The potential health benefits of a novel symbiotic yogurt fortified with purple-leaf tea in modulation of gut microbiota

Background: The use of symbiotic functional yogurt is a trending dietary approach of positively modulating the gut and alleviating dysbiosis. These yogurts are fermented using probiotic live microorganisms that confer health benefits on the host. Purple-leaf tea (Camellia sinensis) which contains prebiotic polyphenolic compounds, has all the health benefits of tea in addition to high content of flavonoid bioactive anthocyanin compounds.  Objective: The goal of the current study was to investigate the effect of a novel symbiotic yogurt fermented using probiotic microbes and fortified with purple leaf tea puree in modulating gut bacteria profile using an in vivo animal experiment with white male Wilstar rats. Methods: An in vivo animal study was used to investigate the effect of symbiotic yogurt (PYPT) produced by fermentation of milk with probiotic starter culture ABT 5 (Lactobacillus acidophilus LA-5, Bifidobacterium bifidum BB-12 and Streptococcus thermophiles) and fortified with purple-leaf tea puree. A total of 16 Wistar rats were intraperitoneally injected with 8 doses of 4mg/g of monosodium glutamate (MSG) to induce obesity. In a randomized control design, 8 of the experimental control rats were fed with normal standard rat feed, while 8 intervention rats were fed with the formulated yogurt for a period of 28 days. The gut health bacteria biomarkers were determined from the rats’ fecal matter by extraction of DNA using the ZymoBIOMIC kit protocol and profiled by the polymerase chain reaction (qPCR) molecular technique, of 16S rRNA. The data of the bacteria taxonomic classifications and abundance was processed and interpreted using DADA2 package and Quantitative Insight into Microbial Ecology 2 (Qiime2).  Results: No statistical differences in diversity of bacterial phyla were reported, but the composition of Actinobacteria increased in the intervention group and decreased in the control, while Proteobacteria decreased drastically in the intervention rats. Notably, the population of beneficial Lactobacillales and Bifidobacteriales in the intervention cohort increased significantly, while there was a reduction of bacteria with species with potential of pathogenic activity. Conclusions: Fortification of probiotic yogurt with purple tea with prebiotic polyphenols increased the population of beneficial gut modulating bacteria while reducing the pathogens. Therefore, the study demonstrates the constructive collaboration of probiotic microbes and the purple tea bioactive compounds in the novel symbiotic yogurt in improving the healthful gut commensal bacteria. Future research can profile more commensal bacteria and analyze gut metabolites such as butyrate as well as conducting human clinical trials.  Keywords: Gut bacteria modulation, Symbiotic yogurt, Probiotics, Prebiotics, Purple-leaf tea, Fortification, Functional foods