In Vitro Modulation of Fecal Microflora Growth Using Fermented “Pisang Mas” Banana and Red Guava Juices

Abstract

Probiotic drink like yoghurt from dairy milk is one of the most popular functional food. However, some people are not able to consume dairy milk due to lactose intolerance. Thus, a substitute substrate such as fruit juice, is needed. It refers to prebiotic compounds that are found in some of fruits like banana and guava. The aim of this research was to determine the effect of fermented banana and guava juices on the viability of fecal microflora. The juices were made from banana or red guava fermented by Lactobacillus casei (15% v/v). In vitro test was conducted using indigenous human fecal bacteria (1% w/v). The viability of enteropathogens, lactic acid bacteria (LAB), and total microbes was determined by enumeration as well as the prebiotic index of the fermented juices. The in vitro test results showed that both fermented juices could elevate the total microbes and LAB as compared to control sample. The viability of the total microbes and LAB increased by 2.16 log CFU/mL and 2.90 log CFU/mL for fermented banana juice (FBJ), respectively. The same trend was also observed in fermented guava juice (FGJ) with an increase by 1.92 log CFU/mL for total microbes and 2.99 log CFU/mL for LAB. Interestingly, both fermented juice could decrease the population of most enteropathogens compared to control sample. FBJ could decrease the population of E. coli, Klebsiella sp. and Salmonella as low as 3.78, 3.32, and 1.37 log CFU/mL respectively. Meanwhile, FGJ could drop the number of E. coli (1.44 log CFU/mL), and Klebsiella sp. (1.29 log CFU/mL). Moreover, the prebiotic index for FBJ and FGJ were 2.57 and 2.16. In conclusion, both FBJ and FGJ were potential substrate for probiotic drink and had good effect for fecal microflora health.