Your body is filled with billions of bacteria, viruses and fungi. They are collectively known as the microbiome.
While some bacteria are associated with diseases, others are really important for your immune system, heart, weight and many other aspects of health.
This article serves as a guide for the gut microbiome and explains why it is so important to your health.
What is the intestinal microbiome?
Bacteria, viruses, fungi and other microscopic living beings are known as micro-organisms, or microbes, for short.
Trillions of these microbes exist mainly inside your intestines and on your skin.
Most of the microbes in your intestines are in a "pocket" of your large intestine called the caecum, and they are called an intestinal microbiome.
Although many different types of microbes live inside you, bacteria are the most studied.
In fact, there are more bacterial cells in your body than human cells. There are approximately 40 trillion bacterial cells in your body and only 30 trillion human cells. That means you are more bacteria than human (1, 2).
In addition, there are up to 1,000 species of bacteria in the human gut microbiome, and each of them plays a different role in your body. Most of them are extremely important for your health, while others can cause diseases (3).
In total, these microbes can weigh as much as 2 to 5 pounds (1 to 2 kg), which is approximately the weight of your brain. Together, they function as an additional organ in your body and play a very important role in your health.
Summary: The gut microbiome refers to all the microbes in your intestines, which act as another organ that is crucial to your health.
How does it affect your body?
Humans have evolved to live with microbes for millions of years.
During this time, microbes have learned to play very important roles in the human body. In fact, without the intestinal microbiome, it would be very difficult to survive.
The intestinal microbiome begins to affect your body the moment you are born.
First, it is exposed to microbes when it passes through its mother's birth canal. However, new evidence suggests that babies may come into contact with some microbes while they are inside the uterus (4, 5, 6).
As you grow, your gut microbiome begins to diversify, which means that it begins to contain many different types of microbial species. A greater diversity of microbiomes is considered good for health (7).
Interestingly, the food you eat affects the diversity of your intestinal bacteria.
As your microbiome grows, it affects your body in several ways, including:
- The digestion of breast milk: Some of the bacteria that start to grow inside the babies' intestines are called Bifidobacteria. They digest healthy sugars in breast milk that are important for growth (8, 9, 10).
- Digestion fibers: Certain bacteria digest fiber and produce short-chain fatty acids, which are important for intestinal health. Fiber can help prevent weight gain, diabetes, heart disease and cancer risk (11, 12, 13, 14, 15, 16, 17).
- Helping to control your immune system: The gut microbiome also controls how your immune system works. By communicating with immune cells, the gut microbiome can control how your body responds to infection (18, 19).
- Helping to control brain health: New research suggests that the gut microbiome can also affect the central nervous system, which controls brain function (20).
Therefore, there are several different ways in which the gut microbiome can affect key bodily functions and influence your health.
Summary: The gut microbiome affects the body from birth and throughout life by controlling the digestion of food, the immune system, the central nervous system and other bodily processes.
The intestinal microbiome can affect your weight
There are thousands of different types of bacteria in your intestines, most of which benefit your health.
However, having too many unhealthy microbes can cause illness.
An imbalance of healthy and unhealthy microbes is sometimes called intestinal dysbiosis and may contribute to weight gain (21).
Several well-known studies have shown that the gut microbiome was completely different between identical twins, one of whom was obese and the other was healthy. This showed that the differences in the microbiome were not genetic (22, 23).
Interestingly, in one study, when the microbiome of the obese twin was transferred to mice, they gained more weight than those who had received the lean twin microbiome, even though both groups ate the same diet (22).
These studies show that microbial dysbiosis may play a role in weight gain.
Fortunately, probiotics are good for a healthy microbiome and can help you lose weight. However, studies suggest that the effects of probiotics on weight loss are probably quite small, with people losing less than 2.2 pounds (1 kg) (24).
Summary: Intestinal dysbiosis can lead to weight gain, but probiotics can restore intestinal health and help reduce weight.
It affects intestinal health
The microbiome can also affect intestinal health and may play a role in intestinal diseases such as irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) (25, 26, 27).
The swelling, cramping and abdominal pain experienced by people with IBS may be due to intestinal dysbiosis. This is because microbes produce a large amount of gases and other chemicals, which contribute to the symptoms of intestinal discomfort (28).
However, certain healthy bacteria in the microbiome can also improve intestinal health.
True Bifidobacteria Y Lactobacilli, which are found in probiotics and yogurt, can help seal the gaps between intestinal cells and prevent leaky gut syndrome.
These species can also prevent disease-causing bacteria from attaching to the intestinal wall (29, 30).
In fact, by taking certain probiotics that contain Bifidobacteria Y Lactobacilli It can reduce the symptoms of IBS (31).
Summary: A healthy intestinal microbiome controls intestinal health by communicating with intestinal cells, digesting certain foods and preventing disease-causing bacteria from attaching to intestinal walls.
The intestinal microbiome can benefit the health of the heart
Interestingly, the gut microbiome can even affect the health of the heart (32).
A recent study of 1,500 people found that the gut microbiome played an important role in the promotion of HDL cholesterol and "good" triglycerides (33).
Certain unhealthy species in the gut microbiome may also contribute to heart disease by producing trimethylamine N-oxide (TMAO).
TMAO is a chemical that helps block arteries, which can lead to heart attacks or strokes.
Certain bacteria in the microbiome convert choline and L-carnitine, which are nutrients found in red meat and other food sources of animal origin, into TMAO, potentially increasing the risk factors for heart disease (34 , 35, 36).
However, other bacteria within the intestinal microbiome, particularly Lactobacilli, can help reduce cholesterol when taken as a probiotic (37).
Summary: Certain bacteria within the gut microbiome can produce chemicals that can block the arteries and cause heart disease. However, probiotics can help reduce cholesterol and the risk of heart disease.
It can help control blood sugar and decrease the risk of diabetes
The gut microbiome can also help control blood sugar, which could affect the risk of type 1 and type 2 diabetes.
A recent study examined 33 babies who had a high genetic risk of developing type 1 diabetes.
He found that the diversity of the microbiome suddenly decreased before the onset of type 1 diabetes. He also found that the levels of several unhealthy bacterial species increased just before the onset of type 1 diabetes (38).
Another study found that even when people ate exactly the same foods, their blood sugar level could vary a lot. This may be due to the types of bacteria in their bowels (39).
Summary: The gut microbiome plays a role in the control of blood sugar and can also affect the onset of type 1 diabetes in children.
It can affect the health of the brain
The gut microbiome can even benefit the health of the brain in several ways.
First, certain species of bacteria can help produce chemicals in the brain called neurotransmitters. For example, serotonin is an antidepressant neurotransmitter that occurs mainly in the intestine (40, 41).
Second, the intestine is physically connected to the brain through millions of nerves.
Therefore, the gut microbiome can also affect brain health by helping to control the messages that are sent to the brain through these nerves (42, 43).
Several studies have shown that people with various psychological disorders have different species of bacteria in their bowels, compared to healthy people. This suggests that the gut microbiome can affect brain health (44, 45).
However, it is not clear if this is simply due to different eating and lifestyle habits.
A small number of studies have also shown that certain probiotics can improve the symptoms of depression and other mental health disorders (46, 47).
Summary: The gut microbiome can affect the health of the brain by producing brain chemicals and communicating with the nerves that connect to the brain.
How can you improve your gut microbiome?
There are many ways to improve your gut microbiome, including:
- Eat a wide range of foods: This can lead to a diverse microbiome, which is an indicator of good intestinal health. In particular, legumes, beans and fruits contain a lot of fiber and can promote the growth of healthy foods. Bifidobacteria (48, 49, 50, 51).
- Eat fermented foods: Fermented foods, such as yogurt, sauerkraut and kefir, contain healthy bacteria, mainly Lactobacilli, and can reduce the number of species that cause diseases in the intestine (52).
- Limit your intake of artificial sweeteners: Some evidence has shown that artificial sweeteners such as aspartame increase blood sugar by stimulating the growth of unhealthy bacteria such as Enterobacteria In the intestinal microbiome (53).
- Eat prebiotic foods: Prebiotics are a type of fiber that stimulates the growth of healthy bacteria. Foods rich in prebiotics include artichokes, bananas, asparagus, oats and apples (54).
- Breastfeed for at least six months: Breastfeeding is very important for the development of the intestinal microbiome. Children who are breastfed for at least six months have more benefits Bifidobacteria than those fed with a bottle (55).
- Eat whole grains: Whole grains contain lots of fiber and beneficial carbohydrates such as beta-glucan, which are digested by intestinal bacteria to benefit weight, risk of cancer, diabetes and other disorders (56, 57).
- Try a herbal diet: Vegetarian diets can help reduce the levels of disease-causing bacteria, such as E. coli, as well as inflammation and cholesterol (58, 59).
- Eat foods rich in polyphenols: Polyphenols are plant compounds found in red wine, green tea, dark chocolate, olive oil and whole grains. The microbiome decomposes them to stimulate healthy bacterial growth (60, 61).
- Take a probiotic supplement: Probiotics are live bacteria that can help restore the intestine to a healthy state after dysbiosis. They do it by "replanting" with healthy microbes (62).
- Take antibiotics only when necessary: Antibiotics kill many bad and good bacteria in the gut microbiome, possibly contributing to weight gain and resistance to antibiotics. Therefore, only take antibiotics when medically necessary (63).
Summary: Eating a wide variety of fermented and high-fiber foods contributes to a healthy microbiome. Taking probiotics and limiting antibiotics can also be beneficial.
The bottom line
Your intestinal microbiome is made up of billions of bacteria, fungi and other microbes.
The gut microbiome plays a very important role in your health by helping to control digestion and benefit your immune system and many other aspects of health.
An imbalance of unhealthy and healthy microbes in the intestines can contribute to weight gain, high blood sugar levels, high cholesterol and other disorders.
To help support the growth of healthy microbes in your gut, eat a wide variety of fruits, vegetables, whole grains and fermented foods.
Reference: https: //www.healthline.com/nutrition/gut-microbiome-and-health