A new study led by Dr Dan Knights from the University of Minnesota (USA), has found that the gut microbiome responds more to particular foods than to combinations of nutrients and that microbiome responses to diet are personalized.

The researchers studied the impact of habitual diet on the gut microbiome in 34 subjects for 17 consecutive days. Both the fecal microbiome and the participants’ diet were sampled every day through shotgun metagenomic sequencing and daily 24-hour dietary records, respectively.

Although the relative abundance of gut microbial species showed a high variation within and between individuals, functional traits tended to remain stable across individuals. In contrast, a specific group of functions related to stress response, the conversion of nitrate to nitrogen and the conversion of formate to methane showed a high interindividual variability that did not correlate with nutrient and food intake.

While dietary intake shown as food groups revealed a high level of variability across individuals, the number of macro- and micronutrient profiles remained stable for each subject across the study period. These findings allowed researchers to hypothesize that the observed changes in microbial composition and metabolism could be explained by the impact of particular microbiota-accessible carbohydrates and non-nutritive compounds that cannot be characterized with conventional nutrition databases.

Read more: Cell Host & Microbe