Rob Knight: How our microbes make us who we are

Summary

This script delves into the crucial yet often overlooked role of microbes in our bodies, particularly in the gut, and their impact on our health and identity. It explores how these microorganisms influence our susceptibility to diseases, drug reactions, and even behaviors. The speaker discusses the Human Microbiome Project, which aims to map the DNA of these microbes, and shares insights from studies like American Gut. The script also touches on the potential of microbial therapies to treat conditions like obesity and malnutrition, highlighting the revolutionary possibilities of microbial science in medicine.

Takeaways

• 🧠 The ancient Egyptians preserved organs for the afterlife but disregarded the brain, highlighting our historical lack of understanding of the brain's importance.
• 🌐 There is an 'organ' in our bodies as significant as the brain but is often overlooked: our gut microbes, which are crucial to our health and identity.
• 🦟 Microbes on our skin can affect our attractiveness to mosquitoes, demonstrating the influence of microbes on everyday experiences.
• 💊 The presence of certain microbes in our gut can determine the effectiveness and toxicity of medications, including painkillers and heart drugs.
• 🧬 The Human Microbiome Project, funded by NIH, has mapped the DNA sequences of microbes across the human body, revealing their vast diversity.
• 🌈 The microbial communities vary significantly across different body sites, with each site hosting a unique set of microbes.
• 🌱 The method of birth significantly influences a baby's initial microbial community, with vaginal birth and C-section leading to distinct microbial profiles.
• 🔬 Microbial imbalances have been linked to various diseases, including inflammatory bowel disease, heart disease, colon cancer, and obesity.
• 🧬 The microbial genes within us outnumber human genes, suggesting that our microbial makeup plays a significant role in our biology.
• 🌎 The American Gut project allows individuals to participate in microbiome research, contributing to the understanding of how microbes affect health.

Q & A

What mistake did the ancient Egyptians make in preserving body parts for the afterlife?

The ancient Egyptians carefully preserved organs like the stomach, lungs, and liver but disregarded the brain, mushing it up and draining it through the nose, believing it was unimportant.

What is the 'neglected organ' in our bodies that the speaker refers to?

The speaker refers to the gut and its microbes as the 'neglected organ,' emphasizing that, like the brain, it plays a crucial role in our health and identity.

How do microbes affect the likelihood of being bitten by mosquitos?

Microbes on our skin produce different chemicals, which mosquitos detect, making some people more attractive to mosquitos than others.

What is one way microbes influence our medical treatment?

Microbes in our gut can determine whether certain painkillers are toxic to our liver and whether specific drugs will work for heart conditions.

How do different regions of the human body compare in terms of microbial diversity?

Different body regions, such as the mouth, skin, vagina, and gut, host vastly different microbial communities, sometimes more distinct than ecosystems separated by hundreds of miles.

How genetically similar are human gut microbes compared to human DNA between individuals?

While human DNA is 99.99% similar between individuals, gut microbes can be only 10% similar, showing far greater variation.

How do the microbes in our gut outnumber human cells and genes?

We have approximately 10 trillion human cells but up to 100 trillion microbial cells. Additionally, our microbial genes can number between two million and 20 million, vastly outnumbering our 20,000 human genes.

How does a person's microbial identity remain stable over time, even with close contact with others?

Despite living closely with others, like family members, microbial communities in adults remain relatively stable and maintain their unique identity over time.

What significant impact does a baby’s mode of birth have on their initial microbial communities?

Babies born through vaginal delivery inherit microbes resembling the vaginal community, while C-section babies acquire skin-like microbes, potentially influencing later health outcomes like asthma, allergies, and obesity.

How can antibiotics affect the development of a child's gut microbiome?

Antibiotics, especially early in life, can cause significant disruptions in microbial development, potentially leading to long-term health effects, such as an increased likelihood of obesity.

How have fecal transplants been used to treat severe cases of C. diff infections?

In patients with C. diff infections, transplanting healthy donor stool dramatically shifts their gut microbiome, clearing symptoms like diarrhea within a day and restoring health.

Why are microbes increasingly being linked to various diseases, and what does the future hold for microbial research?

Microbes have been connected to diseases like inflammatory bowel disease, heart disease, obesity, and even autism. Future research aims to map and manipulate the microbiome to develop personalized treatments for a range of conditions.