Microbes and Disease, Microbes and the Human Microbiome

Gut brain communication

2-way signaling network between the gastrointestinal tract and the brain and which involves the action of gut microbes on the autonomic nervous system

antibiotic

A chemical that kills bacteria or slows their growth without harming body cells.

Commensalism

A relationship between two organisms in which one organism benefits and the other is unaffected

Parasitism

A relationship between two organisms of different species where one benefits and the other is harmed

Mutualism

A relationship between two species in which both species benefit

Role of PCR in studying the human microbiome

Allows for the amplification of DNA (and RNA) from microbes within and on the human body.

Pathogen

An organism that causes disease

m. smithii

Major mutualistic flora of the human gut and play a role in releasing extra energy from the food we eat

Bacteriodetes

Major mutualistic flora of the human gut and play a role in releasing nutrients from the food we eat

quorum sensing

The ability of bacteria to communicate with other bacteria via secreted chemical signals.

Ways that microbes are beneficial

aid with digestion, fighting infection, brain development, and immunity

microbiome disturbance

alteration of a normal microbiome away from a state of balance

microbe

any tiny organism that cannot be seen with the unaided eye.

commensal bacteria

are microorganisms that normally live harmlessly in symbiosis with their host (for example the gut bacteria in humans and other animals). Many confer a positive benefit on their host in some way.

common human microbes

bacteria, archea, viruses*, protists, fungi, and microscopic animals

Clostridium difficile (C. diff)

bacterial infection, generally associated with antibiotic use, causing severe, watery loose stools

How microbes help with digestion

break down macronutrients, make vitamins and make digestion easier

gut brain

collection of microbes in the abdomen that communicate with the brain to help drive bodily functions

Staphylococcus epidermidis

common skin bacteria that is usually beneficial to the human microbiome

Body systems with microbiomes

digestive system, integumentary system, urogenital system, and respiratory system

Microbes and obesity

gut bacteria have been linked to the processing of nutrients that can lead to excess sugars produced

Microbes and protective barriers

keep bad microbes out by creating biofilms

vagus nerve

nerve that connects the gut microbiome to the central nervous system

Different types of human microbiomes

oily, damp, dry, acidic

Role of competition in pathogenic infections

pathogenic bacteria outcompete normal flora to overun an area often resulting in disease. Ex. irritable bowel disease (IBS).

Microbes and organ system development

play a role in helping the brain develop and in the growth and functioning of the lymphatic system

Microbes and nutrition

produce vitamins, breakdown/digest nutrients, storage of nutrients

microbes and immunity

regulate inflammation, trains immmune system, produces antibodies to fight infection

Body systems that typically NOT associated with a microbiome

skeletal system, nervous system and muscular system

human microbiome

the complete collection of microorganisms in the human body's ecosystem

antibiotic resistance

the evolution/mutation of populations of pathogenic bacteria that antibiotics are unable to kill

fecal microbial transplant (FMT)

the transfer of microbiota from the colon of one individual into the colon of another

Recurrence

this is when a disease mechanism is persistant and returns even after multiple treatments.