Introduction
Although we view ourselves as individuals, each person is in fact a superorgan-
ism that includes trillions of microbes. The human body functions alongside
these microbes, forming an ecosystem. Increasingly, health researchers are
appreciating that in order to understand health and disease, we must explore
the interplay between humans and the microbes that inhabit their bodies.
The community of microbes that lives in the gastrointestinal tract, called
the gut microbiota, is known as the forgotten organ because of its immense
influence on many systems in the body. In fact, the combined genomes of
these microbes, called the gut microbiome, provide a vast amount of genetic
material that affects human health. Gut microbes regulate our natural immune
responses and determine risk for developing chronic illness. For example,
altered gut microbes are associated with obesity, type 2 diabetes, and heart
disease, and may also have implications for neurological disorders like autism,
multiple sclerosis, and Parkinson’s disease. Cutting-edge research has even
identified links between microbes and our mood and mental health. These
connections between the microbiota and health outcomes raise the question of
whether the microbiota can be manipulated to improve human health. Indeed,
numerous lifestyle factors, such as diet, antibiotic use, sleep, and exercise, may
influence health through mechanisms involving gut microbes.
This book will cover a variety of topics involving the gut microbiota, but
there are a few overarching themes woven throughout the chapters. One of
these themes is the role of gut microbes in many of the body’s immune func-
tions, including its ability to fight off infectious disease; the development of
autoimmunity, where the immune system attacks healthy human cells; as well
as the development of environmental allergies. Another theme that will appear
throughout the book is dysbiosis, a state of imbalance in the composition of
microbe populations, which can alter the interactions microbes have with their
human host in ways that promote disease. This book focuses most deeply on
the role of nutrition in maintaining balanced and healthy gut microbe popula-
tions, which can mitigate the development of disease.
Although we view ourselves as individuals, each person is in fact a superorgan-
ism that includes trillions of microbes. The human body functions alongside
these microbes, forming an ecosystem. Increasingly, health researchers are
appreciating that in order to understand health and disease, we must explore
the interplay between humans and the microbes that inhabit their bodies.
The community of microbes that lives in the gastrointestinal tract, called
the gut microbiota, is known as the forgotten organ because of its immense
influence on many systems in the body. In fact, the combined genomes of
these microbes, called the gut microbiome, provide a vast amount of genetic
material that affects human health. Gut microbes regulate our natural immune
responses and determine risk for developing chronic illness. For example,
altered gut microbes are associated with obesity, type 2 diabetes, and heart
disease, and may also have implications for neurological disorders like autism,
multiple sclerosis, and Parkinson’s disease. Cutting-edge research has even
identified links between microbes and our mood and mental health. These
connections between the microbiota and health outcomes raise the question of
whether the microbiota can be manipulated to improve human health. Indeed,
numerous lifestyle factors, such as diet, antibiotic use, sleep, and exercise, may
influence health through mechanisms involving gut microbes.
This book will cover a variety of topics involving the gut microbiota, but
there are a few overarching themes woven throughout the chapters. One of
these themes is the role of gut microbes in many of the body’s immune func-
tions, including its ability to fight off infectious disease; the development of
autoimmunity, where the immune system attacks healthy human cells; as well
as the development of environmental allergies. Another theme that will appear
throughout the book is dysbiosis, a state of imbalance in the composition of
microbe populations, which can alter the interactions microbes have with their
human host in ways that promote disease. This book focuses most deeply on
the role of nutrition in maintaining balanced and healthy gut microbe popula-
tions, which can mitigate the development of disease.
