You’d be forgiven for thinking that the war on obesity and type 2 diabetes has been won. This is due to the rise of a superstar class of drugs such as Ozempic.

Sure, these drugs that mimic the GLP-1 hormone have set the world on fire. This is because, beyond conferring weight loss, they promise to be a potential cure-all for heart disease, addiction and more.

But they’re expensive, and have side effects, some of them serious. And they need to be taken for life, or all the weight returns.

Nevertheless, the vibe is so loud that other new treatments for obesity tend to go unnoticed. Until now.

A simpler, safer, cheaper option

News came this week that scientists have discovered a simpler, cheaper and safer option.

In a clinical trial, carried out by researchers from China and Germany, obese participants were given a diet richly supplemented with resistant starch.

Previous studies have suggested that certain foods can be used to selectively modify the gut microbiota. The idea is to benefit our metabolism, our health more broadly, and to reverse or prevent obesity.

And that’s precisely what happened in this trial.

The intervention led to a favourable transformation in the gut microbiome, resulting in significant weight loss and enhanced insulin sensitivity.

How did this happen?

First of all, regular starch, the sort you get from potatoes and rice, burns up quickly in the small intestine, and little of the potato survives long enough to pass through to the large intestine.

Resistant starch gets its name from how it ‘resists’ digestion in the small intestine. When it moves into the large intestine, it behaves like a form of fibre by fermenting and feeding the resident ‘good’ bacteria.

Resistant starch can be found naturally in some wholegrains, beans and legumes, raw oats and green bananas.

However, it can also be created in potatoes, rice and pastas –  foods that ordinarily turn quickly to sugars – by cooking them and allowing them to cool.

The gut microbiome

You’ve probably heard of the gut microbiome – essentially all of the microbes in your intestines, including many species of bacteria. The microbiome acts as another organ that’s vital for your health.

Altogether, those microbes weigh one to two kilos, the same as your brain.

In the clinical trial, the resistant starch supplements led to an abundance of the bacteria Bifidobacterium adolescentis. It was this bacteria that played the key role in promoting weight loss.

In a separate experiment, with mice, Bifidobacterium adolescentis prevented fat absorption in the intestine and protected against diet-induced obesity.

The researchers recruited 37 overweight people who consumed a sachet of starch mixed with water twice a day before meals.

For eight weeks, they were given resistant starch. Over another eight weeks, the sachet contained ordinary sugary starch by way of comparison and control.

The participants also ate three balanced healthy meals a day. Various health markers were measured.

The results

After eating the resistant starch for eight weeks, the participants lost an average of 2.8 kilograms. (The regular starch had no effect on weight one way or the other.).

The resistant starch also caused less of a rise in blood sugar after meals, which suggests it may be protective against type 2 diabetes.

Stool samples revealed that while people were taking resistant starch, several bacterial species became more abundant. Bifidobacterium adolescentis was deemed the most significant of these.

It’s early days and there is a lot to explore here in future studies.