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The NiMe Diet: What is it, and How Might it Affect Dietetic Practice?

Posted: 2025-09-29
The NiMe Diet: What is it, and How Might it Affect Dietetic Practice?


What’s Happening?

A new diet, the NiMe diet (1), has been designed to restore our industrialized gut microbiomes to their “ancestral” state. The PEN Team asked: what is this diet, and what does it mean for dietitians in practice?

What is the NiMe Diet?

Nutrition researchers and dietitians at the University of Alberta recently published a crossover randomized controlled trial (RCT) evaluating the effect of a diet they created to investigate whether they could restore industrialized gut microbiomes to an “ancestral” state (1). The NiMe Diet (Non-industrialized Microbiome Restore) is based on the traditional diet of people living in non-industrialized societies, modified to include only foods available in Canada. It consists of traditional foods such as beans, sweet potato, rice, cucumber, and cabbage, as well as foods that encourage Limosilactobacillus reuteri (L. reuteri) growth, such as Jerusalem artichokes, peas, and onions. Vegetables and fruits comprise the majority of the diet with smaller amounts of protein foods (primarily plant-based proteins and smaller amounts of fish, poultry and yogurt) and whole grains. 

Additionally, the authors aimed to use L. reuteri to colonize the gut microbiomes of study participants. The authors chose L. reuteri as a target because it is not typically found in people with industrialized gut microbiomes but is dominant in the gut microbiomes of people from Papua New Guinea, who have non-industrialized gut microbiomes. In addition, L. reuteri is generally recognized as safe and has been linked to positive health effects. 

The Study

Thirty healthy participants were randomized in a crossover design to follow either the NiMe diet (all meals provided) or their regular diet for 3 weeks. They were then switched to follow the other diet for 3 weeks after completing a 3-week washout period. All participants were also assigned to one of three treatment arms on day 4 of each diet period: 1. placebo (n=10), 2. inoculation with a L. reuteri strain found in industrialized microbiomes (n=11) or 3. inoculation with a L. reuteri strain found in non-industrialized microbiomes (n=9). 

The Results

On average, dietary fibre intake doubled during the NiMe Diet compared to the control diets. Saturated fat intake decreased significantly, while energy intake was held constant. Despite no change in energy intake, participants lost a small amount of body weight while consuming the NiMe Diet (average decrease in both body weight and BMI was 1.4% + 1.9%). 


Cardiometabolic biomarkers such as total cholesterol, LDL cholesterol, fasting glucose, insulin sensitivity and insulin resistance were positively affected by the NiMe diet. According to the authors, the size of these improvements was comparable to improvements reported when following a vegan or Mediterranean diet, which may be attributed to the high fibre intake of these dietary patterns (1). 

Participant reaction to inoculation with either L. reuteri strain was highly variable, and it was difficult to colonize participants’ gut microbiomes with L. reuteri with any lasting stability. In addition, following the NiMe diet reduced gut microbial diversity, although it increased species interconnectedness, stability and growth of known health-promoting species. Importantly, the authors also point out that even if returning the gut microbiome to an “ancestral” state were possible, what constitutes an “ancestral” microbiome is open to discussion, and it remains unclear whether an “ancestral” gut microbiome would confer health benefits to individuals living in industrialized communities.

Overall, microbiome changes did not appear to affect cardiometabolic outcomes. However, the NiMe diet showed consistent cardiometabolic improvements despite the variation in participants’ gut microbiomes. 

Limitations

Although the study was an RCT, its sample size was small and lacked statistical power for calculating the significance of some outcomes. In addition, it used a volunteer sample of mostly students or university employees who received all prepared meals on the NiMe diet, making the generalizability of the findings unclear. It is, however, the first study to analyze the feasibility and health effects of the NiMe Diet. More research is required to confirm and substantiate the authors’ findings in a real-world setting.

The Bottom Line

The NiMe Diet was found to be equivalent to other plant-heavy diets (e.g. vegan, Mediterranean) in its effect on cardiometabolic outcomes. Like these other diets, it is relatively high in fibre and low in saturated fat. At this time, the NiMe Diet’s effect on the gut microbiome does not appear to affect cardiometabolic health outcomes.

If a client wants to try the NiMe Diet, there is no known harm in doing so, and it may have positive health effects. The PEN team will continue to watch for future research on this new diet.

Additional Content:
PEN System Gastrointestinal System - Microbiota Background

Further Reading

The study authors have created a cookbook of recipes that are compliant with the NiMe Diet. It can be downloaded free of charge here: https://ualberta.scholaris.ca/items/fe23792e-0584-4d7d-a657-1392bad5880b  

References

  1. Li F, Armet AM, Korpela K, Liu J, Quevedo RM, Asnicar F, et al. Cardiometabolic benefits of a non-industrialized-type diet are linked to gut microbiome modulation. Cell. 2025 Mar 6;188(5):1226-1247.e18. doi: 10.1016/j.cell.2024.12.034. Epub 2025 Jan 23. PMID: 39855197. Abstract available from: https://pubmed.ncbi.nlm.nih.gov/39855197/
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