Human Microbiome - Gut Microbiota
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Transcript of Human Microbiome - Gut Microbiota
GUT MIROBIOTA
GUT MICROBIOTAThe Human Bacteria
The very quest of Human Being is not targeted to Economic Progress, nor it is to achieve DEIFORM GLORY, but to reflect upon a simple question. Who are we?
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Humans as micro biomes:-- 100 trillion microbes in human intestine. 3 million genes (100X). 2 kg weight. 300-1000 species of bacteria. control almost all body functions.
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COMPOSITION
99 % from 30 40 species.
4 dominant phyla : - Bacteriodetes. - Fermicutes. - Actinobacteria. - Proteobacteria.
Enterotypes : - Prevotella. - Bacteroides. - Ruminococcus.
Variation of Gut Micro biota : - Dependence on Age - Dependence on Geography - Dependence on Diet
Variation with Age
Variation with Diet
Acquisition Of Micro Biota
The 1st week bacteria create a reducing environment.
Strict anaerobic species genera : Bifidobacterium, Bacteroides, Clostridium, and Ruminococcus.
Breast-fed babies : BifidobacteriaFormula-fed infants : Enterobacteriaceae, Enterococci, Bifidobacteria, Bacteroides, and Clostridia.
Immune inactivation in early age.
FUNCTIONS
NUTRITION30% more calories.Short-Chain Fatty Acids (SCFAs)SACCHAROLYTIC FERMENTATIONAcetic acid, Propionic acid and Butyric acid.SCFAs in the caecum. Intestinal SCFAs directly provide energy to colonocytes, absorption into the portal circulation, stimulates adipogenesis.PROTEOLYTIC FERMENTATION Collagen and ElastinToxins, Carcinogens, SCFAs
TROPHIC EFFECTSGrowth of intestinal epithelial cells, lymphoid tissue and control their proliferation and differentiationSodium/Glucose transporters
METABOLISMPositively control the intestinal epithelial cell differentiation , proliferation by production of Short-Chain Fatty Acids.Syntheses of vitamins like Biotin and Folic AcidAbsorption of ions including Magnesium, Calcium and Iron.Metabolize dietary carcinogens - Micro components & Macro componentsMicro - Genotoxic , Heterocyclic Amines (HCAs) Macro - Excessive intake of Fat and Sodium Chloride
IMMUNITYOral ToleranceImmune Exclusion - IgAExpression of TLRs
PROTECTIVE FUNCTIONSCompetitive Exclusion by BARRIER EFFECTBacteriocinsproduces lactic acid and fatty acids, serves to lower the pH in the colonIn alergic patients, C. difficile and S. aureus are higher and lower prevalence of Bacteroides and BifidobacteriaPrevention of IBD
SPECIATIONNasonia giraulti, N. longicornis, N. vitripennisHalogenome
INFLUENCE IN DISEASE
OBESITYfewer Bacteroidetes and more Firmicutesdifferences in the energy-reabsorbing potentialRoux-en-Y gastric bypass (RYGB)Results in significant weight loss improvements in conditions like Type 2 diabetes.29% of their body weight within 3 weeks, despite no change in net food intake.
IBDUlcerative Colitis and Crohn's disease
CANCER Bacteroides and ClostridiumLactobacillus and BifidobacteriaTRANSLOCATIONToo much growth of bacteria in the small intestineReduced immunity of the hostIncreased gut lining permeability in diseases like cirrhosis
MENTAL HEALTHkids with autism were twice as likely as children with other types of disorders to have frequent diarrhoea or colitismice with autism-like symptoms were given a diet with Bacillus fragilisProbiotics have been used to treat ObsessiveCompulsive Disorder (OCD) and Attention- Deficit/Hyperactivity Disorder ADHD.Anxiety often causes nausea and diarrhoea, and depression can change appetite.sociability and risk taking
HEART DISEASETrimethylamine N-oxide (TMAO)AtherosclerosisL-carnitine & Red Meat.
ALTERATIONS
ANTIBIOTICSAntibiotic-Associated Diarrhoea (AAD)Antibiotic-Resistant bacteria.C. difficile and Salmonella kedougouSelective Digestive Tract Decontamination (SDD)Children who were given antibiotics during the first 6 months of life were more likely to have a higher body mass
PHARMABIOTICSProbiotic bacteriaProbiotic-derived biologically active metabolitesPrebioticsSynbiotics or genetically modified commensal bacteriaIBD, Atopy, Infection, Diarrhoea, Cancer & Arthritis
STUDY OF MICROBIOTA
TECHNIQUES OF STUDY
CULTURE DEPENDENT TECHNIQUEScost-effective and reproducible.strict anaerobes, and it is estimated that >80% of the gut micro biota cannot be cultivated under standard laboratory conditions.
CULTURE INDEPENDENT TECHNIQUESMolecular-based techniques.16S ribosomal RNA (rRNA) gene.
MODELS OF STUDYGerm Free AnimalsMono-, Bi-, Poly- Associated AnimalsHuman Flora Associated Animals.
ARE WE REALLY MORE OF BACTERIAL MICROBIOME THAN MAMMALS?
Microbiota as a FORGOTTEN ORGAN ?
What would be the advantage of unicellular organisms becoming multi-cellular?
What differentiates a multi-cellular unit from a colony of unicellular beings living in proximity?
Whether this association will evolve into a more complex system in further evolution of human digestive system?