Effect of Hibiscus Sabdariffa Extract on Growth and Survival of Lactobacillus Acidophilus in vitro

Abstract

Maintaining the growth and long-term survival of probiotic bacteria is a major challenge in the development of functional and probiotic based food products, thereby highlighting the need for natural growth supporting agents. The present in vitro study assessed the effect of Hibiscus sabdariffa extract on the growth and survival of the probiotic bacteria Lactobacillus acidophilus under controlled laboratory conditions. A 60 day experimental study was conducted using De Man, Rogosa and Sharpe (MRS) broth and agar media supplemented with and without supplementation of hibiscus extract. Bacterial growth and survival were assessed on days 0, 15, 30, 45 and 60 using the serial dilution and spread plate method and the results were expressed as colony forming units per milliliter (CFU/mL). The study design allowed the assessment of both short-term growth patterns and long-term survival trends of the probiotic under supplemented and control conditions, this helped to understand how the plant extract affected the probiotic growth and survival over time. The hibiscus-supplemented samples showed higher CFU counts compared to the control, with maximum bacterial growth seen on day 15. The highest growth was observed in sample B at 10-3 dilution medium (150 CFU/mL) followed by sample A at 10-3 dilution medium (134 CFU/mL) and control at 10-3 dilution medium (120 CFU/mL). After day 15, a gradual decline was observed in CFU values across all samples and better survival of bacteria was seen in hibiscus-supplemented media at day 60. Statistical analysis indicated significant differences between supplemented and control groups. The findings of this study indicated that Hibiscus sabdariffa extract enhanced the growth and prolonged the survival of Lactobacillus acidophilus highlighting its potential application as a natural functional ingredient for improving probiotic viability in food and nutraceutical formulations.