Why we should be copying the diets of villagers from this remote Pacific nation

Scientists are exploring ways to cultivate healthy gut microbiomes, the complex communities of bacteria, fungi, and viruses residing in our intestinal tracts that play a crucial role in our overall health. This pursuit has led researchers, including myself, to the remote valleys of Papua New Guinea.

Papua New Guinea, an island nation north of Australia, offers a unique glimpse into a non-industrialised lifestyle. Until 1930, many of its valleys remained largely untouched by the modern world. The people of Papua New Guinea, largely practice sustenance agriculture, growing their own food.

This traditional way of life, coupled with a diet vastly different from typical Western fare, inspired a nine-year research project involving scientists from eight countries. The findings, recently published in Cell, offer intriguing insights into the relationship between diet, lifestyle, and gut health.

Typical Western diets, often low in fibre and high in processed foods, are linked to various health problems, including diabetes, heart disease, and obesity. These diets not only harm our bodies but also negatively impact our gut microbiomes.

Previous research on rural Papua New Guineans revealed gut microbiomes significantly more diverse than those of individuals consuming Westernised diets. These microbiomes are rich in fibre-loving bacteria and contain lower levels of inflammation-causing bacteria commonly found in people who eat highly processed foods. This research underscores the potential benefits of a traditional, non-industrialised lifestyle on gut health and overall well-being.

This information provided hints on how to perhaps redress the damage caused to our gut microbiomes.

The traditional diet in rural Papua New Guinea is rich in unprocessed plant-based foods that are full of fibre but low in sugar and calories, something I was able to see for myself on a field trip to Papua New Guinea.

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Determined to create something everyone could use to benefit their health, our team took what we saw in Papua New Guinea and other non-industrialised societies to create a new diet we call the NiMe (non-industrialised microbiome restore) diet.

What sets NiMe apart from other diets is that it is dominated by vegetables (such as leafy greens) and legumes (such as beans) and fruit. It only contains one small serving of animal protein per day (salmon, chicken or pork), and it avoids highly processed foods.

Dairy, beef and wheat were excluded from the human trial because they are not part of the traditional diet in rural Papua New Guinea. The other characteristic distinction of the diet is a substantial dietary fibre content. In our trial, we went for around 45g of fibre a day, which exceeds the recommendations in dietary guidelines.

One of my PhD students got creative in the kitchen designing recipes that would appeal to a person used to typical Western dishes. These meals allowed us to develop a meal plan that could be tested in a strictly controlled study in healthy Canadian adults.

We saw remarkable results including weight loss (although participants didn’t change their regular calorie intake), a drop in bad cholesterol by 17 per cent, decreased blood sugar by 6 per cent, and a 14 per cent reduction in a marker for inflammation and heart disease called C-reactive protein. These benefits were directly linked to improvements in the participants’ gut microbiome, specifically, microbiome features damaged by industrialisation.

On a western diet low in dietary fibre, the gut microbiome degrades the mucus layer in the gut, which leads to inflammation. The NiMe diet prevented this process, which was linked to a reduction in inflammation.

The diet also increased beneficial bacterial metabolites (byproducts) in the gut, such as short-chain fatty acids, and in the blood, such as indole-3-propionic acid – a metabolite that has been shown to protect against type 2 diabetes and nerve damage.

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Research also shows that low dietary fibre leads to gut microbes ramping up protein fermentation, which generates harmful byproducts that may contribute to colon cancer.

In fact, there is a worrying trend of increased colon cancer in younger people, which may be caused by recent trends towards high-protein diets or supplements. The NiMe diet increased carbohydrate fermentation at the expense of protein fermentation, and it reduced bacterial molecules in the participants’ blood that are linked to cancer.

The findings from our research show that a dietary intervention targeted towards restoring the gut microbiome can improve health and reduce disease risk. The NiMe diet offers a practical roadmap to achieve this, by providing recipes that were used in our study. It allows anyone interested in healthy eating to improve their diet to feed their human cells and their microbiome.