Beyond Digestion: The Hidden Powers of Your Gut Microbiota

Contents

Introduction

The food that we eat not only provides nutrition for us; it also acts as a substrate for the trillions of bacteria that are present in our gut. The organs from the stomach to the colon comprise the gut in common language. The digestion of food starts in the mouth, and the major portion of digestion is completed by the time the food reaches the duodenum, the upper opening of the small intestine. The small intestine hordes the gut microorganisms or the gut microbiota.

Picture of intestine showing the gut microbiota.

Image source: Canva

How does the gut microbiota influence gut health ?

There are about a thousand species of the gut microbiome, or gut microorganism, of which an adult individual can have at least a hundred species in his gut. Most of these organisms belong to the phylum Bacteroidetes, Proteobacteria, Firmicutes, Verrucomicrobia, etc. Of these, the majority of the bacteria belong to the phylum Bacteroidetes and Firmicutes. Some bacteria of the phylum Proteobacteria can become pathogenic under certain conditions. An unusual increase in these organisms is observed in Irritable Bowel Syndrome (IBD)

This image details the effect of bad and good gut health.

How gut microbiota improve gut health

The diet that we eat has a profound effect on the gut microbiome, as the undigested food acts as a substrate for these microorganisms. The artificial sweetener added to the diet will not increase the calories of the food but it causes drastic change in the gut microflora. Also the emulsifiers added to the processed foods causes a reduction in the gut flora.

A food rich in carbohydrate and low in fibre also causes reduction in the gut flora. Also, the SCFAs produced in the gut reduce, as the fermentation of the fibre in the food causes the release of SCFAs.

Thus, to have a normal gut microbiota, we have to consume foods rich in fibre, protein, and low calories. Also, we have to include whole grains and fermented foods. Fermented foods are rich in probiotic bacteria, which are usually part of the gut microbiota.

The role of gut microbiome in weight loss and immunity

Acetate, Propionate, and butyrate are the major SCAFs produced by the gut microbiomes. Butyrate provides energy for colon cells and destroys cancer cells in the colon. Also, it induces glucose production in the intestine through intestinal gluconeogenesis, thereby reducing calorie intake. Also, butyrate increases oxygen consumption of the gut epithelial cells and helps in providing oxygen to the gut microbiome, thus maintaining a balance between aerobic and anaerobic organisms.

Propionate moves to the liver, regulates gluconeogenesis there by releasing the satiation hormone, and reduces calorie intake. Acetate, which is produced in abundance, mediates the cholesterol metabolism and metabolic formation of fats (Lipogenesis), thereby signalling the hypothalamus for satiation and reducing calorie intake. Also, acetate is needed for the growth of the gut microbiome. Thus, maintaining a proper gut microflora helps with weight loss.

The gut bacteria interact with the mucosal immune cells directly; these kill the pathogenic microorganisms, and these antigens are presented to the mucosal immune cells by the antigen presenting cells, and thus an immune response is elicited against these organisms. The gut microbiome eliminates the pathogen directly and also improves our immune health.

Conclusion

The normal flora of the gut plays an important role in the overall health, and immunity . It is important to have a properly balanced diet with low calories, high protein, high fibre and fermented foods to improve gut health. Thus, if the gut remains healthy, we will also be healthy and can reduce the risk of lifestyle diseases like cardiovascular disease, obesity, and diabetes.