in Screening, Diagnosis and Prognosis of Esophageal Cancer / 胃肠病学

Esophageal cancer is a common and poorly prognostic cancer, and early screening and early diagnosis arc the keys to improve the prognosis of patients. In recent years, more and more studies have shown that changes in gastrointestinal flora are associated with the occurrence, progression, recurrence, metastasis and chemotherapy resistance of esophageal cancer. This article mainly reviewed the changes of gastrointestinal flora in esophageal cancer patients and the progress of research on gastrointestinal flora in the screening, diagnosis and prognosis of esophageal cancer.

Total Gastrointestinal Flora Transplantation in the Treatment of Leaky Gut Syndrome and Flora Loss.

Introduction The aim of this work was to treat patients with leaky gut syndrome (LGS) and gastrointestinal flora loss in a simple, inexpensive, permanent and effective way without the need for further treatment. Methods A total gastrointestinal flora transplantation (TGFT) procedure is performed by simultaneously transferring the "flora" taken from approximately 30 different anatomical sites, from the mouth to the anus, of healthy donors to the corresponding anatomical site of the patient using the endoscopic lavage method. Results Of the patients, 25 (44.6%) were female and 31 (55.4%) were male, totaling 56 (100%). The mean age was 32.88±15.78 years. Among the 56 patients enrolled in the study, TGFT had no efficacy in one patient, five patients underwent repeat TGFT during a mean follow-up period of 23.73±16.74 months, and the treatment was permanent in 50 patients; our success rate during the follow-up period was 89.3%. Conclusion In LGS, TGFT should be the gold standard treatment.

Impact of intestinal dysbiosis on breast cancer metastasis and progression.

Breast cancer has a high mortality rate among malignant tumors, with metastases identified as the main cause of the high mortality. Dysbiosis of the gut microbiota has become a key factor in the development, treatment, and prognosis of breast cancer. The many microorganisms that make up the gut flora have a symbiotic relationship with their host and, through the regulation of host immune responses and metabolic pathways, are involved in important physiologic activities in the human body, posing a significant risk to health. In this review, we build on the interactions between breast tissue (including tumor tissue, tissue adjacent to the tumor, and samples from healthy women) and the microbiota, then explore factors associated with metastatic breast cancer and dysbiosis of the gut flora from multiple perspectives, including enterotoxigenic Bacteroides fragilis, antibiotic use, changes in gut microbial metabolites, changes in the balance of the probiotic environment and diet. These factors highlight the existence of a complex relationship between host-breast cancer progression-gut flora. Suggesting that gut flora dysbiosis may be a host-intrinsic factor affecting breast cancer metastasis and progression not only informs our understanding of the role of microbiota dysbiosis in breast cancer development and metastasis, but also the importance of balancing gut flora dysbiosis and clinical practice.

Multiple Hepatic Abscesses Secondary to Streptococcus anginosus Infection: A Case Report and Review of the Literature.

Hepatic abscesses are rare and generally present as solitary lesions in immunocompromised patients. The development of multiple hepatic abscesses in an immunocompetent patient is relatively uncommon. We report a rare case of a 73-year-old woman who presented with fever and right upper quadrant abdominal tenderness. Laboratory findings were significant for leukocytosis, transaminitis, and elevated inflammatory markers. Peripheral blood culture grew Streptococcus anginosus. Computed tomography of the abdomen and pelvis (CT A/P) revealed multiple hypoattenuating ill-defined cystic lesions in the liver consistent with abscesses formation; this was confirmed by magnetic resonance cholangiopancreatography (MRCP). The patient underwent appropriate treatment with antibiotics. Upon a three-week follow-up, the patient's symptoms subsided, and her laboratory parameters normalized. Although Streptococcus anginosus is a normal gastrointestinal flora, it has the potential to form abscesses. Our report indicates the importance of considering Streptococcus anginosus in the differential diagnosis. Management includes four to six weeks of antibiotic therapy together with drainage of larger abscesses.

Gut microbiota: The key to the treatment of metabolic syndrome in traditional Chinese medicine - a case study of diabetes and nonalcoholic fatty liver disease.

Metabolic syndrome mainly includes obesity, type 2 diabetes (T2DM), alcoholic fatty liver (NAFLD) and cardiovascular diseases. According to the ancient experience philosophy of Yin-Yang, monarch-minister compatibility of traditional Chinese medicine, prescription is given to treat diseases, which has the advantages of small toxic and side effects and quick effect. However, due to the diversity of traditional Chinese medicine ingredients and doubts about the treatment theory of traditional Chinese medicine, the mechanism of traditional Chinese medicine is still in doubt. Gastrointestinal tract is an important part of human environment, and participates in the occurrence and development of diseases. In recent years, more and more TCM researches have made intestinal microbiome a new frontier for understanding and treating diseases. Clinically, nonalcoholic fatty liver disease (NAFLD) and diabetes mellitus (DM) often co-occur. Our aim is to explain the mechanism of interaction between gastrointestinal microbiome and traditional Chinese medicine (TCM) or traditional Chinese medicine formula to treat DM and NAFLD. Traditional Chinese medicine may treat these two diseases by influencing the composition of intestinal microorganisms, regulating the metabolism of intestinal microorganisms and transforming Chinese medicinal compounds.

Role of Gut Microbiome in Cardiovascular Events: A Systematic Review.

The gut microbiome helps maintain homeostasis in the body, but what if the gut experiences imbalance? It would lead to dysbiosis - which is involved in multiple diseases, including but not limited to cardiovascular diseases, the most common cause of mortality around the globe. This research paper aims to explain all the possible mechanisms known linking the gut microbiome to the contribution of worsening cardiovascular events. PubMed and Google Scholar were thoroughly explored to learn the role of the gut microbiome in cardiovascular events. A systematic review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to analyze the possible pathways and the metabolites included in the study. Thirteen review articles were selected based on the assessment of multiple systematic reviews (AMSTAR) and the scale for the assessment of non-systematic review articles (SANRA) checklist scores. In this article, we have discussed the role of the gut microbiome in atherosclerosis, hypertension, metabolic disorders such as diabetes and obesity, coronary artery disease, etc. Various pathways to modify the gut microbiome are also discussed, along with the use of probiotics. Finally, we discussed the role of trimethylamine N-oxide (TMAO), a gut microbiome metabolite, as a biomarker for the prognosis of various diseases. This study concluded that the gut microbiome does play a crucial role in the worsening of cardiovascular diseases and the metabolites of which can be used as biomarkers in the prognosis of cardiovascular events.

Galectin-3 as a Therapeutic Target for NSAID-Induced Intestinal Ulcers.

Non-steroidal anti-inflammatory drugs (NSAIDs) induce ulcers in the gastrointestinal tract, including the stomach and small intestine. NSAID-induced gastric ulcers can be prevented by taking acid-neutralizing/inhibitory drugs and cytoprotective agents. In contrast, there are no medicines to control NSAID-induced small intestinal ulcers, which are accompanied by a mucosal invasion of bacteria and subsequent activation of immune cells. Galectin-3 (Gal3), an endogenous lectin, has anti-microbial and pro-inflammatory functions. In the small intestine, since Gal3 is highly expressed in epithelial cells constitutively and macrophages inducibly, the Gal3 level can affect microbiota composition and macrophage activation. We hypothesized that the modulation of Gal3 expression could be beneficial in NSAID-induced intestinal ulcers. Using Gal3 knockout (Gal3KO) mice, we determined whether Gal3 could be a therapeutic target in NSAID-induced intestinal ulcers. Following the administration of indomethacin, an NSAID, we found that small intestinal ulcers were less severe in Gal3KO mice than in wild-type (WT) mice. We also found that the composition of intestinal microbiota was different between WT and Gal3KO mice and that bactericidal antibiotic polymyxin B treatment significantly suppressed NSAID-induced ulcers. Furthermore, clodronate, a macrophage modulator, attenuated NSAID-induced ulcers. Therefore, Gal3 could be an exacerbating factor in NSAID-induced intestinal ulcers by affecting the intestinal microbiota population and macrophage activity. Inhibition of Gal3 may be a therapeutic strategy in NSAID-induced intestinal ulcers. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT03832946.

Ventilator-associated pneumonia: The central role of transcolonization.

Ventilator-associated pneumonia remain frequent and serious diseases since they are associated with considerable crude mortality. Pathophysiology is centered on modifications of regional bacterial flora, especially tracheobronchial tree and oropharyngeal sphere. Bacterial migration from an anatomical area to another seems to be the main explanation of these alterations which are called "transcolonization". The association of transcolonization and lack of tightness of the endotracheal tube cuff provides a direct pathway for bacteria from the upper to the subglottic airways, eventually leading to ventilator-associated pneumonia. Although modification of bacterial flora has been largely studied, the mechanism which underlays the ability of the implantation, growing and interactions with the local microbiome that leads to the observed transcolonization remains to be more clearly deciphered. The aim of our review is to emphasize the cornerstone importance of the "transcolonization" as a nosological entity playing a central role in ventilator-associated pneumonia.

Relationship between gastrointestinal flora and gastrointestinal neoplasms / 国际外科学杂志

The gastrointestinal flora is composed of a large number of microorganisms with complex structure,which participates in the process of decomposition,digestion and absorption of nutrients,promotes the development of the body's immune system,inhibits the colonization of pathogenic bacteria,and affects the health and disease of the body.In recent years,with the advancement of sequencing technology,the relationship between gastrointestinal flora and gastrointestinal neoplasms has became a research hotspot.This article reviews the carcinogenic pathways of the gastrointestinal flora and the possible carcinogenic mechanisms of the gastrointestinal flora.

The longitudinal effect of a multi-strain probiotic on the intestinal bacterial microbiota of neonatal foals.

REASONS FOR PERFORMING THE STUDY: The microbiota plays a key role in health and disease. Probiotics are a potential way to therapeutically modify the intestinal microbiota and prevent disease. OBJECTIVES: The aim of this study was to investigate the effects of probiotics on the bacterial microbiota of foals during and after administration. STUDY DESIGN: Randomised placebo controlled field trial. METHODS: Thirty-eight healthy neonatal foals enrolled in a previous study were selected. The foals had received a multi-strain probiotic (four Lactobacillus spp. 3-4 × 103 colony-forming units (cfu)/g each, Bifidobacterium animalis spp. lactis, 1 × 103-4 cfu/g) or placebo once daily for 3 weeks. A total of 3 faecal samples were collected from each foal at 2-week intervals and assessed via metagenomic sequencing. The Wilcoxon test was used to compare data between treatment groups. RESULTS: There were no changes on the phylum, order or class level between treatment groups at any age (all P>0.05) but some significant changes in relative abundance of families. Probiotic administration did not result in an increased relative abundance of lactobacilli or bifidobacteria at any age (Lactobacillus: P = 0.9, P = 0.1 and P = 0.2, Bifidobacterium: P = 0.3, P = 0.6 and P = 0.1 for Weeks 2, 4 and 6, respectively). Lactobacillus was enriched in the probiotic group at Week 6 on LEfSe analysis (linear discriminant analysis score 0.34, P = 0 .02). There was no effect on alpha diversity (all P>0.2) or community structure when parsimony and unifrac analysis were applied (all P>0.6). CONCLUSIONS: There were limited effects of probiotic treatment on the bacterial microbiota of foals. The studied probiotic based on lactobacilli and bifidobacteria has a limited potential for therapeutic modification of the gastrointestinal microbiota.

Effects of transport, fasting and anaesthesia on the faecal microbiota of healthy adult horses.

REASONS FOR PERFORMING STUDY: The intestinal microbiota is important for health and disease. Factors that disturb the equine intestinal microbiota need further investigation. OBJECTIVES: To determine the effects of transport, fasting and anaesthesia on the faecal microbiota of healthy adult horses using next-generation sequencing. STUDY DESIGN: Experimental trial. METHODS: Faecal samples were taken from 8 horses at baseline, after transport, 12 h of fasting and 24, 48 and 72 h after a 6 h anaesthesia. Next generation sequencing of the V4 region of the 16S rRNA gene was used to assess the microbial composition of faeces. Alpha diversity, phylogenetic structures and beta diversity were assessed. RESULTS: There were significant changes in the relative abundances of phyla, classes, orders and families after transport, fasting and anaesthesia. Most notably horses had a significantly lower abundance of Clostridiales after transport compared with baseline (P = 0.03) and a decreased abundance of Rickettsiales after fasting (P = 0.024). Alpha diversity was not significantly different between time points (all P>0.21). When parsimony analysis was applied, anaesthesia had a significant effect on community membership and structure (Jaccard index and Yue and Clayton index both P = 0.02). CONCLUSIONS: There was some effect of transport, fasting and anaesthesia on the composition and structure of the microbiota of healthy horses. This indicates these are potentially stress factors for the equine intestinal microbiota. Further investigation is required to look at the potential impact of changes in the microbiota on the development of disease in the post anaesthetic period.

Probiotic and lactulose: influence on gastrointestinal flora and pH value in minimal hepatic encephalopathy rats.

AIM: The present study was conducted to investigate the influence on gastrointestinal flora, counts of bifidobacteria and Enterobacterceae in colon and pH value of gastrointestinal after lactulose and probiotic treatment on rat experimental minimal hepatic encephalopathy (MHE) induced by thioactamide (TAA). METHODS: MHE was induced by intraperitoneal injection of TAA. 48 male MHE models were then randomly divided into 4 groups: control group (n = 12); MHE group (n = 12) received tap water ad libitum only; lactulose group (n = 12) and probiotics group (n = 12) gavaged respectively with 8 ml/kg of lactulose and 1.5 g/kg of probiotic preparation Golden Bifid (highly concentrated combination probiotic) dissolved in 2 ml of normal saline, once a day for 8 days. The latency of Brainstem auditory evoked potentials (BAEP) I was used as objective index of MHE. Counts of gastrointestinal flora, counts of bifidobacteria and Enterobacterceae in colon and pH value of gastrointestinal were examined respectively. RESULTS: Compared to MHE group, counts of gastrointestinal flora has greatly decreased, ratio of bifidobacteria and Enterobacterceae has greatly increased, pH value of colon has greatly descended (P < 0.05). However, there was no significant difference between lactulose group and probiotic group (P > 0.05). Both lactulose and probiotics can effectively prevent bacteria translocation and overgrowth, intensify CR, improved value of B/E, and acidify intestinal, decreased pH value of colon. CONCLUSION: Probiotic compound Golden Bifid is as useful as lactulose for the prevention and treatment of MHE. Probiotic therapy may be a safe, natural, well-tolerated therapy appropriate for the long-term treatment of MHE.

Metagenomic analysis of the impact of nitrofurantoin treatment on the human faecal microbiota.

OBJECTIVES: The objective was to study changes in the faecal microbiota of patients with uncomplicated urinary tract infections (UTIs) treated with nitrofurantoin and of non-treated healthy controls using 16S rRNA analysis. METHODS: Serial stool samples were collected from patients receiving nitrofurantoin treatment at different timepoints [before treatment (day 1; T1), within 48 h of end of treatment (days 5-15; T2) and 28 days after treatment (days 31-43; T3)], as well as from healthy controls. Direct DNA extraction (PowerSoil DNA Isolation Kit, MoBio Laboratories, Carlsbad, CA, USA) from stool samples was followed by pyrosequencing (454 GS FLX Titanium) of the V3-V5 region of the bacterial 16S rRNA gene. RESULTS: Among UTI patients, mean proportions of the Actinobacteria phylum increased by 19.6% in the first follow-up sample (T2) in comparison with the pretreatment baseline stool sample (T1) (P = 0.026). However, proportions of Actinobacteria reversed to 'normal' pre-antibiotic levels, with a mean difference of 1.0% compared with baseline proportions, in the second follow-up sample (T3). The increase in Actinobacteria was specifically due to an increase in the Bifidobacteriaceae family (Bifidobacterium genus), which constituted 81.0% (95% CI ±7.4%) of this phylum. CONCLUSIONS: No significant impact was observed other than a temporary increase in the beneficial Bifidobacterium genus following nitrofurantoin treatment, which supports its reintroduction into clinical use.

Effect of cefovecin on the fecal flora of healthy dogs.

Cefovecin is an extended-spectrum long-acting third generation cephalosporin used to treat canine infections. The study objective was to determine the effect of cefovecin on the absolute number and antimicrobial susceptibility of fecal enteric bacteria in healthy dogs. Fourteen Beagles were randomly assigned to a treated (n=7, 8 mg/kg cefovecin subcutaneously on day 1) or untreated (n=7) group. LC/MS was used to determine plasma cefovecin concentration on day 14. E. coli, enterococci, and Salmonella were isolated and enumerated from fecal samples collected on days 0, 3, 7, 14, and 28. Antimicrobial resistance was determined using disc diffusion, MIC, and detected using PCR for the blaCMY-2 gene on select isolates. Mean plasma concentration of cefovecin on day 14 was 9.59 µg/mL in treated dogs; untreated dogs had no measurable plasma cefovecin. The absolute number of E. coli was lower in treated dogs on day 3 (P ≤ 0.0001), and the absolute number of cefovecin-resistant E. coli was higher in treated dogs on days 7 (P=0.002), 14 (P=0.004) and 28 (P ≤ 0.0001), compared to untreated dogs. Enterococci increased and were higher in the treatment group on day 7 (P=0.0226). Isolation of Salmonella was rare. After cefovecin treatment, beta-lactam resistance was more common in fecal E. coli from treated dogs than untreated dogs, while resistance of enterococci was not altered. On day 28, treated dogs were 3.25 times more likely to carry the blaCMY-2 gene than untreated dogs (95% CI 1.27 - 8.35). The implications of these findings in clinically ill patients require further research.

Colitis y trasplante de microflora intestinal: ¿cuándo plantearlo? / Colitis and fecal microbiota transplantation: who benefits?

The gastrointestinal microbiota acts as a metabolic organ that provides enzymatic pathways, contributes to the development and maintenance of local and systemic lymphoid organs, regulates the homeostasis of the intestinal epithelial barrier, modulates the systemic inflammatory and metabolic processes and activates the immune system, providing protection against bacterial and viral agents. Clostridium difficile diarrhea is the leading cause of nosocomial diarrhea with high morbidity and mortality rates. This occurs, among other causes, due to dysbiosis. Fecal microflora transplantation is an option, particularly in recurrent episodes. There are case reports on fecal microflora transplantation used for the treatment of inflammatory bowel disease, with promising results.

La microbiota gastrointestinal funciona como un órgano metabólico que provee de rutas enzimáticas no presentes en nuestro organismo; contribuye al desarrollo y mantenimiento de órganos linfoides locales y sistémicos, a la homeostasis de la barrera epitelial intestinal; modula los procesos inflamatorios sistémicos y metabólicos y activa el sistema inmunológico sitémico, brindando protección frente agresiones bacterianas y virales. La diarrea por Clostridium difficile es la principal causa de diarrea intrahospitalaria con una alta morbilidad y mortalidad. Esta se produce entre otras causas por una disbiosis. El trasplante de microflora fecal ha demostrado ser una opción terapéutica eficaz, especialmente en los episodios recurrentes. Existen reportes de casos con resultados promisorios en que se utiliza el trasplante de microflora fecal para el tratamiento de enfermedad inflamatoria intestinal crónica.

Probióticos e prebióticos na prevenção e no tratamento de doenças em lactentes e crianças / Probiotics and prebiotics in prevention and treatment of diseases in infants and children

OBJETIVO: Avaliar o impacto do uso de probióticos e prebióticos na saúde das crianças. FONTES DOS DADOS: Foram pesquisados os bancos de dados MEDLINE e LILACS, selecionando-se artigos relevantes em inglês e francês. SÍNTESE DOS DADOS: O leite humano é rico em oligossacarídeos prebióticos e pode conter probióticos. Não existem dados sugerindo que a adição de probióticos a fórmulas para lactentes possa ser prejudicial, mas as evidências de sua eficácia são insuficientes para que seja recomendada. Visto que dados sugerem que a adição de oligossacarídeos prebióticos específicos pode reduzir infecções e atopia em lactentes saudáveis, sua adição parece razoável. Os benefícios a longo prazo dos pro e prebióticos para o sistema imunológico em desenvolvimento ainda precisam ser comprovados. Probióticos selecionados reduzem a duração da diarreia infecciosa em 1 dia, mas faltam evidências quanto à prevenção, exceto na diarreia associada a antibióticos. Alguns probióticos específicos previnem a enterocolite necrosante, e outros micro-organismos podem ser benéficos nos casos de gastrite por Helicobacter pylori e de cólica do lactente. Não há evidências suficientes para recomendar o uso de probióticos na prevenção e no tratamento da dermatite atópica. A utilização de probióticos nos casos de constipação, síndrome do intestino irritável, doença inflamatória intestinal e infecções extraintestinais requer mais estudos. CONCLUSÕES: A duração da administração, a dosagem microbiana e as espécies utilizadas necessitam de maior validação, tanto para probióticos quanto para prebióticos. Alegações de saúde injustificadas são uma grande ameaça ao conceito de pro e prebióticos.

OBJECTIVE: To evaluate the impact of probiotics and prebiotics on the health of children. SOURCES: MEDLINE and LILACS were searched for relevant English and French-language articles. SUMMARY OF THE FINDINGS: Human milk is rich in prebiotic oligosaccharides and may contain some probiotics. No data suggest that addition of probiotics to infant formula may be harmful, but evidence of its efficacy is insufficient for its recommendation. Since data suggest that addition of specific prebiotic oligosaccharides may reduce infections and atopy in healthy infants, their addition to infant formula seems reasonable. Long-term health benefits of pro- and prebiotics on the developing immune system remain to be proven. Selected probiotics reduce the duration of infectious diarrhea by 1 day, but evidence in prevention is lacking, except in antibiotic-associated diarrhea. Some specific probiotics prevent necrotizing enterocolitis, and other microorganisms may be beneficial in Helicobacter pylori gastritis and in infantile colic. Evidence is insufficient to recommend probiotics in prevention and treatment of atopic dermatitis. The use of probiotics in constipation, irritable bowel syndrome, inflammatory bowel disease, and extra-intestinal infections requires more studies. CONCLUSIONS: Duration of administration, microbial dosage, and species used need further validation for both pro- and prebiotics. Unjustified health claims are a major threat for the pro- and prebiotic concept.