The fermented soy beverage Q-CAN® plus induces beneficial changes in the oral and intestinal microbiome

BACKGROUND: Soy products are associated with many beneficial health consequences, but their effects on the human intestinal microbiome are poorly characterized. OBJECTIVES: To identify the changes in the oral and fecal microbiome in lean and obese participants due to consumption of Q-CAN®, and to assess the expected consequences of these changes based on the published literature. METHODS: Prospective study of lean (10) and obese (9) participants consuming Q-CAN® twice daily for 4 weeks with 8 weeks follow-up. Microbial DNA was extracted from saliva and stool samples, amplified against the V4 region of the 16S ribosomal RNA gene and data analyzed using QIIME 1.9.1 bioinformatics. Four hundred forty-four samples were collected in total, 424 of which were productive and yielded good quality data. RESULTS: STOOL. In the lean population Bifidobacteria and Blautia show a significant increase while taking Q-CAN®, and there was a trend for this in the obese population. ORAL. There were relatively fewer major changes in the oral microbiome with an increase in the family Veillonellaceae in the lean population while on Q-CAN®. CONCLUSION: Q-CAN® consumption induced a number of significant changes in the fecal and oral microbiome. Most notably an increase in the stool microbiome of Bifidobacteria and Blautia, both of which are associated with positive health benefits, and in the saliva an increase in Veillonellaceae. TRIAL REGISTRATION: This trial was registered with Clinicaltrials.gov on January 14th 2016. ClinicalTrials.gov Identifier: NCT02656056 SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40795-021-00408-4.