Lecture 13: Fungi, Metagenomics and the Human Microbiome PDF Summer 2024

7/9/24 Lecture 13 Fu...

7/9/24 Lecture 13 Fungi, Metagenomics and the Human Microbiome Exam 3 We will finish the topic of fungi, so bring outline Date: Friday, July 12 from last time. Time: 9:00 AM – 10:30 AM New Topics and Reading: Metagenomics: Chapter 18 Sect. 18.3 Covering: Lectures 10 - 13 Microbiome: Microbiome Fact Sheet posted on Canvas and Chapter 33 all sections 1 2 How do we characterize microbial Culture-Dependent Approach communities in humans or in nature? Metagenomics – analysis of genetic material derived from microbial communities – can reveal diversity and metabolic potential of microbial communities – culture-independent 3 A Metagenomic Approach The human Microbiome is the collection of all microorganisms living in association with the human body - also called Microbiota or Microflora ② ① PCR amplify In 2007, the National Institute of Health launched rRNA the Human Microbiome Project to better Isolate SSU > - understand the microbiome and its role in human > (165 rRNA - genomic genes health and disease. DNA in bacterial ↓ Metagenomic studies are being used to define Compare to and sequence the microbiome. For example, studies indicate Clone DNA > database of 500 – 1000 different species of microbes live in amplified - the gut, representing all three domains. known genes 6 1  7/9/24 The large intestine or colon has the largest microbial community in the body Home to one of the most diverse microbial communities on earth. Counts of feces approach 10 12 microbes/gram, with over a 1,000 different bacterial species identified in feces Metagenomic profile of colonic bacteria in healthy adults includes 2 major phyla: 60-80% Firmicutes (gram +) 20-40% Bacteroidetes (gram -) Remainder Proteobacteria and Actinobacteria 7 8 Can our gut microbiota communicate with us? The vagus nerve that connects the visceral organs and the brain is an important communication pathway for the gut microbiota to influence the brain and behavior. Microbiota-Gut-Brain Axis the microbial Neurotransmitter ? What are Ex: Short Chain Fatty Acids (SCFAs) Microbial neurotransmitters are chemicals produced by microorganisms that can interact with the nervous systems of host organisms. These neurotransmitters can influence the behavior, mood, and overall health of the host. A variety of studies have linked loss of Dysbiosis – imbalance in the gut microbial microbiome diversity to health and disease. community Obesity - Firmicutes/Bacteroidetes ratio higher in obese Type I Diabetes Gain or loss of community members Cancer Change in relative abundance of microbes Autism Depression Alzheimer’s Factors include: Parkinson’s antibiotic use Multiple Sclerosis (MS) changes in diet and hygiene Germ-free animals receiving gut microbiota from patients develop motor deficits and neuroinflammation. 11 Microbiome 12 manipulation, a new therapeutic strategy? 2