BIOL 101 1nd Edition Lecture 27 Outline of Last Lecture I. DigestionII. Macromolecule BreakdownIII. Types of CellsIV. DuodenumV. CecumOutline of Current Lecture I. Germ Free vs Conventional MiceII. Second Digestive SystemIII. Experiment OneIV. Experiment TwoCurrent LectureClass Discussion Digestion III. Comparing/contrasting physical characteristics of germ free and conventionally raised mice: Germ free = are sterileConventionally raised = have a lot of bacteria in their gut Germ free Conventionally raisedVisually Skinny Fatter Body composition Low body fat percent Higher body fat percentThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Food consumptionEat a lot Eat lessDigestion/energy extraction from foodMice cannot digest/extract energy from foodNormal digestion and can extract energy from foodSource of genesMouse genomeBacteria genome and mouse genome What would happen if bacteria were added back to a germ free mouse?The mouse eats less, feels full, but gains weight II. Our gut bacteria can be considered a second __digestive system__.III. Basic science example (from Turnbaugh PJ 2008, Cell Host & Microbe): Can diet affect the structure and function of our gut microbial community?Experiment 1:Genetically identical mice with same gut microbial community were divided into one of the following diet groups:GROUP A: Normal mouse diet (high fiber, low fat and sugar)GROUP B: High sugar and fat diet Which group of mice gained the most weight? BWhich group of mice gained the most body fat? BWhat happens to the gut microbial communities of these mice after 8 weeks? Normal mouse diet (high fiber)High fat & sugar dietGut microbial structural changes (use graphs above)Bacterial group one 75% group two 25%Bacterial group one 95%Group two 5%Preferred energy source of newly abundant bacteria Group two Group oneWhat conclusions can you make on the effect of diet on the gut microbial community?Bacterial group 1Bacterial Group 2Bacterial Group 1aMouse foodWesternMouse foodWestern% bacteria of total community% bacteria of total communityHealthy diets can induce more microbial diversity in your gut.Experiment 2: Germ free mice on the normal mouse diet (high fiber) received fecal transplants from mice on one of the following diets:GROUP A: Normal mouse diet (high fiber, low fat and sugar)GROUP B: High sugar and fat diet After 2 weeks After 8 weeks Normal mouse diet High sugar and fat dietDonor:Mouse foodDonor:WesternDonor:Mouse foodDonor:Western(high fiber)Amount of food eatenSameSameAmount of body fat Higher HigherWeight gain Higher HigherEnergy harvesting capacity of gut microbiotaRelatively less energy harvestedMore energy harvested How did a high fat/high sugar diet change the function of the microbiota?Provide an advantage for fat and high sugar microbiota.What do you think would happen in 6 weeks if the mice given the “Western” microbiota continued on the normal mouse diet (use empty graph above)? What diet is more representative of the American diet? How are these studies important in the search for successful treatments for obesity? If we could change the microbiota in the peoples guts we could use it to treat
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