Week 3: Normal Flora & Body Regions

Both organisms benefit from a ___ relationship

Mutualistic

Only one organism benefits and the other remains unchanged during a ___ relationship

Commensalistic

Some commensal organisms are ___, meaning they have the potential to cause infection and become parasitic

Opportunistic

All pathogens engage in ___ relationships with their hosts

Parasitic

An example of an opportunistic pathogen is ___ ___, which is present on the skin but can cause bloodstream infections when it contaminates catheters

Staphylococcus epidermidis

S aureus is carried by what percentage of the population?

32%

MRSA is carried by what percentage of the population?

0.8%

The Corynebacterium genus is gram-___ and ___-shaped

Positive, rod

C diphtheriae creates a ___ on the tonsils and swells the ___

Pseudomembrane, neck

S epidermidis reduces the replication of what species?

S aureus

What species of bacteria causes acne?

Cutibacterium acnes

C acnes is gram-___ and ___-shaped

Positive, rod

C acnes is (aerobic/anaerobic) and feeds on ___

Anaerobic, sebum

Clogged pores create an ___ environment

Anaerobic

What species of bacteria causes gingivitis and cavities?

Streptococcus mutans

S mutans can lead to ___ if left untreated

Endocarditis

Another species of bacteria that can cause gingivitis is ___ ___, which is gram-___ and ___-shaped

Porphyromonas gingivalis, negative, rod

Humans are carriers for Streptococcus ___, Neisseria ___, and Haemophilus ___

Pneumoniae, meningitidis, influenzae

Streptococcus pneumoniae causes what two diseases?

Pneumonia and meningitis

Haemophilus influenzae is gram (positive/negative), ___-shaped, and can cause ___

Negative, rod, meningitis

Which bacteria is a common cause of meningitis in young adults?

Neisseria meningitidis

Pneumonia is typically a ___ infection from Haemophilus influenzae

Secondary

If a 20-year-old has symptoms of meningitis, which bacteria is likely to be the cause?

Neisseria meningitidis

Lactobacillus is gram (positive/negative), ___-shaped, and found in the ___ ___

Positive, rod, vaginal tract

Lactobacillus prevents the growth of what two species?

Candida albicans, Gardnerella vaginalis

Overgrowth of Gardnerella vaginalis causes what pathology?

Bacterial vaginosis

Lactobacillus is often given as a ___

Probiotic

As Lactobacillus grows, what happens to the pH of the environment?

Decreases

Which species of Lactobacillus is NOT desirable?

Lactobacillus iners

What are the four desirable species of Lactobacillus?

Cripatus, gasseri, acidophilus, rhamnosus

Approx. how many bacteria are present in the intestinal tract?

100 trillion

What percentage of fecal dry weight is composed of bacteria?

50%

Which two phyla compose around 90% of the microbiome?

Firmicutes, Bacteroidetes

What part of the GI tract has the highest concentration of bacteria?

Large intestine

Microbiome dysbiosis has been linked to ___ ___ and ___ disorders, as well as GI ___ and ___ disorders

Mental health, eating, cancers, neurological

Breakdown of what three nutrients is facilitated by the GI microbiome?

Polysaccharides, fats, fiber

Anatomically, what is a function of the microbiome?

Occupy space

__% of the body’s serotonin is produced in the GI tract by which type of cells?

90, enterochromaffin cells

A reduction in bacteria causes (more/less) serotonin to be produced

Less

Which two genera of bacteria interact with EC cells and can reduce depression?

Clostridium and bifidobacterium

Aside from Clostridium and Bifidobacterium, what are two other genera that can reduce depression?

Coprococcus, Dialister

Coprococcus is gram (positive/negative) and ___-shaped

Positive, cocci

Dialister is gram (positive/negative) and ___-shaped

Negative, rod

Obesity has been related to levels of ___, and it is desirable to have (more/less) of this bacteria

Bacteroides, more

Bacteroides is gram (positive/negative) and ___-shaped

Positive, rod

Antibiotics given during the first 6 months of life have been linked to higher probability of ___

Obesity

Bacteroides produces and captures what nutrient?

B12

Bacteroides fragilis results in 90% of ___ infections, often following ___

Peritoneal, surgery

Increased levels of which two genera has been linked to obesity?

Clostridium, bacillus

H pylori is associated with (more/less) acid reflux and childhood asthma

Less

Crohn’s disease is linked with a (more/less) diverse microbiome

More

What cells are dysfunctional in Crohn’s?

Th17

Enterococcus faecalis is gram (positive/negative) and ___-shaped

Positive, cocci

E faecalis is linked to what conditions?

Colorectal cancer and diverticulosis

Which two genera of bacteria are generally higher in low fiber diets?

Clostridium and bacillus

Clostridium and bacillus are linked to ___ and ___, and (increases/decreases) systemic inflammation a (large/small) amount

Diabetes, obesity, decreases, small

E coli is typically (parasitic/commensalistic)

Commensalistic

What are the two proteins in gluten that contribute to sensitivity?

Gliadin and glutenin

What two genera of bacteria can break down the proteins in gluten that lead to intolerance?

Lactobacillus and bifidobacteria

Lactose intolerance is primarily ___

Genetic

Autism has been linked to an overgrowth of which two genera of bacteria?

Clostridium and Desulfovibrio

Parkinson’s disease has been linked to overgrowth of what genus of bacteria?

Desulfovibrio

Type II diabetes in one study was associated with increased ___ and decreased ___ and ___. In another study, T2D was treated with ___ and ___

Clostridium, Lactobacillus, Bifidobacterium, Lactobacillus, Bifidobacterium

A healthy person shows 3-5% of their microbiome populated with ___

Akkermansia muciniphilia

Low levels of A muciniphilia have been associated with ___, ___ disorders, and ___ lesions

T2D, metabolic, aortic

A 3 month study on A muciniphilia supplementation saw patients experience (increased/decreased) body weight and (improved/impaired) liver function

Decreased, increased

Excessive levels of A muciniphilia have been found in patients with ___ disease and ___

Parkinson’s, eczema

In a fetus, bacteria established in what period of life are most important?

First few days

A C-section increased risk for fetal inoculation of what genera?

Staphylococcus and enterococcus

Breast milk contains what bacterial genus?

Bifidobacterium

What cells transport and deposit Bifidobacteria into breast tissue?

Macrophages

Diet can change the composition of normal flora in how long?

1 day

What are two major hormonal changes that can influence the microbiome?

Puberty, menopause

Probiotics are ideally around how many bacteria?

100 million

Prebiotics contain ___ to help with specific bacterial growth

Nutrients

Probiotics are given for ___ effects (e.g. Peyer’s patches)

Immune

What does lactobacillus require to grow?

Estriol, lactose, lactitol

What do fungi need to grow?

Starch and sugars

___ are compounds produced by beneficial bacteria during fermentation

Postbiotics

Intestinal probiotics typically target what condition?

SIBO

Breath testing for SIBO analyzes what two compounds to determine whether excess bacteria are present?

Hydrogen and methane

___-___ probiotics are designed to pass through the stomach and open up somewhere in the intestines

Enteric-coated

Taking probiotics decreases the likelihood of what bacterial infection?

C. difficile

What are three genera of bacteria that are often contained in probiotics?

Lactobacillus, bifidobacterium, Bacteroides

What fungus is often included in probiotics?

Saccharomyces boulardii

S boulardii controls overgrowth of ___

Candida albicans

Which strain of Lactobacillus plantarum increases IBS symptoms?

MF1298

Which strain of Lactobacillus plantarum decreases IBS symptoms?

299v

List 3 genera that are commonly present in probiotics

Bifidobacterium, lactobacillus, Bacteroides

What species is present in probiotics to help limit candida overgrowth?

Saccharomyces boulardii

What species can come from yogurt, kimchi, sauerkraut, and tempeh?

Lactobacillus

Yogurt and tempeh contain lactobacillus and what other genus?

Bifidobacterium

What genus is found in miso and kombucha?

Saccharomyces

Comprehensive DNA sequencing of all a patient’s microbes is known as ___

Metagenomics

Atopic dermatitis is linked to excess ___

Staphylococcus aureus

Lactobacillus acidophilus and Bacteroides bifidum are used as probiotics to treat ___

Acne

Psoriasis is is activation of the ___ ___ and can be treated with Lactobacillus ___

Immune system, sakei

What bacteria has been shown to reduce plaque? What bacteria does it reduce the levels of?

Streptococcus A12, reduces Streptococcus mutans

Lactobacillus salvarius has been shown to reduce ___ ___ in rats

Oral cancer

Lactobacillus brevis and reuteri have been shown to prevent ___ ___ and reduce oral ___

Gum disease, inflammation