You Are What You Eat – Why The Future of Nutrition Is Personal

Humans are complicated, and there are many things that influence our health. There are things we can’t change, like our age or genetic makeup, and the things we can, such as our choice of food and drink. There are also the trillions of bacteria that live in our guts – collectively known as the microbiome – that have a significant impact on our health and digestion.

The foods we eat are mixtures of many nutrients that affect the body and microbiome in different ways, so unravelling the relationship between diet, metabolism and health is no simple matter. A new study from the University of Minnesota adds yet another layer of complexity, showing that foods that have comparable nutritional profiles can have very different effects on the microbiome.

Feeding the five trillion

While we know that a more diverse microbiome is usually an indicator of better gut health, we understand little about how specific foods affect the abundance of different microbial species.

In their recent study, the Minnesota team asked 34 healthy volunteers to collect detailed records about everything they ate over 17 days, mapping this information against the diversity of microbes in daily stool samples. As expected, although there were several foods that were eaten by most of the participants – such as coffee, cheddar cheese, chicken and carrots – there were plenty of choices that were unique.

The researchers found that while each participant’s food choices affected their own microbiome, with certain foods boosting or reducing the abundance of particular bacterial strains, there wasn’t a straightforward correlation that carried over between people. For example, beans boosted the proportion of certain bacteria in one person but had far less effect in another.

Intriguingly, although closely related foods (such as cabbage and kale) tended to have the same impact on the microbiome, unrelated foods with very similar nutritional compositions had strikingly different effects. This tells us that conventional nutritional labelling may not be the best way of judging how healthy a food is likely to be.

The results also show that making dietary recommendations for improving the microbiome won’t be simple and will need to be personalized, taking into account a person’s existing gut microbes and the effects of specific foods on them.

Read the full article here.