Lung microbiome (Marta Martins lecture 2)

environmental conditions in the lungs

warm, moist and rich in O2

COPD is a common lung disease causing restricted … when airways become … and …

airlfow, inflammed and narrowed

regional growth conditions that determine which microbes can survive

1. … availability

2. … tension

3. …

4. …

5. concentration of … …

6. activation of … …

7. local microbial …

8. host … cell …

1. nutrient

2. oxygen

3. temperature

4. pH

5. inflammatory cells

6. inflammatory cells

7. competition

8. epithelial, interactions

microbial immigration occurs through … of bacteria, … and direct … …

inhalation, microaspiration, mucosal dispersion

microbial elimination occurs through …, … clearance and … and … host defences

cough, microciliary, innate and adaptive

normally the travel of microbes is … mainly moving downward through the GI tract, however during … or … … movement can become …

unidirectional, vomiting, eosophageal reflux, bidirectional

… and … are (like the gut) lined with heavily … … of secreted mucus, while the vast majority of the … surface area is lined with … rich surfactant, which has … effects (prevents bacteria from reproducing and growing)

trachea, bronchi, glycosylated proteins, lungs, lipid, bacteriostatic

in the gut, there is much more direct contact between … and the … surface, and … and … play a major role in controlling them

microbes, mucosal, IgA and MALT

what do MALT and BALT stand for?

mucosa and bronchus associated lymphoid tissue

in the lungs host-bacterial interactions are more influenced by … cells outside the lumen, especially … …, along with … and …

immune, alveolar macrophages, IgE and BALT

compared to the gut, the host-bacteria interactions in the lungs are more …

extraluminal

in which part of the respiratory tract is microbiota density the highest?

oropharynx

what is the pH of the lungs?

7.5

the lung microbiome mainly consists of … microbes and its composition is determined by the balance between microbial … and …

transient, immigration and elimination

in the nasal cavity the most abundant bacteria are … and … while in the oral cavity, lungs and stomach the most abundant bacteria are … and …

actinobacteria and firmicutes, bacteroidetes and firmicutes

… … … cells are thin … cells in the lungs essential for … … and form the …-… barrier

type 1 alveolar, epithelial, gas exchange, air-blood

… … … cells are cuboidal … cells in the lungs that produce … … to reduce … … to prevent alveolar collapse and also act as … cells

type 2 alveolar, epithelial, pulmonary surfactant, surface tension, stem

diseased lungs can chane in … availability, … levels and …

nutrient, oxygen, pH

sources of mircoorganisms in the lungs

1. nasopharyngeal aspiration

2. inhalation

3. reflux and aspiration

4. bloodstream

the … microbiome is the primary source of bacterial microbiota in the lungs

oral

the microbiome of the nose more closely resembles that of the … than the …

skin, lungs

… (runny nose) can provoke exacerbations of lung disease associated with … bacteria

rhinorrhea, nasal

a healthy lung microbiome is composed of a …, … and … (so bacteria, fungi and viruses)

bacteriome, mycobiome and virome

which four things mentioned help keep the lung microbiome selective?

coughing, cilia, macrophages and alveolar surfactant

alveolar surfactant contain … … which help … recognise and clear pathogens

alveolar proteins, macrophages

the lung microbiome changes during … with a previously low … … becoming high

disease, microbial density

respiratory diseases in which the lung microbiome is altered

1. cystic fibrosis

2. COPD

3. idiopathic pulmonary fibrosis

4. asthma

… … … a chronic lung disease characterized by irreversible … (fibrosis) of lung tissue, causing … of the lungs and … difficulties

idiopathic pulmonary fibrosis, scarring, stiffness, breathing

the most common bacterial phyla in healthy lungs is … but in diseased lungs the microbiota is characterised by an outgrowth of the … phylum

bacteroidetes, proteobacteria

airways of CF patients have a unique microbial … and reduced … compared to healthy individuals

structure, diversity

in COPD patients lung microbiota … is reduced and the abundance of … is increased

diversity, proteobacteria

dysbiosis in the oropharynx microbiome can:

1. induce …

2. promote lung …

3. protect … …

4. stimulate …

1. COPD

2. damage

3. opportunistic pathogens

4. inflammation

in healthy lungs, presence of microbes in the oropharynx would stimulate production of … such as … (name 4) and elicit a normal … response

cytokines, IL6, IL8, IL10, TNF alpha, immune

gut-lung axis connections between lung and gut microbiomes

1. LPS can contribute to … …

2. SCFAs such as … can help protect against …

3. … …. … promote a … immune response

4. … and … from the gut can promote … and … in the lungs

5. lung disorders such as … and … are associated through the gut-lung axis with gut disorders such as … and …

1. oxidative stress

2. butyrate, asthma

3. segmented filamentous bacteria, Th17

4. viruses and bacteria, inflammation and dysbiosis

5. ARDS and COPD, IBD and IBS

what do SFB and ARDS stand for

segmented filamentous bacteria and acutre respiratory distress syndrome

acute COPD exacerbations are commonly treated with … and …

corticosteroids and antibiotics

smoking … and … the lung microbiome notably increasing … and … of dominant bacterial groups

disrupts, reshapes, variability, balance

severe asthma is associated with reduced … and a microbiota enriched with … bacteria

diversity, pathogenic

revise slide 35

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5 techniques to sample airways

1. sputum

2. bronchoalveolar lavage

3. protected endobronchial brush

4. bronchoscopic biopsy

5. sterile tissue sample

revise slide 39

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BAL samples contain numerous bacterial taxa not found in the mouth, indicating … pressure in the lungs for …, …, … and …

selective pressure, elimination, persistance, colonisation and growth