Understanding Anatomy and Physiology Chapter 4: Human Microbiome

Biome

A naturally occurring community of plants or animals occupying a particular habitat

micro

microscopic

Microbiome

A collection of microorganisms residing within distinct communities on and in the human body

Importance of the microbiome

Essential for normal body functions: digest food, absorb nutrients, prime immune system, produce vitamins, play a role in energy production, guard against disease, influence mental health

The human microbiome

An organized system of microbes within every healthy adult

Consist of 100 trillion organisms

Discovered by "the human microbiome project"

Genetic implications of the microbiome

22,000 human here's vs 8,000,000 microbial genes

Stages of Microbiome Development

In utero: from placenta

Birth: passage through birth canal

First year:breast feeding

Second year: solid foods

Ages 2-5: resembles that of an adult

Adulthood: altered by food, environment, antibiotics

Old age: decreased diversity

Boosting the Microbiome

High-fiber, plant-based diet

Foods rich in polyphenols

Probiotics

Prebiotics

Fermented foods

Exercise

Being outdoors

Avoiding unnecessary antibiotics

Threats to the microbiome

Antibiotics

High-fat, high- sugar diet

Stress

Smoking

Air pollution

Sedentary lifestyle

Overuse of sanitizing products

Invasion by disease-causing bacteria

Components of the microbiome

bacteria, viruses, fungi, archaea

Identifying Bacteria

Gram-positive bacteria: have a thick layer of peptidoglycan in cell wall

Retain dye

Stain purple

Gram negative bacteria

Have a thin layer of peptidoglycan in cell wall; also have outer membrane

Lose dye when rinse

Appear red or pink after counterstain is applied

Fungi

Include mold and yeasts

Live in soil, on plants, and in the air

Millions of fungal species reside in the human microbiome

Can overgrow and cause illness when immune system is compromised

Math fungal infections begin on the skin or in the lungs

What bacterial structure allows bacteria develop drug resistant

Plasmids

To reproduce, viruses?

Assume a hosts DNA

Humans share 99.9% of the same

DNA

No two individuals have the same

Microbiome

Greater microbial diversity

A stronger immune system

Low diversity microbiomes linked to multiple disorders

Obesity, arthritis, inflammatory bowl disease, psychiatric disorders, cancer, osteoporosis

cocci, bacilli, spirilla

3 shapes of bacteria (sphere, rod, spiral)

diplococci, streptococci, staphylococci

these are the 3 possible cellular arrangements of cocci bacteria

Viruses

Viruses are a 1 cell organism

Viral Shapes

helical, polyhedral, complex capsid

Viral Replication

DNA viruses all replicate in the nucleus (except poxvirus) All RNA viruses replicate in the cytoplasm (except influenza virus and retroviruses)

The presence of fungi in the intestinal microbiota is ? In most instances

A normal finding

Archaea are microscopic, single-called organisms that are biochemically ?

Distinct from

When found in the microbiome, archaea are considered to be ?

Normal contributing occupants

Archaea have a cell membrane that is ? That of any other organism

Distinct from

The appearance of archaea is ? That of bacteria

Similar to

The cell wall of archaea ? Peptidoglycan

Lacks

round bacteria

cocci

frequent culprit in microbiome disruption

antibiotic

Spiral shape bacteria cell

spirillum

Bacteria lack ?

Nucleus

Microorganisms known to cause disease

Pathogen

Bacterial structure that allows bacteria to be extremely adaptable

Plasmid

Gram-negative bacteria stain this color

pink

Molds and yeast

Fungi

Structure that allows bacteria to ward off white blood cells

Capsule

Complex virus that attaches to the surface of a cell before injecting its nuclei acid into target cell

Bacteriophage

Bacteria having rod shape

bacilli

The human microbiome

Builds over time

Scientist have learned that inhabitants of specific bacterial communities— such as those in the mouth or intestines—? Between individuals

Often vary widely

? Make up bulk of human microbiome

Bacteria

Children acquire the bulk of their microbiomes

From their mothers

The most complex and densely populated microbial community is in the

Intestinal tract

? Are foods containing indigestible fibers that nourish and feed healthy bacteria in the gut

Prebiotics

Low-diversity microbiomes ?

Have been linked to multiple disorders

The first step in colonizing an infants gastrointestinal tract occurs

Before birth

A child has an individually distinct microbiome by age

Two

With advanced age, the number of microbial species in the intestinal micrbiota

Decreases

Breast feeding makes ? Difference in a child's health over the long term

A significant