Human Microbiome 2

What is microbiota?

The living microorganisms (bacteria, fungi, viruses, etc.) found in a specific environment (e.g., gut, skin).

What does microbiome refer to?

The collective genomes of all microorganisms in an environment, including their structures, metabolites, and environmental interactions.

Is there a single 'normal' microbiome?

No, there is no single 'normal' microbiome; multiple healthy versions exist.

What factors influence the microbiome?

Age, environmental factors, and personal history.

What is dysbiosis?

Microbial imbalance which may cause disease or result from disease.

Where is dysbiosis most often discussed?

In the gastrointestinal tract.

What are some conditions linked to dysbiosis?

Asthma, Crohn’s disease, IBD (Inflammatory Bowel Disease), and Type 1 Diabetes.

How does the microbiota change as one ages?

Infants have low microbial diversity, which increases and stabilizes by age 3.

What happens to the microbiota during pregnancy?

There are temporary changes in the microbiota, unrelated to BMI or diet.

What microbial changes are observed in old age?

A shift in microbial community, linked to increased disease risk.

What influences the colonisation of microbiota in newborns?

Delivery method, feeding type, and environment.

What is the impact of vaginal delivery on newborn microbiota?

Infants acquire vaginal and gut flora.

How does caesarean section affect microbiota acquisition?

Decreases Bacteroides, Lactobacillus, Bifidobacterium; increases Clostridium difficile, Staphylococcus.

What benefits does breastfeeding provide for gut health?

Promotes gut health via prebiotics, immunoglobulins, cytokines, enzymes, and live bacteria.

How does bottle feeding compare to breastfeeding?

Bottle formula is nutritionally regulated but lacks complex bioactives.

What is one strategy for managing dysbiosis in infants?

Vaginal seeding (applying maternal vaginal fluids to CS-born infants).

What environmental factors can influence microbiota?

Pets, air quality, hygiene.

What was a key finding from the TEDDY study regarding microbiomes?

More Bacteroides correlates with fewer SCFA-producing bacteria.

What impact does aging have on the immune system?

A decrease in the immune system and an increase in infection risk.

What are common factors contributing to dysbiosis in the elderly?

Decreased stomach acid, urine flow, mucus clearance, hormonal changes, and altered GI motility.

What is 'inflamm-ageing'?

Chronic inflammation resulting from microbiota related to aging.

What are residents of the skin microbiome?

Long-term inhabitants like Staphylococcus spp.

What is a defining characteristic of upper respiratory tract microbiota?

Contains Staphylococcus aureus, Streptococcus pneumoniae, Corynebacterium, Neisseria.

How is the lower respiratory tract microbiome defense maintained?

Through cilia, mucus, IgA, and macrophages.

What effect do smoking and vaping have on lung microbiota?

Smoking creates diverse microbiota, while vaping increases Haemophilus and leads to higher inflammation.

What contributes to dental plaque formation?

Microbial biofilm on tooth surfaces that produces acid damaging enamel.

How does the distribution of bacteria vary in the gastrointestinal tract?

The stomach has limited microbes; more bacteria are found distally in the small intestine and high density in the large intestine.

What do healthy gut microbiota produce that helps reduce inflammation?

Short-Chain Fatty Acids (SCFA).

What are the three main enterotypes of microbiota?

1. High Bacteroides, 2. Low Bacteroides/high Prevotella, 3. High Ruminococcus.

What is the use of faecal transplants?

To treat C. difficile infections and potentially influence weight gain/obesity.

What is a defining feature of the oral microbiota?

It has a rich bacterial population due to food, saliva, and epithelial debris.

What defines transient microbes in the skin?

Temporary colonisers of the skin microbiome.

How does early exposure to animals influence immunity?

It is linked to stronger immunity and reduced allergy/asthma.