Antibacterial phenolic components of New Zealand manuka honey

This paper describes several methods for isolation of the antibacterially active phenolic fraction of honey derived from the native New Zealand manuka tree, Leptospermum scoparium (Myrtaceae). This fraction consists of phenolic derivatives of benzoic acids, cinnamic acids and flavonoids, all of which have been identified previously in honeys which do not exhibit non-peroxide residual antibacterial activity. The flavonoids had not previously been identified in manuka honey. Furthermore, the flavonoids were different from those found in the leaves of manuka trees but were the same as those found in European honeys and propolis. While most of these phenolic products possess antibiotic activity, they do not individually or collectively account for the antibacterial activity of `active' manuka honey. Essentially all of this activity is associated with the carbohydrate fraction of the honey.     

Identification of phenolic compound in manuka honey as specific superoxide anion radical scavenger using electron spin resonance (ESR) and liquid chromatography with coulometric array detection

Apitherapy has become the focus of attention as a form of folk and preventive medicine for treating certain conditions and diseases as well as promoting overall health and well‐being. In apitherapy, honey is the therapeutic agent used for dressing surgical wounds, burns or skin ulcers, as well as for dyspepsia, peptic ulcer, etc., because of its antioxidant activity. Therefore, it is important to determine the antioxidants in honey by analytical techniques. In the present study, the antioxidant activities of honeys from different floral sources were investigated by electron spin resonance (1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) and H₂O₂/NaOH/DMSO scavenging systems), liquid chromatography with coulometric array detection (LC‐ED), and liquid chromatography with electrospray mass spectrometry (LC‐MS). The antioxidant activities of some unifloral honeys (acacia, Chinese milk vetch, buckwheat and manuka) were evaluated using the radical scavenging systems. It was shown that DPPH radical scavenging activity was significantly different among the honeys, with buckwheat and manuka honeys having significantly higher scavenging activity than acacia honey. In addition, only manuka honey had specific scavenging activity for superoxide anion radicals. The compound responsible for this activity in manuka honey was identified by LC‐ED and LC‐MS. Careful examination of the LC‐ED chromatographic patterns of manuka and other honey samples revealed a distinct peak in the chromatogram of manuka honey to be methyl syringate (MSYR). The radical scavenging activity of MSYR was specific for superoxide anion radicals, similar to the case of manuka honey. Copyright © 2005 Society of Chemical Industry     

Functional cultures and health benefits

A number of health benefits have been claimed for probiotic bacteria such as Lactobacillus acidophilus, Bifidobacterium spp., and L. casei. These benefits include antimutagenic effects, anticarcinogenic properties, improvement in lactose metabolism, reduction in serum cholesterol, and immune system stimulation. Because of the potential health benefits, these organisms are increasingly being incorporated into dairy foods, particularly yoghurt. In addition to yoghurt, fermented functional foods with health benefits based on bioactive peptides released by probiotic organisms, including Evolus^® and Calpis^®, have been introduced in the market. To maximize effectiveness of bifidus products, prebiotics are used in probiotic foods. Synbiotics are products that contain both prebiotics and probiotics.     

Probiotic Strains as Starter Cultures Improve Angiotensin-converting Enzyme Inhibitory Activity in Soy Yogurt

Suitability of soy yogurt as a system for delivering probiotics and other bioactive compounds was assessed by fermenting soy milk using starter culture containing Lactobacillus delbrueckii ssp. bulgaricus Lb1466, Streptococcus thermophilus St1342, and probiotic organisms (Lactobacillus acidophilus LAFTI® L10, Bifidobacterium lactis LAFTI® B94, and Lactobacillus paracasei LAFTI® L26). Fermentations were terminated at different pH of 4.50, 4.55, and 4.60 and metabolic patterns of cultures (viability, proteolytic activity, organic acids production, angiotensin‐converting enzyme (ACE) inhibitory activity) were investigated during 28 d of storage at 4 °C. The presence of probiotics enhanced the growth of L. delbrueckii ssp. bulgaricus Lb1466 and S. thermophilus St134 in soy yogurt in comparison to the control produced by sole yogurt culture. In general, different termination pH had no effect (P > 0.05) on the viability of probiotic organisms that maintained good viability in soy yogurt during cold storage. Higher levels of essential growth factors in the form of peptides and amino acids in soy yogurts may have promoted the growth of L. acidophilus LAFTI® L10, B. lactis LAFTI® B94, and L. paracasei LAFTI® L26. The use of probiotic strains as a part of starter culture in soy yogurt resulted in a substantial increase in in vitro ACE inhibitory activity compared with the control produced by yogurt culture only. This improvement of ACE inhibition in soy yogurt is partly due to higher proteolytic activity of probiotics.     

Effects of 4 Probiotic Strains in Coculture with Traditional Starters on the Flavor Profile of Yogurt

To study the influence of probiotics on the flavor profile of yogurt, 4 probiotics, including Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus rhamnosus, and Lactobacillus casei, were cofermented with traditional starters. The changes of bacterial growth, acid contents and volatile compounds of yogurt were investigated during fermentation and refrigerated storage. The strains that exhibited a low growth rate in milk did not significantly affect the bacterial population dynamics, acidity, or organic acid content during fermentation and storage. However, high viability and enhancement of postacidification were clearly observed in the samples that contained strains with a high growth rate in milk, particularly L. casei. A total of 45 volatile compounds, detected in most samples, were identified by headspace solid‐phase micro‐extraction followed by gas chromatography‐mass spectrometry. Among these compounds, ketones and aldehydes were the most abundant. The presence of either L. rhamnosus or L. plantarum did not significantly affect the major volatile compounds, while contributions of L. casei and L. acidophilus were found in the formation of minor volatile metabolites. Electronic nose measurements exhibited a good discrimination of samples that contained different probiotics during refrigerated storage.     

Blackcurrant anthocyanins modulate CCL11 secretion and suppress allergic airway inflammation

CCL11, a chemokine, is linked to the early development of airways eosinophilia in allergic asthma. Therefore, CCL11 production is a target for abrogating eosinophilic‐driven airway inflammation. Blackcurrants are high in compounds that regulate inflammation, particularly anthocyanins. In this study, we investigated the effect of oral blackcurrant supplementation on allergen‐induced eosinophilia and CCL11 production; we also profiled key compounds in blackcurrants that were linked to this effect. Ten milligram per kilogram (total anthocyanins) of a commercially available, anthocyanin‐rich New Zealand “Ben Ard” blackcurrant extract (“Currantex 30”) attenuated ovalbumin‐induced inflammation, eosinophilia (by 52.45 ± 38.50%), and CCL11 production (by 48.55 ± 28.56%) in a mouse model of acute allergic lung inflammation. Ten blackcurrant polyphenolic extracts were also found to suppress CCL11 secretion by stimulated human lung epithelial cells in vitro. Correlation analysis identified potential blackcurrant polyphenolic anthocyanin constituents specifically delphinidins and cyanidins, involved in CCL11 suppression. Our findings show oral supplementation with New Zealand blackcurrant is effective in reducing lung inflammation, and highlight the potential benefit of developing cultivars with specific polyphenolic profiles for the creation of functional foods with desirable biological activity.     

Evaluation of Probiotic Potential of Lactic Acid Bacteria Isolated from Different Sources in Western India

Lactic acid bacteria isolated from unconventional sources are often attractive targets in the quest for obtaining better probiotics. In the present study, 16 members of the genus Lactobacillus, isolated from 3 different sources in western India, viz., plants, fermented foods and beverages, and human feces, were evaluated for their probiotic and bioactive properties. The isolates were closely related to Lactobacillus fermentum, Lactobacillus pentosus, and mainly Lactobacillus plantarum. The isolates were tolerant to bile salt, acidic pH and pancreatin, although pancreatin tolerance was generally low. Cellular extracts of several isolates displayed antioxidant activity, while cell-free supernatants displayed antibacterial activity against human pathogens. Antioxidant activity of Lactobacilli of human origin was higher than those from vegetables or fermented foods and beverages. L. plantarum AG40V prevented spoilage of fresh-cut fruits, vegetables and sprouted mung-beans. Lactobacilli from all sources displayed equal probiotic potential and those of human origin displayed superior antioxidant activity over others.     

Biomedical Activity and Related Volatile Compounds of Thai Honeys from 3 Different Honeybee Species

This study investigated the effect of 3 factors (floral source, honeybee species, and postcollection processing) that influence the antibacterial activity, free radical reduction, and other biochemical compositions of different honey types typical of Thailand. Honey samples from 3 honeybee species (Apis mellifera, Apis cerana, and Apis dorsata) were obtained from 9 floral sources (longan, wild flower, lychee, coffee, sunflower, sesame, bitter bush, para‐rubber, and manuka as a control) in different regions of Thailand. These samples were evaluated for both their total and nonperoxide antibacterial activity against 10 human pathogens by agar incorporation technique. Honey samples were further analyzed to evaluate the capacity for free radical‐scavenging activity, total phenolic content, and the total flavonoid contents by the 2,2‐diphenyl‐1‐picrylhydrazyl assay, Folin–Ciocalteu method, and aluminum chloride colorimetric assay, respectively. Furthermore, the volatile organic compounds (VOCs) of Thai honey samples were investigated by headspace solid‐phase microextraction and gas chromatography‐mass spectrometry analysis. Findings of this study suggest a strong correlation between floral origin and honeybee species on one hand, and differences in %Brix, total acidity, protein content, antimicrobial activities, free radical reduction, phenolic, and flavonoid contents on the other hand. Moreover, VOCs of wild and coffee honey types were remarkably different, depending on the floral source. Both honeys contained characteristics of VOCs, some of which are involved in antibacterial and antioxidant activities.     

Prebiotic effect of soluble fibres from modern and old durum-type wheat varieties on Lactobacillus and Bifidobacterium strains

BACKGROUND: Wheat grains are a rich source of dietary fibres, particularly in the western human diet. Many of the health effects attributed to dietary fibres are believed to be related to their microbial fermentation in the gut. This study evaluated the ability of two potentially probiotic strains, Lactobacillus plantarum L12 and Bifidobacterium pseudocatenulatum B7003, to ferment soluble dietary fibres (SDFs) from modern and ancient durum‐type wheat grains. RESULTS: Fibre microbial utilisation was highly variable and dependent on the strain. SDFs from the varieties Svevo and Solex supported the growth of L. plantarum L12 the best, whereas those from the varieties Anco Marzio, Solex and Kamut^® Khorasan were good carbohydrate substrates for B. pseudocatenulatum B7003. The highest prebiotic activity scores (describing the extent to which prebiotics support selective growth of probiotics) for B7003 were obtained with SDFs from the varieties Solex (0.57), Kamut^® Khorasan (0.56) and Iride (0.55), whereas for L12 the highest scores were achieved with the varieties Orobel (0.63), Kamut^® Khorasan (0.56) and Solex (0.53). CONCLUSION: The present study has identified some SDFs from durum‐type wheat grains as suitable prebiotic substrates for the selective proliferation of B. pseudocatenulatum B7003 and L. plantarum L12 in vitro. The results provide the basis for the potential utilisation of wheat‐based prebiotics as a component of synbiotic formulations. Copyright © 2012 Society of Chemical Industry     

Potential interactions among phenolic compounds and probiotics for mutual boosting of their health-promoting properties and food functionalities – A review

Several foods are rich sources of phenolic compounds (PC) and their beneficial effects on human health may be increased through the action of probiotics. Additionally, probiotics may use PC as substrates, increasing their survival and functionality. This review presents available studies on the effects of PC on probiotics, including their physiological functionalities, interactions and capability of surviving during exposure to gastrointestinal conditions and when incorporated into food matrices. Studies have shown that PC can improve the adhesion capacity and survival of probiotics during exposure to conditions that mimic the gastrointestinal tract. There is strong evidence that PC can modulate the composition of the gut microbiota in hosts, improving a variety of biochemical markers and risk factors for chronic diseases. Available literature also indicates that metabolites of PC formed by intestinal microorganisms, including probiotics, exert a variety of benefits on host health. These metabolites are typically more active than parental dietary PC. The presence of PC commonly enhances probiotic survival in different foods. Finally, further clinical studies need to be developed to confirm in vitro and experimental findings concerning the beneficial interactions among different PC and probiotics.     

Growth inhibition of foodborne pathogens by co‐microencapsulation of lactobacilli cell free and propolis extracts

Cell free extracts (CFE) obtained from Lactobacillus plantarum FI 8595 and Lactobacillus reuteri ATCC 55730 alone or in combination with propolis ethanolic or water extracts (1%) were microencapsulated with maltodextrin (25%) before the subsequent spray drying process. They were morphologically characterized by scanning electron microscope. Chemical compositions of pure extracts were identified by gas chromatography–mass spectrometry. Antimicrobial activities of pure and microencapsulated extracts against four foodborne pathogens (Staphylococcus aureus ATCC29213, Listeria monocytogenes ATCC19112, Klebsiella pneumoniae ATCC700603 and Salmonella Paratyphi A NCTC13) were determined using agar well diffusion, broth microdilution and time kill assays. CFE from L. reuteri and L. plantarum consisted of acetic acid, pyrrolo[1,2‐a]pyrazine‐1,4‐dione, hexahydro‐3‐(phenylmethyl)‐, 2,3,4‐trihydroxybenzaldehyde and 9‐octadecenoic acid. The results also indicated the presence of two respective major compounds, namely, 2‐methoxy‐4‐vinylphenol (19.03%) and trans‐cinnamic acid (27.67%) in water and ethanolic propolis extracts. Presence of propolis extracts mainly ethanolic extract in microencapsulation led to higher inhibition zones against all foodborne pathogens (p < .05). The co‐microencapsulation of CFE from L. reuteri in combination with ethanolic or water extract of propolis resulted in 2.34‐ and 2.2‐fold higher inhibition zone towards L. monocytogenes. Pure and microencapsulated CFE from L. reuteri resulted in 2.89 and 2.14 log cfu/ml reduction in growth of S. Paratyphi A at 3 hr, respectively. The co‐microencapsulation of CFE from lactobacilli and propolis extracts mainly ethanolic extract could be suggested as a novel antimicrobial on inhibition of food pathogens, as they contain abundant bioactive substances.     

Proteolytic and angiotensin‐converting enzyme‐inhibitory activities of selected probiotic bacteria

This study was carried out to examine the proteolytic and angiotensin‐converting enzyme (ACE‐I) activities of probiotic lactic acid bacteria (LAB) as influenced by the type of media, fermentation time, strain type and media supplementation with a proteolytic enzyme (Flavourzyme^®). Lactobacillus casei (Lc210), Bifidobacterium animalis ssp12 (Bb12), Lactobacillus delbrueckii subsp. bulgaricus (Lb11842) and Lactobacillus acidophilus (La2410) were grown in 12% of reconstituted skim milk (RSM) or 4% of whey protein concentrates (WPC‐35) with or without combination (0.14%) of Flavourzyme^® for 12 h at 37 °C. All the strains were able to grow in both media depending on type of strains used and fermentation time. All the strains showed higher proteolytic activity and produced more antihypersensitive peptides when grown in RSM medium at 12 h, when compared to WPC. Combination with Flavourzyme^® also increased LAB growth and proteolytic and ACE‐I activities. Of the four strains used, Bb12 and La2410 outperformed Lc210 and Lb11842. The highest ACE‐I activity and proteolytic activity were found in B. animalis ssp12 combined with Flavourzyme^®. Flavourzyme^® led to an increase in the production of bioactive peptides with ACE‐I activity during 12 h at 37 °C.     

Identification of lactic acid bacteria in the rumen and feces of dairy cows fed total mixed ration silage to assess the survival of silage bacteria in the gut

The survival of silage lactic acid bacteria (LAB) in the gut of dairy cows was evaluated by examining the LAB communities of silage and gut contents. Samples were collected at 2 different research institutes (Mie and Okayama) that offered total mixed ration (TMR) silage throughout the year. Silage and feces were sampled in August, October, and November at the Mie institute, whereas silage, rumen fluid, and feces were sampled in June and August at the Okayama institute. Denaturing gradient gel electrophoresis using Lactobacillus-specific primers was performed to detect LAB species in the samples. The selected bands were purified for species identification and the band patterns were used for principal component analysis. Lactic acid was the predominant fermentation product in all the TMR silages analyzed, and the lactic acid level tended to be constant regardless of the sampling time and region. A total of 14 LAB species were detected in the TMR silage samples, of which 5 (Lactobacillus acetotolerans, Lactobacillus pontis, Lactobacillus casei, Lactobacillus suebicus, and Lactobacillus plantarum) were detected in the dairy cow feces. Most of the denaturing gradient gel electrophoresis bands for the feces samples were also detected in the rumen fluid, suggesting that any elimination of silage LAB occurred in the rumen and not in the postruminal gut segments. The principal component analysis indicated that the LAB communities in the silage, rumen fluid, and feces were separately grouped; hence, the survival of silage LAB in the cow rumen and lower gut was deemed difficult. It was concluded that, although the gut LAB community is robust and not easily affected by the silage conditions, several LAB species can inhabit both silage and feces, which suggests the potential of using silage as a vehicle for conveying probiotics.     

Physiological Changes of Surface Membrane in Lactobacillus with Prebiotics

Synbiotics are always considered to be beneficial in healthy manipulation of gut environment; however, the purpose of this research was to investigate the dominance of synbiotic over the individual potential of probiotics and prebiotics. Four different types of prebiotics, fructo‐oligosaccharides, raffinose, inulin, and cellobiose, were evaluated based on their varying degree of polymerization, combined each with 2 different Lactobacilli strains, including Lactobacillus paracasei 276 and Lactobacillus plantarum WCFS1. The effects of synbiotics combination on the surface structure were evaluated by analyzing auto‐aggregation, membrane hydrophobicity, and adhesion to Caco‐2 cells. Our results showed that both Lactobacilli exhibited significantly greater degree of attachment to Caco‐2 cells (23.31% and 16.85%, respectively) when using cellobiose as a substrate than with other prebiotics (P < 0.05). Intestinal adhesion ability was in correlation with the percent of auto‐aggregation, both Lactobacillus exhibited higher percent of auto‐aggregation in cellobiose compared to other prebiotics. These behavioral changes in terms of attachment and auto‐aggregation were further supported with the changes noticed from infrared spectra (FT‐IR).     

The Applications of Polysaccharides from Various Mushroom Wastes as Prebiotics in Different Systems

The bases or stipes of mushrooms are normally discarded as low‐economic value animal feed and compost. There are no known reports on deriving polysaccharides from these mushroom wastes for use as prebiotics. This study showed that the relatively low concentration (0.1% to 0.5%) of polysaccharides from Lentinula edodes stipe, Pleurotus eryngii base, and Flammulina velutipes base can enhance the survival rate of Lactobacillus acidophilus, Lactobacillus casei, and Bifidobacterium longum subsp. longum during cold storage. The polysaccharides had synergistic effects with the peptides and amino acids from a yogurt culture to maintain probiotics above 10⁷ CFU/mL during cold storage, and they also had significant protective effects on these probiotics in simulated gastric and bile juice conditions to achieve beneficial effects in the host. These results showed that mushroom wastes, which are cheaper than other sources, could be an important, new, alternative source of prebiotics.     

Functionality of different probiotic strains embedded in citrus pectin based edible films

The inclusion of probiotics into the packaging films has emerged as a novel approach to provide edible packaging with new functionalities. In this study, probiotic films were developed by embedding four different probiotics (Lactobacillus casei, Bifidobacterium bifidum, Lactobacillus acidophilus, and Lactobacillus rhamnosus) into citrus pectin films and their viability was checked at 25 and 4 °C for 30 days. A reduction of 0.44, 1.04, 0.32, and 1.0 log CFU g⁻¹ was observed in probiotic films containing L. casei, B. bifidum, L. acidzophilus, and L. rhamnosus respectively during drying process of film’s formation. The viability of all probiotics (except B. bifidum) was decreased from 10⁹ to 10⁶ CFU g⁻¹ in 30 days storage at 25 °C. Whereas, only 2 log reduction was observed for films stored at 4 °C during 30 days. The physical and optical properties of the films were affected slightly by inclusion of bacterial cells. The presence of live cells in films made them less resistant to elongation and less stretchable. All bacterial films inhibited the growth of L. monocytogenes by 1.5 logs compared to control. The results suggest the entrapment of probiotics in pectin can be used as an effective packaging technology for ensuring food safety.     

How to routinely assess transition,adhesion and survival of probiotics into the gut: a case study on propionibacteria

Two commercial promising probiotic strains (Propionibacterium jensenii and Propionibacterium freudenreichii) were studied to evaluate two basic probiotic requisites (adhesion and survival during the transit into the gut); two commercial starter cultures (Lactobacillus plantarum and Lactobacillus delbrueckii subsp. bulgaricus) were used as references. As an additional goal, the technological robustness was evaluated as growth as a function of pH, temperature and salt. Adhesion was studied as biofilm formation and hydrophobicity, whereas a simplified protocol was used to simulate the transit into the gut, along with the assessment of survival at pH 2.5 and in the presence of 0.3% bile salts. Propionibacteria were hydrophobic and form biofilm on glass slides, thus confirming the correlation of these properties and with the ability to adhere. None of the strains survived after the simulation of the transit into the gut, but this property could be induced in propionibacteria using a simple protocol of adaptive evolution. This paper suggests the possibility of using hydrophobicity as a screening tool to assess adhesion in propionibacteria and highlights the necessity of using a complete protocol of simulation of the gut to study the resistance to the conditions of stomach and intestine to avoid false‐positive results.     

Phenolic compounds and methylglyoxal in some New Zealand manuka and kanuka honeys

The principal phenolic compounds and methylglyoxal were analysed in New Zealand Leptospermum scoparium (manuka) and Kunzea ericoides (kanuka) honeys. These honeys shared six phenolic acids as primary components and differentiation was possible as relative proportions varied. Manuka honey contained an elevated concentration of a trimethoxybenzoic acid and methylglyoxal; and 2-methoxybenzoic acid and methylglyoxal concentrations were linearly correlated in fresh manuka honey. Kanuka honey contained an elevated concentration of methoxyphenyllactic acid. The concentration of the phenolic components increased with maturation in both honey types; and this profile development, along with a corresponding increase of methylglyoxal concentration, was linear in manuka honey. Nectar analysed from the plant species contained the same phenolic components as the honeys. These results demonstrated the phenolic profile could be used to differentiate the honey types, heat treatment of honey could be identified, and the presence of these components may contribute to the efficacy of these honeys in therapeutic uses.     

Effect of prebiotics on viability and growth characteristics of probiotics in soymilk

BACKGROUND: Soy products have attracted much attention lately as carriers for probiotics. This study was aimed at enhancing the growth of probiotics in soymilk via supplementation with prebiotics. RESULTS: Lactobacillus sp. FTDC 2113, Lactobacillus acidophilus FTDC 8033, Lactobacillus acidophilus ATCC 4356, Lactobacillus casei ATCC 393, Bifidobacterium FTDC 8943 and Bifidobacterium longum FTDC 8643 were evaluated for their viability and growth characteristics in prebiotic‐supplemented soymilk. In the presence of fructooligosaccharides (FOS), inulin, mannitol, maltodextrin and pectin, all strains showed viability exceeding 7 log₁₀ colony‐forming units mL^?1 after 24 h. Their growth was significantly (P < 0.05) increased on supplementation with maltodextrin, pectin, mannitol and FOS. Additionally, supplementation with FOS, mannitol and maltodextrin increased (P < 0.05) the production of lactic acid. Supplementation with FOS and maltodextrin also increased the α‐galactosidase activity of probiotics, leading to enhanced hydrolysis and utilisation of soy oligosaccharides. Finally, prebiotic supplementation enhanced the utilisation of simpler sugars such as fructose and glucose in soymilk. CONCLUSION: Supplementation with prebiotics enhances the potential of soymilk as a carrier for probiotics. Copyright © 2009 Society of Chemical Industry     

The effect of probiotic‐fermented soy milk on enhancing the NO‐mediated vascular relaxation factors

BACKGROUND: Soy milk is one of the common soy‐based foods in Asia. In this study the effects of soy milk fermented with selected probiotics on nitric oxide (NO)‐mediated vascular relaxation factors in cell model systems were investigated. RESULTS: Soy milk fermented with Lactobacillus plantarum TWK10 or Streptococcus thermophilus BCRC 14085 for 48 h showed a greater transformation of glucoside isoflavones to aglycone isoflavones (P < 0.05). An increase in aglycone isoflavones in ethanol extracts from fermented soy milk stimulated NO production and endothelial NO synthase (eNOS) activity in human umbilical vein endothelial cells. It also had a stimulating effect on superoxide anion scavenging and prostaglandin E₂ production. In addition, it enhanced mRNA expression of the E‐prostanoid 4 receptor in rat thoracic aorta smooth muscle cells. Moreover, a small amount of O induced by water extracts from fermented soy milk at low concentration (1 mg mL^?1) increased the content of calcium ions and activated eNOS, thereby promoting NO production and the coupling state of eNOS. CONCLUSION: Soy milk fermented with selected probiotics promotes the relaxation factors of vascular endothelial cells and can be applied in the development of functional foods. © 2012 Society of Chemical Industry