A Novel Streptococcus thermophilus FUA329 Isolated from Human Breast Milk Capable of Producing Urolithin A from Ellagic Acid

Abstract

Urolithin A, a metabolite of ellagic acid, has many beneficial biological activities for people. Strains capable of producing urolithin A from ellagic acid have the hope of becoming the next-generation probiotics. However, only a few species of these strains have been reported. In this study, FUA329, a strain capable of converting ellagic acid to urolithin A in vitro, was isolated from the breast milk of healthy Chinese women. The results of morphological observation, physiological and biochemical tests, and 16S rRNA gene sequence analysis confirmed that the strain FUA329 was Streptococcus thermophilus. In addition, the S. thermophilus FUA329 growth phase is consistent with the degradation of ellagic acid, and urolithin A was produced in the stationary phase, with a maximum concentration of 7.38 μM at 50 h. The corresponding conversion efficiency of urolithin A from ellagic acid was 82%. In summary, S. thermophilus FUA329, a novel urolithin A-producing bacterium, would be useful for the industrial production of urolithin A and may be developed as a next-generation probiotic.

Changes in Polyphenols and Antioxidant Properties of Pomegranate Peels Fermented by Urolithin A-Producing Streptococcus thermophilus FUA329

“…In a trial conducted in middle-aged and older adults, pomegranate juice consumed daily for 1 year positively impacted cognition . In our previous study, we screened and identified strain S. thermophilus FUA329 capable of transforming EA to UA in vitro . We also elucidated its safety and probiotic properties by conducting acid and bile salt resistance tests in vitro, a drug sensitivity test in a simulated GIT environment in vitro, etc.…”

“…38 In our previous study, we screened and identified strain S. thermophilus FUA329 capable of transforming EA to UA in vitro. 18 We also elucidated its safety and probiotic properties by conducting acid and bile salt resistance tests in vitro, a drug sensitivity test in a simulated GIT environment in vitro, etc. We here observed that pomegranate peel itself contained 10 phenolic acids and 16 flavonoids; this result is the same as those of Marra et al 3 Some phenolic acids and flavonoids exhibited a decreasing trend in the unfermented pomegranate peels and peels fermented by S. thermophilus FUA329, especially EA.…”

“…10 Interestingly, in our previous study, we screened the UAproducing Streptococcus thermophilus FUA329 strain from healthy human breast milk. 18 High safety and various bioactivities, such as acid, bile, and oxidation resistance, have been predicted and tested for the screened strain through whole-genome sequencing and in vitro experiments. These results indicated that the FUA329 strain has a probiotic potential.…”

“…Although the gut microbiota of UM-A individuals can produce UA, only a limited number of UA-producing bacteria were screened from the GIT of these UM-A individuals . Interestingly, in our previous study, we screened the UA-producing Streptococcus thermophilus FUA329 strain from healthy human breast milk . High safety and various bioactivities, such as acid, bile, and oxidation resistance, have been predicted and tested for the screened strain through whole-genome sequencing and in vitro experiments.…”

Differential Role of Active Compounds in Mitophagy and Related Neurodegenerative Diseases

“…In studies by Li, F. et al it was found that intestinal microflora metabolite nicotinamide n-oxide promotes mitophagy in microglia, thereby preventing herpes simplex encephalitis [ 170 , 171 ]. In a recent study, it was demonstrated that Streptococcus thermophilus FUA329 can produce urolithins from ellagic acid, which opens the prospect of a new generation of probiotics [ 172 ]. It can be assumed that intestinal dysbacteriosis or sterilization can lead to suppression of the production of mitophagy inducers by the intestinal microbiota, and that was shown in experiments on mice with Ochratoxin A-induced hepatitis.…”