A&P - Chapter 5 Test: Human Microbiome

Human microbiome

a group of microbes that is essential for human life

Functions of the human microbiome:

• digesting food

• synthesizing vitamins

• forming barricades against disease-causing bacteria

Dysbiosis

an imbalance in the microbiome, linked to numerous disorders

Largest endocrine organ

the microbiome, due to its ability to influence other organs while also responding to secretions from other organs

(T or F) The human genome contains about 22,000 genes, whereas the human microbiome contains about 8,000,000 genes.

True

(T or F) the human microbiome is considered our “second genome”

True

(T or F) Humans share around 99.9% of the same DNA, but no two people share the same microbiome.

True

The steps of building a microbiome

1. Starts before birth in the mother’s placenta

2. the newborn passes through the birth canal

3. the newborn is exposed to bacteria from its external environment, educating its immune system

The more varied and complex a child’s microbiome…

the more robust his immune system will be

The first 3 years of life…

are critical in establishing a microbiome that will enhance neurodevelopment and lifelong health

(T or F) Infants delivered by cesarean section (c-section) have a significantly increased risk of developing diseases such as asthma, immune deficiencies, and leukemia.

True

The greater the diversity of the microorganisms in the microbiome…

the stronger the immune system

Stages of Microbiome development

• intrauterine life

• birth

• first year of life

• second year of life

• ages 2-5

• adulthood

• ages 65+

Intrauterine life

microbes pass through the placenta from mother to fetus, creating th efoundation for a microbial community

Birth

passage through the birth canal coats the newborn with the mother’s own bacteria, helping to create a diverse microbiome; skin-to-skin contact helps organize the microbiota

First year of life

breastfeeding exposes babies to 700+ species of bacteria and is crucial for establishing long-term health; at the end of the first year, babies have an individually distinct microbial profile

Second year of life

introducing solid food boosts microbial diversity

Ages 2-5

the intestinal microbiome resembles an adult’s in composition and diversity

Adulthood

changes in diet, environment, and antibiotics can alter the microbiome composotion; healthy adults have microbiomes that can regulate over time

Ages 65+

broad shift in microbiome populations; number of microbial species decreases; unclear why this happens or what this may lead to

Boosting the microbiome

• consumption of a high-fiber, plant-based diet

• eating foods rich in polyphenols

• taking probiotics (live bacteria)

• consuming prebiotics

• eating fermented foods (i.a. yogurt and sauerkraut)

• exercising

• avoiding unnecessary antibiotics

Threats to the microbiome

• antibiotics

• a high-fat, high-sugar diet

• stress

• smoking

• air pollution

• sedentary lifestyle

• overuse of sanitization

• invasion of disease-causing bacteria

Bacteria

• makes up the bulk of the microbiome

• single-celled organisms

Capsules

surrounds the bacteria and keeps them from drying out

Peptidoglycan

makes up the cell wall for bacteria

Flagella

helps bacteria move around

Ribosomes

helps with protein production in bacteria

Plasmids

• small loops of DNA within bacteria that can be traded among other bacteria

• allows for extreme adaptability

Pili

small hair-like projections that are used to attach bacteria to other cells or surfaces

Bacterial shapes

• Cocci — round or spherical

• Bacilli — rod-shaped

• Spirilla — spiral-shaped

Diplococci

round bacteria that exist in pairs

staphylococci

round bacteria that occur in clusters

Streptococci

round bacteria that exist as long chains

Fecal transplantation

the transfer of feces from a healthy person to the intestines of sick patients

Gram staining

a test that uses purple dyes to help identify disease-causing bacteria

Gram-positive bacteria

• stains purple, showing they have a thick layer of peptidoglycan in their cell walls

• antibiotics like penicillin are great for attacking peptidoglycan, making them more effective against these bacteria

Gram-negative bacteria

lose the dye and appear red or pink, showing that they have a thinner layer of peptidoglycan

Pathogens

microorganisms known to cause disease

Viruses

• extremely small(er than bacteria) infectious agents that are not made of cells, therefore lacking the functions of cells

• causes many human diseases like smallpox, AIDS, influenza, some cancers, and the common cold

Capsid

• a shell made of capsomeres surrounding a virus’s genetic material (DNA or RNA)

• some viruses have an additional surrounding layers called the envelope

Bacteriophages

viruses that specifically infect bacterial cells

Viral Replication

• viruses require a host to replicate

• 1. the virus binds to the cell’s surface

• 2. the virus penetrates the cell by either fusing with its membrane or by causing the cell to voluntarily engulf it

• 3. the virus hijacks the cell’s mechanisms and causes the nucleus to produce viral nucleic acids instead of its own

• 4. the viruses burst from the cell, often resulting in the death of the host cell

Fungi

includes molds and yeasts

Mycobiome

the fungi community within the human microbiome

What kind of relationship does the microbiome and mycobiome have?

symbiotic