השפעת חיידקים פרוביוטיים

Transcription

1 השפעת חיידקים פרוביוטיים החיים בחלל )המעי(... על רון שאול יחידת גסטרו ילדים מרכז רפואי רמב"ם

2 Introduction The intestinal microflora primarily in the large bowel consists mostly on benign bacterial species with advantageous effects. The growth and metabolism of these microorganism depends primarily on the substrates available to them, mostly from the host diet.

3 The human Flora Once established, bacterial enteric flora are fairly difficult to modify or change. Temporarily, flora may be modified negatively through the use of antibiotics, chemotherapy, radiation or positively through the introduction of desirable bacterial species (probiotics).

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5 Who and what Predominantly anaerobic microflora. What they can do for us salvage energy through bacterial fermentation of undigested carbohydrates and protein to short chain fatty acids, a substantial fuel to the colonocytes. Synthesize vitamins and possibly contributes to the economy of essential amino acids

6 What affects infant micro flora Delivery mode (vaginal vs. Cesarean delivery) Industrialized vs. developing countries Breast-fed vs. formula-fed Antibiotics in neonatal intensive care

7 Probiotics - Definition Probiotics are defined as microorganisms, which, when ingested, may have a positive effect in the prevention and treatment of a specific pathological condition Traditionally are of human origin These organisms are: non pathogenic and non toxigenic retain viability during storage survive passage through the stomach and small intestine.

8 Lactobacillus species TABLE 1 Microorganisms considered as probiotics Bifidobacterium species Other lactic acid bacteria Nonlactic acid bacteria L. acidophilus B. adolescentis Enterococcus faecalis 2 Bacillus cereus var. toyoi 2,3 L. amylovorus B. animalis Enterococcus faecium Escherichia coli strain nissle L. casei B. bifidum Lactococcus lactis 4 freudenreichii 2,3 Propionibacterium L. crispatus B. breve L. delbrueckii subsp. Bulgaricus 4 B. infantis L. gallinarum 2 B. longum L. gasseri L. johnsonii L. paracasei L. plantarum L. reuteri L. rhamnosus B. lactis 5 Sporolactobacillus inulinus 2 Leuconstoc mesenteroides Saccharomyces cerevisiae 3 Pediococcus acidilactici 4 Saccharomyces boulardii 3 Streptococcus thermophilus 4 2 Main application for animals. 3 Applied mainly as pharmaceutical preparations. 4 There is either little known about the probiotic properties or the microorganism is nonprobiotic. 5 Probably synonymous with B. animalis.

9 Probiotics may colonize mucosal surfaces outside of the gastrointestinal tract and confer health benefits at sites such as the oral cavity and the genitourinary tract after oral administration.

10 Prebiotics - Definition Prebiotics are non-digestible substances that, when ingested, selectively promote the growth and establishment of beneficial probiotic-like bacteria normally present in the gut. fructo-oligosaccharides (FOS) e.g. chicory or inulin Lacutulose Lactitol

11 Synobiotics Synbiotics = Prebiotics +Probiotic bacteria Potential advantages is survival for the probiotic bacteria Possible combinations: Bifidobacteria with fructo-oligosaccharides Lactobacilli with lactitol

12 Diarrhea Clinical Studies

13 PEDIATRICS Vol. 109 No. 4 April 2002, pp Lactobacillus Therapy for Acute Infectious Diarrhea in Children: A Meta-analysis Cornelius W. Van Niel, MD*, Chris Feudtner, MD, PhD, MPH, Michelle M. Garrison, MPH and Dimitri A. Christakis, MD, MPH

14 Van Niel: Lactobacillus Therapy for Acute Infectious Diarrhea in Children: A Meta-analysis Background and research question: Study sought to assess whether treatment with Lactobacillus improves clinical outcome in children with acute infectious diarrhea Outcome measure: Diarrhea intensity Duration (days of diarrhea) Frequency (number of stool per day) Amount (volume of diarrheal stool)

15 Van Niel: Lactobacillus Therapy for Acute Infectious Diarrhea in Children: A Meta-analysis Results Summary point estimates indicate: A reduction in diarrhea duration of 0.7 days (95% CI: days) A reduction in diarrhea frequency of 1.6 stools on day 2 of treatment (95% CI: fewer stools)

16 Fig 1. Diarrhea duration. Summary point estimate of reduction in diarrhea duration in 7 included studies that reported mean reduction and variance. Box size is proportional to the inverse of the magnitude of the study variance.

17 Fig 3. Dose-effect relationship between Lactobacillus dose and reduction in diarrhea duration in 8 included studies that reported diarrhea duration as an outcome. Cfu, colony-forming units.

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19 Prevention of diarrhea

20 Probiotics for treatment of diarrhea Supplementation of infant formula milk with B. bifidum and Streptococcus thermophilus reduced rotavirus shedding and episodes of diarrhea in hospitalised children. Saavedra JM et al. Lancet;1994;344;

21 Aim: To study the effect of a formula supplemented with Bifidobacterium bifidum or Lactobacillus reuteri, on infections in day care infants. Methods: prospective double-blind placebocontrolled trial, full-term healthy infants between 4 10 months of age, were randomly assigned to receive a formula supplemented with probiotics or placebo for 12 weeks.

22 Parameter Placebo B. bifidum L. reuteri p Number Febrile episodes 0.41± ± ± GI illness 0.31± ± ± Resp. Illness 0.24± ± ±

23 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 their study was to investigate the role of Lactobacillus GG (LGG) in preventing nosocomial gastrointestinal and respiratory tract infections at a pediatric hospital.

24 METHODS They conducted a randomized, double-blind, placebo controlled trial of 742 hospitalized children. They were randomly allocated to receive for their hospitalization LGG at a dose of 10 9 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).

25 RESULTS In the LGG group, they found a significantly reduced risk for gastrointestinal infections (relative risk [RR]: 0.40), respiratory tract infections (RR: 0.38); vomiting episodes (RR: 0.5) and diarrheal episodes (RR: 0.24). Groups did not differ in hospitalization duration.

26 CONCLUSIONS LGG administration can be recommended as a valid measure for decreasing the risk for nosocomial gastrointestinal and respiratory tract infections in pediatric facilities.

27 Antibiotic associated diarrhea

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29 RR 0.44

30 RR 0.43