Enhanced health benefits of Psidium guajava peel fermented with Lactiplantibacillus from Myeolchi-jeot: Antioxidant, anti-inflammatory, and anti-cancer properties

Psidium guajava, commonly known as guava, is a fruit with well-documented health benefits due to its rich phytochemical content. In this study, we investigated the potential health-enhancing properties of Psidium guajava fermented with Lactiplantibacillus sp., FSA-4 isolated from salted and fermented anchovies. The fermentation condition was optimized for maximum total phenolic content (TPC) which was attained at 25 °C, at pH 7 under blue light intensity (470 nm). The pre/post fermented guava peel extracts were analyzed for their biomedical applications. The results demonstrated that the fermented guava peel extract exhibits remarkable antioxidant activity evidenced by its capacity to scavenge free radicals and reduce oxidative stress. Additionally, the fermented extract showcases potential anti-inflammatory properties, as it effectively mitigates inflammatory responses in in vitro conditions. Furthermore, the fermented guava peel extract revealed promising anti-cancer property demonstrated by its ability to inhibit the proliferation of B16–F10 cell lines by inducing apoptosis. The UPLC MS/MS analysis revealed a distinctive group of flavonols present in the fermented guava peel extract with characteristic properties. Overall, the Psidium guajava fermented extract prepared using Lactiplantibacillus sp. FSA-4 presents a multifaceted health-promoting profile, offering significant antioxidant, anti-inflammatory, and anti-cancer potential. These discoveries highlight the value of investigating traditional fermented foods and their associated microbial strains to pave the way for pioneering functional products that can have extensive applications in therapy and well-being.