This was the message from Jens Walter, professor of ecology, food, and the microbiome at University College Cork (UCC), Ireland, presenting at the IPA World Congress + Probiota 2026 (Feb. 11-13).
He spoke about the research behind the Non-Industrialized Microbiome Restore Diet (Nime diet), a high-fiber, plant-forward diet modelled on the traditional, largely unprocessed diets of the rural Papua New Guinea (PNG) population. Despite being poor and having less access to healthcare, the population has much lower rates of chronic diseases than industrialized populations, leading to interest in their diet.
The NiMe diet aims to restore gut health by focusing on vegetables, legumes, and fruits, while keeping fat intake low and limiting animal protein to one small serving daily (chicken, pork, or fish).
Unexpected findings
Research into the health impacts of the NiMe diet in a Canadian population published in 2025 revealed it successfully reversed several microbiome effects linked to industrialized diets.
Interestingly, overall microbial diversity decreased initially but slowly increased again through the three weeks of the study intervention, which Walter suggested was an indication of an ‘adaptation process’. The diet also led to gut community stability and interconnectedness, improved fiber fermentation capacity, reduced pro-inflammatory microbes, and more abundant health-promoting bacteria.
The diet further led to broader cardiometabolic benefits, reduced risk markers for non-communicable diseases, modest but significant weight loss, lower cholesterol measures and improved insulin sensitivity.
He noted the weight loss was unexpected, as the participants had been put on a calorie matched diet.
“This really surprised us but now we understand that structurally whole foods are very different to processed foods, fibre is three dimensional and energy accessibility is much, much lower.”
There was also a significant drop in fecal PH, which Walter suggested is an under appreciated for its importance in indicating “all kinds of metabolic processes”.
“There’s a lot of evidence that by lowering the PH in the gut a lot of detrimental metabolites in the gut are actually prevented. We can see this through the data as the ratio of branched-chain fatty acids (BCFAs) to short-chain fatty acids (SCFAs), which a recognized marker of protein fermentation (proteolytic fermentation), is reduced.”
All the changes in the microbiome quickly shifted back to previous status once the participants reverted back to their usual Canadian diets.
When it came to pinpointing what changes in the microbiome led to which health outcomes, the researchers found the number one predictor for improvements in cholesterol was the reduction in Bilophila bacteria. The number one predictor of inflammation (measured through CRP levels in the blood) was the mucin-targeted total metagenome read ratio.
Ultimately, the research revealed a clear link between microbiome markers and health outcomes as well as revealing that even microbiomes damaged by an industrialized diet can be quickly reshaped by a non-industrialized diet.
Yet, even the strongest scientific evidence cannot change the reality that large‑scale, long‑term dietary shifts are extremely difficult to achieve in the general public.
“Scientists have realized we should be eating healthier for 50-60 years but if you look at success rate in trying to get people to eat healthy, despite dietary guidelines and despite knowledge campaigns, successes have been few. ”
As such, the NiMe team has partnered Gourmet Fuel in Ireland to make NiMe ready meals available to the wider public to make it as easy as possible to access the food.
There is also a NiMe science and cookbook freely available to download online and a social media campaign to improve awareness amongst the masses.
