Metagenomic characterization of the culturable bacterial community structure of Tapuy, a Philippine indigenous rice wine, reveals significant presence of potential probiotic bacteria

Background@#Tapuy is an indigenous fermented rice wine produced in the Northern areas of the Philippines. Fermented foods and drinks have gained interest due to their associated health benefits, attributable to probiotic bacteria in the food items. However, pathogenic bacteria may also be present in fermented food and pose health risks, signifying a need for standardization. Currently, there is limited knowledge on the bacterial content of tapuy. @*Objectives@#This study aimed to characterize the bacterial diversity and community structure of culturable bacteria in traditionally fermented tapuy samples, to perform standardization of tapuy fermentation, and to compare the bacterial diversity and community structure of culturable bacteria in laboratory fermented tapuy with that of the traditional samples. @*Methods@#Tapuy samples were obtained from four municipalities in Benguet, Philippines. Laboratory fermentation of tapuy was performed simultaneously with the fermentation in the sampling site using a standardized protocol. Samples were plated on de Man, Rogosa, and Sharpe (MRS) agar and NA, and the colonies were harvested for DNA extraction. DNA samples were sent for 16S rDNA metagenomic sequencing. Results. Metagenomic analysis revealed the presence of many bacterial species that were previously unreported in tapuy. Traditional tapuy samples were composed primarily of members of the genera Bacillus and Lactobacillus in varying proportions. Potential probiotic bacteria were abundant in Kapangan (97.42%) and Sablan (99.89%) field samples. B. wiedmannii was present in all samples and was identified as a harmful species. Laboratory fermentation increased the abundance of potential probiotic bacteria in Itogon and La Trinidad samples (differences of 75.36% and 78.36%, respectively). It decreased the quantity of B. wiedmannii in La Trinidad (a difference of 97.1%). Laboratory fermented samples generally exhibited higher bacterial diversity and species richness compared to field samples. @*Conclusions@#Traditionally fermented tapuy samples contained a significant proportion of potential probiotic bacteria belonging to the genera Bacillus and Lactobacillus. Laboratory fermented samples were found to have higher bacterial diversity and richness compared to field samples. The significant presence of potential probiotic bacteria suggests that tapuy is a good candidate for development into functional food and a good source of likely probiotic species that could be explored for health applications. The presence of harmful bacteria suggests the need for possible standardization of fermentation practices.

Screening extracts of seven edible mushrooms for reduction of regeneration time in the Planarian Dugesia hymanae

Objective@#This study aimed to determine the effect of seven edible mushrooms in the regeneration rate of planarian Dugesia hymanae (D. hymanae). @*Methods@#The ability of D. hymanae to regenerate was used to test extracts of seven mushrooms to reduce regeneration time, using eyespot and tail formations as endpoints. The planarians were amputated and were allowed to heal and regenerate in planarian water (control) and varying concentrations of Crude Ethanolic Extracts (CEE) of the seven edible mushrooms. The CEE with the most significant effect in reducing the regeneration time will be further sub-fractionated into hexane, ethyl acetate, and ethanol solvent extracts. @*Results@#In untreated planarian water, amputated planarians' eyespot and tail formations took 4.65 (SD 0.34) and 4.1 (SD 0.21) days, respectively. The CEE of four mushrooms (Shiitake var Benguet, Tea tree, Shiitake var flower, and Black & White) significantly reduced the regeneration time, with Shiitake var Benguet extract reducing the regeneration time the most at 2.56 (SD 0.30) days and 2.61 (SD 0.22) days for both eyespot and tail formations (P<.0001) respectively. The solvent extracts of the Shiitake (Benguet variety) did not reduce the planarian regeneration time relative to the control (P>.05). @*Conclusion@#Lentinula edodes (L. edodes) [Benguet variety CEE] had reduced the regeneration time most significantly for both the eyespot and tail formations compared to the other six tested fungi extracts. The L. edodes (Benguet variety) CEE may contain compounds that can hasten the regeneration of the planarian D. hymanae.

Lowland and highland Varieties of Dioscorea esculenta tubers stimulate growth of Lactobacillus sp. over enterotoxigenic E. coli in vitro

@#<p style="text-align: justify;"><strong>Objectives:</strong> Probiotic supplementation often only leads to transient improvement in the gut microbiome. Potential prebiotics, such as the oligosaccharide-rich varieties of Dioscorea esculenta tubers, can potentially bridge the gap between supplementation and persistent colonization. Thus, this study aimed to assess the ability of D. esculenta tubers to promote the growth of probiotic Lactobacillus sp. in vitro selectively.</p><p style="text-align: justify;"><strong>Methods:</strong> The prebiotic activity of the selected varieties of Dioscorea esculenta tubers was evaluated via compe titive growth assay, wherein the ratios of probiotic Lactobacillus sp. over enterotoxigenic Escherichia coli (ETEC) or "prebiotic ratios" were compared following treatment.</p><p style="text-align: justify;"><strong>Results:</strong> Negative control (0.9% NaCl solution) produced a ratio of 0.88, Lowland and Highland varieties produced ratios of 1.26 and 1.29, respectively, and positive control (inulin) produced 1.54. The two varieties had comparable ratios to one another (p > 0.05), and significantly higher ratios than the negative control (p < 0.05). Both varieties have significant prebiotic activity. Compared to inulin, the two varieties' prebiotic activity was 84% as effective.</p><p style="text-align: justify;"><strong>Conclusion:</strong> Overall, the tubers promoted the growth of Lactobacillus sp. over ETEC. The crude tuber samples, given their availability and affordability, can be easily integrated into the local diet to contribute to the improvement of the general population's health.</p>