The Importance Of Microbes In The Human Body

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BY: SIMANG CHAMPRAMARY

Microbiota is the community of organism that dwells at different sites in the human body. There are billions of different organisms but the only known communities which could be identified are Firmicutes, Bacteroidetes, Actinobacteria, Fusobacteria, ProteobacteriaandVerrucomicrobia. They are important to us because:

• They are responsible in providing us with necessary vitamins

• Digesting oligosaccharides

• Training our immune system and inhibiting pathogenic organisms

The presence of various community of microbes are shaped by:

• Mode of delivery in birth: children born in normal delivery mode will have different community of microbes compared to children born with C-section.

• Food: Different types of food

Most of the researchers wanted to know how microbes affect our body or how our body affects microbes. But with time, some group of researchers came up with an idea that they had something to do with obesity. To address this question they performed an experiment, where they introduced microbiota of obese mice to lean mice which was grown in sterile environment. After few days they observed that there was gradual improvement of weight of the lean mice. With this they could prove that microbes played a role in obesity. To find which community of microbes affects which the organisms they observed microbiota of different animals that were obese and lean. They found out that there was number difference in different communities of microbes that were found in obese and lean mice. The lean mice had more Firmicutes while the obese mice had more number of

With 370 trillion of them colonizing our gut, they outnumber our own body cells. These invisible creatures have all together altered our understanding of obesity in the last few years. Sedentary lifestyle and diet, now, do not even make 50% of the ‘obesity puzzle’. (2)

Scientists have shown in mice the significant role of microbiota in impacting the body weight and fat distribution. So when it comes to obesity, there are two categories of bacteria- ‘fat-loving’ microbes or the selfish bacteria and the good bacteria.These ‘fat-loving’ microbes are known to extract more energy (fat) from the food and thus circulate greater levels of fat in the blood stream. (3)Also, obesity in children has been linked to various factors that detract from flourishing a diverse range of microbiota. These include C-section epidemics, lack of breast-feeding and prolonged use of antibiotics.

In the healthy individuals, two major metabolites have been identified as secreted by the gut microbiota: Fasting induced adipose factor (FIAF) and Adenosine Monophosphate kinase (AMPK). In healthy individuals, FIAF prevents the release of fat from triglycerides and thus reduces fat deposition. AMPK provides obesity resistance even when the subject was on a fat rich diet.