Microbiota - Community types

The human gut microbiota is different in all the humans being worldwide, so your microbiota is like your personal fingerprint. However, there are many similarities between different microbiota, and this information can be used by us to develop health biomarkers and to define therapeutic strategies.

The human gut consists in trillions of microbes and the whole ecosystem varies between individuals in diversity, distribution and abundance. In any ecosystem the selective pressures, disturbances and survival conditions are very important in defining the species leading to a distinct community type in that area. There was a study on human microbiome investigating the impact of possible steering factors such as the dietary habits. The observation underlines that certain combination of microbes, distribution and diversity can lead to a distinct community structure. But, even more important, the people can be grouped in 3 main groups, in a similar way to the blood group type. They can have a high number of Bacteroides, Prevotella or Ruminococcus. People eating a diet with less fibre and high in animal fat tend to have the Bacteroides community, people with a diet high in fibre and low in animal fat tend to have Prevotella community type and finally, was shown that every individual will have a gradient from high to low abundances on these three groups of bacteria. You can see that different dietary habits can support different microbes, and changes to diet can shift the percentage of each community type.

There is also the concept of the genes present in the microbial complex, which will define the potential of degrading complex fibres. So now the community type will also include this microbial gene into information. It turned out that some of us have high gene righness and others can have low gene richness. This low and high gene count can be used to separate individuals in a population. If you got inflammatory bowel disorder and obesity, you will usually have low gene richness. You are also more likely to get more weight than someone with high gene richness. All these concepts can be used to predict individual susceptibility to gain weight.

Even if the individual microbiota is different for each person, there are characteristics that are overlaping. Knowing how a community will respond to a diet and other pressures helps to develop health biomarkers and therapies.

Next post will be about twins and siblings microbiota.

Have a nice evening!
G.

Microbiota - dietary habits

As I promised, after i finished the Autism course, i will come back to the microbiota series.

Now, the course is finished, so we will talk today about dietary habits. We all know that our diet determine what our microbiota can feed off. So, knowing this, we can change our microbiota changing our diet.

How can we do that? Easy, but you need to learn about it. You want to lose weight, you will use a calorie deficit diet, and once you reached the desired weight, you stop. This move will have a drastic effect on your microbiota, but as soon as your eating habits are back to normal, your microbiota will regulate too, because it developed a stable state over the years, and that it is not easily disturbed.

I have read about an interesting study, where they switched the diets of a population of African-Americans with that of the rural Africans. The African-Americans were given a high fibre, low fat African style diet. The rural Africans were given high fat, low fibre Western style diet. After a while, the African style diet was shown to support beneficial microbes and improved function, the Western style diet increased the risk of cancer. This research shows how short dietary changes can affect our microbiome and health.

In order to understand the long term effects of dietary habits, the researchers studied a number of individuals from different countries. People from Western world with  a diet of high protein and low fibre content tend to have more Bacteroides bacteria. People from rural Africa tend to have more Prevotella bacteria. With all the advances regarding food, we are losing our ancestral microbiome due to changes in our dietary habits and surrounding environmental factors. This can have a negative effect on health, leading to diabetes development, colon cancer, I.B.D., all of them being more prevalent in the western world.

I hope you enjoyed this new introduction. Next post will be about community types.

See you soon.
G.