Diets, nutrients, genes and the microbiome: Recent advances in personalised nutrition
Matusheski, N., Mezgec, S., Koroušić Seljak, B., et al. (2021)
Dietary recommendations are based on population averages, but many would like to know what we should eat individually. Complex interactions among genetics and environment make individualized advice difficult at least for the moment, but here are four advances in personal nutrition:
1. Folate during pregnancy – inadequate folic acid/ food folate intake before and during the first trimester of pregnancy (up to 12 weeks’) raises the risk of neural tube defects (e.g., spina bifida). But, what about folate later in pregnancy? A follow-up of the FASSTT Offspring Trial showed increased performance on several cognitive measures in 7-year-olds amongst mothers who took folic acid supplements for longer.
Take home: Make sure you meet the recommended daily amount (RDA) for folic acid (600 micrograms/day) if you might become pregnant and during the first 12 weeks, as well as throughout pregnancy and lactation (500 micrograms/day).
2. Vitamin B12 and cardiometabolic disease (CMD) – variations in B12-associated proteins suggest effects of this vitamin might be linked to ethnicity. Studies in Sri Lanka, Malaysia, and India showed a relationship between B12, proteins and risk of obesity and diabetes.
Take home: It is too soon to know if ethnicity should be reflected in B12 recommendations, but it is important that recommended daily amounts of b12 (2.5 micrograms/day) are consumed, regardless of ethnicity, and this might mean taking a supplement if you eat diet based solely of plant-foods.
3. Microbial enterotypes and obesity – primary gut microbe populations are associated with long-term dietary habits: Prevotella spp. with high carb and high fibre diets and Bacteroides spp. with high fat, high refined sugar ‘Western diets’. Three independent European studies suggested those with predominantly Prevotella spp. gut microbes lose more weight following a fibre-rich diet and are more likely to keep it off. Complexity comes from many varieties of Prevotella and Bacteroides spp. and from interactions with other contributors to digestion.
Take home: Establishing a Prevotella and Bacteroides spp.-type microbiota is influenced by long-term eating habits and contributes to responses to diet. It is worth eating well for the long term.
4. Digitalising dietary assessment – NutriNet, food image recognition software, based on deep-learning architecture, can recognise pictures of hundreds of foods; to-date it has been hard for computers to distinguish between mashed potato and custard. This software might eventually be used to monitor dietary intake via a smartphone, although testing is in early stages.
Take home. If you want to keep a record of your dietary intake, use a validated app or pen and paper.
Evidence for personal responses to foods and bioactive compounds continues to emerge, but although the science is maturing, real-world applications are at an early stage and care must be taken to avoid damaging consumer trust.