The richness and stability of gut bacteria play an important role in microbiome homeostasis. We’ve chronicled many ways to perturb or alter the microbiome but diet is an area that has long been studied as a way to modify the microbiome. Specifically, dietary fiber has been shown to alter the microbiome and a recent study out of France looked at the microbiome of individuals who were given high fiber diets compared to normal diets.

19 people participated in a nutritional study and ate a normal diet for five days supplemented with 10 or 40 grams of dietary fiber per day. After the short-term intervention, there was a 15 day washout period and fecal samples were analyzed using qPCR and 16s RNA sequencing at various stages of the experiment.

The scientists found that the increase in dietary fiber intake did have an effect on the microbiota populations however it was dependent on the richness which varied from individual to individual. They also found that for the individuals on the 10 g fiber per day diet, microboime changes were not associated with richness and therefore it may be possible that other factors are playing a role in microbiome dynamics. Higher microbiome stability was seen with increased richness as well as a higher Prevotella:Bacteroides ratio.

This study showed that microbiome richness is a key factor that needs to be analyzed when comparing individuals’ responses to dietary interventions. Microbiome richness should be studied as we look at other factors such as antibiotic intake, aging, among others. This study also proposes that subjects with low microbiome richness should undergo long-term interventions such as diets with high vegetable diversity to try and improve overall microbiome richness.