What is Healthy Gut Bacteria?

Since ancient times, humanity has thought that bacteria and other microorganisms are totally harmful to our health. However, some types of microorganisms, mainly bacteria, are beneficial and necessary for our well-being and with which we have lived in symbiosis since the beginning of the human as a species. Between 300 and 500 different types of bacteria are living inside our intestines, approximately 100 billion organisms. These bacteria, working together with various types of microorganisms, make up what is known as our microbiota. The number of bacteria that we can have lodged inside our intestines is ten times more than the number of cells in our body; there are so many that they can even represent 1 kg of our body weight. The human genome consists of more than 23,000 genes, while the genome of the community of bacteria that live within us is made up of more than 3 million genes. Thus, 99% of our genes are microbial and are necessary for the proper functioning of our body and to keep our levels of healthy gut bacteria.

The community of bacteria that live inside us is unique to each person the same as our fingerprints are; each one has a different composition. There are several factors that influence the composition of our microbiota:

• The microbiota of our mother
• The environment to which we were exposed at birth
• Our feeding
• Drugs

The community of bacteria within our intestines evolves throughout our entire lives, from birth to old age. Inside our mother’s womb we lack microbiota. At birth, the gastrointestinal tract is immediately colonized by bacteria by a simple microbiota that comes from the mother. Good bacteria such as bifidobacteria are acquired during lactation. During the first three years of life, the microbiota is mainly composed of this type of bacteria. The diversity of our healthy gut bacteria also depends on the environment during early childhood. Less diversity of bacteria has been seen in children in Western countries, which may be related to excessive hygiene. As the microbial community grows, it diversifies and reaches its maximum complexity in adulthood, dominated by Bacteroides and Firmicutes.

The variations are more noticeable during the third age. The microbiota is impoverished due to physiological changes, such as a decrease in immunity, a less varied diet, the intake of numerous medications, including antibiotics, and, above all, a sometimes less independent way of life. Older people who reside in nursing homes tend to show a more considerable impoverishment of their microbiota than those who remain at home and maintain their usual diet.

Healthy gut bacteria play an important role throughout our lives, influencing the development of the immune system, nutrition, and metabolism, and even affecting our mood. The importance of these healthy intestinal bacteria is so great that it has gone from being considered a commensal to being considered a metabolic organ. A proportion of the food we consume is not digested when it leaves the small intestine; the microbiota ferments it within the colon. During this fermentation process, gases and numerous metabolites are produced, including short-chain fatty acids, which represent a true “fuel” for the cells of the colon.

They also have a defense function as the intestine faces a major challenge: to tolerate the beneficial bacteria in the microbiota and effectively oppose the colonization of dangerous bacteria, called pathogens. The microbiota participates in this barrier function. The “good” bacteria in the microbiota fight directly against pathogens to compete for the same nutrients. Also, some bacteria release antimicrobial molecules against pathogens. Finally, there are others that stimulate the production of mucus to protect intestinal cells from aggressions and avoid harmful effects on the body.

A healthy gut bacteria community is one that has good species and gene diversity and resistance to disturbances. There are different situations that can unbalance our intestinal flora and therefore cause alterations in our health:

1. Infections from pathogens such as viruses and other bacteria.
2. Antibiotics, because these reduce the number of healthy intestinal bacteria.
3. Bad habits such as sedentary lifestyle, poor diet, insomnia, consumption of tobacco, alcohol, living in highly polluted environments, etc.

The alteration in our intestinal flora can be a reason for the development of some symptoms such as constipation, diarrhea, infections, weakness of the immune system, inflammation, and gas. These can all be signs of some diseases that develop when our community of healthy gut bacteria becomes unbalanced such as:

• Irritable bowel syndrome
• Crohn’s disease
• Celiac Disease
• Fatty liver
• Obesity
• Diabetes
• Ulcerative colitis
• Anxiety
• Depression
• Arthritis

Keeping our microbiota healthy is therefore essential, and since the human body does not generate it, it is necessary to acquire it from abroad through diet.

In the case of diet, it is essential to ingest fiber, as it reaches the colon undigested and serves as food for healthy intestinal bacteria. We can find fiber in fruits, vegetables, and seeds. It is also important to include prebiotics and probiotics in our daily diet because they stimulate the microbiota’s growth and proper functioning. Limiting the use of antibiotics will also improve the state of our beneficial bacteria.

Healthy intestinal bacteria are part of our body, and we need them; maintaining a healthy diet and habits will keep them in good condition, and they can continue to work as a team with our bodies.