Impact of a pulse-based vegetarian lunch meal on the modulation of gut bacterial populations

Introduction: The current global trend to adopt more plant-based diets is expected to increase the intake of pulses in the near future, given their potential as eco-friendly nutrient-rich alternatives to animal-based protein food sources. Still, more comprehensive data, as well as higher quality food intervention trials, are needed to fully understand the health benefits of such dietary shift, namely at the gut microbiota level. In this context, the use of molecular biology research tools, such as quantitative Polymerase Chain Reaction (qPCR) could be useful to monitor the dietary modulation of gut bacterial populations. Objectives: To investigate the modulation of gut bacterial populations after an 8-week pulse-based food intervention using qPCR optimized for 5 bacterial genera.
Methods: Non-vegetarian healthy young adults were asked to replace a typical omnivorous lunch meal with a vegetarian pulse-based meal, 5 times per week, for 8 consecutive weeks. Stool samples were collected at weeks 0 (baseline) and 8 and total DNA was extracted using NZY Tissue gDNA isolation Kit (NZYTech, Lisbon, Portugal). A specific sequence region of the gene 16S rRNA was quantified using qPCR specific for the following bacteria: Akkermansia muciciphilamuciniphila, Roseburia spp., BiffidobacteriumBifidobacterium spp., Clostridium leptum subgroup, and Faecalibacterium prausnitzii, was quantified using qPCR. Results: A total of 50 stool samples, from a group of 25 individuals, were collected and analyzed using qPCR. Results revealed an evident interindividual variability after the 8-week pulse-based food intervention, apparently with no clear net tendency on the modulation of the analyzed gut bacterial sub-groups analyzed. Conclusion: An 8-week pulse-based food intervention caused different gut bacteria modulation in each individual, masking any potential generalized effects of the diet. This highlights the need for personalized approaches concerning health and nutrition research fields.