Thread by @MSUPedsPulm

Good morning! I will be “live tweeting” (not sure streaming is considered live) #ATS2020 #D85 ENVIRONMENTAL EXPOSURES AND THE AIRWAY MICROBIOME. #Thread (1/?)

First up, Traffic-Related Air Pollution, Host Defense, and Effects on the Airway Microbiome. Christopher Carlsten, MD, MPH. UBC, Vancouver, BC, Canada.

Inhalants could change microbiome by: acting as vectors, acting on host immunity and/or altering gut microbiome which then alters lung microbiome. #ATS2020 #D85

Higher diversity of bacteria airway microbiome in children associated with less asthma. (Smit et al Pneumonia 2017.)

Intense Saharan dust event associated with higher airway bacterial levels. (Federici Sci Tot Env 2018) #ATS2020 #D85

Higher levels of air pollution increase the abundance of pathogenic bacteria. Vector effect? Opposite seen with ozone. (Liu et al. Environmental Pollution 2018.) #ATS2020 #D85

Filter samples of particulate matter in China suggest species number and diversity increase with higher levels of particulate matter. This is somewhat contrary to prior studies. Acute vs chronic change explains the difference? (Qin et al Genome Biology 2020) #ATS2020 #D85

Household air pollution associated with increase BAL Strep, lower Tropheryma, and higher Neisseria (Rylance BMC Micro 2016)

Increased air pollution associated with decreased alpha diversity in nasal swabs. (Mariani Env Research 2018) #ATS2020 #D85

Work by Carlsten (not yet published) shows COPD patients have lower airway bacterial diversity. Exposure to diesel exhaust have a higher evenness but not richness, alpha or beta diversity in the short term. #ATS2020 #D85

Cinnamaldehyde (found in e-cigs) inhibits immune cell function. (Clapp et al AJP-Lung 2017)

Bacterial & viral clearance in mice decreased by vaping, Staph more virulent. MRSA more invasive. (Hwang et al. J Mol Med 2016) #ATS2020 #D85

Alpha defensin level suppressed by diesel exhaust. Increases infection susceptibility. (Piyadasa et al AJRCCM 2018)

Risk for inflammatory bowel disease increase with higher exposure to inhaled pollutants. (Kaplan Am J Gastro 2010) #ATS2020 #D85

Next up, E-Cigarettes' Influence on the Upper Airway Microbiome. Ilona Jaspers, PhD. Univ of North Carolina At Chapel Hill, Chapel Hill, NC. #ATS2020 #D85

Factors that modify the nasal microbiome: Increase with age, increases with asthma and chronic sinusitis, household makeup, smoking, and medications. (Fazlollahi 2018, Schenck 2016, Ramakrishnan 2013) #ATS2020 #D85

Nasal microbiome changes in those with exacerbated asthma (Fazlollahi 2018). Corynebacterium associated with loss of asthma control. (Zhou 2019) #ATS2020 #D85

E-cigs impair antiviral response in mouse model (Sussan 2015 Madison 2019) Changes virulence, bacterial persistence and biofilm development (Gilpin 2019) Staph virulence increase and antimicrobial resistance and biofilm development increased (Hwang 2016) #ATS2020 #D85

E-cigs increase platelet activating factor receptor expression which increases pneumococcal adherence (Miyashita Eur Res J 2018)

E-cigs lead to signs of periodontitis pro-inflammatory signature and overrepresentation of pathogenic bacteria (Ganesan Sci Advances) #ATS2020 #D85

Work by I Jaspers lab: Decreased nasal microbiome alpha diversity in women. More prominent in female e-cig users. E-cigs users have more Staph, Strep & Cornybacterium. Less Moraxella & propionbacterium.
E-cigs disrupt the immune-protein networks. #ATS2020 #D85

Thirdly, The Hygiene Hypothesis and the Microbiome of Airway Disorders. Erika von Mutius, MD, MSc. Klinikum der Universitaet Muenchen, Muenchen, Germany. #ATS2020 #D85

Farm homes have more cattle and less human associated taxa. Lot of overlap though. Urban home children if farm like microbiome protected from asthma. Related to soil bacteria? (Kirvajainen Nat Med 2019) #ATS2020 #D85

More diversity, less asthma. More diversity, less Moraxella. More Moraxella more asthma. (Birsele Allergy 2016, Depner JACI 2016) #ATS2020 #D85

PASTURE/EFRAIM: Children with cow contact in first year of life protected from wheezing. #ATS2020 #D85

Chromosome 17q21 locus: GG > GA > AA regarding risk of wheezing (Loss AJRCCM 2015) Low detectability of cytokines after LPS stimulation associated with increased wheeze in those at higher risk. #ATS2020 #D85

Farm milk consumption made it more likely to be in the higher cytokine group. Gut microbiome mediated. #ATS2020 #D85

At age 6: rapid gut microbiome maturation decreases asthma risk. These features are related to maternal smoking, C-section, sibling #, diet and environmental exposures. Independent of 17q risk allele. #ATS2020 #D85

#4 Airway-Relevant Cross-Talk Between the Exposome and the Microbiome. Hind Sbihi, PhD. University of British Columbia, Vancouver, BC, Canada. #ATS2020 #D85

Gut-lung microbiome axis (GLA) has extensive interactions. (Enaud Front in Cell and Inf Micro 2020) #ATS2020 #D85

Exposome is the combination of gut microbiome, environment, breastfeeding, early life stressor. Interacts with epigenome and modifies risk of childhood asthma. #ATS2020 #D85

Early life perturbations in gut microbiota alter composition and how bacteria interact with host. Impacted in early life by diet, antibiotics, birth mode and air pollution. Leads to atopic disease through immune dysregulation. (Stiemsma Immunotargets Ther 2015) #ATS2020 #D85

CHILD study. Looks at home environment, prenatal maternal nutrition, child nutrition, breastfeeding, viral infections, and maternal stress vs risk of asthma. #ATS2020 #D85

Gut microbiome dysbiosis observed at 3mo in asthmatic children. Persistent lack of diversity at 12mo. “Immature” gut in first year. #ATS2020 #D85

Traffic air pollution in pregnancy doubles risk of asthma. Does not alter gut microbiome in alpha or beta diversity. Those with asthma have trend towards more “immature” microbiome. Infants of C-section also show “immaturity” #ATS2020 #D85

Indirect effect of traffic pollution of asthma through alteration of the gut microbiome. #ATS2020 #D85

Had to take a break. Clinical duties called! #ATS2020 #D85

Up fifth, Dietary Exposure and Host-Microbe Interactions: Impact on Respiratory Disease. Niki Ubags, PhD. CHUV, Epalinges, Switzerland. #ATS2020 #D85

Diet alters gut microbiome. (Maslowski Nature Immunology 2011) Fiber intake over time inversely correlated with atopic disease in population data (Devereux Nat Rev Imm 2006) #ATS2020 #D85

Low fiber diet increases eosinophils, IL-4 and IL-5 in response to dust mote protein in mice. Fiber rich diet ameliorates this. Gut and lung microbiota altered by fiber in diet. High fiber diet enhances production of short chain fatty acids (Trompette Nat Med 2014) #ATS2020 #D85

Treatment of mice with short chain fatty acids increase dendritic cell formation and decreases Th2 activation and inflammation (Marsland Nat Rev Imm 2014) #ATS2020 #D85

High fiber diet protects against influenza in mice. Decreases airway resistance in response to infection. (Trompette Immunity 2018) #ATS2020 #D85

Short chain fatty acid level high in the serum of mice with high dietary fiber. SCFA supplementation in mice decreases neutrophil counts in mouse BAL after influenza. This is responsible improved survival. (Trompette Immunity 2018) #ATS2020 #D85

Maternal obesity associated with asthma/wheeze (Forno Peds 2014)
Children born to mothers with disrupted gut microbiota have increased risk of asthma/wheezing. (Gohir Ped Res 2015) Neonatal gut micobiome varies with maternal fat intake (Chu Genome Medicine 2016) #ATS2020 #D85

High fat diet and maternal obesity lead to decreased diversity in milk microbiome increased bacterial load can lead to gut dysbiosis in infant and increase risk of asthma. (Ubags and Marsland 2018) #ATS2020 #D85

Last but not least: The Microbial Gut-Lung Axis as a Key Mediator of Host Response to Environment Philip Hansbro, PhD. University of Technology Sydney, Sydney, Australia. #ATS2020 #D85

This one too long to type. #ATS2020 #D85

Gut microbiome can allow bacterial components (LPS or PGN) to increase inflammation or good bacteria can regulate inflammation (Budden Nat Rev Micro 2017) #ATS2020 #D85

Diet of short chain fatty acids improves COPD in mice. Probiotics reduce inflammation. NLR-stimulating bacteria regulate lung immunity with GM-CSF. (Budden Nat Rev Micro 2017) #ATS2020 #D85

COPD patients with high fiber diet have improved lung function. COPD and healthy controls have very different microbiomes. (Budden unpublished) #ATS2020 #D85

Bifido/lactobac/strep/veillonell increased in COPD. Strep are the biggest difference. Lipid metabolism, xenobiotics metabolism and amino acid metabolism all altered. (Bowermann Rehman unpublished)

In COPD mouse models of smoke vs normal mouse microbiome transfer show less inflammation in smoke exposed mice and less emphysema and fibrosis after exposure to non-smoke gut microbiota. (Shukla Budden Gellatly) #ATS2020 #D85

Gut metagenomics shows gut microbiomes from smoking vs nonsmoking mice different but move closer to one another after fecal/gut microbiome “transplant” (Shukla Budden Gellatly) #ATS2020 #D85

Mouse exposed to smoke: colon length decreased, inflammation increases, colon hypoxemia, decreased barrier permeability reverses with fecal transfers. (Fricker JCI 2018) #ATS2020 #D85

#ATS2020 #D85