High blood pressure-lowering and vasoprotective effects of milk products in experimental hypertension

In Vitro and In Vivo Antihypertensive Effect of Milk Fermented with Different Strains of Common Starter Lactic Acid Bacteria

Currently, functional dairy products pave a promising way for the prophylaxis of essential hypertension, and the search for new strains capable of producing such products is a constant challenge for scientists around the world. In this study, the antihypertensive properties of milk fermented with several strains of traditional yogurt starters (Lactobacillus delbrueckii strains Lb100 and Lb200; Lactococcus lactis strains dlA, AM1 and MA1; Streptococcus thermophilus strains 159 and 16t) and one strain of non-conventional probiotic starter (Lacticaseibacillus paracasei ABK) were assessed. The in vitro assessment using angiotensin-converting enzyme inhibition assay was performed for all fermentation products, and the best performed products were tested in vivo using Spontaneously Hypertensive Rat (SHR) animal model. In addition, for the best performed products the fatty acid (FA) composition and FA-related nutritional indices were determined. As a result, the milk fermented with two strains (Lb. delbrueckii LB100 and Lc. lactis AM1) demonstrated significant antihypertensive effect during both in vitro and in vivo experiments. Moreover, the milk fermented with Lb. delbrueckii Lb100 demonstrated significantly better FA-related nutritional indexes and lowered total cholesterol in SHRs upon regular consumption. The obtained results can be used in the future to develop new starter cultures producing effective functional antihypertensive dairy products.

Regulatory effect of gut microbes on blood pressure

Hypertension is an important global public health issue because of its high morbidity as well as the increased risk of other diseases. Recent studies have indicated that the development of hypertension is related to the dysbiosis of the gut microbiota in both animals and humans. In this review, we outline the interaction between gut microbiota and hypertension, including gut microbial changes in hypertension, the effect of microbial dysbiosis on blood pressure (BP), indicators of gut microbial dysbiosis in hypertension, and the microbial genera that affect BP at the taxonomic level. For example, increases in Lactobacillus, Roseburia, Coprococcus, Akkermansia, and Bifidobacterium are associated with reduced BP, while increases in Streptococcus, Blautia, and Prevotella are associated with elevated BP. Furthermore, we describe the potential mechanisms involved in the regulation between gut microbiota and hypertension. Finally, we summarize the commonly used treatments of hypertension that are based on gut microbes, including fecal microbiota transfer, probiotics and prebiotics, antibiotics, and dietary supplements. This review aims to find novel potential genera for improving hypertension and give a direction for future studies on gut microbiota in hypertension.

Exploring the Gut Microbiota and Cardiovascular Disease

Cardiovascular disease (CVD) has been classified as one of the leading causes of morbidity and mortality worldwide. CVD risk factors include smoking, hypertension, dyslipidaemia, obesity, inflammation and diabetes. The gut microbiota can influence human health through multiple interactions and community changes are associated with the development and progression of numerous disease states, including CVD. The gut microbiota are involved in the production of several metabolites, such as short-chain fatty acids (SCFAs), bile acids and trimethylamine-N-oxide (TMAO). These products of microbial metabolism are important modulatory factors and have been associated with an increased risk of CVD. Due to its association with CVD development, the gut microbiota has emerged as a target for therapeutic approaches. In this review, we summarise the current knowledge on the role of the gut microbiome in CVD development, and associated microbial communities, functions, and metabolic profiles. We also discuss CVD therapeutic interventions that target the gut microbiota such as probiotics and faecal microbiota transplantation.

The effect of probiotics supplementation on blood pressure: a systemic review and meta-analysis

Background

Fermented milk has over the last decade been intensively studied because of the putative antihypertensive effect. The aim of our study is to investigate the role of probiotics support therapy in blood pressure and, as a kind of convenient and economic drugs for prevention and auxiliary treatment of hypertension.

Materials and methods

We performed a systemic review and meta-analysis to examine the effect of probiotics consumption on blood pressure. Databases including MEDLINE, EMBASE, Clinical trials, CNKI and the Cochrane library were searched. Also, the grey literature and references were searched.

Results

Twenty-three randomized controlled trials (RCTs) involving 2037 participants met the inclusion criteria and were included. Probiotic consumption significantly changed systolic blood pressure (SBP) by − 3.05 mmHg (95%CI: − 4.67, − 1.44; P < 0.001) and diastolic blood pressure (DBP) by − 1.51 mmHg (95%CI: − 2.38, − 0.65; P = 0.001). Subgroup analysis indicated that the benefit effect of probiotics supplementation in SBP was only observed in hypertension [weight mean difference (WMD) = − 3.31 mmHg, 95%CI: − 5.71, − 0.92; P = 0.007] or type 2 diabetes (WMD = -4.85 mmHg, 95%CI: − 9.28, − 0.42; P = 0.032) patients, and the decreased DBP level by probiotics supplementation was only observed in hypertension patients (WMD = -2.02 mmHg, 95%CI: − 3.68, − 0.36; P = 0.017).This effect could only last for a short-term time of 8 or 10 weeks, but not for a long-term time.

Conclusion

This meta-analysis found a moderate and statistically significant reduction for either SBP or DBP with probiotics supplement compared with controls. Thus, probiotics is a potential for the dietary treatment of hypertension.

Preparation, Bioavailability, and Mechanism of Emerging Activities of Ile-Pro-Pro and Val-Pro-Pro

Ile-Pro-Pro and Val-Pro-Pro are two most well-known food-derived bioactive peptides, initially identified as inhibitors of angiotensin I-converting enzyme (ACE) from a sample of sour milk. These two peptides were identified in fermented and enzymatic hydrolyzed cow and non-cow (that is, goat, sheep, buffalo, yak, camel, mare, and donkey) milk, as well as sourdough prepared from wheat, rye, and malt. Similar to other bioactive peptides, bioavailability of these peptides is low (about 0.1%), reaching picomolar concentration in human plasma; they showed blood pressure lowering activity in animals and in human, via improved endothelial function, activation of ACE2, and anti-inflammatory property. Emerging bioactivities of these two peptides toward against metabolic syndrome and bone-protection received limited attention, but may open up new applications of these peptides as functional food ingredients. Further studies are warranted to determine the best source as well as to identify novel enzymes (particularly from traditional fermented milk products) to improve the efficiency of production, to characterize possible peptide receptors using a combination of omics technology with molecular methods to understand if these two peptides act as signal-like molecules, to improve their bioavailability, and to explore new applications based on emerging bioactivities.

Fermente Süt Ürünlerinin Kan Basıncını Düşürücü Etkisi

Hypertension (HTN) is a major risk factor for the development of cardiovascular diseases. Therefore, there is a need to lower blood pressure (BP) to reduce the risk of these degenerative diseases. Fermented milks contain several potential factors that can lower BP including calcium and microbial metabolites particularly the angiotension-converting enzyme (ACE) inhibitory peptides and γ-aminobutyric acid. &nbsp;Animal studies clearly demonstrated the BP lowering effect of fermented milk while results from clinical trials were controversial due to a large number of variables that should be considered in clinical trials. An overview on the antihypertensive effect of fermented milk products is presented and discussed in this review.

Peptides-Derived from Thai Rice Bran Improves Endothelial Function in 2K-1C Renovascular Hypertensive Rats

In recent years, a number of studies have investigated complementary medical approaches to the treatment of hypertension using dietary supplements. Rice bran protein hydrolysates extracted from rice is a rich source of bioactive peptides. The present study aimed to investigate the vasorelaxation and antihypertensive effects of peptides-derived from rice bran protein hydrolysates (RBP) in a rat model of two kidney-one clip (2K-1C) renovascular hypertension. 2K-1C hypertension was induced in male Sprague-Dawley rats by placing a silver clip around the left renal artery, whereas sham-operated rats were served as controls. 2K-1C and sham-operated rats were intragastrically administered with RBP (50 mg·kg⁻¹ or 100 mg·kg⁻¹) or distilled water continuously for six weeks. We observed that RBP augmented endothelium-dependent vasorelaxation in all animals. Administration of RBP to 2K-1C rats significantly reduced blood pressure and decreased peripheral vascular resistance compared to the sham operated controls (p < 0.05). Restoration of normal endothelial function and blood pressure was associated with reduced plasma angiotensin converting enzyme (ACE), decreased superoxide formation, reduced plasma malondialdehyde and increased plasma nitrate/nitrite (p < 0.05). Up-regulation of eNOS protein and down-regulation of p47^phox protein were found in 2K-1C hypertensive rats-treated with RBP. Our results suggest that RBP possesses antihypertensive properties which are mainly due to the inhibition of ACE, and its vasodilatory and antioxidant activity.

Transport of IRW, an ovotransferrin-derived antihypertensive peptide, in human intestinal epithelial Caco-2 cells

IRW is an egg ovotransferrin-derived ACE inhibitory peptide. The purpose of this study was to evaluate the stability and transcellular transport of IRW in Caco-2 cell monolayers. The stability of IRW was monitored on the apical (AP) surface while its transport was studied from AP to basal (BL) and from BL to AP surfaces. The results revealed that IRW is resistant against intestinal peptidase up to 60 min. Transport of IRW was not affected by addition of wortamanin, a transcytosis inhibitor. However, in the presence of cytochalasin D, a gap junction disruptor, transport of IRW was significantly increased, suggesting a possible passive transport from AP to BL surface. A higher transport of IRW from AP to BL surface than that from BL to AP surface suggests a passive-mediated transport. Moreover, in the presence of glycyl-sarcosine, a substrate for peptide transporter PepT 1, transport of IRW was reduced from AP to BL surface. The above observations showed atypical transport of IRW in Caco-2 cell monolayers. Thus, IRW may possibly be absorbed intact into the site of action for controlling hypertension.

Antihypertensive effects of bioactive tripeptides-a random effects meta-analysis

A meta-analysis of possible antihypertensive effects of small doses of bioactive tripeptides isoleucine-proline-proline and valine-proline-proline in commercial milk products or tablets was carried out. A random effects model was used on 19 randomized, placebo-controlled clinical intervention trials (published 1996-October 2010) consisting of about 1500 prehypertensive or mildly hypertensive subjects.The overall blood pressure lowering for systolic blood pressure was -4.0 mmHg (95% CI -5.9 to -2.1 mmHg, P < 0.001) and for diastolic blood pressure -1.9 mmHg (95% CI -3.1 to -0.8 mmHg, P < 0.001). However, a positive effect was not reported in all the studies. The results suggest that rather small daily doses of the lactotripeptides in different functional food products may offer a valuable option as a non-pharmacological treatment of prehypertension or mild hypertension as part of life-style advice.

A spread containing bioactive milk peptides Ile-Pro-Pro and Val-Pro-Pro, and plant sterols has antihypertensive and cholesterol-lowering effects

Lifestyle intervention is recommended as the primary treatment for mild hypertension and hypercholesterolemia. We studied the effects of a spread containing bioactive milk peptides IPP and VPP, as well as plant sterols, on cardiovascular risk factors in 104 hypertensive, hypercholesterolemic subjects in a randomised, placebo-controlled double-blind intervention. Middle-aged subjects consumed 20 g day⁻¹ of a spread containing 4.2 mg of IPP and VPP as well as 2 g of plant sterols for 10 weeks after a 2 week run-in period. Blood pressure was measured at home 3 times a week. Office blood pressure and 24 h ambulatory blood pressure measurements were performed at the end of the run-in and intervention periods. Blood samples were analysed for serum lipids, plasma glucose and inflammation markers. A significant decrease (-4.1 mmHg vs. -0.5 mmHg, p = 0.007) in systolic blood pressure was seen in the active group, compared to placebo at home measurements. Office blood pressure and 24 h nighttime or daytime ambulatory systolic or diastolic pressure did not differ between the groups. Total (-0.16 vs. 0.25 mmol l⁻¹, p = 0.005) and LDL cholesterol (-0.16 vs. 0.18 mmol l⁻¹, p = 0.006) decreased significantly in the active group compared to the placebo. No significant differences between groups were seen for plasma glucose or inflammation markers. The results thus suggest that milk peptides IPP and VPP and plant sterols, in a low-fat spread matrix, produce a clinically significant reduction in systolic blood pressure as well as serum total and LDL cholesterol without adverse effects. Functional foods that affect 2 major risk factors offer a safe and convenient way to reduce the risk of cardiovascular disease by supporting lifestyle intervention.