***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    ***EXAMPLES*** 
    Input: BACKGROUND Probiotics have a possible role in the treatment of pediatric acute gastroenteritis . We report the effect of the probiotic Lactobacillus rhamnosus GG ( LGG ) on intestinal function , immune response , and clinical outcomes in Indian children with cryptosporidial or rotavirus diarrhea . METHODS Children with gastroenteritis aged 6 months to 5 years , testing positive for either rotavirus or Cryptosporidium species in stool ( coinfections were excluded ) , were r and omized to LGG ( ATCC 53103 ) or placebo , once daily for 4 weeks . Baseline demographic and clinical details were obtained . Sera were tested for immunoglobulin G ( IgG ) and immunoglobulin A ( IgA ) antibodies to Cryptosporidium and rotavirus , and the lactulose to mannitol ratio for intestinal permeability was determined at baseline and at the end of follow-up . RESULTS Of the 124 children enrolled , 82 and 42 had rotavirus and cryptosporidial diarrhea , respectively . Median diarrheal duration was 4 days ; one-third of the children had severe diarrhea . Baseline and clinical parameters were comparable between children receiving LGG and placebo . At the end of follow-up , fewer children with rotavirus diarrhea on LGG had repeated diarrheal episodes ( 25 % vs 46 % ; P = .048 ) and impaired intestinal function ( 48 % vs 72 % ; P = .027 ) . Significant increase in IgG levels postintervention ( 456 vs 2215 EU ; P = .003 ) was observed in children with rotavirus diarrhea receiving LGG . Among children with cryptosporidial diarrhea , those receiving LGG showed significant improvement in intestinal permeability . CONCLUSIONS LGG has a positive immunomodulatory effect and may be useful in decreasing repeated episodes of rotavirus diarrhea . Improvement in intestinal function in children with rotavirus and cryptosporidial gastroenteritis emphasizes the role of probiotics in treating intestinal impairment after infection . CLINICAL TRIALS REGISTRATION CTRI/2010/091/000339 BACKGROUND The aim of the present study was to investigate the effect of a probiotic beverage on gastrointestinal symptoms in patients with chronic constipation . METHODS A double-blind , placebo-controlled , r and omized study was conducted over a four-week period in patients with symptoms of chronic constipation ( n=70 ) . To all patients , 65 mL/day of a probiotic beverage containing Lactobacillus casei Shirota ( LcS ) or a sensorially identical placebo was administered . Patients completed a question naire on gastrointestinal symptoms , well-being and stool habits and underwent a medical examination weekly . Severity of constipation , flatulence and bloating was summarized into four categories ( severe , moderately severe , mild and no symptoms ) . RESULTS The consumption of LcS result ed in a significant improvement in self-reported severity of constipation and stool consistency , starting in the second week of the intervention phase ( P<0.0001 ) . Severe and moderately severe constipation was observed less in the LcS group . The occurrence and degree of flatulence or bloating sensation did not change . In the final examination , 89 % of the LcS group and 56 % of the placebo group showed a positive effect of their beverage on constipation ( P=0.003 ) . No adverse reactions were reported . CONCLUSIONS The results indicate a beneficial effect on gastrointestinal symptoms of patients with chronic constipation . The administration of probiotic foodstuffs may be recommended as an adjunctive therapy of chronic constipation RATIONALE Enteral administration of probiotics may modify the gastrointestinal environment in a manner that preferentially favors the growth of minimally virulent species . It is unknown whether probiotic modification of the upper aerodigestive flora can reduce nosocomial infections . OBJECTIVES To determine whether oropharyngeal and gastric administration of Lactobacillus rhamnosus GG can reduce the incidence of ventilator-associated pneumonia ( VAP ) . METHODS We performed a prospect i ve , r and omized , double-blind , placebo-controlled trial of 146 mechanically ventilated patients at high risk of developing VAP . Patients were r and omly assigned to receive enteral probiotics ( n = 68 ) or an inert inulin-based placebo ( n = 70 ) twice a day in addition to routine care . MEASUREMENTS AND MAIN RESULTS Patients treated with Lactobacillus were significantly less likely to develop microbiologically confirmed VAP compared with patients treated with placebo ( 40.0 vs. 19.1 % ; P = 0.007 ) . Although patients treated with probiotics had significantly less Clostridium difficile-associated diarrhea than patients treated with placebo ( 18.6 vs. 5.8 % ; P = 0.02 ) , the duration of diarrhea per episode was not different between groups ( 13.2 ± 7.4 vs. 9.8 ± 4.9 d ; P = 0.39 ) . Patients treated with probiotics had fewer days of antibiotics prescribed for VAP ( 8.6 ± 10.3 vs. 5.6 ± 7.8 d ; P = 0.05 ) and for C. difficile-associated diarrhea ( 2.1 ± 4.8 SD d vs. 0.5 ± 2.3 d ; P = 0.02 ) . No adverse events related to probiotic administration were identified . CONCLUSIONS These pilot data suggest that L. rhamnosus GG is safe and efficacious in preventing VAP in a select , high-risk ICU population . Clinical trial registered with www . clinical trials.gov ( NCT00613795 ) Background Simple and safe strategies for the prevention of viral respiratory tract infections ( RTIs )  are needed . Objective We hypothesized that early prebiotic or probiotic supplementation would reduce the risk of virus-associated RTIs during the first year of life in a cohort of preterm infants . Methods In this r and omized , double-blind , placebo-controlled trial ( Clinical Trials.gov no. NCT00167700 ) , 94 preterm infants ( gestational age , ≥32 + 0 and ≤36 + 6 weeks ; birth weight , > 1500 g ) treated at Turku University Hospital , Turku , Finl and , were allocated to receive oral prebiotics ( galacto-oligosaccharide and polydextrose mixture , 1:1 ) , a probiotic ( Lactobacillus rhamnosus GG , ATCC 53103 ) , or placebo ( microcrystalline cellulose ) between days 3 and 60 of life . The primary outcome was the incidence of clinical ly defined virus-associated RTI episodes confirmed from nasal swabs by using nucleic acid testing . Secondary outcomes were the severity and duration of RTIs . Results A significantly lower incidence of RTIs was detected in infants receiving prebiotics  ( rate ratio [ RR ] , 0.24 ; 95 % CI , 0.12 - 0.49 ; P < .001 ) or probiotics ( RR , 0.50 ; 95 % CI , 0.28 - 0.90 ; P = .022 ) compared with those receiving placebo . Also , the incidence of rhinovirus-induced episodes , which comprised 80 % of all RTI episodes , was found to be significantly lower in the prebiotic ( RR , 0.31 ; 95 % CI , 0.14 - 0.66 ; P = .003 ) and probiotic ( RR , 0.49 ; 95 % CI , 0.24 - 1.00 ; P = .051 ) groups compared with the placebo group . No differences emerged among the study groups in rhinovirus RNA load during infections , duration of rhinovirus RNA shedding , duration or severity of rhinovirus infections , or occurrence of rhinovirus RNA in asymptomatic infants . Conclusions Gut microbiota modification with specific prebiotics and probiotics might offer a novel and cost-effective means to reduce the risk of rhinovirus infections Background Recent review s suggest common infectious diseases continue to be a major cause of death among preschool children in developing countries . Identification of feasible strategies to combat this disease burden is an important public health need . We evaluated the efficacy of adding prebiotic oligosaccharide and probiotic Bifidobacterium lactis HN019 to milk , in preventing diarrhea , respiratory infections and severe illnesses , in children aged 1–4 years as part of a four group study design , running two studies simultaneously . Methods and Findings In a community based double-masked , r and omized controlled trial , children 1–3 years of age , willing to participate , were r and omly allocated to receive either control milk ( Co ; n = 312 ) or the same milk fortified with 2.4 g/day of prebiotic oligosaccharide and 1.9 × 107 colony forming unit (c.f.u)/day of probiotic Bifidobacterium lactis HN019 ( PP ; n = 312 ) . Children were followed up for 1 year providing data for 1–4 years . Biweekly household surveillance was conducted to gather information on compliance and morbidity . Both study groups were comparable at baseline ; compliance to intervention was similar . Overall , there was no effect of prebiotic and probiotic on diarrhea ( 6 % reduction , 95 % Confidence Interval [ CI ] : −1 to 12 % ; p = 0.08 ) . Incidence of dysentery episodes was reduced by 21 % ( 95 % CI : 0 to 38 % ; p = 0.05 ) . Incidence of pneumonia was reduced by 24 % ( 95 % CI : 0 to 42 % ; p = 0.05 ) and severe acute lower respiratory infection ( ALRI ) by 35 % ( 95 % CI : 0 to 58 % ; p = 0.05 ) . Compared to children in Co group , children in PP group had 16 % ( 95 % CI : 5 to 26 % , p = 0.004 ) and 5 % ( 95 % CI : 0 to 10 % ; p = 0.05 ) reduction in days with severe illness and high fever respectively . Conclusions / Significance Milk can be a good medium for delivery of prebiotic and probiotic and result ed in significant reduction of dysentery , respiratory morbidity and febrile illness . Overall , impact of diarrhea was not significant . These findings need confirmation in other setting s. Trial Registration Clinical Trials.gov Intestinal luminal microbiota likely contribute to the etiology of necrotizing enterocolitis ( NEC ) , a common disease in preterm infants . Microbiota development , a cascade of initial colonization events leading to the establishment of a diverse commensal microbiota , can now be studied in preterm infants using powerful molecular tools . Starting with the first stool and continuing until discharge , weekly stool specimens were collected prospect ively from infants with gestational ages ≤32 completed weeks or birth weights≤1250 g.  High throughput 16S rRNA sequencing was used to compare the diversity of microbiota and the prevalence of specific bacterial signatures in nine NEC infants and in nine matched controls . After removal of short and low quality reads we retained a total of 110,021 sequences . Microbiota composition differed in the matched sample s collected 1 week but not < 72 hours prior to NEC diagnosis . We detected a bloom ( 34 % increase ) of Proteobacteria and a decrease ( 32 % ) in Firmicutes in NEC cases between the 1 week and < 72 hour sample s. No significant change was identified in the controls . At both time points , molecular signatures were identified that were increased in NEC cases . One of the bacterial signatures detected more frequently in NEC cases ( p<0.01 ) matched closest to γ-Proteobacteria . Although this sequence grouped to the well-studied Enterobacteriaceae family , it did not match any sequence in Genbank by more than 97 % . Our observations suggest that abnormal patterns of microbiota and potentially a novel pathogen contribute to the etiology of NEC OBJECTIVE : The incidence of nosocomial infections , predominantly gastrointestinal and respiratory , in children in developed countries is high , ranging from 5 % to 44 % . There is no effective strategy for preventing these infections . The objective of our study was to investigate the role of Lactobacillus GG ( LGG ) in preventing nosocomial gastrointestinal and respiratory tract infections at a pediatric hospital . METHODS : We conducted a r and omized , double-blind , placebo-controlled trial of 742 hospitalized children . They were r and omly allocated to receive for their hospitalization LGG at a dose of 109 colony-forming units in 100 mL of a fermented milk product ( LGG group , n = 376 ) or placebo that was the same postpasteurized fermented milk product without LGG ( placebo group , n = 366 ) . RESULTS : In the LGG group , compared with the placebo group , we found a significantly reduced risk for g 
    Output:
    
Probiotics act through diverse mechanisms positively affecting the composition and /or function of the commensal microbiota and alter host immunological responses .
Well-controlled intervention trials , systematic review s , and meta- analysis provide convincing evidence for the benefit of  probiotics  in prevention and treatment of gastrointestinal as well as extraintestinal disorders