Dual Role of Probiotic Lactic Acid Bacteria Cultures for Fermentation and Control Pathogenic Bacteria in Fruit-Enriched Fermented Milk.

The food industry has been developing new products with health benefits, extended shelf life, and without chemical preservation. Bacteriocin-producing lactic acid bacteria (LAB) strains have been evaluated for food fermentation to prevent contamination and increase shelf life. In this study, potentially probiotic LAB strains, Lactiplantibacillus (Lb.) plantarum ST8Sh, Lacticaseibacillus (Lb.) casei SJRP38, and commercial starter Streptococcus (St.) thermophilus ST080, were evaluated for their production of antimicrobial compounds, lactic acid and enzyme production, carbohydrate assimilation, and susceptibility to antibiotics. The characterization of antimicrobial compounds, the proteolytic activity, and its inhibitory property against Listeria (List.) monocytogenes and Staphylococcus (Staph.) spp. was evaluated in buriti and passion fruit-supplemented fermented milk formulations (FMF) produced with LAB strains. Lb. plantarum ST8Sh was found to inhibit List. monocytogenes through bacteriocin production and produced both L(+) and D(-) lactic acid isomers, while Lb. casei SJRP38 mainly produced L(+) lactic acid. The carbohydrate assimilation profiles were compatible with those usually found in LAB. The potentially probiotic strains were susceptible to streptomycin and tobramycin, while Lb. plantarum ST8Sh was also susceptible to ciprofloxacin. All FMF produced high amounts of L(+) lactic acid and the viability of total lactobacilli remained higher than 8.5 log CFU/mL during monitored storage period. Staph. aureus ATCC 43300 in fermented milk with passion fruit pulp (FMFP) and fermented milk with buriti pulp (FMB), and Staph. epidermidis KACC 13234 in all formulations were completely inhibited after 14 days of storage. The combination of Lb. plantarum ST8Sh and Lb. casei SJRP38 and fruit pulps can provide increased safety and shelf-life for fermented products, and natural food preservation meets the trends of the food market.

Functional Fermented Milk with Fruit Pulp Modulates the In Vitro Intestinal Microbiota.

The effect of putative probiotic fermented milk (FM) with buriti pulp (FMB) or passion fruit pulp (FMPF) or without fruit pulp (FMC) on the microbiota of healthy humans was evaluated. FM formulations were administered into a simulator of the human intestinal microbial ecosystem (SHIME®) to evaluate the viability of lactic acid bacteria (LAB), microbiota composition, presence of short-chain fatty acids (SCFA), and ammonium ions. The probiotic LAB viability in FM was affected by the addition of the fruit pulp. Phocaeicola was dominant in the FMPF and FMB samples; Bifidobacterium was related to FM formulations, while Alistipes was associated with FMPF and FMB, and Lactobacillus and Lacticaseibacillus were predominant in FMC. Trabulsiella was the central element in the FMC, while Mediterraneibacter was the central one in the FMPF and FMB networks. The FM formulations increased the acetic acid, and a remarkably high amount of propionic and butyric acids were detected in the FMB treatment. All FM formulations decreased the ammonium ions compared to the control; FMPF samples stood out for having lower amounts of ammonia. The probiotic FM with fruit pulp boosted the beneficial effects on the intestinal microbiota of healthy humans in addition to increasing SCFA in SHIME® and decreasing ammonium ions, which could be related to the presence of bioactive compounds.

Fruit bioactive compounds: Effect on lactic acid bacteria and on intestinal microbiota.

The benefits of bioactive compounds to human health have been highly explored in recent years; they are widely distributed in nature, mainly in fruits. In this review, the effect of the main fruit bioactive compounds (FBC) on lactic acid bacteria (LAB) and on gut microbiota composition was discussed. The fruit dietary fibers, phenolic compounds, fatty acids, carotenoids, and vitamins have important health benefits. Furthermore, they can interact with LAB and modulate the human intestinal microbiota, which favor the diversity of beneficial bacterial groups, thus providing several benefits to human health, such as reducing weight gain, improving the mucosal barrier function of gastrointestinal (GI) tract against pathogens, decreasing chronic inflammation and incidence of diseases, such as cardiovascular ones, diabetes, hypertension and chronic diseases. Additionally, FBC are able to change the Firmicutes/Bacteroidetes ratio and inhibit the putrefactive bacteria in the gut. Due to the complex composition of human gut microbiota and variations among individuals, additional research must be carried out to elucidate the mechanism of interaction between the bioactive compounds and the human microbiota.

Detection of Intestinal Dysbiosis in Post-COVID-19 Patients One to Eight Months after Acute Disease Resolution.

The intestinal microbiota plays an important role in the immune response against viral infections, modulating both innate and adaptive immune responses. The cytokine storm is associated with COVID-19 severity, and the patient's immune status is influenced by the intestinal microbiota in a gut-lung bidirectional interaction. In this study, we evaluate the intestinal microbiota of Brazilian patients in different post-COVID-19 periods, and correlate this with clinical data and the antibiotic therapy used during the acute phase. DNA extracted from stool samples was sequenced and total anti-SARS-CoV-2 antibodies and C-reactive protein were quantified. Compared with controls, there were significant differences in the microbiota diversity in post-COVID-19 patients, suggesting an intestinal dysbiosis even several months after acute disease resolution. Additionally, we detected some genera possibly associated with the post-COVID-19 dysbiosis, including Desulfovibrio, Haemophillus, Dialister, and Prevotella, in addition to decreased beneficial microbes, associated with antibiotic-induced dysbiosis, such as Bifidobacterium and Akkermansia. Therefore, our hypothesis is that dysbiosis and the indiscriminate use of antibiotics during the pandemic may be associated with post-COVID-19 clinical manifestations. In our study, 39% (n = 58) of patients reported symptoms, including fatigue, dyspnea, myalgia, alopecia, anxiety, memory loss, and depression. These data suggest that microbiota modulation may represent a target for recovery from acute COVID-19 and a therapeutic approach for post-COVID-19 sequelae.

Açaí extract powder as natural antioxidant on pork patties during the refrigerated storage.

The current trends among consumers are pushing for the use of natural antioxidants options. Açaí fruit is rich on polyphenolic components but no studies have been carried out to evaluate their effect in meat products. The objective was to investigate the effect of açaí extract on refrigerated pork patties quality. Five treatments were done: without antioxidant (CON), Sodium Erythorbate 500 mg.kg -1 (ERY), Açaí Extract: 250 (AEL), 500 (AEM), 750 mg.kg -1 (AEH). Açaí extract did not affect the proximate composition, pH and cooking parameters. The concentrations of açaí extract studied increased antioxidant activity and reduced lipid oxidation (0.379, 0.293, and 0.217 vs. 0.889 mg MDA.kg-1 for AEL, AEM, AEH vs. CON, respectively). However, only the AEL treatment did not affect the color parameters, showing the best option for the application on pork patties. Thus, açaí extract at 250 mg.kg-1 can be used as a natural antioxidant replacing sodium erythorbate to preserve the quality of refrigerated pork patties.

Lactobacillus casei and Lactobacillus fermentum Strains Isolated from Mozzarella Cheese: Probiotic Potential, Safety, Acidifying Kinetic Parameters and Viability under Gastrointestinal Tract Conditions.

The objective of this study was to evaluate the probiotic properties of Lactobacillus casei and Lactobacillus fermentum strains, as well as to select novel and safe strains for future development of functional fermented products. The in vitro auto-aggregation, co-aggregation, hydrophobicity, ß-galactosidase production, survival to gastrointestinal tract (GIT), and antibiotic susceptibility were evaluated. The selected strains were additionally tested by the presence of genes encoding adhesion, aggregation and colonization, virulence factors, antibiotic resistance, and biogenic amine production, followed by the evaluation of acidifying kinetic parameters in milk, and survival of the strains under simulated GIT conditions during refrigerated storage of fermented milk. Most strains of both species showed high auto-aggregation; some strains showed co-aggregation ability with other lactic acid bacteria (LAB) and/or pathogens, and both species showed low hydrophobicity values. Seven L. casei and six L. fermentum strains produced ß-galactosidase enzymes, and ten strains survived well the simulation of the GIT stressful conditions evaluated in vitro. All strains were resistant to vancomycin, and almost all the strains were resistant to kanamycin. L. casei SJRP38 and L. fermentum SJRP43 were distinguished among the other LAB strains by their higher probiotic potential. L. fermentum SJRP43 presented fewer genes related to virulence factors and antibiotic resistance and needed more time to reach the maximum acidification rate (Vmax). The other kinetic parameters were similar. Both strains survived well (> 8 log10 CFU/mL) to the GIT-simulated conditions when incorporated in fermented milk. Therefore, these strains presented promising properties for further applications in fermented functional products.