We’ve known for years that gut microbes in the gut microbiome play a big role in human health. But we didn’t really understand how important they were until recently. Now we do.
It turns out that our gut microbiome plays a huge role in everything from weight loss to mental health. In fact, scientists believe that our gut microbiome may even impact our brain chemistry.
As researchers continue to learn more about the gut microbiome, we’ll eventually unravel the mystery around living a healthy life free from diseases. This can also advise on lifestyle needs and changes specifically tailored to each person’s unique needs.
Table of Contents
What is GUT (Gastrointestinal Tract)?
The gastrointestinal tract is made up of the mouth, esophagus, stomach, intestines, liver, gallbladder, pancreas, spleen, appendix, colon, rectum, anus, and genital organs. The digestive system is responsible for breaking food into nutrients and absorbing those nutrients. The GI tract is divided into three parts: upper, middle, and lower. The upper part includes the mouth, pharynx, larynx, trachea, bronchi, lungs, and nasal passages. The middle part includes the esophagus, stomach and duodenum. The lower part includes the ileum, jejunum, and colon.
What Forms The GUT?
Mouth and Esophagus
The mouth and esophagus form the first part of the digestive tract. They consist of three main components: the oral cavity, pharynx, and larynx. The oral cavity contains teeth, gums, tongue, lips, palate, cheeks, and jawbone. The pharynx is located behind the nasal passages and above the trachea. The larynx is located just below the vocal cords and helps regulate breathing.
Stomach
The stomach is divided into four sections: cardia, fundus, pylorus, and antrum. The cardia is located at the top of the stomach and connects to the esophagus. The fundus is located near the bottom of the stomach and holds food and liquid. The pylorus is located at the very base of the stomach and controls the flow of food and fluids into the duodenum. Finally, the antrum is located between the cardia and fundus.
Small Intestine
After passing through the stomach, food travels through the small intestine. The small intestine has five parts: duodenum, jejunum, ileum, cecum, and ascending colon. The duodenum is located at the beginning of the small intestine and is responsible for breaking down carbohydrates and fats. The jejunum is located next to the duodenum and is responsible for absorbing vitamins and minerals. The ileum is located after the jejunum and is responsible for absorbing proteins. The cecum is located at the end of the small intestine and stores bacteria used to aid digestion. Lastly, the ascending colon is located after the cecum and absorbs water and wastes.
Large Intestine
Next, food passes through the large intestine. The large intestine has three parts: descending colon, transverse colon, and sigmoid colon. The descending colon is located at the end and absorbs water and waste products from the large intestine. The transverse colon is located next to the descending colon and absorbs water and electrolytes. Finally, the sigmoid colon is located at the back of the large intestine and absorbs sodium chloride.
The microbiome in the Small and Large Intestines form the intestinal flora with many bacterial strains. The intestinal bacteria is what constitutes to the intestinal microbiota and are responsible for the health of the host.
Liver, Gall Bladder, Pancreas, Spleen, Appendix, Rectum
Finally, the food enters the liver, which filters toxins and blood cells from the bloodstream. Next, the food passes through the gallbladder, which stores bile salts and cholesterol. Then, the food continues through the pancreas, which produces insulin and glucagon. Insulin regulates sugar levels in the blood, while glucagon increases glucose levels. Glucose is stored as glycogen in the muscles and fat cells. Glycogen is later converted into glucose when needed. The pancreas also secretes hormones called cholecystokinin and somatostatin, which increase the secretion of pancreatic juices. The pancreas is located behind the stomach. At the end of the pancreas, the spleen filters red blood cells and platelets. Finally, the food enters the rectum, which absorbs water and wastes. The rectum ends at the anus.
What Is the Gut Microbiome?
Microbes are everywhere! They live in soil, water, air, plants, animals, and even humans. The human body contains trillions of microorganisms including bacteria, fungi, protozoa, viruses, and some worms. This collection of organisms is collectively referred to as the human microbiota.
Scientists have discovered that the composition of the human gut microbiome has a profound impact on our overall health and well-being.
Gut microbiomes are made up of hundreds of different species of bacteria, archaea, and viruses. Each individual carries thousands of unique microbial genes, and each gene encodes proteins that perform specific functions within the host.
A healthy gut microbiome supports immune system function, protects against infection, regulates metabolism, improves digestion, and helps maintain intestinal epithelial integrity.
What Is the Role of Gut Microbiome in Health?
Studies suggest that the gut microbiome plays a major role in maintaining normal physiological processes, regulating immunity, preventing infectious diseases, and promoting gastrointestinal health.
Researchers believe that the gut microbiome influences many aspects of human physiology, including digestion, metabolism, neurological development, and the regulation of hormones. However, scientists are just beginning to understand the complex relationship between the gut microbiome and human health.
What Does Research Tell Us About the Role of Gut Microbiome?
Research suggests that the gut microbiome contributes to the maintenance of normal physiological processes, including digestion, metabolism and immunity.
Many studies have shown that changes in the gut microbiome can cause or contribute to various diseases, including inflammatory bowel disease, obesity, diabetes, cardiovascular disease, allergies, asthma, autism, cancer, and neuropsychiatric disorders.
Some researchers speculate that certain probiotic supplements could potentially alter the gut microbiome and promote health.
How to Improve Our Gut Microbiome?
The human gut microbiome is composed of trillions of bacteria living inside our digestive tract. We share about 90% of our genes with other species such as viruses, fungi, protozoa, worms, insects, plants, and animals. In addition, we share about 50% of our genes with archaea, single-celled organisms. The remaining 10% of our genes are unique to us.
Our gut microbiome plays a vital role in maintaining homeostasis within the host. It protects against pathogenic microorganisms, modulates immune responses, metabolizes nutrients, synthesizes vitamins, produces hormones, and regulates energy metabolism.
It is estimated that the total number of microbial cells present in the human body exceeds 100 trillion! That’s roughly 1 million times more microbes than the number of human cells in our entire body!
In fact, the gut microbiota is now considered to be an organ of the body. It contains approximately 3 pounds of DNA, compared to the weight of the liver alone.
A healthy gut microbiome is essential for overall well-being. When this balance is disrupted, the resulting dysbiosis can lead to various diseases including obesity, inflammatory bowel disease, allergies, asthma, autoimmune disorders, cancer, depression, anxiety, autism, cardiovascular disease, diabetes, osteoporosis, arthritis, Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, and others.
There are three main reasons why we want to maintain a balanced gut microbiome. First, it provides protection against pathogens. Second, it supports normal digestion and absorption of nutrients from the food we consume. Third, it maintains a healthy immune system.
We can change the composition of our gut microbiome through diet, lifestyle, medications, and probiotics. Diet is the primary factor influencing the diversity and abundance of gut microbiota. High-fat diets increase Firmicutes and decrease Bacteroidetes. Low fiber diets increase Proteobacteria. Antibiotic usage reduces the diversity of gut microbiota. Probiotics can restore the gut microbiome balance.
Microbial Composition of The Human Gut Microbiota
It is estimated that approximately 100 trillion microbes from over 1000 species and more than 7000 strains reside in the gut. Although enormous gut microbes in addition to bacteria have recently been identified (including helminths, protozoa, archaea, viruses, phages, yeast, and fungi), bacteria are still the main participants in gut and host homeostasis.
The five major bacterial phyla in the gut are Firmicutes, Bacteroidetes, Actinobacteria, Proteobacteria, and Verrucomicrobia, accounting for more than 90% of the total bacterial population that inhabit the gut. The rest of the bacterial community are from less abundant phyla, such as Fusobacteria and Fibrobacteres. These microbial communities reside with varied densities in different segments of the gut and play a crucial role in many aspects of physiological processes, including facilitating food digestion and energy utilization, synthesizing vitamins and essential amino acids, promoting the development of the immune system, maintaining the integrity of the gut mucosal barrier, and protecting against enterogenous pathogens.
Some Facts About the Gut Microbiome
• The gut microbiota is composed of hundreds of different species of bacteria, fungi, protozoa, viruses, archaea, and worms.
• Each individual carries up to 10 times more bacterial cells than human cells.
• The average adult human host harbors between 100 trillion and 1000 trillion microbial cells.
• Most of these microbes reside in the colon and upper part of the small intestine.
• The number of microbes increases after birth and reaches its peak around age two.
• The majority of the gut microbiota is acquired through breastfeeding, although solid foods also contain microbes.
• The gut microbiota continues to change throughout childhood and into adulthood.
• The makeup of the gut microbiota differs from person to person. Even among congenital twins there is a varied microbial diversity and does not feature the same microbes in the microbiome
• The gut microbiome influences our physiology and behavior. For example, the presence of specific bacteria in the gut can alter appetite, increase insulin sensitivity, improve cognitive performance, and regulate stress responses.
• Gut dysbiosis, or changes in the composition of the microbiota, can cause inflammation and disrupt normal physiological functions.
• Changes in the gut microbiota can affect the risk of developing certain types of cancers.
• Certain probiotic strains can be used to treat various gastrointestinal ailments.
• Antibiotics can disturb the balance of the gut microbiota, leading to increased susceptibility to infections and autoimmune diseases.
• Some antibiotics can kill beneficial gut bacteria, leaving patients vulnerable to infection.
• Probiotics can restore the balance of the gut microbiome and promote overall wellness.
• Fecal transplants can transfer beneficial bacteria from donor to recipient.
• Prebiotics are an essential ingredient for the growth and sustenance of beneficial bacteria in the gut microbiome.
• Microbiota transplantation could become a new therapeutic approach for treating chronic diseases such as type 2 diabetes, metabolic syndrome, and nonalcoholic fatty liver disease.
In conclusion, we know that our gut microbiome plays a huge role in our overall health. However, it’s often overlooked as a factor in disease prevention and treatment. In fact, recent studies show that the composition of our gut microbiota has a direct impact on our mental health, moods, and behavior. This means that taking care of our gut microbes is essential to maintaining a positive outlook and improving our quality of life.
The good news is that there are simple steps you can take to improve your gut health. For example, cutting back on processed foods, sugar, alcohol, and caffeine can help reduce inflammation and stress levels. On top of that, consuming probiotics (such as yogurt) and prebiotics (like fiber) can increase the number of beneficial bacteria in your system.
While these changes won’t cure depression or anxiety, they can definitely help you live happier, healthier lives.
Source:NIH Article, NIH