As part of the BBC’s Trust Me I’m A Doctor series I took part in a research project looking into what makes some people, but not others, put on weight. Previously genes were blamed. But actually it’s to do with our guts. Literally.
I spent a week at the Weizmann Institute of Science, Tel Aviv – home to the project run by Professor Eran Segal and Dr Eran Elinav. So far they have results from 1,000 participants and a waiting list of 4,000. They believe their work could change the way we view diets. We are all unique, down to our own DNA sequence, so why should we respond to food in the same way? It looksas if we don’t.
The plan was to identify my own gut bacteria profile or microbiome and monitor my blood sugar response to food. We now know gut bacteria are extremely significant players within health.
Firstly, I was connected to a glucometer attached through the skin, recording my blood sugar levels 24 hours a day for the entire week.
I followed a strict but varied meal schedule, logging eating, sleeping and other activity all week into a specially designed app. I also recorded glucose readings by pricking my finger immediately before and after eating.
The aim was to see how different food affected my blood sugar levels compared with others in the study. High sugar readings or spikes lead to weight gain and increased risk of diabetes.
At the end of the week my results meeting with Segal changed my life. I was presented with two lists of food created from my results and from an algorithm based on the researchers’ results so far.
One list contained “green” food – those that did not spike my blood sugar levels. The other was a “red” list – foods that caused spikes and were therefore considered bad for me.
The most shocking revelation was finding that “healthy” food such as grapes, salmon, orange juice and new potatoes all spiked my sugar levels. Then there was my good list – containing food not present in my cupboard for years. Croissants, chocolate and ice-cream apparently did not spike my blood sugar levels. The chocolate and croissants are wasted on me – I don’t like them – but ice-cream was good news.
The explanation lies in my gut microbiome profile, obtained via a stool sample. Gut bacteria play a fundamental role in host functions. Their reaction with food goes on to direct physiological pathways and hormonal release around the rest of the body, including energy release and storage, thus affecting our weight.
Mine showed showed an imbalance in the bacteria linked to obesity and development of diabetes.
As part of the research, I undertook to eat only green-list foods. No red foods have since passed my lips. The results have been astonishing. After just three weeks I started to notice the difference. No longer was I feeling tired during the day. I used to blame myself for feeling lazy but it’s more scientific than that.
After a blood sugar spike, there is a fall, which is when you feel lethargic and hungry, driving you to eat again. No wonder people get fat. Now I was eating food that produced a more steady sugar response I was no longer having the downs or the hunger pangs. My skin looked better and I lost half a stone.
Even more amazingly, my new gut microbiome profile changed. There was a marked decrease in gut bacteria associated with obesity and diabetes.
Parts of the world are facing an obesity and diabetes epidemic. Until now a doctor managing pre-diabetic patients would have advised them to eat less and move more. In the future they will instead “prescribe” a diet based on their gut microbiome.
Instead of counting calories or banning carbs we will be working with our own gut bacteria to shift the pounds and at the same time protecting ourselves from diabetes.