Microbiome and Normal Flora Practice Flashcards

A set of vocabulary flashcards covering the human microbiome, normal flora across various body sites, the hygiene hypothesis, and the impact of microbial dysbiosis.

Microbiome

A collection of ~ 1014 prokaryotic and eukaryotic microorganisms harbored by the body.

Dysbiosis

An imbalance in microbial diversity that promotes disease, contrasting with normal diversity which promotes health.

Hygiene hypothesis

The theory that antibiotics and lifestyles that decrease microbial exposure predispose people to autoimmune disease by disturbing the co-evolutionary relationship between the immune system and symbionts.

Bacteriocins

Chemicals such as acids, alcohols, or antibiotics excreted by microbiota that are made against closely related organisms.

Bifidobacterium

The number one primary bacterial species found in the intestinal flora of breast-fed babies.

Oligosaccharides

Complex and dynamic short-chain sugars found in breast milk, with over 200 different varieties that vary in concentration and content.

Probiotics

Living microorganisms administered orally to promote health and reestablish the natural microbial balance.

Prebiotics

Nondigestible dietary fiber, such as inulin, that acts as food to promote the growth of probiotics.

Lysozyme

An enzyme found in all body secretions that destroys peptidoglycan by breaking eta 1 ext{-}4 linkages between NAM and NAG.

Propionibacterium acnes

Gram-positive bacteria that secrete enzymes to degrade complex lipids in oil glands into volatile fatty acids, which can increase skin inflammation.

Thiopeptides

Protective substances produced by certain strains of P. acnes on normal skin that block other gram-positive bacteria.

Biofilm

A community of bacteria that excrete a sticky matrix for attachment and persistence, which is typically antibiotic resistant.

Secretory IgA (sIgA)

An antibody found in all body secretions that protects the epithelial layer and blocks microbes from binding to host receptors.

Ciliary escalator

A continuous stream of mucus generated by ciliated epithelial cells in the respiratory tract to remove microbes.

Gardasil 9

An HPV vaccine consisting of virus-like particles (VLPs) of purified L1 protein that induces neutralizing antibodies to prevent virus attachment.

Recurrent respiratory papillomatous (RRP)

A condition caused by HPV that can be spread to a baby during childbirth, resulting in airway obstructions and tumors.

Obligate anaerobes

The type of bacteria that make up >90% of the resident flora in the large intestine, including Bacteroides and Clostridium perfringens.

GALT (Gut Associated Lymphoid Tissue)

Tissue containing all the cells needed for a robust immune response that is 'trained' by interactions with the intestinal normal flora.

BDNF (Brain-derived neurotrophic factor)

A brain factor that decreases when the normal flora of the gut is disrupted by antibiotics, leading to increased depression and anxiety.

Microbial supplementation

A strategy for disease management and prevention involving the addition of beneficial microbes to the body's ecosystem.