Browsing by Author "Mucheru,Patrick Kamau"

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    Efficacy of Probiotic Yoghurt Enriched With Purple-Leaf Tea on Gut Microbiota and Lipid Profile
    (Kenyatta University, 2025-11) Mucheru,Patrick Kamau
    The gut microbiome has been found to have a significant impact on the health status and diseases of humans. Dysbiosis increases gut permeability that subsequently lead to increased gut inflammations and metabolic disorders such as obesity, type 2 diabetes and inflammatory Bowel Diseases (IBD). These disorders cause chronic systemic inflammation, which subsequently alters the lipid profile and gut microbiota composition. The purple tea variety (TRFK 306/1) produced in Kenya is loaded with polyphenols and more anthocyanins than the green tea showing great promise in production of nutraceuticals and functional foods. Dairy products such as yoghurt have been used as a vehicle for probiotic microbes delivery. Probiotics are living microorganisms which provide health benefits to the consumer when taken in sufficient amounts. However, limited intervention studies consider the impact of probiotics on health outcomes. Therefore, the current study investigated the synergy of dual health effects of a novel formulated probiotic yoghurt enriched with purple leaf tea (PYEPT) against the control without the purple tea. The yoghurt was produced by fermenting pasteurized milk with probiotic starter culture ABT 5. The benefits were assessed by analysing the yoghurt nutritional properties (proximate composition, profiling of minerals and anthocyanin content), consumer sensory acceptability, gut bacterial community and diversity changes and lipid profile of Wistar rats fed on the yoghurt. The study adopted a randomized control trial design using an in vivo animal model. A total of 16 male white Wistar rats were used in the study whereby eight rats were the control group, while the other 8 were the experimental group. The proximate results showed significant differences (p<0.05) between the PYEPT and control yoghurt with higher levels of protein and carbohydrates content. Moreover, the study found that the mineral profile of the purple tea puree used in enrichment of the yoghurt potassium was highest with 282 parts per million (ppm), and the total anthocyanin was 211.2 ppm. The sensory evaluation showed that PYEPT had significantly higher scoring in terms of appearance, colour, taste, odour and overall acceptability (p<0.05) than the control yoghurt. The current study found that Bacteroidetes were the most dominant phyla at the baseline, with 61% of all the bacteria. Moreover, after supplementation with PYEPT, the level of Bacteroidetes reduced to 48.65%. At the baseline, the species level of Lactobacillus helveticus was found to be at 0.1% while in the endline enriched group, it was found to be at 0.8%. The current study found the baseline group had a species richness of 49. After four weeks of the experiment, the control group increased the species richness to 51, while the enriched yoghurt group reduced the richness to 45. Both endline control and endline enriched yoghurt groups were associated with higher levels of beneficial bacteria after the experiment. Particularly, there were significant reductions in the pathogenic microorganism between endline control and endline enriched yoghurt (p≤0.05). Independent sample t-test showed there was no statistically significant difference between total cholesterol, serum triglycerides, serum high density lipoprotein and serum low-density lipoprotein between the control yoghurt and enriched yoghurt group (p>0.05). The current study concludes that the probiotic yoghurt enriched with purple tea positively modulated the gut microbiota and can be recommended as an avenue to provide a functional food for dietary intervention of dysbiosis. However, further clinical studies with humans should be done to confirm the conclusions and further in vitro studies for understanding the mechanisms of interventions before releasing the yoghurt as a commercial product