Exploring the probiotic potential of yeast strains isolated from ripe banana and plantain peels: in vitro and in vivo assessment.

Probiotics have been shown to improve host access to vitamins, generate vitamins and improve gastrointestinal tract functions throughout transit yeasts which are indicated to potentially function as probiotics with some health benefits. The aim of this study was to evaluate the probiotic potential of yeast isolates from banana and plantain peels. Yeast strains were isolated from ripe banana and plantain peels, using the standard procedures. Isolates that showed negativity for pathogenicity assays were used for in vitro and in vivo probiotic screening. For the in vivo assay, 30 male Wistar rats, divided into six treatment groups (five rats per treatment), were used. At the expiration of administration, the rats were euthanized for the estimation of yeast translocation and haematological parameters. A total of 16 yeasts were isolated, out of which, five (Hanseniaspora uvarum, Hanseniaspora lachancei, Hanseniaspora opuntiae and two species of Kodamaea ohmeri) isolates that showed negative results for pathogenicity assays were used for in vitro and in vivo assays. The study revealed the growth of the test yeast strains at the different incubation temperatures (25-45 °C) and pH (4-9). However, significantly highest growths were observed at pH 4 and 5 and NaCl concentration of 4%. All the isolates showed remarkable growth at the bile concentrations used. In addition, the strains showed resistance to the antibiotics and antimycotics at the concentration used for investigation. In vivo assay results showed no significant differences between weight gain, haematological parameters and behavioural scores between control and treatment groups of the rats. The ability of the yeasts to show tolerance to stress conditions and lack of negative impacts to haematological, behavioural and yeast translocations are indications of their probiotic capabilities.