Pediococci are lactic acid bacteria (LAB) which have been used for centuries in the production of traditional fermented foods. There fermentative abilities were explored by the modern food processing industry in use of pediococci as starter cultures, enabling the production of fermented foods with distinct characteristics. Furthermore, some pediococci strains can produce bacteriocins and other antimicrobial metabolites (AMM), such as pediocins, which are increasingly being explored as bio-preservatives in various food matrices. Due to their versatility and inhibitory spectrum, pediococci bacteriocins and AMM are being extensively researched not only in the food industry, but also in veterinary and human medicine. Some of the pediococci were evaluated as potential probiotics with different beneficial areas of application associated with human and other animals' health. The main taxonomic characteristics of pediococci species are presented here, as well as and their potential roles and applications as starter cultures, as bio-preservatives and as probiotic candidates.
Bacteriocins produced by lactic acid bacteria are proteinaceous antibacterial metabolites that normally exhibit bactericidal or bacteriostatic activity against genetically closely related bacteria. In this work, the bacteriocinogenic potential of Pediococcus pentosaceus strain ST58, isolated from oral cavity of a healthy volunteer was evaluated. To better understand the biological role of this strain, its technological and safety traits were deeply investigated through a combined approach considering physiological, metabolomic and genomic properties. Three out of 14 colonies generating inhibition zones were confirmed to be bacteriocin producers and, according to repPCR and RAPD-PCR, differentiation assays, and 16S rRNA sequencing it was confirmed to be replicates of the same strain, identified as P. pentosaceus, named ST58. Based on multiple isolation of the same strain (P. pentosaceus ST58) over the 26 weeks in screening process for the potential bacteriocinogenic strains from the oral cavity of the same volunteer, strain ST58 can be considered a persistent component of oral cavity microbiota. Genomic analysis of P. pentosaceus ST58 revealed the presence of operons encoding for bacteriocins pediocin PA-1 and penocin A. The produced bacteriocin(s) inhibited the growth of Listeria monocytogenes, Enterococcus spp. and some Lactobacillus spp. used to determine the activity spectrum. The highest levels of production (6400 AU/ml) were recorded against L. monocytogenes strains after 24 h of incubation and the antimicrobial activity was inhibited after treatment of the cell-free supernatants with proteolytic enzymes. Noteworthy, P. pentosaceus ST58 also presented antifungal activity and key metabolites potentially involved in these properties were identified. Overall, this strain can be of great biotechnological interest towards the development of effective bio-preservation cultures as well as potential health promoting microbes.
The aim of this project was to screen for bacteriocinogenic Bacillus strains with activity versus Staphylococcus spp. with future application in formulation of pharmaceutical antimicrobial preparations. Putative bacteriocinogenic strains, isolated and pre-identified as Bacillus spp. were selected for future study and differentiated based on repPCR and identified as Bacillus subtilis for strains ST826CD and ST829CD, Bacillus subtilis subsp. stercoris for strain ST794CD, Bacillus subtilis subsp. spizizenii for strain ST824CD, Bacillus velezensis for strain ST796CD, and Bacillus tequilensis for strain ST790CD. Selected strains were evaluated regarding their safety/virulence, beneficial properties, and potential production of antimicrobials based on biomolecular and physiological approves. Expressed bacteriocins were characterized regarding their proteinaceous nature, stability at different levels of pH, temperatures, and the presence of common chemicals applied in bacterial cultivation and bacteriocin purification. Dynamic of bacterial growth, acidification, and cumulation of produced bacteriocins and some aspects of the bacteriocins mode of action were evaluated. Based on obtained results, isolation and application of expressed antimicrobials can be realistic scenario for treatment of some staphylococcal associated infections. Appropriate biotechnological approaches need to be developed for cost effective production, isolation, and purification of expressed antimicrobials by studied Bacillus strains.
The aim of this study was to investigate the different immunological and antimicrobial properties of breast milk from women with (W) or without (WO) vaginal yeast infections during pregnancy in 85 lactating women (W, n = 43; WO, n = 42). Concentrations of IL-10, IgA, IgM, IgG, EGF, and TGF-α were similar in both groups. However, breast milk of women aged below 31 years old from the W-group showed higher concentration of EGF than the WO-group (p = 0.031). Breast milk from WO-group exhibited higher anti-Candida properties than W-group, both via growth inhibition and aggregation of yeast cells (p
Skin aging, which affects all living organisms, is associated with oxidative stress. Probiotics exhibit antioxidant properties by producing reactive metabolites that counter oxidative stress. We hypothesized that Limosilactobacillus fermentum USM 4189 (LF 4189) has antioxidative properties and may prevent skin aging. In the present study, we used a D-galactose senescence-induced rat model to evaluate the potential antioxidative capability of LF 4189. The results indicated that rats administered LF 4189 exhibited increased plasma antioxidative activity (P=0.004), lipid peroxidation capacity (P=0.007), and skin elasticity compared with untreated aged rats (P=0.005). LF 4189 prevented telomere length shortening (P<0.05), indicating the potential to prevent senescence. A higher apoptotic activity was observed in old rats compared with young rats, whereas LF 4189 reduced the expression of four antioxidative enzyme genes that function as radical scavengers (all P<0.05), suggesting that the LF 4189 group had a reduced need to scavenge free radicals. Our findings indicate the potential of probiotics, such as LF 4189, as an anti-aging dietary intervention with antioxidant potential to improve skin health.
The development of probiotics has now included the areas along the gut-vaginal axis. We thus aimed to investigate the effects of lactobacilli probiotic to modulate and restore vaginal and gut microbiota of pregnant women with vaginal candidiasis (VC). A randomised, double-blind and placebo-controlled study was performed in 78 pregnant women with VC. Patients were randomised to either the probiotic (SynForU-HerCare) or placebo which were administered at baseline and continued for 8-weeks (two capsules/day of 9.5 log cfu/capsule). Microbiota profiles were assessed at time points of weeks-0, 4 and 8 for high vaginal swab and faecal samples. Shannon diversity index showed that after 8-weeks amid VC, a shift in microbial community compositional changes occurred in the high vaginal region at both genus (P=0.025) and species (P=0.044) levels, where the administration of probiotic prevented such a shift. These changes were mainly attributed to a decreased in abundance of Lactobacillus (P=0.042) accompanied by increased abundance of Prevotella (P=0.002) and Atopobium (P=0.002) in the placebo group while the probiotic group remained unchanged over time. The administration of probiotics also prevented a reduced abundance of faecal phylum Firmicutes after 8-weeks as seen in the placebo group (P<0.0001), which also showed reduction at subsequent taxonomic levels of class, family, genera and species. VC has not only altered the microbiota of vagina regions but also gut microbiota profiles, causing lessening of gut microbiota that are crucial for gut nutrient availability, protection and immunity. The administration of lactobacilli probiotics has prevented such a shift, leading to better modulated gut and vaginal microenvironment amid VC. The study was registered at ClinicalTrials.gov: identifier number NCT03940612.
Constipation, which refers to difficulties in defecation and infrequent bowel movement in emptying the gastrointestinal system that ultimately produces hardened fecal matters, is a health concern in livestock and aging animals. The present study aimed to evaluate the potential effects of dairy-isolated lactic acid bacteria (LAB) strains to alleviate constipation as an alternative therapeutic intervention for constipation treatment in the aging model. Rats were aged via daily subcutaneous injection of D-galactose (600 mg/body weight [kg]), prior to induction of constipation via oral administration of loperamide hydrochloride (5 mg/body weight [kg]). LAB strains (L. fermentum USM 4189 or L. plantarum USM 4187) were administered daily via oral gavage (1 × 10 Log CFU/day) while the control group received sterile saline. Aged rats as shown with shorter telomere lengths exhibited increased fecal bulk and soften fecal upon administration of LAB strains amid constipation as observed using the Bristol Stool Chart, accompanied by a higher fecal moisture content as compared to the control (p < 0.05). Fecal water-soluble metabolite profiles showed a reduced concentration of threonine upon administration of LAB strains compared to the control (p < 0.05). Histopathological analysis also showed that the administration of LAB strains contributed to a higher colonic goblet cell count as compared to the control (p < 0.05). The present study illustrates the potential of dairy-sourced LAB strains as probiotics to ameliorate the adverse effect of constipation amid aging, and as a potential dietary intervention strategy for dairy foods including yogurt and cheese.
We previously reported that breast milk from women with (W) or without (WO) vaginal yeast infection during pregnancy differs in its immunological and antimicrobial properties, especially against pathogenic vaginal Candida sp.. Here, we investigated the differences in microbiota profiles of breast milk from these groups. Seventy-two breast milk samples were collected from lactating mothers (W, n=37; WO, n=35). The DNA of bacteria was extracted from each breast milk sample for microbiota profiling by 16S rRNA gene sequencing. Breast milk from the W-group exhibited higher alpha diversity than that from the WO-group across different taxonomic levels of class (P=0.015), order (P=0.011), family (P=0.020), and genus (P=0.030). Compositional differences between groups as determined via beta diversity showed marginal differences at taxonomic levels of phylum (P=0.087), family (P=0.064), and genus (P=0.067). The W-group showed higher abundances of families Moraxellaceae (P=0.010) and Xanthomonadaceae (P=0.008), and their genera Acinetobacter (P=0.015), Enhydrobacter (P=0.015), and Stenotrophomonas (P=0.007). Meanwhile, the WO-group showed higher abundances of genus Staphylococcus (P=0.046) and species Streptococcus infantis (P=0.025). This study shows that, although breast milk composition is affected by vaginal infection during pregnancy, this may not pose a threat to infant growth and development.