Professor Marju Ohro-Melander Melander and her research team at Lund University, Sweden, used data from the large population-based cohort study SCAPIS. In total, data from approximately 10,000 individuals from Malmö and Uppsala were used. One thing the researchers investigated was the link between dietary habits and the richness of the gut bacteria, the microbiota. They chose dietary guidelines that are based on the Nordic Nutrition Recommendations, both what to eat more of and what to limit or replace with better alternatives. People in the study were asked how much, and how often, they eat different foods. Orho-Melander’s colleague, Ulrika Ericson then processed the data.

We looked at twelve dietary components, such as wholegrain, vegetables, fruit and nuts.

“We looked at twelve dietary components, such as wholegrain, vegetables, fruit and nuts. The responses were then converted, at individual level, into an index that shows how well the recommendations were followed,” says Orho-Melander. The next step was to investigate how the gut microbiota was linked to eating habits. They found a clear pattern: the more closely the recommendations were followed, the richer the gut flora. From a research perspective, the best thing about SCAPIS is that it includes a follow-up about nine years after the first study was conducted. Orho-Melander says she is looking forward to seeing what happens in the body – and the gut flora – over such a long period. “For example, once the follow-up is complete, we can look at the difference in gut flora in someone who didn’t have diabetes in the first round but developed it since. And because we are getting dietary data again, we can see who changed their eating habits for the better or worse, or maintained them, and how that has affected gut flora and disease development.”

“Many diseases have been linked to the gut microbiota, usually one that is less species-rich,” explains Orho-Melander. Examples includes obesity, type 2 diabetes, cardiovascular disease, Parkinson’s and Alzheimer’s. This large-scale study with repeated measurements makes it easier to perform analyses that can provide more than just correlations. They can also provide clues about causality, meaning whether and how your gut microbiota affects the risk of developing a disease in the future", concludes Marju Ohro-Melander.

Text: Linda Swartz
Photo: ISTOCK