Segments in this Video

Microbial Companions (05:23)


Billions of bacteria, viruses, and fungi live on and inside of us. Entomologist Piotr Naskrecki was bitten by a mosquito that deposited parasitic bot fly larvae under his skin. See it emerge. The experience illustrated that humans are ecosystems.

Face Mites (02:52)

Michelle Trautwein researches microscopic arachnids that live on our faces and lay their eggs in our pores. They have lived longer than humans; two species are eighty million years divergent.

Microbiome (02:38)

Microbes living on and inside us comprise a complex ecosystem and help maintain our health. Bacteria evolved three billion years before multi-celled animals and have remained the most abundant life forms.

Discovering Microbes (03:09)

Scientists first viewed bacteria through crude microscopes in the 17th century. Louis Pasteur's germ theory led to the discovery of specific pathogens, including Vibrio cholerae and Clostridium botulinum. Some microbes kill competing microbes.

Antibiotics (02:36)

Learn about Alexander Fleming's discovery of penicillin that has saved millions of lives. Antibiotics have existed in nature for billions of years; pharmaceutical versions led to the "war" on germs—but some microbes are beneficial.

Bacteria and Immune Related Diseases (02:47)

Microbiologist Jack Gilbert enjoys creating ecosystems in jars. He believes indoor, modern lifestyles have isolated us from microbes essential to our health—increasing child diseases like allergies and asthma across the nation.

Health Benefits of Microbial Exposure (03:15)

The Amish live near their livestock and have fewer allergies than average Americans. Learn about the role of soldier cells in overactive immune responses. "Allergic" lab mice exposed to Amish farm dust do not develop symptoms.

Gastric Ulcers (04:11)

Doctors used to believe stress caused ulcers. In the 1980s, Barry Marshall and Robin Warren discovered Helicobacter pylori were responsible. Physicians have prescribed antibiotics to patients—but eliminating the bacteria has correlated with disease incidence, including allergies and obesity.

Mapping the E. Coli Genome (02:59)

One strain of Escherichia coli causes illness when ingested; most are beneficial. Researchers use supercomputers to analyze microbial DNA sequencing. Data suggests balance and diversity are key to maintaining healthy a microbiome.

Fecal Transplants (08:47)

Scientists are discovering that intestinal microbial diversity is crucial for health. Individuals with healthy gut bacteria donate their stool to Clostridium difficile patients through OpenBiome. Learn about the bacterium, antibiotic resistance, and treatment process.

Microbiome and the Brain (02:18)

A 2004 study found the gut bacteria of an obese person made a lab mouse obese. The vagus nerve links the gut to the brain; certain microbes produce neurotransmitters that affect neurology.

Neurological Diseases and Gut Bacteria (04:19)

Researcher Sarkis Mazmanian tests microbes from Parkinson's patients on germ-free mice, who develop motor impairment—suggesting that microbes may trigger the disease. He also gives B. fragilis to "autistic" mice with leaky gut; their repetitive behavior subsides.

Future Microbiome Research (04:49)

OpenBiome screens donors for gastrointestinal, psychiatric, and other diseases. Kelly Poole takes fecal transplant capsules; her C. difficile symptoms subside within 24 hours. Scientists are beginning to discover the roles gut bacteria play in our health, including their potential for treating disease.

Credits: What's Living in You? (01:01)

Credits: What's Living in You?

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What's Living in You?

Part of the Series : NOVA: Wonders, Season 1
3-Year Streaming Price: $169.95



Whether they make you fat, fart, or freak out, microbes play a central role in your life. Right beneath your nose—on your face, in your gut, and everywhere in between—trillions of bacteria, viruses, and fungi are so abundant in your body, they outnumber your human cells. But these aren’t just nasty hitch-hikers. Many are crucial to your survival.

Length: 54 minutes

Item#: FPT191962

Copyright date: ©2018

Closed Captioned

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