Over the past five years, more than 70 thousand studies have been conducted concerning the gut flora. Scientists are discovering amazing properties of the bacteria that reside in the human body. It turns out that a great deal depends on them—from digestion to mood. We have explored why the microbiome is the most vital component of health.
Tens of trillions of bacteria inhabit the human body. Their total mass is about 200 grams (it was previously thought to be two kilograms). Most microbes live in the intestines. There, they perform various functions:
process fiber,
synthesize vitamins,
regulate the immune system’s function,
compete with pathogenic bacteria (preventing the latter from multiplying).
There are also conditionally pathogenic microorganisms in the gut. When their numbers increase (due to an imbalance in the microflora), this can lead to uncomfortable symptoms (such as flatulence) or illnesses.
Microbiome and Obesity
In one experiment, noted in the journal Science, fecal matter from “obese” mice was transplanted into “lean” ones. This resulted in the lean mice gaining weight faster. Obese mice that received transplants from thin animals began to lose weight.
This mechanism is less studied in humans, but the results of some research suggest similar processes. Therefore, fecal transplantation is being considered as a potential method for treating obesity.
Microbiome and the Heart
The journal Circulation Research states that diverse, balanced microflora helps maintain an optimal blood lipid profile. This, in turn, lowers the risk of cardiovascular ailments.
Certain types of gut bacteria can convert food components (such as choline and L-carnitine, found in animal-derived products) into the molecule TMAO (trimethylamine N-oxide). High levels of TMAO are linked to the formation of atherosclerotic plaques, vessel blockage, and an increased risk of heart attacks and strokes.
Microbiome and Sugar Levels
A study by Israeli scientists, published in the journal Cell, indicates that people with different types of microflora can have vastly different blood sugar levels after consuming the same foods.
There is growing evidence that an imbalance in microflora impairs cells’ sensitivity to insulin, increases inflammation, and contributes to glucose spikes. Therefore, correcting the microbiome can be viewed as an additional measure for normalizing blood sugar levels.
Microbiome and the Brain
A portion of gut bacteria participates in the production of neurotransmitters—chemical substances through which nerve cells transmit signals. For example, approximately 95% of all serotonin in the body is synthesized precisely in the intestines.
Notably, the gut is connected to the brain by millions of nerve fibers, including the vagus nerve. This system has been named the “gut-brain axis.” Through it, the microbiome can influence mood, anxiety levels, and the response to stress.
A study published in Translational Psychiatry showed that the microbiome of individuals with neurological and psychiatric disorders differs from that of healthy people. This does not prove that bacteria cause the illness but points to their involvement in the process. There is data suggesting that some probiotics may alleviate symptoms of anxiety and depression.
How to Diversify the Microbiome
The most effective method is to consume more fiber (the gut microflora “loves” it). Eat more vegetables, fruits, whole grains, and legumes. The more varied the plant-based foods in the diet, the richer and more resilient the microbiome becomes. Fermented foods are also beneficial: yogurt (without sugar), kefir, and pickled vegetables.
Limit sugar, fast food, and ultra-processed products. Antibiotics should ideally be taken only when indicated and according to a schedule prescribed by a physician.
The following also positively impact the microbiome:
regular physical activity,
adequate sleep,
stress reduction.
How Effective is Fecal Transplantation?
Fecal microbiota transplantation (FMT) is a medical procedure whose efficacy is actively being studied. Currently, it has a strong evidence base only for recurrent Clostridium difficile infection.
Its effectiveness and safety for rejuvenation, weight loss, or general wellness have not been proven (these methods are currently being explored only in clinical trials).
The Main Point
The gut microbiome affects digestion, immunity, blood sugar levels, heart function, and even mood. A diverse and resilient microflora is one of the key factors for good health.
You can support the microbiome with plant-based food, sufficient sleep, and physical activity. Fecal transplantation is not a universal health method but a strictly medical procedure with narrow indications.
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