indulge in all their favorite food but still do not gain weight, while others
follow various types of diet to shed the extra kilos, despite which they
fail to lose weight. For the first time, a study conducted in
Israel has shed light on the reason behind it. The revolutionary study was
carried out by a team at the Weizmann Institute of Science in Rehovot and led
by Professor Eran Segal and Dr Eran Elinav.
Dr Saleyha Ahsan
traveled to Israel to take part in the study as part of Trust Me, I'm a Doctor.
The researchers monitored 1,000 people to study how their bodies react to food.
Foods can make some individuals put on weight and have no effect on others.
Every person reacts differently to different foods. The blood sugar level
rises after each meal. Theoretically,
it is suggested that some foods, for example, white bread, causes a sudden rise in the blood sugar level
. The constant rise in blood sugar level
can result in type 2 diabetes, obesity and increases the risk for other diseases.
It is also thought that other foods, for example, whole grain rice does not drastically increase the blood sugar level. Therefore, foods have been classified as 'high GI' (glycemic index
) food and 'low GI' foods, based on the rise in blood sugar levels.
‘Gut microbes might be the key to why the blood sugar level rises with different foods and vary with different individuals.’
Microflora is the Key
Based on the
data collected from monitoring 1,000 participants, the researchers were able to
make firm links between a person's individual response to food, and to their gut bacteria. The researchers have developed a computer algorithm that uses an individual's gut
to predict how their blood sugar levels may react to a whole range of foods. A study was carried out to test the accuracy of the
algorithm, and it indeed appeared to predict the good and bad foods for individuals based on their gut microflora. This shows the vital role of gut
microflora in regulating an individual's response to food and overall health.
carried out a small study using an algorithm and provided the list of good and
bad diet for 25 people. The researchers took stool samples of the participants
to discover the composition of the gut microbes. Every individual carries thousands of different bacteria, fungi, and viruses in their gut.
These microbes help break down the food and also produce an enormous range of
compounds that the body absorbs and that can have an influence on the immune system
, metabolism, and neurotransmitters.
participants were given only the food 'good' for them for a week and 'bad' for
another. The participants were unaware of the good and bad foods. Over the week, the researchers observed changes in blood
sugar levels as predicted and also changes in the gut microflora of the
participants. The changes observed during the week of 'good' food appeared to
be beneficial. The results of the study suggest that personalizing diets based
on an individuals response to food can benefit overall health.
The foods that
were found to be good for Dr Saleyha's (who participated in the study) blood
sugar levels included avocado, croissant, yogurt, granola, banana, walnuts,
omelet, chocolate, ice cream and cola. The foods that were found to be bad for
Dr Saleyha's blood sugar levels included, grapes, cereal with milk, pizza,
pasta, tomato soup, chicken sandwich (on wholemeal bread), orange juice and
sushi. In a short and uncontrolled trial, the gut microflora changed for the participants
, who were given only the foods identified as good and
avoiding the bad for two weeks.
In future, the
researchers Dr Segal and Elinav hope to be able to make the results of their
work available to everyone, worldwide. They hope to provide a list of foods
that are predicted as good and bad for an individual to help maintain stable
and healthy blood sugar levels.
The research team also plans to study the
long-term effects of diet on gut microflora.