GUT MICROFLORA HAVE TO BE MODERNLY CONSIDERED A - PowerPoint PPT Presentation

Loading...

PPT – GUT MICROFLORA HAVE TO BE MODERNLY CONSIDERED A PowerPoint presentation | free to view - id: 7ae796-ZTI2N



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

GUT MICROFLORA HAVE TO BE MODERNLY CONSIDERED A

Description:

GUT MICROFLORA HAVE TO BE MODERNLY CONSIDERED A MICROMIAL ORGAN PLACED WITHIN A HOST ORGAN. The intestinal habitat of an individual contains 300-500 different ... – PowerPoint PPT presentation

Number of Views:24
Avg rating:3.0/5.0
Slides: 21
Provided by: mcrf
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: GUT MICROFLORA HAVE TO BE MODERNLY CONSIDERED A


1
  • GUT MICROFLORA HAVE TO BE MODERNLY CONSIDERED A
    MICROMIAL ORGAN PLACED WITHIN A HOST ORGAN.

2
  • The intestinal habitat of an individual contains
    300-500 different species of bacteria, and the
    number of microbial cells within the gut lumen is
    about 10 times larger than the number of
    eukariotic cells in the human body. Bengmark S.
    Gut 1998
  • Gastric acid, bile and pancreatic secretion kill
    most ingested microorganisms.
  • The large intestine contains a complex and
    dynamic microbial ecosystem with high densities
    of living bacteria which achieve concentrations
    of up to 1012or 1013 cells/g of luminal contents.
    Simon GL. Gastroenterology 1984

3
Czarniecki M. J Med Chem 2008
4
(No Transcript)
5
  • A large proportion of the faecal mass consists of
    bacteria (around 60). Stephen AM, Cummings JH.
    J.Med.Microbiol.
  • Some of these bacteria are potential pathogens.
    However, the presence of bacterial competition
    and the constant interation between the host and
    its microbial guests can infer important health
    benefits to the human host. Salminen S et al. Br
    J Nutr1998.

6
  • COMPOSITION OF THE FLORA
  • -Colonization of the gastrointestinal tract
    starts immediately after birth, occurs within a
    few days, and it is linked to the type of
    delivery, the type of diet and environmental
    factors.
  • -Pioneer bacteria can modulate expression of
    genes in host epithelial cells, thus creating a
    favourable habitat for themselves, and can
    prevent growth of other bacteria in the
    ecosystem. The initial colonisation is therefore
    very relevant to the final composition of the
    permanent flora. Hooper LV et al. Science 2001
  • -Resident bacteria deliver regulatory signals to
    the epithelium and instruct mucosal immune
    response. Ohara AM. Sci World J 2007

7
  • Anaerobic bacteria outnumber aerobic bacteria by
    a factor of 100-1000. The genera bacterioides,
    bifidobacterium, eubacterium, clostridium,
    peptococcus,peptostreptococcus, and ruminococcus
    are predominant in human beings, whereas
    aerobes(facultative anaerobe) such as
    escherichia, enterobacter, enterococcus,
    klebsiella, lactobacillus, proteus, etc are among
    the subdominant genera. Salminen S. Br J Nutr
    1998
  • Every individual presents a particular
    combination of predominant species that is
    distinct from that found in other individuals.
  • Although bacterial composition can fluctuate
    under some circumstances (acute diarrhoeal
    illnesses, antibiotic treatment, dietary
    interventions), individuals flora composition
    pattern usually remain constant. Willson kh. Appl
    Environ Microbiol 1996

8
  • Several bacteria that can be seen by direct
    microscopic examination of diluted faecal
    specimens cannot be grown in culture media
    40-80 of total microscopic counts are not
    recoverable by culture, although estimates vary
    between individuals and between studies. Suau A
    et al. Appl Environ Microbiol 1999
  • Molecular biological procedures can now be used
    to investigate the microbial ecology in the
    colon. Many DNA sequences correspond to
    previously undescribed bacteria and data suggest
    that every individual has unique strains of
    bacteria. Tannock GW. Am J Clin Nutr 2001

9
  • LA METAGENOMICA E' UN APPROCCIO BASATO
    SULL'UTILIZZO DI
  • TECNICHE GENOMICHE MODERNE PER LO STUDIO DI
    COMUNITA'
  • MICROBICHE DIRETTAMENTE NEL LORO AMBIENTE
    NATURALE,
  • EVITANDO IL PRELIEVO E LA COLTURA IN LABORATORIO.
  • SI BASA SUL SEQUENZIAMENTO DEL GENOMA DI
    MICROORGANISMI
  • LA CUI ANALISI NEL LORO HABITAT NATURALE VIENE
    DEFINITA
  • METAGENOMA.
  • LA METAGENOMICA HA MESSO IN EVIDENZA UNA
    DIVERSITA'
  • SENZA PRECEDENTI NELLA COMPOSIZIONE DELLE
    COMUNITA' MICROBICHE CON UNA LARGHISSIMA
    PROPORZIONE DI NUOVI
  • GENI.

10
  • THE HUMAN GUT HOSTS MORE THAN 100 TRILLION
  • BACTERIA, WHICH TOGETHER MAKE UP THE GUT
    MICROBIOTA. THE GUT MICROBIOTA CO-EVOLVED WITH
    HUMANS TO ACHIEVE A SYMBIOTIC RELATIONSHIP
    LEADING TO PHYSIOLOGICAL HOMEOSTASIS.
  • THE HUMAN MICROBIOTA REMAINS GLOBALLY STABLE OVER
    TIME IN HEALTHY CONDITIONS AND ABSENCE OF
    PERTURBATION.
  • APPLICATION OF METAGENOMICS TO THIS THIS
    ENVIRONMENT MAY HELP IN DECIPHERING KEY FUNCTIONS
    AND KEY BACTERIA INVOLVED IN HEALTH AND DISEASE.

11
  • FAECAL BACTERIOTHERAPY
  • AN UNTHINKABLE APPROACH
  • Faecal bacteriotherapy has a longstanding history
    in animal health. In human beings it has been
    used in selected cases, especially as a treatment
    of last resort for patients with severe
    Clostridium difficile pseudomembranous colitis.

Schwan A, Sjölin S, Trottestam U, Aronsson B.
    Relapsing clostridium difficile
enterocolitis cured by rectal infusion of
homologous faeces. Lancet. 1983 Oct
82(8354)845.
Borody TJ, Warren EF, Leis SM, Surace R, Ashman
O, Siarakas S.     Bacteriotherapy using fecal
flora toying with human motions. J Clin
Gastroenterol. 2004 Jul38 Although it is
unthinkable that this approach will gain the
favour of the people, it could indicate that the
rectal infusion represents an alternative
physiological administration way of probiotics in
selected clinical conditions. Ricci N, Caselli M.
Rectal infusion of bacterial preparations for
intestinal disorders. Lancet 1983 ii1984-85
12
  • IN THE ERA OF METAGENOMICS FECAL TRANSPLANT AND
    SYNTHETIC MICROBIOME TRANSPLANT MIGHT BE VERY
    PROMISING THERAPIES FOR DYSBIOSIS-ASSOCIATED
    DISEASES.

13
  • FUTURE OF MICROBIOME STUDIES
  • NEED FOR STANDARDIZATION
  • NEED FOR LARGE PROSPECTIVE COHORTS
  • NEED FOR HOLISTIC APPROACH
  • NEED FOR AN ECOLOGICAL UNDERSTANDING

14
  • UNDERSTANDING CO-EVOLUTION OF THE MICROBIAL
    GENOMES AND HOST GENOME, FROM GEOGRAPHICALLY AND
    CULTURALLY DIVERSE POPULATIONS, WILL BE KEY FOR
    FUTURE STRATEGIC PREVENTIVE MEASURES THROUGHOUT
    THE LIFE-SPAN.

15
  • METABOLOMIC VIEW
  • METABOLOMIC APPROACHES, IN WHICH A LARGE NUMBER
    OF SMALL MOLECULE METABOLITES CAN BE DEFINED IN A
    BIOLOGICAL SAMPLE, OFFER A VERY PROMISING AND
    POWERFUL AVENUE TO FINGERPRINT MICROBIOTA
    FUNCTIONAL STATUS, WITH FUNCTIONAL
    CHARACTERIZATION OF THE INTESTINAL MICROBIOTA AND
    ITS INTERACTIONS WITH THE HOST.

16
  • WHAT IS MORE IMPORTANT IN INDUCING INFLAMMATORY
    AND CANCEROUS CHANGES?
  • - A GENERAL DESTRUCTURATION OF THE ECOSYSTEM
  • - SOME SPECIFIC BACTERIA

17
  • EXAMPLES OF EMERGIG SPECIFIC BACTERIA
  • -ENTEROTOXIGENIC BACTERIOIDES FRAGILIS
  • INVOLVED IN IBD AND COLORECTAL CANCER
  • -FUSOBACTERIA (NUCLEATUM, VARIUM, etc)
  • INVOLVED IN IBD AND COLORECTAL CANCER
  • -SEGMENTED FILAMENTOUS BACTERIA (SFB)
  • POSSIBLY INVOLVED IN AUTOIMMUNE DISEASES

18
(No Transcript)
19
(No Transcript)
20
  • PER CONOSCERE BENE LE COSE,
  • BISOGNA CONOSCERNE
  • I PARTICOLARI E SICCOME
  • QUESTI SONO INFINITI,
  • LE NOSTRE CONOSCENZE SONO
  • SEMPRE SUPERFICIALI ED
  • IMPERFETTE.
  • Francois de La
    Rochefoucauld, 1665
About PowerShow.com